Variety Screening And Supporting Technology Of High Quality Late Rice With Early Planting Model

Jiangxi Province is one of the important production areas of double cropping rice in China.Stabilizing the planting area of double cropping rice plays a key role in ensuring the stable supply of rice and food security.The short growth cycle of early rice and the existence of high and low temperature stress environment lead to poor quality,poor taste and low production efficiency of rice,which restricts the production area of early rice.In view of the lack of suitable varieties in the promotion and application of the cultivation mode of’high-quality late rice early planting’proposed by the research team in the early stage,the tension between the early and late seasons,the poor quality of early rice,and the low rate of whole milled rice of ratooning rice,this study carried out the screening test of suitable varieties,explored the optimal cultivation measures and fertilizer dosage,and clarified the changes of yield and quality under different cultivation measures and fertilizer conditions,so as to provide the basis for the large-scale promotion and application of’high-quality late rice early planting’mode.The main results are as follows:1.Screening of rice varieties suitable for’high quality late rice as early planting’mode(1)Five early-maturing varieties of high-quality late rice suitable for the cultivation mode of’high-quality late rice early planting-continuous planting’were selected,namely Jinggang Ruanzhan,Taiyou 398,Wanxiangyou 337,Taoyou Xiangzhan and Wuxiangyou398.(2)Four mid-maturing varieties of high-quality late rice suitable for the cultivation mode of’high-quality late rice early planting+regeneration’were selected,which were Wanxiangyou 982,Yexiangyou Liangzhan,Yexiangyouhang 1573 and Longxingliangyou Liangzhan.2.Research on key supporting technologies of’high quality late as rice early planting’mode(1)In the’high quality late rice early planting-continuous planting’model,increasing the amount of seeds appropriately shortened the growth period of early rice,promoted early maturity,and optimized yield and quality.Compared with 45.0 kg/hm~2,the growth period of early rice was shortened by 3 days,the yield was increased by 5.28%,and the chalky grain rate and chalkiness degree were significantly decreased by 4.66%and 2.49%when the seed amount of Jinggang Ruanzhan was increased to 67.5 kg/hm~2.When the seed rate was 90.0 kg/hm~2,the growth period was shortened by 4 days.(2)Under the mode of’early planting-continuous planting of high quality late rice’,appropriate spraying of foliar fertilizer and flower fertilizer can improve rice yield,optimize quality,and achieve yield increase and efficiency increase.Taking Jinggang Ruanzhan as the test material,when spraying foliar fertilizer at 6.0 kg/hm~2,the yield and quality were significantly improved compared with no spraying,in which the yield increased by 12.27%,the chalky grain rate and chalkiness decreased by 8.36%and4.11%.Taking Qiliangyou Liangzhan and Taifengyou Liangcui as experimental materials,when the foliar fertilizer was 3.0 kg/hm~2,the comprehensive quality of rice was better than 6.0 kg/hm~2,and the effect of foliar fertilizer on the quality of primary branch rice was greater than that of secondary branch.Spraying flower-protecting fertilizer can significantly increase the panicle length,total grain number per panicle and head milled rice rate of early rice,thus improving the quality of early rice.(3)Under the mode of’early planting+regeneration of high-quality late rice’,spraying aroma-enhancing substances can increase the aroma of rice and improve the quality of the first season rice.Taking Meixiangzhan 2 as the test material,spraying South China aroma enhancer,potassium dihydrogen phosphate and sodium chloride can improve the aroma value,and the effect of spraying once is obviously better than that of spraying twice.(4)Under the mode of’early planting+regeneration of high-quality late rice’,the height of stubble affected the yield and quality of rice.Compared with high stubble,the head rice rate of low stubble ratooning rice increased by 2.54%,the chalky grain rate and chalkiness decreased by 4.35%and 1.58%,respectively.There were significant differences in the response of different varieties to the height of stubble.Runyou Liangzhan,Shangliangyou Liangzhan,Pu S/Liangying,Gannongxiangsimiao 3,Zaofengyou Liangying and Shengxiangyou Liangying had high yield of ratoon rice under high stubble,while other varieties were the opposite.The appropriate height of stubble should be selected according to the characteristics of different varieties.