Study Of Cotton Canopy Structure On Photosynthesis Characters And Yield Traints

Using hybrid cotton shuofeng 2 as the research material, controlling method and installment in multi-topping combination to shape dwarf type(L)、wave type(W)and high type(H) three different canopy structure, high line(WH) and dwarf line(WL) to construct the wavy canopy structure. Through the study of optical radiation within the canopy transmission characteristics, photosynthetic characteristics, light energy utilization, the accumulation of vegetative organs and reproductive organs in different levels, boll rot and fall off, yield components, etc., revealing the relationship of the optical radiation field vertical distribution and population photosynthesis with dry matter production and distribution and correlation, provides guidance for cotton high yield and good quality cultivation. The main results are as follows:1. W canopy of WL is same with L canopy in plant height, is 90-100 cm, WH is same with H canopy in plant height, 120-130 cm. In the middle of the stage, the buds and bulls of L canopy is the most. In the late of stage, H canopy is the most. Three kinds of canopy structure of stem diameter in the early stage differed, but gradually converge to birth in later period. Boll rot rate of L canopy is the most, H canopy is the least. Within a certain range, W canopy reduce the boll rot rate and fall off rate.2. The LAI of H is maximum, W canopy take second place and L canopy is minimum. In wadding stages L canopy LAI decreased significantly, W and H remained higher canopy LAI; W canopy light transmittance of the middle lower fertility is obviously higher than that of L and H canopy; extinction coefficient shows L>W>H. W canopy is kept high LAI and appropriate extinction coefficient, at the same time the lower light conditions improved.3. The photosynthetic potential of H canopy is maximum, W canopy take second place, L canopy is minimum; The net assimilation rate and crop growth rate of W canopy are higher than L and H. W canopy improves the utilization rate of light energy. In terms of population photosynthetic rate, W and H canopy slightly higher than L canopy.4. The accumulation status of L canopy in the upper vegetative organs and reproductive organs is less, that of H canopy in lower status is less, W canopy at different levels in general is in the center of the state; the total dry matter accumulation and the accumulation of reproductive organs of W canopy shows the highest, the accumulation of vegetative organs of H canopy is highest; the reproductive organ allocation proportion is shown as: W>H>L, the nutritional organ allocation proportion is shown as: H>W>L. The dry matter accumulation of W canopy at different levels is relatively uniform, W canopy coordinates the relationship between the vegetative and reproductive growth.5. The lint and boll number per of three kinds of canopy structure does not appears obviously difference, the single boll weight of W canopy is about 8% higher than L and H canopy, in the same lint and total number, W canopy through increasing single boll weight is helpful to getting higher yield. In 2013 seed cotton yield of W canopy is the highest. In terms of the quality of fiber does not appear obviously different.