Optimizing plant population for drought-tolerant maize cultivar in a rainforest environment

Abstract

Drought tolerant (DT) maize cultivars are increasingly adopted to cope with unpredictable drought conditions in sub-Saharan Africa. Occurrence of incessant dry spells during cropping season, with the concomitant reduction in yield, is becoming a frequent phenomenon in particularly the rainforest of Nigeria. The objective of this research was to identify the ideal plant population of DT maize as climate smart cultivars under drought episodes in a rainforest region of Nigeria. Field trials were carried out in the early growing seasons of 2017 and 2018, in Benin City, with nine DT maize cultivars (DMRLSR-W, DT STR-W SYN2, DT STR-Y SYN2, DT SYN11-W, DT SYN11-Y, IWD C3 SYN F2, TZL COMP3 C3 DT, TZL COMP4 C3 DT and WHITE DT STR SYN) and three plant populations (53,333, 66,666 and 88,888 plants ha⁻¹ ). The experiment was laid out in a randomized complete block design with a split-plot arrangement having three replications. Results showed that 66,666 and 88,888 plants ha⁻¹ plant populations led to taller plants, accumulated greater dry matter content and produced higher grain yield than the standard plant population of 53,333 plants ha⁻¹ . Cultivars had an average yield of 3.0 t ha⁻¹ . Higher grain yield correlated on higher plant height, higher number of ears, higher dry matter, higher 1000-seed weight and higher harvest index. Grain yield indicates that the cultivars can be grown in the agro-ecology. Absence of plant population × maize cultivar interaction for all traits suggests that plant population may not have reached the maximum necessary for growing these cultivars in the zone.