Investigation of yield components and water use efficiency of three maize hybrids with different levels of irrigation in subsurface drip irrigation system

The use of modern irrigation methods, deficit irrigation, the use of cultivars more resistant to drought stress, are ways to increase water use efficiency in agriculture. To study the effect irrigation level and type of maize cultivar on water use efficiency in forage and grain maize production, this research was conducted at the research farm of Agricultural and Natural Resources College of University of Tehran (Karaj) in 2017. The main treatments included two levels of irrigation (100 and 80% of maize water requirement) in subsurface drip irrigation system; sub-treatments included three maize cultivars KSC704, KSC600, KSC400. Experimental design was based on split plots based on randomized complete blocks. The studied traits were forage yield, biomass, grain, water use efficiency in forage, biomass and grain production, 1000-grain weight and harvest index. The results showed that the effect of irrigation level on the measured traits was insignificant and the effect of cultivar on them was significant at both irrigation levels. The highest amount of water use efficiency in biomass production was 4.37 kg / m3 in KSC600 cultivar and the highest water use efficiency in grain production was 2.43 kg / m3 in KSC704 cultivar (with KSC400 cultivar in a Statistical group) obtained at the irrigation level of 80%. Also, KSC400 cultivar, being in the common statistical group with KSC704 cultivar, had the highest 1000-grain weight of 537.3 grams. Deficit irrigation up to 80% of water requirement using subsurface irrigation system had not any significant effect on the yield of maize cultivars.