WEATHER BASED CERCOSPORA INFECTION PREDICTION MODEL FOR THE MANAGEMENT OF TIKKA LEAF SPOT OF GROUNDNUT (Arachis hypogaea L.)
Loading...
Files
Date
2018
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DEPARTMENT OF PLANT PATHOLOGY, NAINI AGRICULTURAL INSTITUTE, SAM HIGGINBOTTOM UNIVERSITY OF AGRICULTURE, TECHNOLOGY AND SCIENCES, ALLAHABAD, U.P.
Abstract
Groundnut (Arachis hypogaea L), is the world‟s third most important oil seed crop, after soybean and cotton. Tikka leaf spot is one of the major diseases of groundnut at national and international level. The yield losses encountered due to tikka disease was reported to the tune of 40 per cent.
A detailed study was carried at “Department of Plant Pathology, S.V. Agricultural College, ANGRAU, Tirupati” on isolation of the pathogen and establishment of pathogenicity of Cercospora arachidicola. Potential fungicidal compatible, endophytic bacteria antagonistic to Cercospora arachidicola were isolated from the groundnut leaf. Weather based Cercospora infection prediction model was used for the management of Cercospora arachidicola.
The Pathogen was isolated from infected leaflet of plant showing typical leaf spot symptoms viz., circular to irregular, light brown to dark brown lesions on adaxial surface of lower leaves surrounded by a prominent yellow halo, purified and identified as Cercospora arachidicola.
The pathogen of ground nut early leaf spot, Cercospora arachidicola was inoculated on potato sucrose agar, oatmeal agar, potato dextrose agar, V8-juice agar, leaf extract agar, carrot juice agar and peanut hull extract agar. Out of all the media tested, the maximum growth was supported by potato sucrose agar followed by oat meal agar at 23±1ºC and more than 90% relative humidity. Maximum sporulation of C. arachidicola was obtained in potato sucrose agar at 6 per cent sucrose followed by 5 per cent.
Weather based Cercospora infection prediction model was developed for scheduling fungicidal spray for management of leaf spot of groundnut (Arachis hypogaea L.) cv. Narayani at Central Agricultural Field, SHUATS, Allahabad during 2015 and 2016. The prediction model was developed based on temperature and relative humidity (leaf wetness) to quantify the disease incidence in groundnut. This model indicates that the temperature ranging from 24oC to 28oC and relative humidity more than 90% was found to be optimum for initiation and development of the disease. If the temperature between 24oC to 28oC and relative humidity
more than 90% prevails continuously for four days indicating the appearance of the disease as per this model.
Among the fungicides, carbendazim+mancozeb was superior one in increasing the pod and haulm yield by 2.29 (Q/ha) and 6.39 (Q/ha) respectively, when compared to control. It gave a net profit of Rs. 5609/- with a benefit cost ratio of 2.95. Predicting the disease well in advance led to the economical fungicidal and potential bacterial leaf endophyte for the management of leaf spot in groundnut which is very crucial especially in rain fed as well as irrigated conditions.
Description
ph. d. thesis
Keywords
null