Abstract
This study examines the effects of variety and plant growth regulators on the growth of some maize varieties in Yola with the aim of proffering vital recommendations towards improving maize yields in the area. Field trials were conducted during 2019, 2020 and 2021 growing seasons at the Department of Crop Production and Horticulture Teaching and Research farm, Modibbo Adama University Yola. The treatments consisted of three varieties of maize (M12M, SAMMAZ-37 and Admiral Improved Seed) and seven plant growth regulators (Cytokinins, Super-gro, Growth force, Boostract, Nanomix, Vitalon and Water as a control). The treatments were laid out in a split plot design replications three times. Maize varieties were assigned to the main plots and plant growth regulators assigned to sub plots. Data were collected on plant height, stem girth, ear diameter, ear length, grain weight per plant and grain yield kg ha-1 . Data collected were subjected to analysis of variance (ANOVA) using the Generalized Linear Model Statistical Package Version 9.1. Least Significant Difference (LSD) was used to separate the means at 5 % level of probability. The results indicated that variety significantly affects plant height, stem girth, ear length and grain yield. The results on plant growth regulators also shows a significant effect on plant height, ear diameter, ear length, grains weight per plant and grains yield. Higher grains yield (5.24 tones ha-1 ) was obtained in variety M12M while application of cytokinins recorded the higher grains yield of 5.73 tones ha-1 though statistically similar with other growth regulators except with vitalon, and control recorded the least (4.06 tones ha-1 ). There was no significant interaction between the varieties and plant growth regulators on all the parameters measured. The best variety in term of grains yield was M12M, while cytokinins was found to be the best plant growth regulator respectively thus recommended for the study area.