Cannabis Seed Storage

[acespicoli]

quick wash in hydrogen peroxide is a bonus for any seed planted?
Soak your seeds in 3% hydrogen peroxide for 30 minutes.
Rinse the seeds several 3X times with DISTILLED water before planting and plant them as usual.
Doing this breaks down the hard outer covering of the seeds and kills any pathogen present on them.

if unsure test on some hemp sprouting seeds this should put your mind at rest...

https://www.researchgate. net/figure/Evaluation-of-biofungicide-and-growth-stimulating-activity-of-Streptomyces-strains_tbl1_358088559

Microbial communities of vegetable seeds and biocontrol microbes for seed treatment
Tinatin Doolotkeldieva* and Saikal Bobusheva
Kyrgyz-Turkish Manas University, Plant Protection Department, Ch. Aytmatov Street, 56, Bishkek city,
Kyrgyzstan, 720044

*Author for correspondence (E-mail: [email protected])
(Submitted July 2021; Accepted January 2022; Published online January 2022)

Abstract
Thirty-one species of vegetable seeds from Kyrgyzstan’s State Register were analysed for mycological and
bacterial composition using various methods, from simple visual to molecular. The modified roll-towel method
simultaneously assesses the degree of contamination and seed germination. Screening in agar medium allows
analysis of species on the outer and inner surfaces of vegetable seeds that are not detected using the roll-towel
method. As a result of the phytopathological examination, 15 fungal and three bacterial species were found.
Direct DNA extraction and amplification of the universal 16S rRNA gene of diseased seeds was used to identify
the plant pathogenic bacteria, which included Pseudomonas syringae, Pseudomonas savastanoi, Pseudomonas
cerasi, Pectobacterium carotovorum, Xanthomonas oryzae, Erwinia sp. and others from the Proteobacteria
phylum.

Keywords: seed-borne pathogens, seed germination, seedling decay,

MANY OF US USE THE "PAPER TOWEL" METHOD AND HAVE WONDERED ABOUT THE MARKS AND COLORS ? -AceS

The modified roll-towel method Fig A,B,C,D
simultaneously assesses the degree of contamination and seed germination.

 

[acespicoli]

WHAT DO WE KNOW ABOUT EMBRYO RESCUE ?


Many of us have lost strains we wished to save, id like to add this to that end, and the already tried methods we've listed in previous posts
Some I understand may not be interested in this
In the past I have been a student of plant culture lab tech also organic chemistry, so this interests me

Bottom line is feed the seeds your sprouting instead of just using plain water to germinate old tired seeds
and please post your

Embryonic Medium Preparation and Recipes with result !!!​

Embryonic medium is used for culturing embryos.


embryo-rescue procedure overview
An embryo-rescue procedure involves three main steps:
(1) ovules are cultured in vitro (embryo formation),
(2) embryos are removed from the ovules and cultured (embryo germination and plantlet development), and
(3) plantlet roots are elongated, acclimated, and transplanted to soil

cite (Pan 2005; Tang 2010; Wang et al.Aug 21, 2013

Mature embryo culture can be resorted to under following conditions:
Prolonged seed dormancy

Embryo culture also known as embryo rescue was developed in 1904 by Hannig,
as an in vitro technique to obtain viable plants from mature or immature embryos,
isolated aseptically and grown on sterile mineral salt medium supplemented with nutrients under aseptic environmental conditions.

ANATOMY OF A CANNABIS SEED- AID IN DISSECTION

THE MOST SENSITIVE PART IS THE ROOT TIP - AVOID DAMAGING THIS IN THE EARLY STAGES IF POSSIBLE





Murashige and Skoog medium (or MSO or MS0 (MS-zero))
is a plant growth medium used in the laboratories for cultivation of plant cell culture

Ingredients​

Major salts (macronutrients) per litre​

• Ammonium nitrate (NH4NO3) 1650 mg/l
• Calcium chloride (CaCl2 · 2H2O) 440 mg/l
• Magnesium sulfate (MgSO4 · 7H2O) 370 mg/l
• Monopotassium phosphate (KH2PO4) 170 mg/l
• Potassium nitrate (KNO3) 1900 mg/l.

Minor salts (micronutrients) per litre​

• Boric acid (H3BO3) 6. 2 mg/l
• Cobalt chloride (CoCl2 · 6H2O) 0.025 mg/l
• Ferrous sulfate (FeSO4 · 7H2O) 27.8 mg/l
• Manganese(II) sulfate (MnSO4 · 4H2O) 22.3 mg/l
• Potassium iodide (KI) 0.83 mg/l
• Sodium molybdate (Na2MoO4 · 2H2O) 0.25 mg/l
• Zinc sulfate (ZnSO4·7H2O) 8.6 mg/l
• Ethylenediaminetetraacetic acid ferric sodium (FeNaEDTA) 36.70 mg/l
• Copper sulfate (CuSO4 · 5H2O) 0.025 mg/l

Vitamins and organic compounds per litre​

• Myo-Inositol 100 mg/l
• Nicotinic Acid 0.5 mg/l
• Pyridoxine · HCl 0.5 mg/l
• Thiamine · HCl 0.1 mg/l
• Glycine 2 mg/l
• Tryptone 1 g/l (optional)
• Indole Acetic Acid 1-30 mg/l (optional)
• Kinetin 0.04-10 mg/l (optional)

For those not interested in buying chem above you may find this on ebay 8-15$ for makes over a gallon liquid mix

The idea has come from: Article at AWeb

How to make Seed Sprout Tea (SST) for cannabis plant (people using this for seed sprouting stubborn seeds)​

hope you do the peroxide 30 min soak before sprouting

What is Seed Sprout Tea or SST?​

Despite forming part of Chinese cuisine and medicine for centuries or even millennia, it's only been in the last 30 or 40 years that the western world has really woken up to the health benefits of eating seed sprouts, or germinated seeds. These days it's widely accepted that adding some sprouted beans or other seeds to our daily diet is highly beneficial for their high content of protein, enzymes, amino acids, vitamins, minerals and antioxidants. But did you know we can get some great results by adding seed sprouts to the diet of our cannabis plants too?
Yes, it's true! Our plants can make the most of the beneficial properties of sprouted seeds and enjoy a natural boost in growth and plant health. Seed sprout tea (SST) is an easy, economical and environmentally-friendly way in which we can irrigate our garden with our own homemade plant growth stimulant, rich in phytohormones, enzymes, minerals and nutrients, and is suitable for use on cannabis plants in vegetative growth as well as during the flowering period, depending on the seeds being used.

Barley grains sprouting in a jar

What seeds can we use to make SST?​

Seeds or grains will sprout when we expose them to air, water and warmth. This sets in motion a series of biochemical reactions that alter the composition of the seed, during which process the macronutrients are broken down and the bioavailability of micronutrients is hugely increased. In short, the sprouted seeds are far more nutritious than either the grown plant or the seed itself, and it's this vitality that we want to capture and apply to our organically-grown cannabis plants, whether we're cultivating outdoors, in greenhouses or indoors using grow lamps.
There are a few types of seed that are most commonly used for this purpose, these are primarily maize, barley, alfalfa and lentils. These are used at different times, depending on what stage of life our plants are in, and the desired effect.

Barley (Hordeum vulgare)​

Sprouted barley grains contain are very high in enzymes and gibberellins, as well as many vitamins, minerals, amino acids and nutrients. As well as the growth-promoting effects of gibberellins, barley SST is principally applied in order to establish and maintain the enzymes in the substrate. These enzymes help to digest dead roots, keeping the substrate and root zone in good health, as well as potentiating the soil food web and improving nutrient uptake. Some of these enzymes, specifically chitinase enzymes, have been shown to have an inhibiting effect against fusarium, a pathogenic fungus that causes great losses in agriculture as well as in cannabis gardens.
If whole barley grains are difficult to find then malted barley is a good substitute. Because the grain has already been sprouted as part of the malting process, this is a much faster method and will only need to be steeped, or "bubbled" in water for a few hours to make a natural enzyme tea, although freshly-sprouted seeds will always be more effective. To use malted barley add 2 tablespoons per gallon of water. Apply this or Barley SST once a week during vegetative growth and then give a top-up application roughly halfway through the flowering period.

Alfalfa (Medicago sativa)​

Rich in enzymes, vitamins, proteins and, most importantly, triacontanol, a potent growth-boosting plant hormone which increases photosynthesis by raising chlorophyll levels, increasing root mass, alfalfa seed sprout tea is a powerful plant stimulant that's perfect for the transition into flowering, when it helps to maintain close internode spacing and increase root mass. It can also be used in combination with Corn SST during vegetative growth and flowering as a general growth booster. More care must be taken with alfalfa as it is very powerful indeed and we recommend to either start the process with half the amount of seeds or to dilute in double the quantity of water before application.

Alfalfa sprouts are rich in triacontanol

Corn (Zea mays)​

Corn or maize sprouts are high in enzymes, minerals and nutrients, and also very rich in cytokinins, a plant growth hormone which promotes lateral budding, branching and the development of thicker stems leading to improved nutrient transport and the capacity for heavier crops. It can even be used at twice the strength to control height, resulting in really squat, bushy plants, perfect for growing spaces with reduced headroom. Organic sweetcorn grains are the most common source of corn to use for sprouting, but all maize grains are easy to germinate and some growers even seek out heirloom varieties like Blue Corn to ensure their SST is GMO-free. Corn SST is best applied in late vegetative growth and up to the fourth or fifth week of flowering.

