Growth And Yield Response Of Maize Varieties To Regulated Deficit Irrigation

Given the many options that agriculture offers for the mitigation of rainfall inadequacy a dry year should not mean that the farmers will harvest nothing. However crop production under limited water requires careful juggling with all the available resources. One of such resources that call for careful decision making under those circumstances is the genotype to be grown. This study investigated the response of two maize varieties DUMA 43 and KDV2 to regulated deficit irrigation RDI treatments in the Kenayan dry areas. The study consisted of fields experiments at Marimanti in Tharaka Nithi county and Isiolo in Isiolo county. Two regulated deficit irrigation treatments deficit irrigation except during exponential growth stage DIE and deficit irrigation except during the reproductive stage DIR were compared to two controls full irrigation throughout the season FI and deficit irrigation throughout the season DI. The experimental design was RCBD replicated three times. Growth parameters measured were plant height from the ground to the flag leaf and plant diameter measured every 15 days from 30 days after sowing while yield indicators used were stand count number of productive plants per plot ear diameter and length above ground biomass grain yield and harvest index. The data collected was summarized in MS Excel and analyzed using SPSS version 22 for ANOVA and post-hoc tests at 5. DUMA 43 gave significantly higher average yield 2379.45 kgha than KDV 2 2117.59 kgha and significantly higher values for ear diameter under DIE and FI ear height under DI above ground biomass under DIE DIR and FI and harvest index under FI. However DUMA 43 produced both the lowest water productivity 0.3137 kgm3under DI and the highest water productivity 0.5510 kgm3 under DIE. The study concluded that RDI increases water productivity and DIE was recommended as a viable practice when water for irrigation is limited especially when a variety of medium yield potential like DUMA 43 is grown.