Temperatures ranging from as little 2C to as high as 38,5C within only three weeks had damaged one of the most promising South African wheat crops in years, Grain SA chairman Bully Botma said on Tuesday.
Botma said frost damage that Free State and North West farmers had suffered in early October had been exacerbated the extreme heat and a lack of spring rain.
Insurance records on farms around Bothaville, Wesselsbron and on the Goldfields showed average damage to the crop of 35% to 40% due to the drought and heat. Frost damage to yield and grades would only be determined during harvesting.
In the irrigated areas of the Northern Cape, the heat was also damaging yields of the crop, which prefers cooler weather. In the Eastern Free State, where the wheat crop was normally planted later and where the plants were in a critical development phase, rain was urgently needed, Botma said. Botma believed the latest national wheat harvest estimate of the National Crop Estimates Committee did not take the heat wave of the past few days into account.
He said further reductions of the crop estimate were ”inevitable”. Research had shown that a farmer may lose up to four percent of his wheat yield per day in heat such as that experienced over the past few days.
Botma said the late frost came ”like a thief in the night” upon farmers on the morning of October 2, causing temperatures to drop to around 2C. The cold snap caused the development of ”ice rings” in the plants, preventing water and nourishment from moving from the roots to the leaves.
The Estimates Committee announced its third wheat harvest estimate of the season on Monday, putting the national harvest at an estimated 2,292 million tons, which was 10 0000 tons less than the previous estimate.
One of the best wheat crops in years — 2,492 million tons — was harvested last year on South African farms. Until two to three weeks ago circumstances were still similar to and even better than those of last season, and harvesting prospects were still very promising.
Botma said there were too many factors influencing grain prices for the wheat price to rise excessively due to news of crop damage. Wheat prices in fact dropped on Monday, despite the decreased harvest estimate.
This was mainly because of the strengthening of the rand against foreign currencies, Botma said. – Sapa