Lentils (Lens culinaris or Lens esculenta) and other legumes​

While alfalfa is, in fact, a legume, here we're talking about other legumes, not only lentils but also larger seeds such as peas, beans or chickpeas. The sprouts of these seeds contain high concentrations of auxins, producing an SST that makes a great rooting stimulant as well as working to boost growth in general. Lentils are a great choice because, due to their relatively small size, they will germinate faster than the larger legumes.
These are the most commonly used seeds for making SSTs, but it doesn't mean that other types of seed won't work equally worth experimenting with. For example, an SST using sprouted hemp seeds ought to be an excellent growth booster for cannabis plants, while sunflower seeds are well known to be high in phytohormones, and many others such as rice, fenugreek, pumpkin have been recommended as well.

How to use plant hormones in cannabis cultivation​

In this blog post, we take a look at the complex world of plant hormones, talking about the wide range of effects they have, and how they control and regulate almost every aspect of our plants' lives.

It's important to always use seeds from organic agriculture for our SSTs, to avoid the possibility of introducing any trace of chemical pesticides and other undesirable compounds into our garden. The organic aisle in the local supermarket or health store is often the most convenient place to source seeds for sprouting, usually providing us with all the seeds listed above, alongside a range of other seeds that we could try out for ourselves at home.

What will we need to make SST?​

• 28g (1oz) of your chosen seeds, beans or grains
• 1/4 tsp Kelp meal
• Clean water
• Sieve
• Glass jar
• Cheesecloth & elastic band
• Blender/food processor

Everything you'll need to make a seed sprout tea

How do we make SST?​

Thoroughly rinse the seeds in clean water to remove any dirt, dust or contamination. This is best done using a sieve under a running tap. This also helps to remove any abscisic acid, a growth-inhibiting hormone that occurs on the outer shell of many seeds.

Soak the seeds overnight in clean water. Adding a quarter-teaspoon of kelp meal at this point will infuse the water with growth-promoting phytohormones and help to accelerate the germination process. In this case, we've used the soluble kelp powder Alga Plus from Jumus.

Drain and rinse the seedsin clean water after soaking for at least 8 hours and put them back into the jar. They should be wet enough so that the seeds will adhere to the sides of the jar, but not sitting in water. Cover the jar mouth with cheesecloth and fix with a rubber band. This gives ventilation while stopping any insects, or dust falling in. Placing the jar on its side allows for a greater surface area of the seeds to be in contact with the air.

Rinse and drain the seeds at least twice a day until the sprouting tails are as long as the seeds themselves. This usually takes a few days. Then blend the sprouted seeds in a food processor along with a cup or so of water. In our experience, the "Nutri-Bullet"type of blender is best, but pretty much any kind of food processor will do the trick to a satisfactory level.

Separate the liquid from the seed pulp
using the sieve, straining the resulting liquid into a container. The pulp can be composted or added directly to the soil surface as an enzyme-rich top-dressing.

Dilute the resulting liquid in 10 litres water before using it to irrigate your plants. In the case of alfalfa SST, which is much more potent, use 20 litres to dilute or, alternatively, start with half the quantity of seeds.

What can we do now?​

At this stage, some growers like to "bubble" or aerate the SST for 12-24 hours in a bucket with an air pump, while others will add molasses to the tea and ferment it to preserve it for a longer time., we recommend diluting and using any SST right away for maximum freshness and effectiveness, it's easy and cheap enough to make a new batch next time you need some more.
If you'd like to boost the SST with more micro and macronutrients, amino acids and other essential elements, you can mix in some more organic, natural ingredients. For example, you could mix in some Nettle Flour, which is ideal for the growth period, or an infusion of dried Comfrey leaves for a nutritional and health boost during the flowering phase.
While SSTs may not be a replacement for the scientifically formulated, high-precision stimulants and boosters used by many cannabis cultivators, there's no question that, when used correctly, they can be a powerful tool for the self-sufficient organic grower, not only giving great results but also rewarding the grower with the satisfaction of having created their own plant stimulators in a natural way.
We hope this article has been of interest to you, please don't hesitate to leave a comment with your own experiences, suggestions or any questions you may have.
Happy sprouting!

“Quick and Easy” Guide to Making Grow Media​

All these ingredients can be found at the grocery store, pharmacy, and/or health food store.
Perfect for beginners or those just getting involved with plant tissue culture.
This recipe comes from Plants from Test Tubes: An Introduction to Micropropagation on page 77.

What you Need

• 1/8 cup table sugar
• 1 cup tap water*
• 1/2 cup nutrient solution (1/4 tsp all-purpose 10-10-10 fertilizer dissolved in 1 gallon of water)
• 125-mg tablet of inosital (1/2 of a 250-mg tablet)
• 1/3 vitamin tablet with thiamine
• 2 tablespoons agar flakes

*Coconut milk can be substituted for tap water but growth will be somewhat different (could be good or bad depending on the type of plant, it’s unknown what effect it has on cannabis)

1. Combine ingredients in flask or beaker
2. Boil while stirring until agar has melted
3. Dispense medium into pint canning jars (or baby food jars)
4. Cover and process in a pressure cooker for 15 minutes at 15 pounds pressure
   1. Sterilize tweezers and razor blades in the cooker at the same time (wrap in aluminum foil before putting in cooker)
   2. Also sterilize pint jars of water (for explant cleaning)

Important Compounds for Cannabis Culture

• Cytokinin – Cannabis plants respond to the cytokinin TDZ (Thidiazuron)
• Auxin – Cannabis plants respond best to auxin IBA (Indole-3-butyric acid) for cannabis rooting
• Callus growth – Can be produced and maintained on cannabis plants with a combination of auxin NAA (naphthalene acetic acid) plus cytokinin TDZ (at concentration 0.5 µM NAA plus 1.0 µM TDZ)
• Rooting – cannabis explants have been rooted successfully on an MS medium supplemented with 0.1 mg·L^-1 IBA and 0.05 mg·L^-1 NAA

Tissue culture creates clones out of a small piece of plant such as a stem or leaf. The same general process (sterile conditions plus a sterile grow medium) can also increase germination rates for old seeds by preventing all contaminants while providing ideal growing conditions. This is an arabidopsis seed germination by BlueRidgeKitties in agar.

Abstract​

Treatment of seeds with an aqueous extract of yucca (YE), Yucca schidigera, was evaluated for antifungal activity against seedborne pathogens as well as its effect on seed germination and seedling growth of sorghum (Sorghum bicolor). The antifungal effect of YE was observed against Leptosphaeria sacchari (syn. Phoma sorghina) when the extract was applied at 2·5 and 10% concentrations. At 10% concentration, YE significantly reduced not only the incidence of L. sacchari, but also that of Fusarium spp., Cochliobolus lunatus (syn. Curvularia lunata) and Cladosporium spp. The effect of 10% YE on seedborne fungi was broader than the fungicide fludioxonil, particularly with regard to Fusarium. Furthermore, the number of normal, healthy-looking seedlings increased in a dose-responsive manner with YE treatment. Seedling vigour was also stimulated by YE but no correlation was observed with the concentrations tested. Under glasshouse conditions, the treatment of seeds with 10% YE increased the emergence of seedlings and plant height and reduced the number of seedlings with crown rot compared to negative controls and saponin. The positive effect was similar to the effect obtained with fungicide-treated seeds. Treatment of seeds with synthetic saponin inhibited seedborne fungi less effectively and also negatively affected germination and vigour of the seedlings, compared to the treatment with YE. The results demonstrate an agronomic potential for the use of YE as a biofungicide for seed treatment of sorghum. The difference between the antifungal and the vigour-stimulating effects of YE warrants further investigation. https://bsppjournals.onlinelibrary.wiley .com/doi/full/10.1111/j.1365-3059.2011.02517.x
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Abstract​

Biostimulants can be used as innovative and promising agents to address current needs of sustainable agriculture. Weeping willow tree (Salix babylonica) extracts are rich in many bioactive compounds, including, but not limited, to salicylates and phenolics. In this study, the potential of willow bark (WB) and willow leaf (WL) extracts is evaluated as plant-based biostimulants to improve the early growth of maize (Zea mays) under control and salinity stress conditions. In 3 days, seed treatment with salicylic acid and willow extract increased the shoot FW of maize seedlings 130% and 225%, respectively. The root area was, on average, enhanced by 43% with SA and 87% with willow extract applications. Moreover, these extracts increased the leaf protein concentration and reduced the negative effects of salinity during early growth. Reductions in lipid peroxidation and specific activities of antioxidative enzymes by seed treatments with willow extracts suggests a mitigation of salinity-induced oxidative stress. For most reported traits, WL applications were at least as effective as WB applications. Results indicate that aqueous extracts of weeping willow leaves, as well as bark, can be used as seed treatment agents with biostimulant activity to improve seedling growth and establishment under control and stress conditions. https://www.ncbi.nlm.nih. gov/pmc/articles/PMC8309356/

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Abstract​

Successful seed germination results in the production of the next generation of plants, and is a critical phase in their growth and survival. Germination involves different processes including imbibition, protein synthesis, and phytohormone production. All of these processes can be manipulated by extrinsic factors including the application of biostimulants. Some biostimulants can be used to increase metabolic efficiencies and thus improve germination in different plants. The effect of biostimulants is often dependent on biostimulant type, concentration, and plant species. Certain seaweed extracts, humic substances, and microbial inoculants play a role in the hormonal metabolism stage, leading to an increased germination rate. This chapter reviews current research on the physiological and biochemical responses influenced by the application of biostimulants during seed germination.
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The application of the biostimulant as a seed treatment increased the percent germination (+6.54%) and fresh biomass (+13%) at 48 h,
and decreased the content of H2O2 in treated seeds at 28°C (−70%) and at 35°C (−80%).May 25, 2020
https://www.frontiersin. org/articles/10.3389/fpls.2020.00836/full
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If you try the organic methods use caution as the results for germination will be variable this I would consider experimental
Also keeping everthing sterile as possible is paramount as it can take weeks to grow a stubborn seed, you dont want pathogens bacteria and fungus to take over ...patience
Also read on pathogen culture on PDA media and identification
Best of luck to you, hope you share your results and have some feedback for this

https://gardenculturemagazine. com/treating-seeds-and-seedlings-with-sea-kelp-delivers-results-in-the-garden/
further research on liquid kelp extracts and dry kelp meal tea and how they can affect seed germination....... more to come

 

[Atom]

What are the indicators when reversed pollen is ready to be plucked. And thanks for putting this up.

