Abstract:
Abstract: Mechanical transplanting of hybrid rice is a difficult problem in rice production mechanization. In order to solve this problem, a new mechanized transplanting method of coupling nursing seedling density and seedling fetching area for hybrid rice is proposed according to the agronomic requirements for mechanical transplanting technology of hybrid rice. The comparison tests of different coupling transplanting methods with different nursing seedling densities are arranged in Jiangmen City, Zhaoqing City and Shantou City of Guangdong Province from 2017 to 2018. The influence of coupling transplanting methods for transplanting quality, root damage rate and rooting ability are analyzed. Based on field production comparison tests, the yield and its characteristics of hybrid rice coupling transplanting with different nursing seedling densities are investigated. The results show that: 1) Under the existing technical conditions, the transplanting quality of coupling transplanting methods under different nursing seedling densities is good. The proportion of 1-3 plants per hole is between 80.67% and 95.33%, and the proportion of 1-4 plants per hole is more than 90.67%. The seed bed soil type is an important factor in seedlings and transplanting quality. When the nursing seedling density exceeds 50 g/tray, the missing plant rate is 3.50%-6.38%, with an average of 5.11%, which basically meets the agronomic requirements of hybrid rice mechanical transplanting. 2) The root damage rate of coupling transplanting with different nursing seedling densities is 15.37%-31.16%. When the nursing seedling density is higher than 40 g/tray, the root damage rate is increased with the increase of the nursing seedling density. There is a negative correlation between rooting ability and root damage rate, and the correlation coefficient is -0.949 3. When the difference of nursing seedling density is no more than 10 g/tray, there is no significant difference of rooting ability. When the difference of nursing seedling density is more than 20 g/tray, the difference of rooting ability reaches a significant level. 3) For the different coupling transplanting methods, the yield of 50 g/tray mechanized transplanting is the highest, the rules of yield of different coupling transplanting methods are as follows: 50 g/tray mechanized transplanting >transplanting by hand of pot seedling >60 g/tray mechanized transplanting >70 g/tray mechanized transplanting or 90 g/tray mechanized transplanting. It is found that the actual yield of different coupling transplanting methods did not reach the yield of variety zone test. The yield performance is that the panicle number per unite area and filled-grain percentage of mechanical coupling transplanting methods are less than that of variety zone test, but the panicle length is reached or slightly exceeded that of variety zone test. The research conclusions have important reference value to overcome the problem of hybrid rice mechanized transplanting.