Field Screening of Maize (Zea mays L.) Genotypes against Turcicum Leaf Blight (TLB) under Artificial Conditions

Abstract

Background: There are a variety of critical problems facing tropical maize cultivation, such as disease infestation, insect/pest and weed problems. Foliar diseases in particular cause significant losses in agricultural yield. Leaf blight, known as northern leaf blight, is a disease of maize leaves caused by an overgrowth fungus. Therefore, it was necessary to develop sources of resistance to TLB and then a field experiment was conducted to study the performance of 64 genotypes (44 test crosses, 11 lines, 4 testers and 5 checks) During Spring 2021-22 at the Agricultural College Farm, Bapatla. Methods: Screening was carried under field conditions by adopting an artificial disease inoculation technique Disease score was recorded at tasseling, 20 DAT and maturity stages by using 1-9 scale. Results and Discussion: At maturity stage 12 crosses, seven lines and one check showed resistant reaction (R); 25 crosses, 4 inbreds, one check showed moderately resistant reaction (MR); 7 crosses, 3 inbreds and one check showed moderately susceptible reaction (MS) and one inbred, two checks showed susceptible reaction (S) under field screening.  Conclusion: The lines VL171488-2, VL18828, VL19705-8, VL18142, VL175869, SNL19582-22 and tester LM13 showed resistant disease reaction for TLB pathogen at phenotypic level. These lines can be used in future TLB resistance breeding programmes.