 

[acespicoli]

What are the indicators when reversed pollen is ready to be plucked. And thanks for putting this up.

Flower and pollen development in genetically male plants of Cannabis sativa. ​

(A-C) Male flowers formed in clusters at leaf axils. Each flower is pedicillate, with individual stalks. ​

(D-F) Opening of male flowers to reveal 5 green-white tepals which expose 5 stamens each attached to a filament that dangles the anther. ​

(G) Large amounts of pollen (arrow) being released through the longitudinal groove (stomium) of the anther. ​

(H) Enlarged view of the stomium showing formation of bulbous trichomes (arrow) forming in the groove of the anther. ​

(I) Close-up of a trichome with a short stalk (arrow). Pollen grains can be seen in the foreground​

Mature flowers of Cannabis sativa. Male Cannabis flowers have sepals and stamens ​

(a) while female Cannabis flowers consist of two carpels enclosed by a perigonal bract ​

(c). Schematic depiction of the structure of Cannabis male flower ​

(b) and female flower ​

(d). The bar = 1 mm. an, anther; b, perigonal bract; fi, filament; s, sepal; ov, ovary; p., perianth; stg, stigma; sty, style.​

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Collect, Dry and Crush the Pods
Have a plant growing great big clusters of male flowers which don't seem to open, or don't have much pollen when they do open?

When the pods have swelled and look like they are fully mature and should be opening, cut them off the stem. Wrap the clusters in paper towels and bury them in a sealed jar of dried rice.
(Heat un-cooked rice in an oven at 150-170F for at least 12hrs and cool in a sealed jar) The rice will absorb the moisture from the pods and dry them completely.

Citation > The_Cream_of_the_Crop

suggest asking more questions on this thread below, there is alot of feminized strain specific talk if you have any problems
Hope you find this helpful @Atom

Tutorial - DIY STS Mixing/Using Guide for Feminized Pollen/Seeds R.C.Clarke Method as Base

Feminized Seeds are Awesome Hermaphrodite plants are not awesome. Fortunately, it's possible to create cleanly produced feminized pollen. This pollen can be used to create seeds which are 99.9% female. As long as logical safeguards are taken, these seeds will not be any more sensitive to...

www.icmag.com

Autistic Diplomat in Training​

Nov 3, 2018 #1

Feminized Seeds are Awesome
Hermaphrodite plants are not awesome. Fortunately, it's possible to create cleanly produced feminized pollen. This pollen can be used to create seeds which are 99.9% female. As long as logical safeguards are taken, these seeds will not be any more sensitive to becoming hermaphrodite than the parent plants

This particular recipe for STS was originally published by Robert C. Clark. Today it is arguably the most recommended and successfully used method of feminizing cannabis. This write up includes the original recipe, along with practical useage tips and other helpful information gained through research and experience.

I know you'll be greatly pleased with your results.

Non-Hermaphrodite Plants Begin With the Parents
Stress testing your female plants is essential to removing breeding plants with hermaphroditic tendencies. Even if you're **not** using feminized pollen, breeding with unstable parents can produce hermaphroditic seeds. It's extremely important to expose your potential parents to the stresses most commonly known to trigger hermaphroditic flower production. These include, but are not limited to, the following stresses:
* Inconsistent Light Schedules
* Pinhole Light Leaks During Flowering
* Excess or Extreme Changes in Temperature
* Bound Roots
* pH too Low/High
* Lighting Spectrum Change
* Media Excessively Wet/Dry
* Excessive Supercropping/Heavy-Trimming
* Root Pruning
* Proximity to Sessions (just making sure you're reading. lol)
* Over/Under Feeding
* Incorrect Nutrient Profile
* Insects/Disease/Fungi
* Pesticide/Chemical Exposure
* Extended Flowering Time

Only the females which stay 100% female through the tests should be used for breeding purposes.

Yes, Stress Testing
Choosing excellent parents can take a long time and consume a lot of resources. These factors are the main reason so many unstable seeds are available today (2018), Patience and persistence pays off here. The more stable the genetics you're working with, the quicker you'll have a large enough number of potential parents. Each stress takes 1-3 weeks to form male flowers. Stressing multiple clones, of the same plant, ensures accuracy of the test results.

The more stable the original female plants, the more valuable the end seeds will be. Keep stressing until you're absolutely sure the plant is stable. Again, be prepared for this process to take quite a while. Every extra ounce of effort you put into this portion of the program will pay you back in greatly increased quality. **You can do it!**

Silver Thiosulfate Solution (STS)
STS is the most commonly used chemical mix for creating stable feminized pollen. While it may not be the only method, it is arguably the most commonly used and is very reliable. Female cannabis plants require ethylene production to form female flowers. Without ethylene being produced, the female cannabis plant will produce male flowers full of feminized pollen. Silver Thiosulfate Solution(STS) suppresses ethylene production in plants. When this solution is properly applied to the bud sites of a cannabis plant, the plant will not produce ethylene. Again, without the ethylene, male flowers form.


The Basics of Making Silver Thiosulfate Solution
Can you mix a powdered drink mix? Congratulations! You have the skills to make Silver Thiosulfate Solution. STS is mixed up in two parts called "stock" solutions. These solutions are labeled A and B. Solution A is a mixture of silver nitrate and distilled water. Solution B is a mixture of sodium thiosulfate and distilled water. These two solutions can be kept in light-proof bottles, sealed and refrigerated, for extended periods of time, even years.

Once solutions A and B are mixed together, the resulting mix is diluted with distilled water before using. Once mixed, the STS (both full strength and diluted) must be kept from light, and can be used up to a month when stored properly. I've used mixed and diluted solution which was kept in my refrigerator for over 9 months, but fresh solution definitely works the best.

Tools and Materials You Will Need
Where possible, I have linked the exact items I purchased and used. The remaining items I had around the house. 500g of Sodium thiosulfate anhydrous is a LOT of thiosulfate, so smaller projects may want to use the pentahydrate verion, because it's available in smaller sizes.
* Silver Nitrate
* Sodium Thiosulfate (Anhydrus or Pentahydrate Both Work)
* Distilled or Reverse Osmosis Water
* A Digital Scale Accurate to 0.1g
* Two (2) 32oz Brown Glass Bottles
* 1 32oz Brown Glass Bottle w/Black Sprayer Top
* 33 Gallon Black Trash Bag
* Tape
* 60 cc/ml Syringe
* Surfactant (Yucca-Extract works great)
* A Cool Dark Place for Storage (Fridge)
* Nitrile Gloves
* 500ml/2 Cup Glass Mixing Container
* Small wire whisk
* Safety Goggles

Basic Safety Recommendations
The following steps require careful measuring, along with basic chemical safety. It is strongly recommended you work on a flat surface with a plastic sheet or several layers of newspaper to protect it. Silver nitrate does stain brown to black, so gloves and safety goggles are recommended.

Sodium thiosulfate has a very low toxicity, make sure you still wash up any spills well to remove all concern. Both of these solutions can be safely rinsed down the drain, when followed by a large amount of water.

Measuring and Mixing Stock Solution "A"
* Fill your 500ml measuring cup with 500ml of distilled water
* Measure out .5g of Silver Nitrate
* Mix the silver nitrate powder into the 500ml of distilled water
* Pour the silver nitrate solution into a brown glass bottle and seal tightly
* Label the bottle "A" Silver Nitrate
* Thoroughly clean the 500ml container and rinse with distilled water

Measuring and Mixing Stock Solution "B"
* Fill the 500ml container with 500ml of distilled water
* Measure out 2.5 grams of sodium thiosulfate **anhydrous**, **OR** 3.9g of sodium thiosulfate **pentahydrate**
* Mix the sodium thiosulfate with the 500ml of distilled water
* Pour the sodium thiosulfate solution into a brown glass bottle and seal it tightly
* Label the bottle "B" Sodium Thiosulfate
* Thoroughly clean the 500ml container and rinse with distilled water

Keep Both "A" and "B" Solutions Cool and Dark!

