A Research Of Machine-picked Cotton Growth And Yield Formation Under Different Row Space

【Objective】The objective of this experiment was to study on the effects of different row spacing on the cotton major agronomical characters, defoliation rate and boll opening rate, analyze the influence of row spacing changes on the machine picked cotton yield and fiber quality and investigate the mechanism of canopy structure characteristics and group photosynthetic production characteristics on machine picked cotton. reveal the physiological mechanism and cultivation pattern for machine picked cotton yield increasing. At the same time, account for the frost-free period is short, the heat resource is limited, and the climate characteristics of frequent natural disasters occurred in spring sowing period, the response mechanism of growth and development and photosynthetic production of cotton on sowing period under different row spacing and the rule of machine picked cotton yield formation with different sowing period is investigated., which has an important significance to establish and improve Xinjiang machine picked cotton comprehensive cultivation technique for high yield and fine quality system. 【Methods】Under field conditions, hybrid cotton Lumianyan 24 and conventional cotton Jinmian 993 was used as material, t three kinds of configuration model: a film of three lines(76cm line spacing), a film of four lines(64+12cm spacing, the average spacing 57cm), a film of six lines(66+10cm spacing, the average spacing 38cm)is employed., photosynthetic active radiation interception rate(FIPAR), canopy structure index, chlorophyll relative content(SPAD value), leaf net photosynthetic rate(Pn) and the change of photosynthetic rate of accumulation and distribution of photosynthetic matter is measured under different row spacing. In addition, we set normal sowing and late sowing(compared to the normal sowing date pushed back 24 days), and based on this cotton growth and development process and the processing characteristics of dry matter accumulation and distribution and yield constitute is investigated. 【Result】The results show that, cotton population density is increasing and plant height, boll number decreased significantly, average branch length of conventional cotton has a tendency to decrease, however, there was no significant in hybrid cotton; the defoliation rate of hybrid and conventional cotton were the highest under equal row spacing condition, boll opening rate have no significant differences; the change of row spacing has an obvious influence on cotton yield factors, single boll weight showed a decreasing trend accompanying the decrease of the row spacing; the number of the boll has a rising trend but the performance is not significant in hybrid cotton, the highest yield of hybrid cotton is under equal row spacing. Compared with the other row spacing, equal row spacing of hybrid cotton Lumianyan 24 in key growth period has a higher radiation interception rate and leaf area index, and larger photosynthesis area, and its leakage loss is small, which ensure a higher group photosynthetic rate, the degradation of chlorophyll is slowly and net photosynthetic rate is fast, photosynthetic rate, photosynthetic function and the photosynthetic material fast accumulation period(T3) duration is long in the late growth stage, peak velocity(Vm) and high accumulation,photosynthetic matter accumulation of activephase(P) long, photosynthesis and dry matter accumulation of large amounts. Hybrid cotton with equal row spacing can hold high boll number and have the highest single boll weight and yield under normal sowing date treatment; cotton early budding, boll opening late, extend the 15 ~ 20 days during the blooming period; Photosynthesis of cotton material fast accumulation phase rate decreased obviously, photosynthesis and dry matter accumulation amount keep low, single boll weight and total boll number per unit area decreased,yield decreased obviously. Among the different configuration,sowing time has a greater influence on hybrid cotton in harvest yield under equal spacing, delayed sowing, boll opening rate dropped 51.2% before harvest, boll opening rate is less than 50%. 【Conclusion】In the cotton field production practice in Xinjiang cotton machine, through the use of such as row spacing and planting hybrid cotton, full use of light and heat resources, play a good Hybrid Cotton Hetero-sis, can achieve the high yield and quality of cotton, achieve the goal of saving cost and increasing efficiency. Due to climate reasons caused the delay of sowing time, we should choose the conventional cotton growing into a wide narrow row configuration, increase of planting density, ensure the harvest yield, reduce disaster losses.