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Sun J.,Yangzhou University | Sun J.,Henan Academy of Agricultural science | Zhang H.,Yangzhou University | Wang S.,Henan Academy of Agricultural science | And 12 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

The objective of the study was to explore the effects of seeding date and variety on the growth characteristics of mechanical transplanted rice in the rice-wheat cropping system in the rice area of southern Henan. Taking 5 rice varieties i.e. conventional medium-maturing medium japonica rice variety, conventional and hybrid late-maturing medium japonica rice varieties, conventional early-maturing late japonica rice variety and hybrid late-maturing medium indica rice variety as experimental materials, sowing experiments were carried out. The effects of different seeding dates on grain yield and yield components, number of stems and tillers, dry matter weight and population growth rate of mechanical planted rice were comparatively analyzed. The results showed that: 1) Within the set range of seeding date in the experiment, average yield of mechanical planted rice showed very significant difference among different sowing dates and varieties (P<0.01), but no significant difference between different years. This was particularly evident for the yield of hybrid late-maturing medium japonica rice variety (10.44 t/hm2) that was 9.20%-17.53% higher than the other 4 varieties (P<0.01). The output of conventional medium-maturing medium japonica rice variety was the highest in the second sowing period (on May 16) and subsequently showed a gradual decrease. The yields of other rice varieties were all the highest in the first seeding period (on May 11), and showed a trend of gradual decline with the delayed seeding date (P<0.01), but the decrease amplitudes were different among different rice varieties and sites. 2) In different yield components of mechanical planted rice, the difference of seed setting rate was not significant between the years but very significant for different sowing dates and varieties, while the differences of other yield components were all very significant for different years, sowing dates and varieties (P<0.01). The seed setting rate of conventional medium-maturing medium japonica rice variety slowly increased at first and then decreased significantly since the second sowing data, but the yield components of other rice varieties such as panicle number, number of spikelets per panicle, total spikelets, seed setting rate, 1000-grain weight all showed a significant (P<0.05) or extremely significant (P<0.01) declining trend. Different seeding dates had a significant influence on number of spikelets per panicle and seed setting rate, but less significant influence on 1000-grain weight and panicle number. Correlation analysis showed that the effects of yield components on the yield from high to low were as follows: number of spikelets per panicle > seed setting rate > panicle number > 1000-grain weight, and grain yield showed significant or extremely significant positive correlation with number of spikelets per panicle, total spikelets and seed setting rate, but showed negative correlation with panicle number and 1000-grain weight. Total spikelets showed an extremely significant positive correlation with number of spikelets per panicle, but showed a negative correlation with panicle number. Further path analysis showed that the rate of contribution to rice yield was total spikelets > seed setting rate > 1000-grain weight, and the rate of contribution to total spikelets was number of spikelets per panicle > panicle number. 3) With the delaying of seeding date, the number of stems and tillers showed an obvious increase at jointing stage and decreased at heading and maturity stage. Dry matter weight per stem and population, and population growth rate showed a gradual decline at jointing, heading and maturity stage depending on different rice varieties and seeding dates, but spike rate and harvest index had significant difference between rice varieties and seeding dates. Overall considering high yield and growth safety for mechanical transplanted rice, the preferred choice should be hybrid late-maturing medium indica rice variety for southern Henan, and the suitable seeding date may be delayed to May 25. The results will provide a reference for the high-yield and efficient production of different rice varieties under mechanical planting and for the choice of best possible varieties in southern Henan Province. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved. Source


Sun J.,Yangzhou University | Sun J.,Henan Academy of Agricultural science | Zhang H.,Yangzhou University | Yin H.,Henan Academy of Agricultural science | And 10 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

This study was conducted to investigate the effects of seeding date and variety type on yield, growth period and utilization of temperature and sunshine under the rice-wheat cropping system in different ecological regions of Henan Province. Taking conventional medium-maturing medium Japonica rice variety, conventional and hybrid late-maturing medium Japonica rice varieties, conventional early-maturing late Japonica rice variety and hybrid late-maturing medium indica rice variety as experimental materials, high-yield cultivation method of mechanization planting of carpet seedlings was used in three different sites, i.e. Luoshan rice-growing district along the Huai River in,southern Henan Province, Xincai in central Henan Province and Yuanyang rice-growing district along the Yellow River in northern Henan Province. The effects of different seeding dates on yield, growth period and utilization of temperature and sunshine of mechanized planting rice were comparatively analyzed. Within the set range of seeding date in the experiment, except that the yields of conventional medium-maturing medium Japonica rice variety were highest for Luoshan and Xincai in the second sowing period (On May 16) and for Yuanyang in the first sowing period (On May 11), the yields of conventional and hybrid late-maturing medium Japonica rice varieties, conventional early-maturing late Japonica rice variety and hybrid late-maturing medium indica rice variety were all highest in the first seeding period (On May 11) for every site, and it showed a trend of gradual decline along with the seeding date delaying(P<0.01), but significance differences were all different among different variety types and sites. With the delaying of seeding date, yield differences among variety types gradually increased in the same site(P<0.01), of which grain yield of hybrid late-maturing medium Japonica rice variety was the highest in every site, and was significantly higher than other variety types in each period. With the delaying of seeding date, the periods of jointing, heading and maturity of all varieties were correspondingly delayed, and whole growth period, and its accumulated temperature, sunshine hours and utilization rate of TPS all showed a significant decreasing trend (P<0.01). And the reduction of growth period along with the delaying of seeding date, was mainly in vegetative growth phase, i.e. from seeding to jointing stages. Therefore, under the condition of rice-wheat cropping system with mechanical planting in Henan Province, the preferred variety that was firstly chosen should be hybird and conventional late-maturing medium Japonica rice varieties in southern Henan, and the variety that was secondly chosen should be conventional early-maturing late Japonica rice variety, and their suitable seeding dates were all from May 11 to May 25. In the northern Henan, the preferred varieties should be the conventional late-maturing medium Japonica rice variety and medium-maturing medium Japonica rice variety, followed by conventional late-maturing medium Japonica rice variety, and their suitable seeding dates were all from May 11 to May 21. The result will provide a reference for the scientific division and the distribution of different rice variety types under mechanical high-yield cultivation and the choosing of its possible seeding date in different ecological areas in Henan Province. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved. Source

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