Open Access Maydica 61-2016 Short Communication RECEIVED 5/28/2016 Determination of susceptible growth stage and efficacy of fungicidal management of Curvularia leaf spot of maize caused by Curvularia lunata (Wakker) Boedijn Sunaina Bisht 1 *, Rekha Balodi 1 , Abhijeet Ghatak 2 , Pradeep Kumar 3 1 Department of Plant Pathology, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand-263145, India 2 Department of Plant Pathology, Bihar Agriculture University, Sabour, Bhagalpur-813210, India 3 Department of Plant Pathology, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand-263145, India *Corresponding author: E-mail: sunaina39486@gmail.com Keywords: Curvularia lunata, maize, developmental stages, fungicide, economic management Introduction Increase in per capita income and rise in the stan- dard of living has led to change in the feeding habits of the people worldwide. Presently, corn (Zea mays L) is the world’s third leading crop after wheat and rice grown in different agro-ecologies of the world (Directorate of Maize Research, 2012). The crop has high economic value as both grain and fodder crop. Maize is easily processed, has high fiber content and is cheaper than other cereals (IITA, 2001) further low cost of cultivation and high nutrient content adds to economic value. Production of maize is limited by many constraints including the diseases, worldwide, about 9% yield losses have been estimated in maize due to diseases (Khokhar et al, 2014). Curvularia leaf spot caused by Curvularia lunata (Wakker) Boedijn, is one of the most destructive foliar disease of the crop (FuHua et al, 2004). This pathogen is seed and soil borne causing disease prevalent in the hot, humid maize growing areas and causes approximately 10- 60% yield losses due to loss of photosynthetic region of the crop and upto 33.4% losses in grain number Abstract Maize is an important food security crop along with rice and wheat globally. Losses caused by biotic stresses in maize are substantial and Curvularia leaf spot is important among them. Further management of Curvularia leaf spot is done primarily through chemicals, therefore an attempt was made to evaluate the efficacy of com- monly used systemic and non-systemic fungicides against the pathogen, and most susceptible growth stage for disease development was identified. In vitro evaluation of four systemic and four non-systemic fungicides was done at different concentrations, for checking the growth of pathogen. The data revealed that Carboxin (at 25 ppm) completely inhibited growth of pathogen. Further among non-systemic fungicides treatment of Mancozeb showed maximum growth inhibition (98. 24% at 200 ppm). Under glass house conditions mancozeb was found to be more effective than Carboxin for controlling the disease severity. Further to determine the time of application of fungicides, developmental stage most susceptible to Curvularia lunata was studied. Three growth stages (Knee height stage, Silking stage and Tasseling stage) were compared. Maximum disease index and severity was found at Silking stage (47% and 53.75%, respectively) followed by Tasseling stage (42.5% and 18.4%, respectively) and Knee height stage (37% and 30%, respectively), indicating that the disease progresses with the maturity of the plant and is maximum at the Silking stage. Results suggest that susceptible maize varieties may give higher yield with the optimisation of the time of application of the fungicides and higher economic and environmental gains can be achieved with judicious use of fungicides. (DingFa et al, 1999).The pathogen can cause dam- age from seedling to harvesting stage of maize plant. Many strategies has been developed for controlling the Curvularia leaf spot in maize including manage- ment strategies based on chemicals, bio-control agents and integrated management of the disease (Kumar and Tomar, 2005). But most common and ef- fective method is use of chemicals for the manage- ment of Curvularia leaf spot (Patil et al, 2001; Praj- apati et al, 2003). This disease is present at all the developmental stages of maize plant while reproductive stage is most susceptible to the pathogen (Akonda et al, 2015). Fur- ther, this disease have the ability to develop into epi- phytotics under favourable environmental conditions on susceptible developmental stage of maize which hampers development of ears and grains formation by decreasing photosynthetic ability (FaChao et al, 1998).The pathogens overwintered on diseased crop residues left in the field therefore, multiple cultural practices can be used for the prevention of disease but are region depended and therefore are not a vi-