Mixing and Diluting STS
The next step is to mix the two stock solutions together properly, creating the actual Silver Thiosulfate Solution (STS).

Before using the STS, it must be diluted to a weak solution for spraying! (Edit 8/2022: Best results are being obtained with Full Strength solution and 2 sprays. One on first day of flower, and the second at day 14. Long flowering may require a spray on day 28)

* Measure 50ml of stock solution "B" with the 60cc syringe and gently squirt it in the 500ml glass measure
* Thoroughly rinse the syringe with distilled water, or change to a new syringe
* Measure 50ml of stock solution "A" with the 60cc syringe
* While whisking solution "B" in the glass measure, slowly squirt solution "A" into the glass measure in less than 30 seconds
* Pour the mixed solution into the 32oz brown glass bottle with black sprayer top
* Add 900ml of distilled water to fill the sprayer the rest of the way, leaving room for a little bit of surfactant
* Add yucca extract in small amounts and shake well
* Test spray on a leaf to if solution still beads up and rolls off
* Add additional yucca extract and shake well, until the solution spreads across the leaf instead of beading up
* Thoroughly rinse all tools using more rinse water than usual


You now have a sprayer bottle with a 1:9 dilution of STS and water. **You want to do your best to protect it from light and heat**. Personally, I wrap the bottle section with a black plastic trash bag and tape it in place. This is for additional light protection while it stores in my fridge. (Edit 4/2020): I've kept the original stock solutions from this tutorial for 2 years now, on the second to bottom rack of the door of my fridge. I haven't changed a thing, and they're still in the same brown bottles you see in the photos. I mixed some fresh solution a few weeks ago for some projects and began spraying a stunted female autoflower with it. (why not, right? lol) Today I noticed a couple open nanners, so you can rest assured the stock solutions do not go 'bad' very quickly.

Successfully Using STS!
I've spent a great deal of time researching the best method(s) to use for success with STS. First I'm going to detail the steps I've used successfully myself. I'm also including the thoughts and tips I've picked up from other growers. Cannabis is a nearly infinitely variable plant, so it's best if you have information from as many sources as possible. Who knows which tip will specifically fit your plants and setup.

Regardless of the spraying schedule you use, **be sure to thoroughly saturate the branch(es) and beginning flower clusters**.

Spraying Schedule I've Used Successfully
* Spray branch(es) you want reversed 5 days before flipping to flower
* Spray every 5 days until major male flower formation has begun

Alternative Spraying Schedule A
* Spray branch(es) you want reversed 2 weeks before flower
* Spray branch(es) you want reversed on the day you flip to flower

Alternative Spraying Schedule B
* Spray branch(es) you want reversed on the day you flip to flower

(Edit 8/2022: As mentioned above, use full strength solution and spray twice. Once on first day of flower and once on day 14. Long flowering may require a spray on day 28.)

A Note on STS "Burning" the Plant
Many growers have reported the STS solution 'burning' the plant. I strongly recommend diluting your spray further than 1:9, if you experience any burning of your plants.
(Edot 8/2022: I believe the burning may be caused by unclean water or chemicals or soap, since I have never seen any burning except with 2yr old solution)

Additional Tips and Tricks
As always, the more information you have, the better you can potentially achieve. The following are little things which can make a big difference in your results.


Using Clones
When possible, I've found it immensely helpful to work with clones of the same plant, reversing one or more for pollen in a small flowering area first. The pollen is collected and stored. At this point, the pollen can be used on any female plants, including clones of itself.

Though it does involve a second step of collecting and preserving the pollen until use, it allows you to create seeds without dealing with a reversed plant in the room. An additional up side is the ability to store the pollen for years, when preserved properly.


Pollen Control
I STRONGLY recommend using filtered intakes and outtakes on any flowering environment you're creating or using pollen in. Many growers have reported developing allergies to cannabis pollen, after working with it for years on end. Filtering the air going in and out of your flowering rooms keeps pollen contained. (mostly lol)

I use spray bottles of r/o filtered water and spray down the air in the room, any time I disturb pollen. Knock the pollen out of the air after every session of working with pollen. Be sure to spray down the insides of tents and flower rooms after each run. This will minimize cross contamination from different pollen sources.

Diluting Your Pollen
Any visible bit of pollen you can see is made up of millions of bits of pollen, making one pollen per pistil pollination impossible. Mixing your pollen at one part pollen to 50 parts corn starch or flour prevents waste. Each pistil requires only one bit of pollen to create a seed and the dilution makes this easy.
(Edit 8/2022: This is best done when you actually go to use it. Dilution before freezing I no longer recommend.)


Using a Makeup Brush to Pollinate With
Many growers report excellent results with evenly pollinating plants, when they use a clean makeup brush. The brush allows easy application of the pollen evenly across the plant. When the pollen is diluted with flour, you're easily able to see which flowers you've already pollinated.
### Storing Your Pollen for Years (Possibly 10+ Years)
Pollen can be stored for a long time in a freezer, as long as it has been thoroughly dried. Silica packs do not absorb down to a low enough relative humidity, so dried rice is used.

Heat an open quart jar of un-cooked rice at 150F-170F for at least 12hrs (anyone know if you can shorten this?). Seal the jar with a lid and ring, and let it cool to room temperature. A wide mouth quart jar is significantly easier to open than a peanut butter jar. The vacuum seal formed while cooling down can be awful. lol

Collect your pollen and carefully transfer it to a foil baking cup or other small container which fits in the jar. Place the foil cup on top of the rice and seal the pollen in the rice container. Set the jar in a cool, dark place for 7 days. Cold temperatures will slow the drying.

(Optional: Toast some flour in a skillet on the stove until it is a dark tan color, then seal hot in another glass, airtight container and let cool to room temperature. This will remove the moisture from the flour. Remove the pollen from the dried rice jar and mix it at a ratio of 1 part pollen to 50 parts flour.) Pollen which has been properly dried does not need flour/cornstarch/rice-grains during storage. You can safely leave the option of 'dilution' till the time you actually use the pollen. I've personally switched to storing pure pollen, since who knows what the future will bring.

Seal the mixed pollen in small containers, foil or plastic sealed pouches or (preferred) 1.5ml centrifuge tubes.

LABEL your containers carefully, using the specific plant name, date and any other information you believe you'll remember later. (Because there's a good chance you won't)

Seal the containers in a thermos and keep it in your freezer. The thermos acts as an additional thermal protection barrier, just in case you have a freezer issue years down the line. It also makes transferring pollen from one place to another a safe operation. Just be sure to keep the thermos at freezing temps, and to limit the amount of time outside the freezer.

Stubborn Female Refusing to Turn?
While the most stable female plants are the type of plants we strongly want to breed with, they are often difficult to get quality amounts of pollen from. These tips should help even the most stubborn female in your stable flip large amounts of viable pollen.

Test Different Spray Schedules
Flower out small clones of the plant you want to reverse. Use a different spray schedule with each clone, keeping careful track. You may find one schedule works much better than the others.

Use Colloidal Silver
Some growers have reported success with the alternative spray schedules, with a follow up spraying of a high ppm colloidal silver solution, 2-3 weeks into flower.


Collect, Dry and Crush the Pods
Have a plant growing great big clusters of male flowers which don't seem to open, or don't have much pollen when they do open?

When the pods have swelled and look like they are fully mature and should be opening (they will look like fat footballs with stripes where the sepals are beginning to split apart), Cut branches and hang them to dry over a collection table until crispy. It should only take a few days. When the relative humidity (RH) is too high for hang drying, using the rice desiccant can get it done.

Drying Pods with Rice:
Strip the clusters of pods from the flowers, leaving as much leaf and stem behind as possible. Wrap the clusters in paper towels and bury them in a sealed jar of dried rice. (Heat un-cooked rice in an oven at 150-170F for at least 12hrs and cool in a sealed jar) The rice will absorb the moisture from the pods and dry them completely. Depending on the volume of the pods you're drying, you may need to stir them once or twice a day. This keeps them from rotting or sprouting fungi before they're dry enough. You should be checking/stirring often enough, you'll definitely be able to tell when they're dry enough for screening.

When the pods are completely dry and crispy, gently crush them through a tea strainer, or similar fine mesh strainer. You'll find large quantities of viable pollen.



What are you waiting for? Go make some fems!!




