One of those questions was asked by me and answered by zeedman last year in a thread about soy beans, which is linked below. The chlorosis on those beans eventually disappeared and the leaves became dark green.

I'm currently seeing yellowing on newly emerged bush beans. There has been frequent rain with overcast days recently. I used no innoculent. I have not fertilized.

I may give them one dose of soluble nitrogen, although that is probably not necessary.

Jim

If your weather has been poor lately, your beans are probably chlorotic (yellowed) as a result. Hopefully, when sun & warmth return, they will recover.

Even if your weather has been good, as Jimster pointed out, legumes in general often go through a period of yellowing shortly after germination. The seeds have exhausted their stored nutrients, and the root system has not yet begun to supply adequate nitrogen. This situation is only temporary, and the plants usually green up in a week or two on their own... under ideal conditions.

A single _light_ application of N (whether chemical or organic) at the time of planting will minimize the yellowing, and might be advisable for cooler climates, where bean growth tends to be slower.

Snap beans can be a struggle in the Sound - but there is another option. The English suffer from a similar climate, and grow runner beans instead (like Scarlet Runner), which are more tolerant of cool temperatures. They are prepared the same, and taste very similar. If you are interested, there are several threads in this forum that discuss sources.

And if snap beans are difficult on Whidbey, limas are impossible. If you still want to eat large green-shelled beans, you might try favas. Like runner beans, they are cool weather tolerant... in fact, they prefer such weather. They should do well in your summers.

Good luck!

They come up nice and green.

When the first set of true leaves come out, the plants start getting pale. Some of them border on yellow.

The plants keep growing with their pale leaves.

When they get about four sets of leaves, they start greening up again.

Now, this is entirely my amateur interpretation of it, but I wonder if they come up nice and green because they're feeding on the nutrients in the seed, then get pale as they struggle a bit to gain hold, and finally green up again as their roots are colonized by rhizobia or as they become acclimated to their conditions.

This process never happens with my peas, though. They come up green and stay green.

I sometimes inoculate my legumes, but it doesn't seem to make a difference in the process except in time. The plants go through the same stages regardless of how long it takes. This year some plants (esp. Medinah) snapped out of the pale stage faster and when I pulled one up to have a look, it already had fat nodules on the roots with nice pink interiors. Plants that were still pale at the same time (Jumbo, Contender) had nodules when I pulled them up but they were small and not pink yet. A week or so later, those plants greened up, too.

The yellowing I mentioned above, a couple of weeks ago, on my bush beans has disappeared. They are now a normal green color and doing fine.

My Southern peas however, which initially were a dark green, now have a lot of bright yellow on them. Weather has been on the cool side for the past couple of weeks, which may be part of the reason. Based on the data which is accumulating here, I suspect they would grow out of it. I gave them a light application of calcium nitrate anyway. So now I've contaminated the data. We'll never know if it was the nitrate or if they would have grown out of it without help. :-)

Jim

We have had lots of rain and cloudy weather. Plus, this particular planting got overgrown with weeds. I weeded them real well, last week (just before they started turning green again ;)

George
Tahlequah, OK

A good point. We are also trained - with some justification - that we should avoid nitrogen for beans. While both of these "rules" are true for the most part, there are other factors to consider.

Farmers locally lay a light fertilizer application on soybeans at the time of planting. I once thought that they were crazy to do so, that they were being duped by the chemical industry (I still believe they are). But it turns out that a light application of N increases bean germination, and helps the seedlings through the "N-gap" between consumption of the stored energy, and full function of the root nodules.

I don't believe that such a treatment is necessary for the home gardener. As mentioned previously, most beans go through this yellowing, and come out of it on their own. By adding N, you run the risk of adding too much - and that leads to lush foliage, and few beans.

But for those in growing beans in difficult conditions, such as cool weather or arid soils without irrigation, a light N application might be helpful, preferably one of a soluble nature. Whether natural or chemical fertilizer is used, my recommendation is that it should be a highly-diluted, one-time application at the time of planting. If too much is used, and the fertilizer persists in the soil until plant maturity, it will adversely affect the yield.

The condition was so severe that it was hard believe it could be the result of a nutrient deficiency. So I did a lot of searching and reading about virus. But, now that the fertilizer is remedying the situation, it is apparent that it was a deficiency. Since I used a complete fertilizer, it is not known whether the deficiency was of nitrogen or of some trace element. Based on previous experience it was probably nitrogen and I am buying zeedman's N-gap theory. I wish I had a better understanding of how those root nodules work, in particular the timing of when they start to provide N to the plant.

I was negligent in not photographing the yellow, crinkled condition. It was vivid and ugly. Hard to believe the established leaves could grow out of it. Next time.

Zeedman or anyone else, are you growing Purplehulls? If so, how does your experience compare?

Jim

The Purplehulls you sent me were planted only a few days ago, and have not yet germinated... they should appear within the next few days. Since my experiment last year showed that cowpeas respond well to the appropriate inoculant, I applied it heavily to the seeds at the time of planting. I'll keep you posted.

Sorry to say, I blew it on the inoculant experiment. Your results have me interested. "Oh, well, there is always next year".

As for experiments, I now think it would be easy to do a conclusive experiment regarding N-gap and settle that question once and for all.

Jim

The same varieties growing outdoors are not doing nearly as well.

And in one bed of NT Half-Runners, one end looks healthy and green and the other end is more yellow and the plants are smaller.

According to a basic home soil test kit, the better end has a pH of about 6.8, low N, low to medium P and medium to high K.

The chlorotic end has a pH of about 7.0, low N, low P, and medium to high K. The main difference is the lower P.

Our night temperatures in mid-summer average around 52F. The greenhouse plants have an advantage in both day and night temperatures.

Some varieties also seem to thrive more than others. Possibly some tolerate cooler nights better than others.