Field Screening of Garlic Genotypes for Identification of Resistant Sources against Purple Blotch Disease
K. N. Vijaykumar *
ICAR-IARI, Regional Research Centre, Dharwad-580 005, Karnataka, India.
Shripad Kulkarni
Department of Plant Pathology, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
S. M. Hiremath
Department of Horticulture, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
T. R. Shashidhar
Department of Horticulture, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
D. N. Kambrekar
Department of Agricultural Entomology, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
Vijay Mahajan
ICAR-Directorate of Onion and Garlic, Rajgurunagar, Pune, India.
Anil Khar
ICAR-Indian Agricultural Research Institute, New Delhi, India.
P. V. Patil
Department of Plant Pathology, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Garlic (Allium sativum L.) is one of the oldest cultivated plants in the world and belongs to the family Amaryllidaceae. Purple blotch caused by Alternaria porri (Ellis) Ciferri is one such disease which causes a great deal of loss for farmers. The best method to manage purple blotch is to adopt resistant genotypes for cultivation, which is highly necessary in areas with a high incidence. In order to identify resistant sources, 37 genotypes were field screened under artificial epiphytotic conditions at AINRPOG (All India Network Research Project on Onion and Garlic), MARS (Main Agricultural Research Station), Dharwad during Rabi, 2019 and 2020. Results from two years showed that no genotype was immune to purple blotch. Among the genotypes tested, five genotypes viz., G50, Bhima Purple, DOGR426, DOGR543 and DOGR569 were resistant to infection (1-10%), 17 genotypes moderately resistant to infection (11-20%), while 4 genotypes were moderately susceptible to infection (21-40%). On a scale of 0 to 5, only one genotype (HRG Local) showed susceptible (41-75%) in reaction. Among the remaining genotypes, disease reactions differed between years. The genotypes that are resistant can be utilized by breeders to produce high yielding purple blotch resistant varieties.
Keywords: Purple blotch, artificial screening, per cent disease index, disease reaction