Last edited: Oct 24, 2022

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https://doi.org/10.21273/HORTTECH04188-18

Foliar Sprays of Silver Thiosulfate Produce Male Flowers on Female Hemp Plants​

Authors:
Jessica D. Lubell




and
Mark H. Brand




Click on author name to view affiliation information
Article Category: Research ArticleOnline Publication Date: Dec 2018
Page(s): 743–747Volume/Issue: Volume 28: Issue 6
DOI: https://doi.org/10.21273/HORTTECH04188-18

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Published print: 01 Dec 2018

Abstract​

Interest in hemp (Cannabis sativa) for its medicinal compounds, cannabidiol (CBD), and Δ-9-tetrahydrocannabidiol (THC), continues to increase. Maximizing yield of CBD and/or THC requires female plants because female inflorescences accumulate significantly greater concentrations of these compounds than male inflorescences. Production of all female seed requires induction of female plants to develop male flowers that produce genetically female pollen. Growers would like access to feminized seed to produce all-female crops. We evaluated the efficacy of 0, 0.3, and 3 mm silver thiosulfate (STS) applied as a foliar spray (on three occasions 7 days apart) to produce male flowers on four strains of female hemp (having a THC concentration of ≤0.3%), designated CBD hemp A, CBD hemp B, CBD hemp C, and industrial hemp. Silver thiosulfate at 3 mm was the most efficacious treatment for all strains. The majority of inflorescences had 100% male flowers at 3 mm STS, and terminal inflorescences had ≥95% conversion to male flowers. Silver thiosulfate at 0.3 mm produced partial conversion to male flowers, whereas most inflorescences had around 50% male flowers, except for CBD hemp A, which demonstrated greater levels of masculinization. At 0.3 mm STS, terminal inflorescences of CBD hemp A had 91% conversion to male flowers. This study demonstrates that male flowers can be produced easily and consistently on female plants through application of foliar sprays of STS under short-day conditions.
Keywords: Cannabis sativa; cannabidiol; CBD hemp; feminized seed
Medicinal interest in hemp is attributable to its production of unique terpenophenolic substances, called cannabinoids, which are concentrated in the glandular trichomes of the plant (Mechoulam, 1970; Potter, 2014). More than 100 cannabinoids have been identified; however, the most abundant and medicinally important cannabinoids are CBD and THC (de Meijer et al., 2003). Recently, interest in the medicinal effects of CBD has increased because, unlike THC, CBD is nonpsychoactive (Russo, 2011; Small, 2015). In the United States, 25 states and the District of Columbia have enacted laws allowing the medicinal use of hemp, and another 17 states allow products that are high in CBD and low in THC (Mead, 2017).
Hemp is an annual dioecious species with females containing homogametic chromosomes XX and males containing heterogametic chromosomes XY (Moliterni et al., 2004). Male plants are taller, more slender, and have a shorter life cycle than female plants. Sex morphology in hemp is believed to be controlled by an X:autosome balance, where the ratio of X:A (autosomal) chromosomes determines sex by an X chromosome counting system, and the Y chromosome is inactive (Negrutiu et al., 2001; Parker, 1990; Shephard et al., 2000; Vyskot and Hobza, 2004). Exogenous application of plant growth regulators can modify or reverse sex morphology in plants (Galoch, 1978). In hemp, auxins, ethylene, and cytokinins promote the formation of female flowers on male plants; gibberellins promote the formation of male flowers on female plants (Galoch, 1978; Mohan Ram and Jaiswal, 1972; Thomas and Vince-Prue, 1997). Mohan Ram and Sett (1982) induced the formation of male flowers on female hemp plants using silver nitrate and STS, which inhibit the action of ethylene.
Monoecious plants occur occasionally in hemp, and cultivars have been selected for use in the production of industrial hemp fiber and seed (Moliterni et al., 2004). Industrial hemp is defined by the 2014 “Farm Bill,” Section 7606 of the Agricultural Act 2014 (7 USC 5904) as hemp having a THC concentration of ≤0.3% on a dry weight basis (Mead, 2017). Monoecious hemp cultivars demonstrate greater seed yields and greater crop homogeneity, and are easier to harvest mechanically than dioecious plants (Hall et al., 2012). Sex expression in monoecious hemp is not as well understood as for dioecious plants, but it is believed to be a heritable trait present on the X chromosome or autosomes (Faux et al., 2014). It has also been suggested that the monoecious state originated from a small translocation from the Y chromosome, or by one or several mutated genes (Razumova et al., 2016).
In the United States, at least 15 states have enacted legislation authorizing research and agricultural pilot programs related to industrial hemp (National Conference of State Legislatures, 2018). Increased interest in CBD has led to increased cultivation of hemp, but because hemp has been selected for fiber and seed production, it is generally low in CBD content (2% to 4%) (Mead, 2017). Therefore, the development of hemp cultivars with increased CBD content is a current breeding objective (Caplan et al., 2017; Soler et al., 2017).
Female plants are preferred for cannabinoid production because females accumulate, predominantly in the inflorescences, significantly greater cannabinoid content than male plants (Small, 2015). Rahn et al. (2016) and Soler et al. (2017) report that hemp growers are using hormones or chemicals like STS to make feminized seed, in which 100% of the seed is female. Mohan Ram and Sett (1982) suggest STS can be used to make male flowers with viable pollen on female hemp plants, but their methods are not directly translatable to commercial applications. Male flowers induced on genetically female plants will produce pollen containing only X gametes, which when crossed with eggs from female plants result in all-female seed (Mohan Ram and Sett, 1982). Foliar sprays of STS have been effective at blocking ethylene production and extending the flowering time for several different species of ornamental plants (Cameron and Reid, 1981, 1983). Green (2015) describes using a single foliar spray of STS to produce feminized hemp seed. This method has been shared among growers online, but this information is not based on scientific research. There are no published reports about using foliar sprays of STS to produce feminized hemp seed. Therefore, the objective of this work was to evaluate the efficacy and rate of foliar sprays of STS for inducing male flowers and producing female seed for different strains of hemp.

Materials and methods​

This study was conducted two times on three different strains of CBD hemp—strains A, B, and C—that differed from one another in their branching density, stem color, and leaf size. One strain of industrial hemp was studied. In the first replication of this study, CBD hemp strains A and C, and the industrial hemp strain were used; in the second replication of this study, CBD strains B and C, and the industrial hemp strain were used. Plants used in the study were propagated vegetatively from female mother plants of each strain. The industrial hemp female mother plant was selected from a population of seedlings that were female, male, or monoecious.
Rooted cuttings were potted into 307-mL square containers filled with a peatmoss-based grower mix (Fafard 3B Grower Mix; Fafard, Agawam, MA) and top-dressed with controlled-release fertilizer (Osmocote Plus 15N–3.9P–10K 5- to 6-month formulation; Everris NA, Dublin, OH) at 2.5 g/container. Plants were allowed to grow and establish for ≈14 d in a greenhouse with set points of 21/17 °C day/night. Plants were provided long-day (16 h) conditions using natural daylight that was extended with 600-W high-pressure sodium (HPS) lamps (Phantom HPS 600W; Hydrofarm, Petaluma, CA). During this time, plants were hand fertigated using a soluble fertilizer (Peters 20N–8.7P–16.6K; Scotts, Marysville, OH) at 100 ppm nitrogen (N) at every irrigation (200 mL/container). Plants were ≈6 inches high with two shoots when foliar sprays of STS were initiated. Silver thiosulfate solutions (0.3 and 3 mm) were prepared by mixing silver nitrate with STS in a molar ratio of 1:4, per Cameron and Reid (1981). Plants were sprayed to runoff (about 20 mL/plant) on three occasions, 7 d apart, beginning on 30 Apr. 2018 for the first replication and on 14 May 2018 for the second replication of this study. Control plants received sprays of water only. On 30 Apr. and 14 May, plants began receiving short-day conditions of ≈8 h using a blackout curtain to initiate the flowering stage. During the flowering stage, plants received a soluble fertilizer (Peters 15N–12.9P–12.5K, Scotts) at 100 ppm N as described previously.
The experiment was a randomized complete block design with two factors: three STS treatments and three strains, with three replicates for each factor combination. Each potted plant was an experimental unit. One week after the third and final STS spray, the number of male and female flowers per terminal inflorescence was counted for two terminal inflorescences per plant, which were averaged, and the percentage of male flowers per inflorescence was calculated for each plant. The degree of masculinization was evaluated using a visual rating. Each inflorescence per plant was rated for degree of masculinization using a scale of 1 to 5, where 1 represented 0% male flowers (all-female inflorescence), 2 represented 1% to 30% male flowers (strongly female inflorescence), 3 represented 31% to 60% male flowers (about equivalent male and female flowers), 4 represented 61% to 99% male flowers (strongly male inflorescence), and 5 represented 100% male flowers (all-male inflorescence) (Fig. 1). SAS software (version 9.2; SAS Institute, Cary, NC) was used for statistical analysis. Analysis of variance using the PROC MIXED procedure indicated no significant difference between replications one and two of this study, so the data were combined. Differences between STS treatments within strain for the percentage of male flowers per terminal inflorescence were determined using multiple comparisons for proportions and Tukey’s honestly significant difference test (Williams and LeBlanc, 1995).

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Fig. 1.
Photograph of (A) an all-female inflorescence, (B) an inflorescence with about equivalent male and female flowers, and (C) an all-male inflorescence from female cannabidiol (CBD) hemp strain C plants.
Citation: HortTechnology hortte 28, 6; 10.21273/HORTTECH04188-18

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Results​

Between 14 and 21 d after the first STS spray treatment, plants transitioned from first flowers to full flowering. Untreated control plants of all four hemp strains produced only female flowers, as expected (Fig. 2). This result confirmed that our starting plants were genetically female and there was no induction of male flowers resulting from other factors. For all strains, the 0.3-mm STS treatment produced partial conversion to male inflorescences (Fig. 2). At 0.3 mm STS, inflorescences were generally a mix of male and female flowers. CBD hemp A at 0.3 mm STS produced more inflorescences with high levels of masculinization than the other hemp strains. At 0.3 mm STS, CBD hemp B and C, and industrial hemp inflorescences ranged from 25% to 75% male flowers, centering around 50% male flowers per inflorescence. The most complete inflorescence conversion to male flowers occurred at 3 mm STS for all hemp strains. At 3 mm STS, the majority of inflorescences had 100% male flowers and the remaining inflorescences had 75% male flowers.

