Journal of Applied and Natural Science 8 (1): 150-153 (2016)
Management of purple blotch and Stemphylium blight of onion in Tarai and
Bhabar regions of Uttarakhand, India
Deepa Nainwal* and Karuna Vishunavat
Department of Plant Pathology, G.B.P.U.A. and T. Pantnagar-263 145, (Uttarakhand), INDIA
*Corresponding author. E-mail: email@example.com
Abstract : Purple blotch [Alternaria porri] (Ellis) Cif.) and Stemphylium blight [Stemphylium vesicarium] (Wallr.)
E. Simmons) of onion cause serious problems in onion seed crop in Tarai and Bhabar region of Uttarakhand. In
present study different bio agents and fungicides have been evaluated in vivo against both the diseases. The severity of both purple blotch and Stemphylium blight varied in both Tarai and Bhabar region and even more pronounced
in Tarai region than in Bhabar region. A correlation was observed in between the severity of both the diseases with
the yield in seed crop. The minimum disease severity of purple blotch and stemphylium blight with the foliar spray of
mancozeb (@ 0.3%) + monochrotophos (@ 0.05%) were observed 2.67% and 2.57% respectively with the total
yield of seed was1844.44 kg/ha over check 893.33 kg/ha in 2011. While with the foliar spray of neembicidine (@
0.3%) disease severity of both the diseases were 5.57% and 4.78% respectively providing a yield of 1827.78kg/ha in
seed crop of onion in 2011. Amongst the applied bio-agents, the foliar spray of Trichoderma harzianum (@ 1%) the
disease severity of purple blotch and stemphylium blight were recorded 15.44% and 13.11% respectively which was
found to be most effective in delaying the disease appearance and providing a yield of 1134.44kg/ha in 2011.
However, all the treatments helped to reduce both the diseases in comparison with check.
Keywords : Alternaria porri, Bio-agents, Onion, Purple blotch, Stemphylium blight.