I have been following Rivero et al 2014 protocols, but I am not sure when I should stop watering because my plants are completely yellow but the siliques are not 80% brown. Any recommendations? Thank you! :)
Stop watering Arabidopsis thaliana when most of the siliques (seed pods) have turned brown and begun to dry out. This typically occurs about 4-6 weeks after flowering. Gradually reduce watering as the plants mature to encourage seed development and prevent mold growth.
They are on week 4, basically they are completely yellow so I should keep watering daily until they are brown? Or should I start reduce watering now? Thank you ✨️ 😊
Can you post a picture of your plants? The typical range of 4-6 weeks really depends on how your plants look. The challenge is giving them enough water to finish making seeds, but not so much that you get lots of mold, and not stopping water too early or you get dead immature seeds.
On the plus side, most Arabidopsis plants make lots of seeds so even if you don't optimize the seed set you usually get enough.
It's also going to vary by ecotype. Col-0 plants will grow much larger & make more seeds than Ws. And ironically, will even sprout new green growth when "mostly dead" if you keep watering.
And "brown" vs "yellow" is also a bit vague of a guideline. When in doubt, gently pinch one of the oldest siliques & see if it shatters. You can do that over a piece of paper if you really, really need all the seeds.
That will give you a good reference for what counts as yellow vs brown.
If the leaves are no longer green, then you can really reduce how much water. The soil should be slightly moistened (like a sponge that has nearly all of the water squeezed out). That will also keep the mold, algae, and fungus gnats reduced.
Good luck!
Hi! Thank you so much! Here are the photos. The first one is the seeds (the plant is still yellow), in the second one even the leaves are brown but the steam is still green. A yellow plant and the last one for the light is hard to see but at the left is brown (leafs,steam,siliques) and at right a yellow plant. Today they finish their 4th week of flowering.
Most of those plants look ready to collect seeds, especially the photo of the two plants by themselves with the tray behind them (your 4th picture). The second photo (mostly dead leaves on the front plant but few seed pods) looks like a water stress issue, try to keep those ones growing a bit longer. I see you use the plastic sleeves to keep the plants from tangling, that's great! Just be very careful with moving/harvesting so that seeds don't fall into other pots, or you can end up with surprise seeds when you collect (if all your plants are the same this doesn't particularly matter, but it is still best practice).