Field screening of pigeonpea for their resistance against Melanagromyza obtusa (Diptera: Agromyzidae)

Abstract

Melanagromyza obtusa (Malloch) has been recorded for the first time on pigeonpea at Nagpur, India and named as 'tur pod fly'. It is a monophagous species and devours the developing seeds of pigeonpea crop. It was reported to infest 12 to 100% pods causing losses of 2.4-95.0% on seed or grain (=250000 tonnes by weight) and are estimated at US $ 256 million annually. Therefore, a field experiment was conducted at Research Farm, Agricultural Research Station, Badnapur (VNMKV), India during kharif 2015-16 to source some promising pigeonpea genotypes against M. obtusa. The present investigations revealed the population of M. obtusa on 20 genotypes ranged from 0.00-277.64 maggots per 100 pods; pod and grain damage were ranging from 0.00-89.75 and 0.00-82.02%. The highest M. obtusa population, pod and grain damage was recorded in BRG-2 (277.64 maggots and 101.26 pupae per 100 pods; and 89.75 and 82.02%). On the basis of pod damage a total of five, two, eight, four and one genotypes were categorized as highly tolerant, tolerant, moderately tolerant, susceptible and highly susceptible; for grain damage these were seven, seven, three, two and one, respectively. The maximum yield was recorded from BDN-2010-1 (22.33 q/ha), followed by V-127 (21.61 q/ha). However, Cajanus scarabaeoides showed no maggot and pupal population, pod and grain damage by M. obtusa indicating its virtue of genetic resistance and it can be used in breeding programmes to develop resistant cultivars for farmer’s welfare.