Evaluation of Agronomic Practices to Improve Mungbean yield in Uganda

Abstract

Mungbean is among the most important pulse crops of the world. The crop has growing demand both in Uganda and East African markets. However, mungbean yields in Uganda are still low (0.3 t ha-1) when compared to the yield in countries like Pakistan (3.1t ha-1). The low yields have been attributed to a number of factors like poor crop management practices, low yielding varieties and pests and diseases among others. In order to increase yields of mungbean in Uganda, a high yielding mungbean variety (VC653 (B-20)) was used to determine the optimum density of mungbean in a maize-mungbean intercropping system and to determine the potential of relay cropping mungbeans within a single growing season of maize. A field study was conducted in two seasons in three sites; Makerere University Agricultural Research Institute – Kabanyolo (MUARIK), National Semi-arid Resources Research Institute in Serere and BUGIZARDI, Mayuge. A Randomized Complete Block Design with factorial arrangement of treatments was used. The Treatments were cropping system which had two levels; Mungbean sole-cropping (control) & inter-cropping mungbean with maize; plant density which had 13 levels; and time of planting the mungbean in the maize crop which had two levels; planting mungbean simultaneously with maize at onset of rains and nine (9) weeks after onset of rains. The plant densities evaluated were; 16 plants m-2 arranged as 40 cm between row spacing x 15 cm within row spacing, 19 plants m-2 arranged as 35 cm between row spacing x 15 cm within row spacing, 22 plants m-2 arranged as 30 cm between row spacing x 15 cm within row spacing, 25 plants m-2 arranged as 40 cm between row spacing x 10 cm within row spacing, 28 plants m- 2 arranged as 35 cm between row spacing x 10 cm within row spacing and 33 plants m-2 arranged as 30 cm between row spacing x 10 cm within row spacing. The treatments were v replicated thrice. Maize in the intercrops and solecrop was planted at a constant density of 4 plants m-2. Mungbean growth and yield were significantly influenced by plant density. In intercrops, the grain yield increased with increasing plant density until the plant density of 25 plants m-2 beyond which yield declined. However, yields of mungbeans grown at these densities of 25 plants m-2 and 22 plants m-2 did not vary in intercrops. The time of planting significantly influenced the mungbean yield and yield parameters. Also, intercropping mungbeans with maize at the plant density of 22 plants m-2 is where the maize/mungbean component crops were neither dominated or dominant making it the most compatible system. The cropping system did not affect some parameters like plant height & leaf area index of mungbeans. Thus at onset of rains and 9WAR, mungbeans can be intercropped with maize at the density of 22 plants m-2. It was concluded that a relay crop of mungbeans in one growing season of maize can be possible. Though participatory trials are recommended to further validate these functions