Fortnightly dynamics and relationship of growth, dry matter partition and productivity of maize based sole and intercropping systems at different elevations

Understanding temporal dynamics of growth and dry matter production of sole and intercropped maize under different agro-climatic and cultural conditions is imperative to devise crop models and optimize resources for better crop production. Field experiments comprising seven cropping systems (maize-mungbean, maize-cowpea, maize-soybean, maize sole, mungbean sole, cowpea sole, soybean sole) were performed for three years (2015, 2016 and 2017) at three elevation sites (1500, 1800 and 2200 m from mean above sea level) using factorial randomized complete block design (RCBD) with three replications. Maize growth (plant height, number of leaves, leaf area), dry matter partitioning (leaf, stem, plant) and absolute growth rate (AGR) were observed for five growth intervals (1-15, 16-30, 31-45, 46-60 and 61-75 days after germination, DAG) while yield components (thousand grain weight, grain yield, biological yield) were recorded at harvesting. Furthermore, productivity, land equivalent ratio (LER) and competition index (CR) of cropping systems computed from biomass and grain yields of maize and legumes were also compared in terms of economic and biological yields. The growth parameters, dry matter production and AGR of maize varied significantly (p <= 0.05) due to individual and interaction effect of year, elevation, and legume during 31-45, 46-60 and 61-75 DAG but did not vary significantly during the 1-15 and 16-30 DAG. Growth parameters, dry matter production, AGR and harvest yields of maize were the highest during 2015, at 1500 m elevation, and in intercropping with mungbean but at par with maize sole cropping. System productivity and LER were greater for maize-mungbean cropping compared to rest of the cropping systems including sole cropping. Growth parameters and dry matter production of maize were found strongly correlated (r = 0.84-0.98) with its grain and biomass yields. It is concluded that 3rd, 4th and 5th fortnightly intervals are critical periods for intercropped maize where its growth and biomass production are significantly influenced due to competition with legumes. Lower elevations and mungbean as intercrop with maize are recommended for greater economic and biological productivity of maize based intercropping systems.