Competitive functions, pest dynamics and bio-economic analysis in traditional maize and legumes intercropping systems under rainfed situation of South India

Abstract

The investigation encompassing traditional maize and legume intercropping systems in various patterns was conducted at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, Karnataka, India and revealed that the maize equivalent yield was significantly higher in maize + blackgram (1:1) with 75 cm × 20 cm spacing (7330 kg ha^-1). Also higher LER (1.4) and ATER (1.2) were recorded in maize + blackgram (1:1) with 90×20 cm spacing. Whereas significantly higher system productivity index was observed in maize + greengram (1:1) with 75 cm × 20 cm spacing (431.4). Further, lower aggressivity (-1.2) and higher relative crowding co-efficient (4.3) of intercrops were noticed in maize + blackgram (1:1) with 90 cm × 20 cm spacing. Competitive ratio of intercrops was higher in maize + cowpea (1:2) (1.27) with wider spacing of 90 cm × 20 cm. In a 1:1 row ratio of 90 cm 20 cm spacing, the lower light transmission ratio values were observed. At a 1:2 row ratio and 90 cm 20 cm spacing, maize and cowpea intercropping produced significantly less weed and dry matter. There was least fall armyworm infestation under maize + greengram at 1:2 row ratio in 90 cm × 20 cm spacing (1.7 %) which followed maize + greengram in 75 cm x 20 cm spacing at a 1:1 row ratio (1.9 %).The study concluded that values of most of the intercropping indices were favourable under maize + blackgram and maize + greengram with alternate row at spacing of 75 × 20 cm and hence, it would be most advantageous for maize-legume cropping system in terms of land utilization and sustainable maize production with least pest effect.