Effect of Silicon and Nitrogen nutrition on major pest and disease intensity in low land rice

Nutrition management is one of the most important factors for enhancing yield, but it may affect the response of rice plants to pests and diseases due, in part, to the change of microclimate under the rice plant canopy. Therefore, knowledge of the relationship of nutrition management and pests and diseases is an important component in setting up a high yield production system. The pest and disease control procedures used by farmers can as also include soil fertility management since these nutrition practices can impact the physiological susceptibility of crop plants to pest and diseases by affecting plant resistance. Silicon content is particularly important in pest and disease reduction in rice and certain rice genotypes are more efficient accumulators of silicon than others making them more resistant. In the absence of natural heritable resistance in rice varieties, resistance can be induced by alternate strategies to suppress certain pest and pathogens. Hence experiments were carried out at Jabugam Farm, Anand Agricultural University Anand Gujarat (India). Treatments were arranged in a factorial randomized block design with the silicon factor at four levels (0, 200, 400 and 600 kg ha-1), four levels of nitrogen (0, 75, 100, and 125 kg ha-1), and with three replicates. Indian improved and high –yielding rice variety, GR-13, was used. The overall yield ranged from 4991 to 6439 kg ha-1 with a mean of 5936 kg ha-1. The plots which did not receive any fertilizer, that is, (N0 + Si0) exhibited the highest pest incidence (dead hearts, leaf folder and stem borer) and disease incidence (leaf blight, brown spot and grain discoloration) compared to other treatments which received both N and Si.   Key words: Nutrition management, conventional rice, silicon, yield, pest and diseases.