COMPARATIVE ASSESSMENT OF POTENTIAL OF MICRONUTRIENTS, BIOFERTILIZERS AND CHEMICAL FUNGICIDES AGAINST CHARCOAL ROT IN SUNFLOWER

Abstract

Charcoal rot incited by Macrophomina phaseolina is yield limiting disease of sunflower (Helianthus annuus L.). Micronutrients and biofertilizers are safer and sustainable alternatives to fending off disease over chemical fungicides. The present investigation aimed to investigate and compare the potential of zinc (Zn), boron (B) and commercial biofertilizers with chemical fungicides on disease management and seedling growth attributes in sunflower. According to principal component (PCA) analysis, the treatments were classified into 4 groups. Highly infected seedlings displaying 81% disease incidence and 50-90% reduction in growth in positive control (provided with M. phaseolina only) occupied group I (left side) as compared to negative control (un-inoculated) located opposite side in group III. Higher concentrations (1000 and 2000 ppm) of both fungicides (carbendazim and thiophanate-methyl) highly significantly managed 80% of the disease also occupied cluster III, while lower (150-350 ppm) and medium (500 ppm) concentrations reduced 20-60% disease belong to group II. Zn (2.5-3.5 ppm) and B (0.4-0.7 ppm) reduced 38-62% and 34-50% disease, respectively in cluster VI, hence these treatments were significantly and closely associated with treatments in cluster III. Biofertilizers and lower doses of micronutrient in cluster I were less effective in managing disease. Effective doses of fungicides, Zn and B were significantly and positively associated with growth variables. However, Zn (2.5 ppm) exhibited comparable effect on disease and growth attributes as was recorded with higher doses of fungicides. Hence, Zn (2.5 ppm) could be used as encouraging control means of charcoal rot disease in sunflower.