Effects Of Water Deficit At Different Growing Stage On Growth And Development Characteristics Of Potted Cotton

By imposing three degree of water deficit which is referring to the natural evaporation 100%, 60% and 40% in potted cotton seeding and bud stage, flowering stage to investigate the effect of water deficit at different growing stages on growth and development characteristics of regular cotton Huamian3109 in different sowing time. The main conclusions are listed as follows:1. Water deficit affects the growth of cotton plants seriously, all the treatment groups of stem diameter and plant height show a trend of growth slowing with the deepening of the degree of stress. Compensatory effects occur in all treatment after rewatering. After mild water deficit, the plant was mainly to increase stem diameter with the moderate water deficit mainly to increase plant height. In the same growing period, with the increase of the degree of water deficit, the compensatory growth of stem diameter is delayed and enhanced, meanwhile the compensatory growth of plant height is advanced and enhanced.2. The water deficit will increase the SPAD value with the influence of the concentration effect, but the leaf area will decrease while the number of leaves growth slow or stop. The treatment of seeding and bud stage increase fruit branches and fruit nodes after re-watering. The treatment of flowering stage increase the plant height, leaf and branch number after re-watering.3.The treatments of seeding and bud stage show that the fiber length and the uniformity index appeared to increase with the water deficit. The treatments of flowering stage show that the fiber length, uniformity index, specific breaking and elongation decreased with the increase of water deficit. The micronaire value decreased with mild water deficit, increased with moderate water deficit.4. With the increase of water deficit, the dry matter quality of cotton root was decreased. In addition to the moderate deficit treatment of seeding and bud stage in the second sowing time, the dry matter quality of reproductive organs showed an increasing trend. Compared with the control group, the dry stem matter in each treatment, in addition to the treatment of first sowing time and the seeding and bud stage of second sowing time, was increased was increased. Compared with the control group, each treatment in addition to the first treatment and the mild deficit treatment of seeding and bud stage was increased in dry matter of leaf. Water deficit resulted in a decrease in yield and mild water deficit of flowering stage increase lint percentage and boll weight, water deficit of seeding and bud stage can reduce lint percentage and increase boll weight.5. With the increase of water deficit, yield and mature boll number reduce, abscission rate of treatments of seeding and bud stage is less than flowering stage. In the first seeding time, water deficit cause the decreased of shedding rate, the number of shedding and the rate of the inner circumference, the increased of boll setting ratio in the treatment of seeding and bud stage.