Growing problem in our summer mung beans

Interveinal chlorosis in mung bean plants has been a bugbear for the past few years.
Interveinal chlorosis in mung bean plants has been a bugbear for the past few years. Contributed

WELL it has been a rugged summer for most crops in Queensland and the mung beans in the above photo are among them.

For the most part, many of us have been amazed at how tough our little mung bean plants have been in the extreme conditions.

The other question that keeps arising is this interveinal chlorosis that is featured here in these plants.

By that I mean that we have a distinct yellowing between these stand-out greenish veins.

This has been a bugbear for the past few years and many of us have scratched our heads over the evidence we have observed in a variety of mung bean paddocks.

Has it been a variety-based problem in our summer environments, is it a nutritional toxicity or deficiency of an element or is it something completely different?

There has been plenty of discussion among agronomic advisors, nutritional experts, crop experts and farmers over the cause of this discolouration and even leaf crinkling.

The trouble with just walking into any paddock with ailing plants, the physical symptoms they display can come down to several possibilities.

Sometimes it is even just an incorrect balance of elements in the plant's system that gives a certain non-healthy look.

The evidence through weight of many observations, and combined with both soil and tissue tests, is certainly leading us to think that this above problem is manganese deficiency.

I for one was mightily unconvinced this was the cause and still shake my head about an element that is usually in abundance in our soils can be the nutritional deficient element causing all this yellowing and associated leaf crinkling across some of our mung bean paddocks.

However, as pointed out by associated nutrition experts, manganese deficiencies can be caused by high levels of nitrate, which can then bring us to another future problem in either getting your inoculation procedure correct and effective or applying bigger rates of nitrogen before planting mungs.

Yes, there have been many crops grow out of this situation as their root system develops and some rain occurs, which is typical for Mn deficiency in legume plants.

So there you have it for some , if not all, of our interveinal chlorosis issues.

A manganese deficiency probably perpetrated by an in-balance of other nutrients, with a particular reference to higher and more available soil nitrogen levels.

If anybody has other had other experiences, please give us a call or send an email to

If you have used a foliar Mn spray in your mung bean crop even as a shotgun method, let me know how it went on your crop.

Topics:  agronomist mung beans paul mcintosh

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