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Fig. 2.
Distribution of masculinization ratings among inflorescences of three different cannabidiol (CBD) hemp strains and one industrial hemp strain treated with foliar sprays of 0, 0.3, or 3 mm silver thiosulfate (STS) applied three times at 7-d intervals. Values are the percentages of inflorescences per plant that received each masculinization rating from 1 to 5, where 1 = 0% male flowers (all female inflorescence), 2 = 1% to 30% male flowers (strongly female inflorescence), 3 = 31% to 60% male flowers (about equivalent male and female flowers), 4 = 61% to 99% male flowers (strongly male inflorescence), and 5 = 100% male flowers (all male inflorescence). Vertical bars indicate ± se.
Citation: HortTechnology hortte 28, 6; 10.21273/HORTTECH04188-18

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In counting the actual number of male flowers per terminal inflorescence, 3 mm STS produced 100% conversion to male flowers for CBD hemp A and industrial hemp, and 97% and 95% for CBD hemp B and C, respectively (Table 1). Depending on the hemp strain, STS at 0.3 mm converted between 42% and 91% female flowers to male flowers. CBD hemp A had the greatest rate of conversion to male flowers at 91% and industrial hemp had the lowest conversion rate at 42%.
Table 1.
Percent of male flowers per terminal inflorescence for three different cannabidiol (CBD) hemp strains and one industrial hemp strain treated with 0, 0.3, or 3 mm silver thiosulfate (STS) applied as a foliar spray three times at 7-d intervals.

View Table
Male flowers that developed on genetically female plants produced pollen. However, the pollen did not appear to be as copious or freely released as observed on true genetically male plants. Pollen from masculinized flowers from CBD hemp strain B was used to fertilize female flowers on CBD hemp strain C to document that this method could be used successfully to generate all female seed. The pollen produced seed, which were harvested, germinated, and exposed to short-day conditions, and their sex was confirmed to be female.

Discussion​

Overall, STS at 3 mm was the most effective treatment for producing the greatest number of male flowers on female hemp plants. Green (2015) suggested that female hemp plants can be masculinized using a single foliar spray of 0.3 mm STS, but did not provide any information about the percent conversion to male flowers. We did not find three foliar sprays of 0.3 mm STS to be as effective for producing male flower formation as three foliar sprays of 3 mm STS. However, there may be specific strains, such as CBD hemp A, which produce primarily male flowers with STS concentrations less than 3mm.
Silver thiosulfate has been used to extend the vase life of cut flowers by blocking the effect of ethylene (Farnham et al., 1981; Veen and van de Geijn, 1978). A similar action of ethylene blocking by STS is likely responsible for the production of male flowers on female hemp plants in our study. It is generally believed that ethylene blocking is extended when a series of sprays of STS is used compared with a single spray of STS (Reid et al., 1980). It may be possible to induce male flowers on genetically female hemp using other ethylene perception inhibiting chemicals such as 1-methylcyclopropene.
Mohan Ram and Sett (1982), using 25 to 100 µg STS applied directly to the growing shoot tip of female hemp plants, were able to produce male flowers. However, they also noted severe necrosis on young leaves covering shoot tips and suspended apical growth for 20 to 25 d before lateral budbreak and subsequent flower formation. In comparison, we did not observe any plant phytotoxicity or delay in flower development. Furthermore, we were able to achieve 95% to 100% conversion to male flowers for all hemp strains, whereas Mohan Ram and Sett (1982) reported ≈60% to 80% conversion.
Producers and breeders should be able to masculinize female hemp plants routinely by using short-day conditions of ≈8 h and three foliar sprays of 3 mm STS at weekly intervals. We suspect that this method will be applicable for a broad range of genetically diverse hemp genotypes. Pollen produced by male flowers on genetically female plants can be used to produce all-female seed, but growers and breeders should be aware that pollen output may be reduced compared with pollen output from genetically male plants.

 

[Atom]

View attachment 18760154

Flower and pollen development in genetically male plants of Cannabis sativa. ​

(A-C) Male flowers formed in clusters at leaf axils. Each flower is pedicillate, with individual stalks. ​

(D-F) Opening of male flowers to reveal 5 green-white tepals which expose 5 stamens each attached to a filament that dangles the anther. ​

(G) Large amounts of pollen (arrow) being released through the longitudinal groove (stomium) of the anther. ​

(H) Enlarged view of the stomium showing formation of bulbous trichomes (arrow) forming in the groove of the anther. ​

(I) Close-up of a trichome with a short stalk (arrow). Pollen grains can be seen in the foreground​

View attachment 18760509

Mature flowers of Cannabis sativa. Male Cannabis flowers have sepals and stamens ​

(a) while female Cannabis flowers consist of two carpels enclosed by a perigonal bract ​

(c). Schematic depiction of the structure of Cannabis male flower ​

(b) and female flower ​

(d). The bar = 1 mm. an, anther; b, perigonal bract; fi, filament; s, sepal; ov, ovary; p., perianth; stg, stigma; sty, style.​

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Collect, Dry and Crush the Pods
Have a plant growing great big clusters of male flowers which don't seem to open, or don't have much pollen when they do open?

When the pods have swelled and look like they are fully mature and should be opening, cut them off the stem. Wrap the clusters in paper towels and bury them in a sealed jar of dried rice.
(Heat un-cooked rice in an oven at 150-170F for at least 12hrs and cool in a sealed jar) The rice will absorb the moisture from the pods and dry them completely.

Citation > The_Cream_of_the_Crop

suggest asking more questions on this thread below, there is alot of feminized strain specific talk if you have any problems
Hope you find this helpful @Atom

Tutorial - DIY STS Mixing/Using Guide for Feminized Pollen/Seeds R.C.Clarke Method as Base

Feminized Seeds are Awesome Hermaphrodite plants are not awesome. Fortunately, it's possible to create cleanly produced feminized pollen. This pollen can be used to create seeds which are 99.9% female. As long as logical safeguards are taken, these seeds will not be any more sensitive to...

www.icmag.com

Very helpful thanks..first time with STS on seriotica cultivar. Can't tell when to pull pods.

 

[acespicoli]

Very helpful thanks..first time with STS on seriotica cultivar. Can't tell when to pull pods.

In an ideal situation you have some gold "pollen" dust

should be visible on your fan leaves,
if the balls dont open id harvest 3-4 times one week apart.
Check with @Douglas.Curtis and send hm some of your pics maybe?
Most of my experience is with reg lines

 

[Vandenberg]

"Soak your seeds in 3% hydrogen peroxide for 30 minutes.
Rinse the seeds several 3X times with DISTILLED water before planting and plant them as usual.
Doing this breaks down the hard outer covering of the seeds and kills any pathogen present on them."

I have some Fem auto 3bears OG knockoff seeds that I have had to literally, physically snap/ crack the seed hulls prior to moistening to obtain any hope of germination, otherwise they just stare at me and do nothing.
I'd like to see this work and will be trying this crack the bean with a H2HO pre-soak tactic soon. Good idea ( I hope).

Vandenberg

 

[Douglas.Curtis]

@Atom Pods grow in size and then begin to split open along the sepal(?) edges. They start looking like striped little footballs before they burst open. At this point I generally cut the largest branches off to put in water for pollen collection. This also leaves the main plant to form new flowers.

When you have pods not opening, the level of STS is too high so use less next time. If all you have are unopened pods, collect them when you see they have quit growing in size and have still not opened after 4 to 5 days. Dry them and gently rub across a fine screen to break them open and release pollen.

 

[acespicoli]

This from: @tobedetermined Post #9 nice example of how to prevent over watering a seedling and being ready for overflows!
Im sure it also makes transplanting a breeze when your ready to up pot to a larger container!

Well Done

 

[acespicoli]

Interesting share from a fellow ICmagger

A Germination Machine

I wanted to share this device with anyone thats had a poor germination rate. This device will crack any viable seed placed inside within 72 hrs. 80% of seeds placed inside will germinate from 12-20 hours but f2 sativa hybrids may take as much as 60 hrs. The machine keeps temps at a constant 76...

www.icmag.com

This may be worth a try, hard to beat sterilized vermiculite...
the paper towel method lacks the airflow, this looks like a viable alternative
pre moistened and approx 2.5 minutes in the microwave can get things up to 160-180 degrees F

AIRNEX Biodegradable Natural Kitchen Sponge - Compostable Cellulose and Coconut Walnut Scrubber Sponge - Pack of 12 Eco Friendly Sponges for Dishes​

4.7 out of 5 stars 1,256 ratings

Amazon's Choice for "natural sponges for dishes"

Price:

$15.26 ($1.27 / Count)

coco fiber

 

[acespicoli]

Male clones transformed to Female to judge male smoking quality

[QUOTE="Sam_Skunkman, post: 2692424"]I have not had much luck stressing male clones to make them turn female, if you look up the Safety data sheet it does not sound dangerous. Remember most of the ethephon will rapidly convert to Ethylene... And as far as I know Ethylene in the amounts we are...

www.icmag.com

Summary​

Interaction between ethephon and the two ethylene antagonists — silver nitrate and cobalt chloride — applied exogenously to the male Cannabis sativa plants was studied. The feminization effect caused by two sprays of 960 mg· l-1 of ethephon could be overcome by 100 μg of AgNO3 or CoCl2. However, neither of the antagonists could suppress the feminization effect of 1920 mg · l-1 of ethephon sprayed twice.

