BLOG POST #6:
Risk of Inbreeding Depression
Fava Bean - Since the Fava bean is mixed-selfing and crossing there is a higher risk of inbreeding depression than with the strict selfers.
Garden Pea & Romaine Lettuce - Self pollinators so no risk of inbreeding depression.
Attract and Detracting Insect Pollinators
Since my selfers are not pollinated by insects it doesn't matter to them too much how many insects are present in the garden scape. My current garden has wild plants and hedgerows around the edges and has a beautiful flower garden that will attract an array of pollinators and insects the garden. Encouraging bio-diversity is important to keep the garden dynamic and natural. If I were growing an insect pollinated crop that easily crosses then I would need to increase the amount of isolation, perhaps with a netted tent and introduced controlled insect into the area.
My fava beans require visits from insects to be effectively pollinated therefore my flowers and level of wild plants in the garden will be beneficial to my favas!!
Population Size
For my self pollinators (Pea and Romaine) I will need to have seed from 20 good plants at the end of the day. So, my crop size for these 2 crops will be 50 plants each to ensure good roguing and to maintain genetic variability.
For the Fava beans I must have a higher population than the selfers to maintain good heterogeneity therefore saving about 40 plants after selection. Thus I will double my population size from the selfers to 100 plants to be on the safe size! Higher the population size the better!
Digram of crop plan to submitted soon. Thx.
Fava Bean - Since the Fava bean is mixed-selfing and crossing there is a higher risk of inbreeding depression than with the strict selfers.
Garden Pea & Romaine Lettuce - Self pollinators so no risk of inbreeding depression.
Attract and Detracting Insect Pollinators
Since my selfers are not pollinated by insects it doesn't matter to them too much how many insects are present in the garden scape. My current garden has wild plants and hedgerows around the edges and has a beautiful flower garden that will attract an array of pollinators and insects the garden. Encouraging bio-diversity is important to keep the garden dynamic and natural. If I were growing an insect pollinated crop that easily crosses then I would need to increase the amount of isolation, perhaps with a netted tent and introduced controlled insect into the area.
My fava beans require visits from insects to be effectively pollinated therefore my flowers and level of wild plants in the garden will be beneficial to my favas!!
Population Size
For my self pollinators (Pea and Romaine) I will need to have seed from 20 good plants at the end of the day. So, my crop size for these 2 crops will be 50 plants each to ensure good roguing and to maintain genetic variability.
For the Fava beans I must have a higher population than the selfers to maintain good heterogeneity therefore saving about 40 plants after selection. Thus I will double my population size from the selfers to 100 plants to be on the safe size! Higher the population size the better!
Digram of crop plan to submitted soon. Thx.
Hi Carla; You've understood the course material well and everything you've planned here meets all the requirements for growing good quality seed. Congratulations! :) One practical point I'll make is around the population size. You will probably find that in the field it is easy to grow the peas and favas in sufficiently large population size to meet the population targets you set. Tomatoes can also be done, and planting 50 plants isn't a huge amount, but at the same time, it does take more space, and will be more cumbersome to harvest, than if you simply planted 20 or 30 plants. So, feel free to reduce your population size a little bit on the tomatoes as it will make life a little easier. This assumes, of course, that the original seed source is reliable and you don't find yourself with a large number of off-types that need to be rogued out.
ReplyDeleteThanks Patrick!
ReplyDeleteAlthough, when you say tomatoes do you mean fava beans? Thx.
Hi Carla - I agree with Patrick that you show a good understanding of the theory regarding selfers and crossers and the risks of inbreeding depression. Your population sizes are good for the three crops you've chosen, in terms of minimum needed to ensure good quality seed. I agree - higher the population size the better! It shouldn't be hard to have a population of 100 for the fava beans as they don't take up a lot of space.
ReplyDeleteRegards,
Mary