Growth, Yield and Productivity of Maize + Cowpea intercropping as affected by varietal combination and Relative times of Planting.

Abstract

Two field trials were carried out from August to December 2021 in the minor rainy season and from March to July 2022 in the major rainy season to determine the varietal combination and relative times of planting effects on growth and yield performance of maize cowpea intercrop system. The experimental design used was 3 x 3 factorial laid out in a Randomized Complete Block Design (RCBD) with four replications. The treatments were: (A) three varietal combinations [(i) Abontem maize + Zamzam cowpea, (ii) Opeaburo maize + Zamzam cowpea and (iii) Omankwa maize + Zamzam cowpea] and three relative times of planting [(i) maize planted 2 weeks before cowpea (M2WBC), (ii) maize planted simultaneously with cowpea (SIM) and (iii) cowpea planted 2 weeks before maize (C2WBM)]. The results showed that, for cowpea phenology, cowpea planted after Opeaburo maize had the highest percentage plant establishment, early flowering and podding. In maize, Opeaburo maize planted before cowpea promoted plant establishment, while sole Opeaburo advanced early tasseling and silking. Regarding vegetative growth, cowpea and Omankwa and Abontem planted simultaneous showed improved plant height while sole cowpea yielded higher dry matter. For maize, sole Omankwa and Opeaburo resulted in taller plants, and intercropping with Omankwa promoted leaf development. The highest cowpea grain yield (346.50 kg ha-1) for the 2021 minor season was recorded by sole cowpea whereas for the 2022 major cropping season, sole cowpea recorded the highest pod yield (450.75 kg ha-1) followed by Opeaburo and cowpea planted simultaneously (405.25 kg ha-1). Again, the sole cowpea produced more pods per plant and higher seed weight. In maize, Abontem planted simultaneous with cowpea had higher 100-seed weight and harvest index, while sole Omankwa and Opeaburo performed better in cob size. Omankwa planted after cowpea had the highest grain yield. The land equivalent ratio (LER) for both maize and cowpea was maximized when maize was planted two weeks before cowpea in the Abontem + Zamzam combination, and in simultaneous planting of Opeaburo + Zamzam. Abontem planted before cowpea and simultaneous are recommended for farmers who prefer intercropping cowpea and maize.