 

[acespicoli]

Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences – Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation​

Female Inflorescence Development​

The sequential development of the female inflorescence in marijuana strains is illustrated in Figure 1. At the early stages of development, the clusters of pistils with protruding stigmas on terminal inflorescences were yellowish-white in color (Figures 1C–E). In some strains where pigmentation was a characteristic feature, the pistils and surrounding bract tissues developed a red or purple pigmentation (Figures 1F–H). With further maturation of the inflorescence, the stigmas shriveled and developed a brown-red color, while the ovules and surrounding bracts swelled and were covered by glandular trichomes that imparted a silvery-white appearance (Figures 1I–K).

Hermaphrodite Inflorescence Development​

During the 6–7 weeks flowering period of strains grown under commercial conditions, female inflorescences were examined at weekly intervals visually with the aid of a hand lens for the development of male anthers within the inflorescence (Figure 2). Around 1,000 plants in total were examined over the course of two repeated cycles of plant production in the study. Individual clusters of anthers appeared bright yellow and measured 2–3 mm in length (Figures 2A–D) and were formed within the bract tissues and surrounded by stigmas. In some cases, the entire female inflorescence was converted to a mass of anthers which emerged through the bracts (Figure 3). They were carefully removed with a pair of forceps, placed inside plastic petri dishes lined with moistened filter paper, and transported to the laboratory for microscopic examination. Scanning electron microscopic observations of anthers and pollen grains were made following preparation of the samples according to the procedure described by Punja et al. (2019). Pollen grains were released from anthers by suspending them in 5 ml of sterile distilled water for 2 min, from which 50 μl were plated onto 1% water agar (Bacto, Difco) and incubated at 23–25°C for 24–48 h. Percent emergence of pollen tubes was rated from 100 grains examined under an inverted compound light microscope (Zeiss). The experiment was conducted twice. In instances where seed formation was observed in the inflorescences of the three strains, they were collected at fruit maturity, counted, and set aside. Germination of a sample of 20 seeds from each strain was induced by placing them in a moist cocofibre:vermiculite (3:1, v/v) potting medium and incubating at 23–25°C for 20 days under supplemental lighting. The seedling tissues (young leaves), as well as anther tissues from hermaphroditic flowers, were used for DNA extraction (minimum of 15 seedlings per strain) as described below.

Male Inflorescence Development​

To examine the course of development of staminate flowers in genetically male plants, seeds of strains “Moby Dyck,” “Blue Deity,” and “Sweet Durga” were provided by a commercial seed producer which were produced from a controlled cross-fertilization cross. Seeds were placed in a moist cocofibre:vermiculite (3:1, v/v) potting medium and incubated at 23–25°C for 20 days under supplemental lighting as before. At least 20 seeds were germinated and 15 seedlings were obtained for each strain. The seedling tissues were used for DNA extraction as described below. The plants were grown for an additional 4 weeks under a 24 h/day photoperiod until staminate inflorescences were produced. These appeared as characteristic clusters of anthers followed by release of pollen (Figure 6). Individual clusters of anthers were carefully removed with a pair of forceps and brought to the laboratory for microscopic examination for the presence of pollen grains and for DNA extraction. In addition, scanning electron microscopic observations of anther and pollen morphology were made following preparation of the samples according to the procedure described above. To observe pollen grain germination and pollen tube growth on stigmas, pollen was manually collected from male flowers of strain “Sweet Durga” by tapping flowers gently over a piece of wax paper. The pollen was dusted onto pistillate inflorescences of strain “White Rhino” which had been collected the previous day, excised and placed in a humid chamber. A minimum of five replicate samples were included. After 72 h, tissue samples (n = 5) were prepared for scanning electron microscopy and germ tube production and growth on the stigmas that bore receptive papillae was determined at various magnifications from a minimum of 25 images.

Frontiers | Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences – Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation

Cannabis sativa L. (hemp, marijuana) produces male and female inflorescences on different plants (dioecious) and therefore the plants are obligatory out-cros...

www.frontiersin.org

 

[acespicoli]

This post is in response to starting your seeds.
This is a simple easy way to get off to a quick and easy start

Germination - Wikipedia

en.wikipedia.org

Cannabis cultivation - Wikipedia

en.wikipedia.org

• Let seeds soak in a shot glass of distilled water for 24-72 hours till root tip shows check daily
• A perfect place is the top of the fridge near the back, warm and out of the way try 75F
• Wait too long and the seed may drown due to lack of oxygen (while soaking)
• Prepare your planting media ahead of time such as this great example by @tobedetermined

• The smaller sized depression in the larger pot dries quicker prevents over watering
• Holes in bottom of cups and pots https://en.wikipedia.org/wiki/Anaerobic_organism <bad
• When the plant is as tall as the cup is high transplant otherwise it will possibly dwarf the plant
• Dwarfism is useful for sativa stretch transplant after the stretch pinch and LST low stress train
• The depression could be filled with sterile vermiculite https://en.wikipedia.org/wiki/Damping_off
• Lightly water with a spray bottle using distilled water https://en.wikipedia.org/wiki/Damping_off
• A word about water quality https://en.wikipedia.org/wiki/Purified_water#Parameters_of_water_purity
• Quality water https://en.wikipedia.org/wiki/Rainwater_harvesting#Quality_of_water_harvesting
• HEPA laminar flow filtered air entering the mylar grow tented or white plastic lined area

Damping off can be prevented or controlled in several different ways. Sowing seeds in a sterilized growing medium can be effective, although fungal spores may still be introduced to the medium, either on the seeds themselves or after sowing (in water or on the wind).

Pre-treatment of seed and soil before sowing​

Before sowing, certain seeds first require a treatment prior to the sowing process. This treatment may be seed scarification, stratification, seed soaking or seed cleaning with cold (or medium hot) water.
Seed soaking is generally done by placing seeds in medium hot water for at least 24 to up to 48 hours[2]

In addition to the mentioned seed pre-treatments, seed germination is also assisted when a disease-free soil is used. The two most used soil treatments are pasteurization and sterilization. Depending on the necessity, pasteurization is to be preferred as this does not kill all organisms. Sterilization can be done when trying to grow truly difficult crops. To pasteurize the soil, the soil is heated for 15 minutes in an oven of 120 °C.[4]

• Pour too much water too fast and your seed will be possibly displaced
• If your environment is very dry low humidity you may want to try a humidity dome (ventilate)
• Humidity domes should be removed at first sign of life or mold
• after plant is a few inches tall allow soil to dry finger deep between watering to prevent
• https://en.wikipedia.org/wiki/Transplanting
• Defoliation is useful in indicas with bud rot issues increases airflow and bud quantity in moderation
• use beneficial nematodes to control fungus gnats
• use ladybugs in North America and ladybirds in Great Britain beneficial insects, because many prey on herbivorous hemipterans such as aphids or scale insects
• beneficial insects usually available for purchase online from places such as Amazon

Final Word about molds Growth in buildings and homes
relative humidity be maintained below 60%, ideally between 30% to 50%, to inhibit mold growth.

​

See also: List of hemp diseases

Cannabis cultivation - Wikipedia

en.wikipedia.org

or just throw them in some dirt and add some tap water , its your time and money
how valuable are those seeds ?

if you see a error or omission please advise this is meant to be a seed sprouting beginner tutorial

 

[grayeyes]

Basic Points in Seed Storage
Storage Jars

Seeds require a cool and dry location in which to be best stored. Temperature and humidity fluctuations are seeds' worst enemies.
The most vigorous seeds at harvest time will keep the longest in storage. (As a principal we only sell the brands that have the most vigorous seeds.)
Improperly dried seeds can deteriorate drastically over time. (The seeds we sell have been dried properly before they are packaged and you only need to store them in a cool, low moisture environment for optimum preservation).
Bags and jars should be clearly labelled at time of storage with strain name, date and other relevant information about the strain you are preserving.


Moisture
Silica Gel Half Gram BagSeeds carry on life processes, at a low rate, whilst dormant. Moisture they absorb from the air combines with stored nourishment within the seed to form a soluble food, which then combines with oxygen from the air to release water and heat. Too much moisture in the air will cause the seed to burn up its stored food too quickly producing excess heat which will further lower the seeds ability to germinate. The need is to keep these exchanges to a minimum during storage to prolong life in the seed.

6-9% moisture is ideal for long term storage of hemp seeds. A test for moisture levels shows that hard shelled seeds like hemp seeds shatter instead of mashing at around 8% moisture when placed on concrete and struck with a hammer.

Silica gel, often used in the drying of seeds, can also be used to help maintain stable moisture levels within a permanent storage container. Equal weights of silica gel to seed are used. In general hemp seeds weigh between 0.01 and 0.02 grams and our silica gel sachets contain 0.5g. We recommend seeds are kept in aluminium zip-lock bags and stored inside seed jars along with the correct amount of silica gel to maintain low moisture levels. Be aware that you can seriously damage seeds by reducing moisture levels too much, so do not use too much dessicant. Silica gel, aluminium zip-lock bags and seed jars are all available to buy from our Seed Storage section.

