I have often been called out to try and solve a mystery that was baffling a farmer. It seems that many farmers expect so-called experts to be able to solve the problems rather than making the effort to try to get to the bottom of the issues on their owns.

There is a big problem with this approach, as the expert who is called in very often, because he/ she has been elevated with trust to be able to solve the problem, is reluctant to say that he/she can’t work out the cause. It is a matter of pride.

This often results in the expert shooting from the hip, so to speak, and telling the farmer what the problem is without being sure and hoping for the best.
An example of this occurred in Mpumalanga. I was visiting a farmer to see how my new bean variety was doing.

After we checked the beans, he took me on a tour of the farm. When we got to the tomato land, I remarked that his crop had the worst magnesium deficiency that I had come across. Surprised, he said, “Is that what it is?” and told me that a rep from a seed company had identified it as a potassium deficiency.

A deficiency is often caused by an imbalance, as potassium, sodium, calcium and magnesium are all taken up together. If one of the elements is present in too high a ratio, it can restrict the uptake of some of the other elements.

The Mpumalanga farmer started applying a lot of potash, which just made the situation much worse, so that symptoms reached the top of the plants whereas it usually shows up on the lower sections.

Another example of poor advice

A vegetable farmer was showing me around his farm, and when we came to the sweetcorn land, I remarked that I knew where he got his seed from. He enquired how I knew this, and I replied that I knew the breeder and he used a three-way cross to make his hybrids, and that was why some tassels were reddish in colour and others were cream-coloured.

He said his consultant told him it was a phosphate deficiency, so he applied phosphate, which had no effect. If I didn’t tell him this, he could have viewed a very healthy crop as though it had a deficiency.

A cabbage farmer called me in to identify why some lands had transplants that would not grow. When the roots were removed, it was clear that they had not grown out of the plugs. The farmer had called in a number of companies to try to find the cause, but none of them could pinpoint it.

In desperation, he did what farmers should always do: he tried to work out the problem himself. He meticulously went through the whole process from sowing to transplanting and fertilisation.

He discovered that his worker had dipped the empty trays in a product that inhibits the roots from penetrating the polystyrene walls of the trays. The worker had a measure to use for the product when he refilled the drum. He was applying this measure before the drum was empty, thereby causing an increase of the concentration.

Getting an expert in should be the last resort after you have tried to solve the problem yourself.

Bill Kerr is a vegetable specialist and breeder.