International Journal of Environment and Climate Change

An investigation was carried out in an experimental field of the College of Agricultural Engineering, University of Agricultural Sciences, Raichur, to investigate the effect of different coloured low tunnel shade nets and different mulches on water use efficiency and nutrient use efficiency of chrysanthemum. The results revealed that the values of daily evapotranspiration under different colours’ low tunnel shade net were less than the values of evapotranspiration under open field for all months. It is because of the green-house effect and low radiation. The values of ET during the seasons were lower under white-coloured shade net compared to open field conditions. The results indicate that significant irrigation water savings occur in chrysanthemums under different coloured low tunnel shade nets as compared to open field cultivation. It is also found that the chrysanthemum crop requires approximately 31%, 28%, and 23% less water under white, green, and black shade net compared to the total water required under open field cultivation. The highest water use efficiency was recorded with the white colour low tunnel shade net (28.78 kg ha^-1 mm^-1) and this was followed by the green shade net (28.64 kg ha^-1 mm^-1), black shade net (13.09 kg ha^-1 mm^-1) and lowest water use efficiency was  recorded under open field conditions (10.58 kg ha^-1 mm^-1). Among the different mulches, the highest water use efficiency was recorded by the use of white coloured mulch (24.36 kg ha^-1 mm^-1) and this was followed by silver mulch (21.75 kg ha^-1 mm^-1), black mulch (20.82 kg ha^-1 mm^-1), and jute mulch (19.38 kg ha^-1 mm^-1). The lowest water use efficiency was recorded where mulch was not used (15.05 kg ha^-1 mm^-1). The highest nutrient use efficiency was recorded with the white colour low tunnel shade net (Nitrogen (N)=72.51 kg ha^-1_, Phosphorous (P)=12.37 kg ha^-1 and Potassium (K)=73.84 kg ha^-1 ) and this was followed by the green shade net (N=66.77 kg ha^-1_, P=10.28 kg ha^-1 and K=64.33 kg ha^-1), open field conditions (N=58.08 kg ha^-1_, P=8.72 kg ha^-1 and K=56.36 kg ha^-1) and lowest nutrient use efficiency was  recorded under black shade net (N=51.60 kg ha^-1_, P=6.98 kg ha^-1 and K=49.75 kg ha^-1). Among the different mulches, the highest nutrient use efficiency was recorded by the use of white colour mulch (N=77.53 kg ha^-1 P=11.74 kg ha^-1 and K=73.20 kg ha^-1) and this was followed by silver mulch (N=70.50 kg ha^-1_, P=10.61 kg ha^-1 and K=66.86 kg ha^-1), black mulch (N=65.08 kg ha^-1_, P=9.51 kg ha^-1 and K=64.09 kg ha^-1), and jute mulch (N=57.75 kg ha^-1_, P=8.96 kg ha^-1and K=64.09 kg ha^-1). The lowest nutrient use efficiency was recorded where mulch was not used (N=40.22 kg ha^-1_, P=7.11 kg ha^-1 and K=44.44 kg ha^-1). The results indicated that there is a bright scope for cultivation of chrysanthemum under white colour low tunnel shade net with white plastic mulch.