I had some great fun thinking of all sorts of funny titles for this thread, but in the end, I decided on some safe-for-work content.
Long ago, I grew some delicious giant kale, and I loved it! It's a sweet take on giant jersey or walking stick kale. Being naive, I thought I would just buy seed again next year, but alas, I haven't found it for sale since. But what luck! I found a few seeds in the bottom of the packet. Four plants, that all I got this year, but hopefully it will do the trick. I've hunted throughout the farm and with luck, eliminated anything it may cross with.
Yesterday the first flower opened. Today, another two are showing their happy faces.
Now, the important question: Will they do their thing and make little baby kale eggs for me?
Is there a way to tell if there is male sterility in my kale blossoms just from looking? I'm fascinated what Joseph Lofthouse writes here and online, hopefully you will see this and chime in. Or maybe someone else knows? If failure is imminent, I'm gonna eat this before it becomes bitter. But if there is even the slightest hope, I'll let it bloom and hopefully seed.
What steps should I be taking to get the maximum procreation from these four plants? I was thinking of being a bee and going around with a paintbrush (actually a feather converted into a paintbrush, but you get the idea) at least once a day. What are your thoughts on this?
R Ranson: Great photos. Yes, it's easy to look at a flower and see if it's got male parts or if they are missing. Your flower looks like a normal kale flower to me. It has anthers. The anthers are the right color. Looks like they have pollen on them. A test I do is brush my finger against the anthers. If it gets a streak of pollen on it then I figure they're good to go.
Hybrids of plants with tiny flowers are often made commercially by using one parent line that doesn't produce pollen. Brassica plants with cytoplasmic male sterility typically lack anthers. And without anthers they can't produce pollen. They also typically lack nectaries. So there is little to attract pollinators except for the color of the flowers. The honeybees can tell. At my place they'll be all over normal brassica flowers and boycott sterile flowers. It's my general policy to not hand pollinate flowers unless I'm making hybrids. But no harm done if you want to try. Brassicas are often self-incompatible, so if you move pollen, best results are expected if you move it between plants, not between flowers on the same plant.
In my garden, brassica plants sometimes get blown over and die before producing seed. To minimize lodging I usually put posts in the row and do a California Weave and/or twist the branches around each other so that they support each other. Some types of brassica pods split open readily when the pods are dry. That can lead to seeds falling onto the ground and getting lost. That can be minimized by watching the plant and picking at the appropriate time, or by bagging the seed head after flowering. In my garden, grasshoppers sometimes eat young brassica seed pods: Even every seed on the plant. I don't try to prevent that. I figure that I want to select for plants that are resistant to grasshopper predation of the seeds. I suppose that finches could also take the seeds.
I don't have a photo of a sterile kale flower, but the same general pattern exists in carrots. So here's what a normal carrot flower looks like. It's got lots of male parts, just like the kale flower in the original post.
A male-sterile carrot flower is devoid of male parts.
This is great news about the flowers having all the necessary parts. When/if it stops raining, I'll tickle them and see if they give me any magic dust. Can't decide yet if I want to be a bee and help move pollen about. I think maybe yes because I haven't seen these kale anywhere else since and they are so incredibly tasty. Next year I can let nature do the selecting and I'll choose the seeds from the most promiscuous plants. The seed company doesn't say it they are hybrid or not, so it will be interesting to see what grows from this endeavour.
As always, you are full of wonderful information. Thank you for taking the time and helping out.
Congratulations on finding pollen! Anthers that are too old, or too young might not produce pollen. Or pollen might have been washed off by a rain storm... As long as the flowers look normal, I wouldn't cull yet. Like you say, there's plenty of time to make a decision.
Cytoplasmic male sterility is related to DNA in the mitochondria and is thus inherited only from the mother. That applies generally to all species. If mother has the trait she passes it on to all of her descendents.
R Ranson: With so many pollinators on those flowers, it seems like you're right on track for getting seeds. Any pods forming yet? They'd start out looking like long tendrils growing out of the withering flower.
As far as inbreeding depression goes... We get to work with the available resources, whatever those happen to be... No point worrying about it unless the crop looses vigor in a few years... My cynical side admits that as far as I can tell, I have never witnessed inbreeding depression in the seeds that I am saving, and I suspect that fears of inbreeding depression are a marketing ploy perpetrated by the seed industry as a method of convincing people to not save their own seeds.
My strategy If I wanted to keep a variety of kale like it is with slightly more diversity, would be to add another cultivar to the patch, and let it share some pollen. I aim for about 10% foreign pollen. I don't save seeds from the pollen donor. That way I can increase the genetic diversity in my crop without totally swamping it with other traits. I go easy on selection in the first crossed generation, so that the new traits can get mixed in well before I do too much culling. Then reselect year by year for traits that match the desired phenotype. Sometimes, I'll make hybrids between my variety and the new variety in a separate location, and then include the F1 or F2 hybrids in my main seed producing patch...
Four kale plants might produce enough seed to supply one gardener with a lifetime supply if stored dry in the freezer. And the seed aughta remain good for 5 years of more if stored dry at room temperature. So you don't have to regenerate the seed every year.
How's that for a long-winded way of saying "Let's cross that bridge when we get to it."