The effect of superabsorbent and biological fertilizers under water deficit stress on leaf area index, relative water content and yield of sugar beet (Beta vulgaris)

Abstract

To investigate the effect of soil additives in reducing the effect of water deficit stress on sugar beet, an experiment was performed as a combined analysis in two regions based on randomized complete block design with four replications. Experimental treatments were location factor at two levels of Miandoab and Malekan, water deficit stress factor at three levels of 50 mm (Lack of stress), 110 mm (moderate stress) and 170 mm (severe stress) evaporation from class A evaporation pan and soil additive factor at four levels of control (no soil additives), superabsorbent, mycorrhiza and livestock manure. In the present study, the use of soil additive treatments in both regions were able to improve the yield of pure sugar compared to control. In irrigation treatment after 170 mm of evaporation, the highest leaf area index (3.28), relative leaf water content (65.96%), shoot dry weight (3.45 t ha^-1), root yield (49.48 t ha^-1), gross sugar yield (9.73 t ha^-1) and pure sugar yield (8.32 t ha^-1) were obtained by mycorrhiza application and sugar content (20.48%) and pure sugar percent (17.11%) were obtained in control and superabsorbent application, respectively. In water deficit stress, application of mycorrhiza and superabsorbent were able to significantly increase the yield of pure sugar compared to the control. Due to the fact that sugar beet is exposed to different periods of water deficit stress in the tested areas, the use of mycorrhiza and superabsorbent can be a suitable method to reduce the effect of water deficit stress in sugar beet.