Pistachionut rust disease and its management under arid temperate conditions of Himachal Pradesh

Pistachionut (Pistacia vera L) is an important nut crop. Studies on its cultivation have been initiated at Regional Horticultural Research Station, Sharbo, Kinnaur of Dr YS Parmar University of Horticulture and Forestry and various other locations in arid temperate region of Himachal Pradesh. Rust caused by a fungus Pileolaria terebinthi (DC) Cast has been reported to be a major disease on this nut crop. The pathogen attacks both leaves as well as fruits and produces typical rusty pustules. The fungus produces uredial and telial stages on infected plant parts under natural conditions. The urediniospores are one-celled, round to ellipsoid while teleutospores are one-celled, pedicillate and typically discoid. The pathogen perpetuates under field conditions on bark of twigs and fallen infected leaves and fruits under orchard conditions. For the management of the disease a field experiment was conducted at Sharbo, Kinnaur during 2008 and 2009. Seven different fungicides namely, Baycor (0.05%), Bayleton (0.05%), Blitox-50 (0.3%), Contaf (0.05%), Indofil M-45 (0.3%), Punch (0.05%) and Score (0.03%) were applied as foliar spray on pistachionut cultivar Kerman. The first spray was given at the time of expression of the disease symptoms and two other sprays at 15 days interval. The data on disease intensity were recorded at the time of fruit harvest. All the fungicides tested reduced the disease index significantly over control during both the years. Baycor, Bayleton, Contaf, Punch, Score and Indofil M-45 were observed to be effective fungicides against the disease.