Nutrient nitrogen management for disease control in strawberry

Abstract

Botrytis cinerea and Colletotrichum acutatum are important strawberry pathogens Nitrogen (N) application can increase yield but also susceptibility to pathogens Strawberry plants (Camarosa and Ventana) were grown in sand fertilised with base nutrients plus ammonium nitrate ammonium sulphate or calcium nitrate at low (40 ppm N) and high (140 ppm N) concentration Controls consisted of base nutrients only and water only Flower production fruit yield and berry size all increased with increasing Nconcentration but Nsource itself was not important Disease susceptibility was affected by both Nconcentration and Nsource At high Nconcentration C acutatum fruit lesions were largest in ammonium sulphate treatments > ammonium nitrate > calcium nitrate; Botryits cinerea lesions were largest in ammonium nitrate > ammonium sulphate > calcium nitrate Similar trends were observed for leaf susceptibility to the two pathogens These data suggest that calcium nitrate may be a suitable source of nitrogen helping growers to reduce disease risk