Studies On Agronomic Traits Of Direct-seeding Rice, Preparation And Application Effect Of Special Pelleting Agent

Rice direct-seeding cultivation is an integrated technology which gathers fewerworkers, lees effort, high efficient and simple operation. It develops quickly from allparts of the world in recent years. One of the restriction factors for its development isthat direct-seeding rice is difficult to emerge. Through split plot design, the effects ofdirect-seeding rice on agronomic traits, yield components were investigated. Thespecial pelleting agent recipe was optimized by the orthogonal test in six factors andfive levels. The effects of this pelleting agent on seed germination, seedlingemergence and establishment, seedlings qualities, physiological characters and yieldswere studied through in laboratory and field experiments. The main results were asfollows:1 There were higher yields under direct-seeding than transplantation, thedifferences were significant. The main reasons for the yields increasing underdirect-seeding cultivation were due to more effective panicle numbers, higher seedsetting rate and 1000-grain weight. Among yield components, the effective paniclenumbers had the biggest effect on the yield.2 The growth duration, plant height, tiller numbers and leaf area were alsoinfluenced under direct-seeding cultivation. The growth period of nutrition was aheadof time and shortened, the whole growth duration was shortened also. The plantheight was reduced, the leaf area increased.3 The orthogonal test results showed that the agricultural tombarthite exerted alargest influence on the seed vigor index, alter it are borax, S3307, CuSO₄ and CaCl₂,the function of ZnSO₄ is minimum. The No. 8 (A2B3C4DSE1F2) seed vigor indexwas highest among 25 pieces of recipes.4 The seeds germination experiment showed that pelleting agent did not reduce thegermination percentage of the hybrid rice seeds; it was safe for seeds germination.5 The pelleting agent could effectively reduce seedling height, promote root system growing and dry matter accumulating. It also made bigger root-shoot ratio. Celest alsoincreased the dry weight but it mainly made the shoot to grow, the function to the rootsystem was little.6 The pelleting agent increased the cold-resistant ability of seedlings. The effects onchlorophyll content, peroxidase (POD) activity, root system vigor and free proline contentin seedlings were significant. There were less rolling leaves and less water deficit in thelow temperature stress than Celest and CK. The functions of Celest were better than CK.7 The field experiment indicated that pelleting agent could accelerate the emergenceof direct-seeding rice, increase the tiller numbers and dry matter accumulation. It alsoprevented the thrips oryzea effectively. It improved the overall qualities of the seedlings,established the foundation for obtaining high yields. The effective panicle numbers wereobviously increased and the yields were enhanced finally.