Farmer's Weekly (South Africa)
No secrets to potato farming
In this article, a Mpumalanga potato farmer described his methods for growing and turning a profit from this crop, the latter of which could be tricky, he claimed.
There are no secrets to potato farming, but what there is to learn the grower must have at his or her fingertips, because when it comes to profit, potatoes can be very dicey.
That is the advice of a farmer who markets 500 000 pockets a year and has been in the potato business for 13 years, GJ ‘Zulu’ du Toit of the farm Kwaggafontein in the Middelburg district of Mpumalanga.
“The price extremes in potato production over a marketing period of 12 years have brought me anything from a loss of 56c [about R13,43] a pocket to a profit of 64c [R15,35] in my best year,” he says.
A glance at expenses, Du Toit adds, shows that in 1968/69 production costs at Kwaggafontein were R450/ha [R40 463/ha].
In 1980/81 the figure was R1 667 [R149 891].
Yield in those years remained much the same. On average, costs have increased fourfold, while the price has gone up about two-and-a-half times.
“Growing potatoes is risky and very dependent on favourable weather, more so than maize. Also, as figures show, market prices vary sharply.
“It is no use being a hit-or-miss producer with potatoes. Plant the same area each year and take the good years with the bad.”
As the balance between profit and loss can be delicate, give yourself a good start, he says, by doing the correct thing. “For instance, you might be successful in keeping pests off while losing out by having a dirty seedbed
– or keeping a perfectly clean seedbed and have potato tuber moth eat up your crop.”
Du Toit has two types of soil at Kwaggafontein, Avalon and Hutton.
He tries to put half his crop on each. In very wet years Hutton does well. In dry years, the grey soil gives better results.
“Potatoes like well-drained, deep soil. It should not be too high in clay, which can give the farmer problems when lifting.”
BETTER CHANCE
The land chosen for his potato crop – land for potatoes is used for one season, then put to maize for the following three or four years – is burnt off straight after harvesting the maize to ensure he has a very clean seedbed. Any stubble left hinders the planters and makes deep ploughing more difficult. A good depth at ploughing gives the soil a better chance of retaining moisture, he says.
Depending on the pH of the soil, the grower should, if required, broadcast gypsum and plough it in to reduce the possibility of brown fleck.
PLANTING AND CULTIVATION
Du Toit says that in July, about three weeks before planting, the lands prepared for potatoes are fumigated with EDB for eelworm. Every year, he plants 400ha to potatoes, 30ha of which are under irrigation. The irrigated potatoes are planted in July and the dryland crop in mid-August.
Du Toit plants 30 000 plants/ha in rows that are 1m apart. At planting, he applies 10kg/ha Dithane to protect the crop from fungal disease in the soil. Also at planting, fertiliser 2:3:2 (27) is put down at 1t/ha. A weedkiller spray (Eptam), mounted on the planter, is used at a rate of 21ha.
He starts cultivating in November when the potato plants are 150mm to 230mm high. The lands are cultivated three times; on the third cultivation, shares are attached to the cultivator and the rows ridged.
“The ridging is done to control tuber moth, and also helps to prevent waterlogging in a very wet season,” Du Toit explains.
When ridging, soil from both sides of the row should be thrown at the base of the plants to cover all cracks made by tuber growth. By closing these gaps, the grower prevents tuber moths from getting at the potatoes. After that, the farmer should not enter the lands until lifting.
Spraying against pests starts when moth infestation is noted, or if the weather tends towards the development of late blight.
Aerial spraying is normally done five to seven times. Dithane M45 is used for the control of blight and tuber moth, and is sprayed at intervals of seven to
14 days, depending on the weather.
Du Toit starts lifting irrigated potatoes in about mid-December, and the harvesting of dry and irrigated crops continue through to May.
Rand values have been adapted for inflation. This article first appeared in the 2 April 1982 issue of Farmer’s Weekly and has been edited to adhere to the current style of the magazine.