Triadimenol drenches and residues in tobacco seedbeds improve growth and disease control in transplants

Abstract

Triadimenol residues in sandy and clay soils, following applications of up to 1 g/m2 in previous seasons to tobacco seedlings 2 days before they were transplanted, had little effect on seedling emergence and growth. Residues were beneficial to transplants; they improved growth and controlled stem and root infection caused by Rhizoctonia solani and Fusarium solani. During the first 4 weeks after transplanting, stem infection was negatively correlated with loge of the pre‐sowing rate of triadimenol and with loge of the soil concentration in seedbeds at pulling. Plant growth increased linearly according to the equation l/Y=a+b/(x‐c), where Y = plant dry mass (g/plant), .x = triadimenol pre‐sowing (mg/m2) and c= ‐ 1 1, determined iteratively, r2= 0‐94; P < 0.001. Triadimenol applications to bare soil increased the soil concentration by 1 μ/g per 50 mg/m2 applied.