Use of Botanicals and Fungitoxicants Against Alternaria helianthi (Hansf.) Tubaki and Nishihara, the Causal Agent of Sunflower Leaf Blight

The efficacy of three botanicals and seven fungicides were tested in vitro and in vivo against Alternaria helianthi (Hansf.) Tubaki and Nishihara, inciting sunflower leaf blight. In in vitro evaluation of fungicides, cyproconazole found to be most effective and showed maximum inhibition of mycelial growth (80.3%) followed by mancozeb (69.5%) and iprodione (60.9%). Tridemorph was least effective. Among plant extracts, neem seed kernel extract showed 9.2% per cent inhibition of mycelial growth. Leaf extracts of Ocimum cannum and Tridex procumbens were least effective. In in vivo evaluation, chlorothalonil (0.2%), mancozeb (0.2%) and cyproconazole (0.1%) were effective in controlling Alternaria leaf blight. Maximum grain yield (9.2 q/ha) was recorded in chlorothalonil treatment, which was on par with cyproconazole and mancozeb (9.1 q/ha) treatments. Further, maximum oil yield (kg/ha) was obtained in chlorothalonil treatment followed by cyproconazole, iprodione and mancozeb. The three plant extracts, viz., NSKE (5%), Ocimum leaf extract (5%) and Tridex leaf extract (5%) were least effective in controlling Alternaria blight.