Abstract:
To study the effect of different forms and levels of phosphorus on the growth, yield and composition of three high yielding varieties of rice, a pot culture experiment was carried out in the Agricultural College and Research Institute, Vellayani, in a randomised block design with 39 treatments and 3 replications. The different forms of phosphorus used were superphosphate, ultrafos, defluorinated rock phosphate and Thomas phosphate. The levels of application were 0,25, 50 and 75 kg P2O5/ha. The rice varieties studied were Culture 28, IR 8 and Taichung Naive 1. The main findings of the experiment are summarised below: 1) The height of plants was a maximum for IR 8. This growth character was not influenced by the form of phosphorus used, but it increased significantly with increase in the rate of phosphorus application, 2) In the matter of tillers, Taichung Native 1 was superior to IR8 and Culture 28. Of the different forms of phosphorus applied, superphosphate and deflurinated rock phosphate produced the maximum number of tillers. As regards the effect of level, the number of tillers increased with increase in the level of phosphorus application.
