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Grittyville, WA

https://youtu.be/uby8sVQJzJw?t=417

This yellow spot issue comes up in the spring, notable example was Tobeck's 2517 Haist plant last year.

Here Charles Dowding shows a correlation of the yellow spots we see in the spring to soil tillage. What the exact link is, I don't know. Tillage could affect a lot of things. Soil temps, density, and soil biology, even the oxidation state of the minerals in the soil. This guy "knows more than we do" about pumpkins??? No fair, I thought we were the experts!

PS the beginning of this video is great too. Good tip about guinea-plant testing your compost for herbicide prior to spreading it. This seems like a good video for both beginners and experts too perhaps... so I am posting it here on the main board. Its time stamped here for the yellow spot issue.

3/11/2021 7:57:09 AM

Boscawen, NH

This was discussed and explained last year. This link- https://extension.unh.edu/blog/whats-making-my-squash-or-pumpkin-leaves-bright-yellow does a great job explaining the cause of the early season yellowing. The gardener in the youtube vid. is making observations not conclusions. Way too many variables to draw any conclusions from what he is presenting.

3/11/2021 9:33:58 AM

Grittyville, WA

He said the only difference between the two plots was that one was hand-tilled the other was not. Maybe he is not trustworthy. But if he is trustworthy... then maybe it's a meaningful observation.

3/11/2021 9:56:12 AM

Grittyville, WA

I grew two of the 1415 Haist which was from the same lineage as the 2517. One did have mottled-yellow leaves at first, and the other had very yellow vines. Very fast and vigorous though. So a gene is involved, yes.

3/11/2021 10:09:32 AM

Deer Park, WI

Thanks for the links, both of you. Each were instructive.

Charles video was like a cool, refreshing drink on a hot summer day.

The "B gene" scenario is fairly obvious here. What I find interesting tho is the epigenetic triggering of an understood genetic characteristic. This is a visual demonstration of the crossroads between environment and genetics. In this situation, cool weather induces yellow leaf growth in plants with the B gene. Environment triggers a genetic characteristic. That is fascinating. Makes one wonder what other epigenetic expressions take place in the patch.

3/11/2021 3:45:26 PM