Bio-efficacy of aliette 80 wp against citrus phytophthora in kinnow mandarin

The bio-efficacy of Aliette 80 WP was evaluated against citrus foot rot/gummosis disease in the Department of Plant Pathology, Punjab Agricultural University, Ludhiana during 2014-15 and 2015-16. Aliette as sprays and soil drench @ 2.5 g and 4.0g/l of water were tested using 10 l water per tree and compared with Aliette spray + Ridomil Gold soil drench (2.5 g/l water). Aliette spray + Ridomil Gold soil drench, Aliette sprays and soil drench and Aliette each @ 2.5 g/l water gave significantly highest reduction in trunk lesion size and increase in feeder root density and fruit yield in the infected Kinnow plants. Aliette sprays were found significantly better than Aliette soil drench application. Aliette @ 2.5 g and 4.0 g per l of water did not show any phytotoxic effect on leaves, fruit surface and yield and safe to use. In vitro, 100 per cent growth inhibition of the pathogen was recorded in Ridomil Gold and Ridomil MZ at 25 ppm where as in Aliette it was more than 200 ppm. Ridomil Gold / Ridomil MZ were found to be highly effective with value < 10 ppm and ED₉₀ value < 25 ppm against the ^ED50 pathogen. The ED₅₀ and ED₉₀value of Aliette was < 50 µg/ml and <200 µg/ml, respectively indicting its less direct effect on the pathogen. For the effective and safe management of the disease Aliette as sprays @ 2.5 g/ l of water can be used as alternative of Ridomil Gold soil drench and trunk paint application.