THE EFFECT OF WATER STRESS ON RADIATION INTERCEPTION, RADIATION USE EFFICIENCY AND WATER USE EFFICIENCY OF MAIZE IN A TROPICAL CLIMATE

Authors : Geneille E GREAVES, YuMin WANG
Pages : 114-125
Doi:10.17557/tjfc.311904
View : 46 | Download : 14
Publication Date : 2017-05-11
Article Type : Research Paper
Abstract :This study was conducted to investigate the effect of deficit irrigation on radiation capture, radiation use efficiency insert ignore into journalissuearticles values(RUE); and water use efficiency insert ignore into journalissuearticles values(WUE); in maize production, and to assess how these factors impact biomass production in water stress environments. Five irrigation levels were investigated: a full irrigation treatment with a water depth of 60 mm insert ignore into journalissuearticles values(I1);, and four deficit irrigation treatments with depths of 50 insert ignore into journalissuearticles values(I2);, 40 insert ignore into journalissuearticles values(I3);, 30 insert ignore into journalissuearticles values(I4); and 20 mm insert ignore into journalissuearticles values(I5);. Crop water stress index values indicated treatments I2 and I3 caused mild water stress while I4 and I5 caused severe stress. Water deficits significantly insert ignore into journalissuearticles values(p<0.05); reduced leaf area index compared to full irrigation. The reduction in biomass for I2 to I5 ranged between 7 and 43% relative to I1. In I1, the RUE was 3.46 g MJ-1, while mild and severe water stress significantly reduced it to 3.11 and 2.69 g MJ−1, respectively. A reduction in both intercepted photosynthetically active radiation and RUE contributed significantly to biomass reduction. Mild and severe water stress improved the WUE within range of 2 and 25% and 10 and 34%, respectively. The results suggest that in mild water stress environments, high RUE aids in minimizing production losses, and in cases of severe water stress, the reduced ability to capture and utilize radiation is compensated by improving the WUE.
Keywords : biomass, crop water stress index, deficit irrigation, maize, photosynthetically active radiation

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