A KEY PRODUCT for controlling spraing in potatoes has received new approval for in-furrow use, Syngenta has announced.

Nemathorin can now be applied by overall incorporation (30kg/ha), or as an in-furrow treatment (150g/100m per row) – which is also approved for wireworm control, the firm said.

Crops are most vulnerable to spraing infection – caused by Tobacco Rattle Virus (TRV) – during tuber formation and it is crucial to protect them during this phase, noted Syngenta potato technical manager, Jon Ogborn.

“Dry soils reduce the risk of spraing, since the nematodes need soil moisture to move and attack newly forming tubers. However, growers on light loam and sandy soils, where spraing incidence is highest, will be irrigating at this stage to encourage tuber numbers.”

Trials in high risk situations have found that Nemathorin can cut the number of tubers affected by spraing by an average of 60%, he said. Failing to control the disease can lead to rejection of pre-pack and processing crops and significant financial losses, he warned.