Sunflower production: threatened by stink bugs and fungi

With continuous management of the insects that predate on sunflowers, significant success can be attained with this crop, which is suited to growing in the drier parts of South Africa

-  Zunel van Eeden.

As marginal cropping and low-input farming grow, sunflowers are gaining recognition as a suitable crop to cultivate rotationally with maize. Producers in dryland producing regions find sunflowers appealing due to their general drought tolerance and capacity to provide relatively constant harvests under adverse weather conditions and promising income due to sunflower oil’s application in food preparation, biofuel production, and cosmetics and skin care products. Sunflower flour and cake are fed to animals and the seeds are used for bird seed and human consumption.

However, sunflower production is challenged by various insect pests. The sporadic occurrence of the false chinch bug (Nysius natalensis) and the disease sclerotinia head and/or stalk rot, caused by the fungus Sclerotinia sclerotiorum, plays a role in the decline of sunflower plantings.

In South Africa, the region between 24°S and 30°S is the primary growing region for sunflowers. Up to 80% of the country’s sunflower production occurs in regions that have a semi-arid environment with variable and infrequent rainfall, low humidity and intense summertime sun radiation.

In the eastern highveld districts of Mpumalanga and the eastern portions of the Free State, the crop is often sown between November and December.

In the western regions of the Free State and North West, planting dates might be extended until mid-January; in the northern portion of the production area, planting takes place in January and February.

The northern region’s late planting date is determined by the area’s late rainfall.

Sunflower planting is frequently delayed past the customary dates by delayed spring rains throughout the whole summer rainfall area.