*Regional Horticultural Research Station, Bajaura, Kullu
Department of Mycology and Plant Pathology, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni (Solan)-73230
National Symposium on Strategic Issues in Plant Pathological Research held at Department of Plant Pathology, CSK HP Krishi Vishvavidayalaya, Palampur on November 24–25, 2011
Fruits constitute a vital component of human diet. Peach occupy an important status and preference for cultivation as well as consumption. Among all the diseases affecting peach, crown gall caused by Agrobacterium tumefaciens (Smith and Townsend) conn. is the main limiting factor in raising quality nursery plants. Various integrated disease management practices have been tested all over the world and found ineffective. Agrobacterium radiobacter strain K-84 was found most effective in controlling crown gall but this strain is not available in India. Therefore, present studies were undertaken and total 158 isolates were collected from different locations of Himachal Pradesh and screened against A. tumefaciens under in vitro and in vivo conditions. Total seventeen (17) isolates out of 158 were found antagonistic against A. tumefaciens. Under in vitro evaluation, A. radiobacter isolate Jd2-(15) showed maximum zone of inhibition (4.16 cm) without exposure to chloroform and 3.57 cm after exposure to chloroform. This isolate (Jd2-15) was further evaluated in combination with soil solarization (75 days) and pre-plant application of formaldehyde (5%) in field against crown gall. Soil drench with Jd2-(15) and soil solarization (75 days) provide complete and 90.89 per cent control of crown gall on peach seedlings. Maximum plant height (187.50 cm), root length (35.42 cm), plant biomass (203.50 g) and stem girth 1.01 cm) were observed in combined treatment of pre –plant application of formaldehyde (5%) and root dip treatment with Jd2-(15).
