Effect of Mulch and Irrigation on growth and water use efficiency of lettuce (Lactuca sativa L) cultivars.

Abstract

A study was carried out to evaluate effect of mulch and irrigation on growth and water use efficiency of lettuce (Lactuca sativa L.) cultivars under irrigation during 2016, 2017 and 2018 in semi arid ecology of Nothern Nigeria at Irrigation Research Sub station farm (IRS) of the Institute for Agricultural Research, Ahmadu Bello University at Kadawa in the Sudan Savannah ecological zone of Nigeria. Treatments were factorial combinations of three irrigation levels (50, 75 and 100% of reference evapotranspiration (ETo), three lttuce cultivars (Great Lake, Slaai and Babyleaf mix) and two levels of mulch (No mulch and mulch) laid out in a Split Plot Design with three replicates. Water applied before and after irrigation was monitored throughout the seasons. Results indicated that different levels of irrigation and mulch on all growth characteristics, crop water use efficiency and irrigation water use efficiency were significant with the highest irrigation level of 100% ETo recording the highest yield of 8.5, 8.4,and 8.6 t/ha in 2016, 2017 and 2018 seasons respectively while 50% ETo recorded the least yield of 7.3, 6.7 and 7.5 t/ha across the three years. Increase in water application increase yield of about 7.6% in 2016: 11.6 and 10.6% in 2017 and 2018 respectively with 100% ETo. Mulching significantly improve the crop water productivity irrespective of the cultivar in the study area. Since there were only minor differences between growth characters of lettuce obtained from 75 and 100% ETo, it can be said that water application should be kept at 75% weekly crop consumptive use in this region