Temperature
Seeds can survive temperatures that would kill the parent plant as long as they are thoroughly dried. Excess moisture in seeds that are then frozen can potentially freeze, damaging the seed.

Seeds need to be stored in a cool or cold place. Therefore, locations at floor level are preferable to those nearer the ceiling which can be significantly warmer. However, for long term storage, placing seeds in the fridge or freezer is ones best bet, as long as moisture content of the seed and storage container is low and the container is air-tight. The ideal temperature in a refrigerator is around 40F.

A freezer is best for long-term storage of seeds although you need to make sure:

You do not take the seeds out too much or for long enough for the temperature change to affect the seeds.
When you want to remove seeds from the freezer, you leave the container closed whilst the seeds warm to room temperature or otherwise condensation will form on the seeds.

Light
Similar to moisture and temperature, light can help stimulate and support the germination process. And, just as many foods, pharmaceuticals and chemicals rapidly deteriorate when exposed to light, so also is seed viability and vigour affected by being exposed to light during storage.

Seed Storage Problems
Mildew/Mould
Seeds which have not been dried to the correct moisture content before being sealed in containers, can and frequently do rot. A simple test: after "drying" and placing in closed glass jars, the appearance of condensation on the inside of the jar within a few hours indicates the need for further drying. Silica gel should help with this.

Insects
Insects that may have escaped notice can wreak havoc on stored seeds. A few pinches of diatomaceous earth (DE) is a safe, inexpensive and non-toxic way of protecting seeds against insect damage. It doesn't take much; just be sure to lightly coat all seeds before final sealing and storage. DE is available at most garden centres.

Rodents
Seeds which are not stored in glass or metal can provide a veritable banquet for mice and other small vermin. Make sure all seeds are kept in well labeled metal or glass containers.

Info provided by SM on cannabis seed storage

Who is "we" Professional seed seller

 

[acespicoli]

Info provided by SM on cannabis seed storage that was from namsdees I think iirc
and yes they are what id consider a professional in the business I guess
Its good to have many viewpoints before you form your own best storage method yes?

 

[acespicoli]

An outline of the embryo rescue process of sorghum. (A) Ten-to 14-d-old embryos were harvested from the panicle. (B) The embryos were sterilized using 50% sodium hypochlorite solution and washed with autoclaved water. (c) The glumes and palea were removed using forceps. (D) All the surrounding covers were removed, leaving only the succulent grain. (e) embryos were mined from the immature seeds using sterilized forceps and scalpel, inside a clean bench to ensure asceptic condition. (F) Freshly excised embryo was grown in Murashige and Skoog (MS) medium. (G) The embryo grew and differentiated into plumule and radical overnight, in less than 12 h. (H) The embryo may be grown in a petri dish or test tube containing MS medium. (i) Seven-day-old seedlings from MS media were transferred to Yoshida culture solution (YcS), where they grew for next 7 d, before they were transplanted into soil. (J) Seedlings transferred from YcS were grown in individual pots.​

More details on this to follow...

 

[acespicoli]

https://www.researchgate.net/profile/Frank-T-Edelmann/post/Does_anyone_have_a_surface_sterilization_protocol_for_hemp_cannabis_seed/attachment/60c8787f6b953100015411ec/AS%3A1034899947536384%401623750783340/download/In-Vitro-Germination-and-Tissue-Culture-Protocol-Establishment-For-Canabbis-sativa-L.pdf

2.2 Viability checking of the seeds
Cannabis seeds (hundred seeds) were germinated under controlled condition on wet blotting paper
kept in petri dish. This helped in verifying the viability of the experimental set of seeds.

2.3 Sterilization of the seeds and germination of seeds on artificial media
The seeds were sterilized by washing the seeds with tap water for removing any contaminants
attached to it. The seeds were exposed to 70 % ethanol for 30 s, washed thrice with autoclaved
distilled water followed by treatment with 0.1% HgCl2 30 s and washed again thrice with autoclaved
sterile water. The sterilized seeds were blot dried and then transferred to half MS medium and water
+ agar (0.8 %) medium for germination. The tube containing the seeds were kept in dark for 48 h
and once the radical emergence was observed, tubes were transferred to were maintained at 2000 lux
light intensity and 25 ºC [10].

---

Hence, the standardized
protocol for TTZ testing was finalized, as given below-
Seeds should be pre-moistened for 1 h, in distilled water and the pericarp should be removed.
These preconditioned seeds should be soaked in 0.1% TTZ, under dark condition, at 40°C, for
a period of 2 h. Seeds that develop TTZ stain in its essential structures, as described under Section
2.1, will be counted as viable. Counts should be made after thoroughly rinsing the seeds in distilled
water and the result should be expressed in percentage values.
Validation of standardized protocol
The three seed lots with 0, 12, and 64 percentage germination values were subjected to TTZ testing
using the standard protocol viz., soaking of pre-conditioned seeds (pericarp removed after pre-
moistening for 1 h) in 0.1% TTZ at 40°C, for 2 h. The staining patterns in all the three sets were
comparable with the actual germination percentage, with non-significant variations. It should be
noted here that for routine application of this standard protocol, a minimum of 50 seeds in three
replications may be used.
Conclusion
The experiment could identify a standard protocol for quick viability testing in Hemp seeds, which will
serve as an easy and effective technique for assessing the viability status in commercial seed lots. This
protocol, which uses preconditioned seeds (with pericarp removed), exposed to 0.1% TTZ at 40°C, for
2 hours, under dark conditions, will be a handy tool for the monitoring of traded hemp seeds, based on
its legalized status within the geo-political boundaries. In the states where cultivation is legalized, we can
use the technique for ensuring high germination percentage in supplied seed lots, whereas, in states
where hemp cultivation is not legalized, this technique can screen out the viable seeds.
Acknowledgments
The authors acknowledge the funding provided by the Indian Council of Agricultural Research, under which the work
was carried out.
Figure 2. A: TTZ staining using a standard protocol (color print required). B: TTZ staining using the standard protocol –first true
leaves stained (color print required)
JOURNAL OF NATURAL FIBERS 5
https://www.researchgate.net/public...t_Protocol_for_Hemp_CannabisSativaL_Seeds#pf6


References
Aytac, S., S. F. Arslanoglu, and A. Kemal. 2018. High temperature inhibition of seed germination of hemp (Cannabis
sativa L.). Fresenius Environmental Bulletin 27 (12):8200–04.
Callaway, J. C. 2004. Hempseed as a nutritional resource: An overview. Euphytica 140 (1–2):65–72. http://dx.doi.org/
10.1007/s10681-004-4811-6.
European Monitoring Centre for Drugs and Drug Addiction. 2017.Cannabis legislation in Europe: An overview.
Luxembourg: Publications Office of the European Union. doi:10.2810/4682.
Guerriero, G., J. F. Hausman, J. Strauss, H. Ertan, and K. S. Siddiqui. 2016. Lignocellulosic biomass: Biosynthesis,
degradation, and industrial utilization. Engineering in Life Sciences 16:1–16. doi:10.1002/elsc.201400196.
Harvest Newyork. (2017). Industrial hemp- From seed to market. (Accessed February 28 2019)

https://sips.cals.cornell.

edu/sites/sips.cals.cornell.edu/files/shared/documents/industrial-hemp-from-seed-to-market.pdf

ISTA. 2019.International rules for seed testing. Zurich, Switzerland: International Seed Testing Association.
Marsh, G. 2003. Next step for automotive materials. Materials Today 6:36–43. doi:10.1016/S1369-7021(03)00429-2.
Raikos, V., G. Duthie, and V. Ranawana. 2015. Denaturation and oxidative stability of hemp seed (Cannabis sativa L.)
protein isolate as affected by heat treatment. Plant Foods for Human Nutrition 70 (3):304–09. doi:10.1007/s11130-
015-0494-5.
Schluttenhofer, C., and L. Yuan. 2017. Challenges towards revitalizing hemp: A multifaceted crop. Trends in Plant
Science 22 (11):917–29. doi:10.1016/j.tplants.2017.08.004.
Simopoulos, A. P. 2002. The importance of the ratio of v-6/v-3 essential fatty acids. Biomedicine & Pharmacotherapy =
Biomedecine & Pharmacotherapie 56:365–79. doi:10.1016/S0753-3322(02)00253-6.
Skoglund, G., M. Nockert, and B. Holst. 2013. Viking and early middle ages northern Scandinavian textiles proven to
be made with hemp. Scientific Reports 3:2686. doi:10.1038/srep02686.
Small, E., and T. Antle. 2007.A study of cotyledon asymmetry in Cannabis sativa L. Journal of Industrial Hemp 12
(1):3–14. doi:10.1300/J237v12n01_02.
6S. R. JACOB ET AL.
https://www.researchgate.net/public...t_Protocol_for_Hemp_CannabisSativaL_Seeds#pf3
https://www.researchgate.net/public...t_Protocol_for_Hemp_CannabisSativaL_Seeds#pf2

 

[acespicoli]

companion post to the earlier post of parfait storage jars found some other sizes

American Metalcraft HMMJ1 1.5 oz. Glass Miniature Hinged Apothecary Jar​

Item#: 124HMMJ1

UPC: 704339912361

 

[acespicoli]

 

[acespicoli]

https://mdpi-res.com/d_attachment/p...ts-09-00665-with-cover.pdf?version=1669136278