Effect of adjuvants on the efficiency of dimethomorph plus mancozeb (Acrobat 2 kg:ha) on the control of late blight

Industrial adjuvants were tested in combination with dimethomorph plus mancozeb (Acrobat 2 kg/ha) in the field to investigate their efficacy on foliar late blight caused by Phytophthora infestans. The tested adjuvant fungicide treatments for late blight control were applied 5 times at 7-day intervals. The effect of the adjuvant fungicide treatments on epidemic development, tuber rot and blight incidence and tuber yields were determined. Last summer late blight development was arrested in July due to high temperatures and lasting drought. August was characterized by rather low temperatures and high rainfall. These weather conditions were very favourable for the development of late blight. Due to the heat waves of June and July the foliage started to die allready in Agust. Because of that no incidence of foliage blight was scored. No significant differences in yield were observed for the different treatments applied. The addition of an adjuvant had a clearly positive effect on the tuber yield. In the control 12,7 % infected tubers were observed. The mean tuber infection of plots sprayed with the Acrobat-adjuvant combinations was 7,4 %