By Engela Duvenage

In September a HORTGRO and Stellenbosch University Apple Replant Disease mini-symposium attracted a near full house, all wanting to learn more about how to deal with the disease without relying on fumigation chemicals such as chloropicrin and 1,3-dichlorpropene.

The mini-symposium was held at the Wallenberg Research Centre in Stellenbosch, and was attended among others by apple producers, researchers and people working with various biological control methods.

According to soil microbiologist Dr Mark Mazzola of the United States Department of Agriculture (USDA), experiments show that soils can adequately be biologically ‘fumigated’ when using anaerobic soil disinfestation and Brassica seed meal treatments. These methods also help to increase yield.

“The active management of the soil microbiome may yield more resilient and productive cropping systems than is attained when using fumigation,” he concluded. Mazzola was the main speaker at the mini-symposium, along with Prof Adéle McLeod of Stellenbosch University’s Department of Plant Pathology and SU PhD student Makomborero Nyoni. Nyoni is one of three postgraduate students at the University whose research on apple plant disease HORTGRO has funded over the past 10 years.

Nyoni is conducting trails to test different ways by which to apply phosphonates on especially young non-bearing apple trees.