Acrobat MZ performance for early management of late blight (Phytophthora infestans) when applied to seed potatoes

ROLON, D.; ADRIANA BALBINA ANDREU; DI RICO, J.; CALDIZ, D.

Quebec, Canadá

Congreso; American Phytopathological Annual Meeting; 2006

American Phytopathological Society

Seed treatments with contact fungicides prevent from tuber to tuber infection of P. infestans during handling, but do not prevent field infections in the young plant. Acrobat MZ (Dimethomorph+Mancozeb, BASF Company) can cover both aspects due to the contact and systemic action of Mancozeb and Dimethomorph, respectively. Seed tubers of cvs. Kennebec, Shepody, Spunta, Russet Burbank and Ranger Russet were cut in pieces, as done in Argentina, and immediately after, treated with Acrobat MZ at doses equivalent to 2, 3, and 4 kg.ha-1. Acrobat MZ (4 kg.ha-1) protected the foliage of all cultivars against P. infestans up to 30 days after emergence (50 days after planting) in greenhouse experiments and up to 28 days after crop emergence (48 days after planting) in two different growing seasons. In cv. Spunta significant foliage protection was observed up to 35 days after emergence (55 days after planting) at field level while in seed tubers of cv. Kennebec planted in sandy soils a higher persistence time with significant foliage protection was assessed. With this strategy there is no need to apply contact or systemic fungicides early in the season, reducing costs and environmental risks.