Study The Cultivation Technique For High Yield Of Mid-season Rice In Jingzhou

Jianghan Plain, located in south-central of Hubei province, is an important production area of middle rice. The unit yield and total output here occupy a pivotal position in Hubei Province as well as the whole country. Over the past decade, despite the relatively faster promotion of high-yielding hybrid rice cultivars, the average unit yield of rice in Jianghan Plain wandered between7000-7780kg/hm2. The yield potential of most hybrid rice cultivars has not been fully explored. Except the improper cultivar, the abnormal climate and other natural factors in some places, the not complete cultivation techniques, not suitable sowing date, degradation of fertilization techniques and extensive water management are the main reasons accounting for it. In view of this, a comprehensive experiment including direct seeding, transplanting, single-factor test and multi-factor test was conducted in Jingzhou, the hinterland of Jianghan Plain. The cultivars are high-quality rice cultivars (lines) Feng-liang-you-xiang1, Teqin and its near-isogenic lines, Lemont and its near-isogenic lines. The effect of different cultural factors on the growth process, agronomic traits and yield components of middle rice was analyzed. And combining with the actual production situation, the comprehensive cultural technology programs suitable for middle rice cultivars (lines) planted in Jingzhou was summed. Some conclusions were made as below:(1) The influence of sowing date, basic seedling number, nitrogen rate and water consumption on the the whole growth duration of Feng-Liang-You-Xiang-1are extremely significant (F=148>F0.01), significant (F=28>F0.05), not significant, not significant respectively. Sowing date and the whole growth duration show a significant negative linear correlation (R=0.9944*).And basic seedling number and the whole growth duration show a negative linear correlation (R=0.9643).(2) The influence of sowing date, basic seedling number, nitrogen rate and water consumption on effective panicles of Feng-Liang-You-Xiang-1are extremely significant (F=50.52>F0.01), significant(F=20.13>F0.05), not significant and not significant separately. Sowing date effects spikes panicle-1significantly (F=357.62>F0.05). The influence of other cultivation factors on spikes panicle-1do not reach a significant level. And the four cultivation factors’influence on seed setting rate and1000-grain weight doesn’t reach a significant level.(3)Sowingdate and basic seedling number effect the yield of Feng-Liang-You-Xiang-1significantly(F=62.81>F0.05,F=20.59>F0.05),nitrogen rate effects it extremely significantly (F=127.35>F0.01), and water consumption doesn’t effect it significantly.(4) Among the9treatments, the yield of treatment5(sowing date-May1, basic seedling number-480,00plants/hm2, nitrogen rate-300kg/hm2, water consumption-just covering the soil surface) was the highest, and cultivation combination of the four factors of treatment5was the best. (5)The influence of seeding rate on the whole growth duration of Feng-Liang-You-Xiang-1is significant (F=5.27>F0.05). And the formula is y=-0.0012x2+0.0538x+119.14(y represents the whole growth duration, x represents seeding rate, R2=0.9432*)(6) An extremely significant positive linear correlation was observed between seeding rate and effective panicles (R=0.9897**). The formula of the relationship between seeding rate and seed setting rate is y=-0.0137x2+0.8753x+76.959,(y represents seed setting rate, x represents seeding rate,(R2=0.9239*). Seeding rate and spikes panicle-1show an extremely significant negative linear correlation (R=0.9906**). And between seeding rate and1000-grain weight, there is also a extremely significant negative linear correlation (R=0.9893**).(7) The influence of seeding rate on the yield of Feng-Liang-You-Xiang-1is extremely significant (F=9.45>F0.01), and the formula is y=-2.4712x2+193.6x+7690.1(y represents yield, x represens seeding rate, R2=0.7324). The yield of treatment A3is the highest, while it is of the lowest to treatment A6.(8) The formula of the relationship between seeding rate and the relative economic output of Feng-Liang-You-Xiang-1is y=-6.4275x2+453.35x+15644(y represents the relative economic output, x represents seeding rate, R2=0.8397). The highest and the lowest relative economic output is that of treatment A3and treatment A6, respectively.(9) Planting density effects the whole growth duration of TQ, NIL1, Lemont and NIL2extremely significantly (F=22.80>F0.01). They show a positive linear correlation (y=0.0517x+126.11, R=0.9737). And varieties (lines) effect the whole growth duration extremely significantly, too (F=983.05>F0.01).(10) The tillering ability of TQ is the strongest, next Lemont, then NIL2, and the tillering ability of NIL1is the weakest. Planting density and the final tillering number of TQ, NIL1, Lemont, NIL2show negative linear correlations(R=0.9826, R=0.9737, R=0.9831, R=0.8723, respectively).(11) A strong significant positive linear correlation was observed between planting density and the effective panicles of TQ, NIL1, Lemont, and NIL2(R=0.9999**). But planting density and spike panicle-1, seed setting rate, and1000-grain weight all show a negative linear correlation(R=0.9738), R=0.9150, R=0.9845, respectively)(12) Planting density effects the yield of TQ, NIL1, Lemont and NIL2significantly (F=12.62>F0.05), and it shows a positive linear correlation between them(R=0.9552). The influence of varieties (lines) on yield is extremely significant (F=130.05>F0.01). Among the4varieties (lines), the yield of NIL1is the highest, next TQ, and the yield of NIL2is the lowest.