Effects of varying nutrition levels (NPK) on growth, yield and quality of two hybrid rice (Oryza sativa L.) varieties

Rice is the most important and delicious food crop of the world. A crop production system with high yield targets cannot maintain unless balanced nutrient inputs are supplied to soil against nutrient removal by crops. So, mineral fertilizer inputs are one of the most important factors to intensive cropping system. The use of mineral fertilizer in suitable amounts is necessary to enhance agricultural production to an economically desirable level. In Pakistan, efforts should be made to increase low yield of rice per unit area to meet the food requirements of growing population. Among various factors, proper fertilizers dose can also increase yield of rice in Pakistan to the yield level of other rice growing countries of the world. Varieties also vary in their response for yield to different levels of fertilizers. Keeping above facts in view a field experiment was conducted during kharif season at the Research Area of Agronomy, University of Agriculture Faisalabad to determine an economically optimal and balanced dose of NPK for hybrid rice. Two hybrid rice varieties PHB71, Leader 555 were grown. Four treatments were used F1 N:P:K @ 108-80-48 kg per ha (20% less than recommended) F2= N:P:K @ 135-100-60 kg per ha (recommended) F3= N:P:K @162-120-72 kg per ha (20% more than recommended) F4= N:P:K @ 189-140-84 kg per ha (40% more than recommended). During the crop growth TDM was calculated. Maturity data regarding plant height, leaf area index, grain yield, straw yield, harvest index. 1000-grain weight and quality characteristics were also determined and analyzed statistically using standard procedures. The result of experiment showed that maximum leaf area index, grain yield, straw yield, harvest index, 1000-grain weight were observed in F3 (N: P: K @ 162-120-72) than all the other treatments. Hybrid V2 (Leader 555) produced more maximum leaf area index, grain yield, straw yield, harvest index, 1000-grain weight on overall variety mean basis, which was significantly higher when compared with V1 (PHB71).