Study Of Influences From Lutaion On Rice Basal Sheath In Controlling Rhizoctonia Solani

According to recent statistic, Rhizoctonia solani is one of the severest diseases on rice and become the main blockade in increasing rice yield. While those used control measures have various deficiencies which make them inadequate to control the disease effectively. Rice-Duck Coexisting Ecosystem (RDCE) have been introduced to synthetically control diseases, pesticides and weeds in paddy as a efficient and safety ecomodel, while there haven't a integral theory built to elucidate its functional mechanism. This research based on the phenomena that the duck movements in paddy lute the basal sheath, and was conducted to illuminate how the phenomenon works in controlling the disease. The results show that:1. Morbidity rates and disease indexes in maturation period from treatments of simulated mud lutation, chemical treatments and blank control. The morbidity was controlled within 16.9%, with no significant difference with chemical treatment 16.6%, and significant lower than the blank control 41.3%; the disease index from lutation treatment was 16.65, significant lower than blank control 61.90%, and similar with the chemical treatment 14.92%.2. Lutation treatment effectively stimulated the catalytic activities of PAL and POD, and the peaks could reach 332 U·mg-1·min-1 and 55 U·mg-1·min-1 during the whole growth period, both were higher than control blank 220 U·mg-1·min-1 and 24 U·mg-1·min-1, and close to chemical treatment 330 U·mg-1·min-1 and 58U·mg-1·min-1; no significant differences were shown on PPO and Chitinase.3. Control efficiencies of lutations vary with the treatments at different morbid phrases. The disease infection was efficiently controlled when the lutation was conducted before the pathogen inoculation, and the disease index was restrained within 22 during the morbid fastigium. Disease indexes were restrained respectively within 31 and 36 when the lutations were conducted at pathogen contact phase and infection phase, with the significant lower control efficiency compared with the first one. Disease indexes reached to 55.11 and 71.77 when the lutation were conducted at pathogen proliferation and control blank, and the data shows the weakest controlling power from the treatment at pathogen proliferation.