Seed Saving Principles (Reading Time: 3 Minutes)

作物留種 種子

In the episode of Gourd Seed Saving, we have talked in detail about the conditions for successful pollination of Cucurbitaceae. There are some seed saving principles that could be applied to different family of crops. Seed saving is a fun process because it is not only treating your crop as food source, but also as a member of ecosystem. Let's take a look at some seed saving principles!

Open-pollinated (OP) & Hybrid (F1) Seed

After a season of hardwork, you found a variety that you like, especially one that tastes good, you will want to save the seeds. The seed saving process of open-pollination (OP) is rather straight-forward, but hybrid (F1) varieties have a more complex genetic background -  Of course you can still save F1 seed, but you won't get the original variety that you were aiming for.  

External Factors of Seed Saving

Seed saving works similarly as you were growing your crop. But there are a few differences:

  • Density: If your goal was to save seeds, you can increase the spatial density of the crops. When you grow at home, it is most usual the case that you will be saving seeds as you harvest the crop. In that case - always remember to choose a plant that is strong, disease-free, and carries the characteristic of the species as your target plant for seed save.
  • Fertilisation: You don't need to input too much Nitrogen for the targeted plant, but towards the end of seed saving, you will want to add more Phosphrus and Potassium
  • Water: Water your plant as you were growing it for harvest, but you will have to reduce the water amount towards the end of seed saving

You should also be aware of the growing cycle of the plant, particularly the flowering condition of a particular species, for example, plants may flower according to:

  • Fertiisation: Species from the solanaceae family, or the lettuce, beans will turn from vegetative growth to reproductive growth if they have the right amount of fertilization
  • Day-length, for example
    • Long day-length: flowering in Summer, such as Lettuce or other chrysanthemum vegetables
    • Short day-length:  flowering in Winter, such as amaranthus, malabar spinach and certain variety of beans
  • Vernalisation, meaning the plant should be exposed to Winter for flowering. Examples include: Brassica or apiaceae such as carrots
香港高華花園 番茄 留種 種子 Hong Kong Seed Saving Tomato seed
Tomato will shift into reproductive growth once they have the right fertilization
 
 
香港潺菜種子 Hong Kong malabar spinach seed
Malabar Spinach will flower and produce seeds during short day-length Autumn and Winter
 
Cucurbitaceae is also affected by day length, but in a different way. Long day-length will activate the growth of male flowers, and short day-length will encourage the growth of female flowers. Therefore, knowing the flowering and fruting process not only helps you with seed saving, but it is also important for your harvesting plans!
 
香港瓜類種子 Hong Kong Gourd Seed
Long Day-length promote the growth of male flowers
 
 
 

Physical and Genetic Purity of Seeds

Physical purity means that a seed lot is contained with only the seeds of the desired crop variety - not mixed with sand or seeds of weed. Genetic Purity asks whether the seed is contaminated by the gene of other undesired varieties, for example, did the variety that you are trying to save seeds from hybridise with an undesired species?
 
To ensure the genetic purity of a variety, we have to know whether a species is self-pollinated or cross-pollinated. Self-pollination suggests that the deposition of anther and stigma occurs on the same flower. Cross-pollination, as you've guessed, only anther from a different flower, different plant, or different species will land onto the stigma of the flower. Cross-pollination is done by wind or insect, for example, corn depends on wind pollination, whereas brassicas, gourds, or many fruit trees usually depends on insect pollination.
 
香港十字花科種子 Hong Kong Brassica Seed
Brassica depends on insect pollination, anther must be deposited to stigma of a different flower for successful pollination
 

Ready to Try?

Okay, we know that you are very excited to try seed saving now!
Here is a list of Flowering and Pollination Worksheet of Autumn Sow Species —— before you start, remember to ask yourself:
  • Is my crop produced from open-polliated (OP) or hybrid (F1) seeds?
  • Does my crop self-pollinated or cross-pollinated?
  • Does my crop flower during long day-length or short day-length?

Autumn Sow Species’ Flowering & Pollination Worksheet

 
Family Name of Species Sowing Season Clover Availability (2023/8) Botanical Name Flower Structure Pollination Pollinating Agent Life Cycle Note
Asteraceae Lettuce Autumn Lactuca satica L. Complete Self / Annual Seeds may be infected by Lettuce Mosaic Virus (LMV)
Asteraceae Garland Crysanthemum Autumn Chrysanthemum sagetum L. Complete Self / Biennial Long Day-length
Brassicaceae Chinese Cabbage Autumn Brassica pekinesis (Lour.) Rupr Complete Cross Insect Biennial May hybridise with Pak Choi or Choi Sum.
Self Incompatible
Brassicaceae Chinese Kale Autumn Brassica alboglabra L.H.Bailey Complete Cross Insect 1 May hybridise with Kohlrabi.
Self Incompatible
Brassicaceae Kohlrabi Autumn Brassica caulorapa DC. Ex Pasq Complete Cross Insect Biennial May hybridise with Chinese Kale.
Self Incompatible
Brassicaceae Cabbage Autumn Brassica oleracea var. capitata L. Complete Cross Insect Biennial  
Brassicaceae Cauliflower Autumn Brassica oleracea L. var. botrytis L. Complete Cross Insect Biennial  
Brassicaceae Broccoli Autumn Brassica oleracea var. italica Complete Cross Insect Biennial  
Brassicaceae Radish Autumn Raphanus sativus Complete Cross Insect Biennial Self Incompatible
Cucurbitaceae Melon Autumn Cucumus melo L. Monoecious Cross Insect Annual May hybridise with other variety of muskmelon
Fabaceae Pea Autumn Pisum sativum L. Complete Self / Annual Seeds may be infected by weevil
Solanaceae Tomato Autumn Lycopersicon esculentum Mill. Complete Self / Annual Seeds may be infected by various diseases
Solanaceae Chili / Pepper Autumn Capsicum annum L. Complete Self / Annual Seeds may be infected by various diseases
Solanaceae Eggplant Autumn Solanum melongena L. Complete Self / Annual Seeds may be infected by various diseases<
Apiaceae Celery Autumn Apium graveolens L. Complete Cross Insect Biennial  
Apiaceae Coriander/Cilantro Autumn Coriandrum sativum L. Complete Cross Insect Biennial  
Apiaceae Carrot Autumn Daucus carota L. var. sativa DC Complete Cross Insect Biennial  
Brassicaceae Pak Choi Spring / Autumn Brassica chinensis Complete Cross Insect Annual May hybridise with Chinese Cabbage or Choi Sum. Self Incompatible
Brassicaceae Choi Sum Spring/Autumn Brassica parachinensis L. H.Bailey Complete Cross Insect Annual May hybridise with Chinese Cabbage or Pak Choi. Self Incompatible
Brassicaceae Chinese Mustard Spring / Autumn Brassica juncea (L.) Czern. Complete Cross Insect Biennial May hybridize with other mustard varieties, such as Brown Mustard.
Self Incompatible
 
 
 


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