ÃÞ »¨ ѧ ±¨ Cotton Science 2009£¬21(2)£º115-120
Effects of Nitrogen Rates on Dry Matter Accumulation and Distribution of Bolls and Fiber Quality Characteristics in Cotton Abstract: To investigated the effects of nitrogen rates on dry matter accumulation and distribution of bolls and fiber quality characteristics,field experiments were conducted in Nanjing (middle lower reaches of Yangtze River Valley) and Xuzhou (Yellow River Valley).The three N rates is 0,240 and 480 kg¡¤hm-2, standing for low,optimum and high nitrogen application level, respectively.The results showed that the effect degree of nitrogen rates on fiber was higher than that on seed or fiber.The decrease in seed/fiber ratio came from an allometric growth between seed and fiber,which could be expressed by the following equation: y=a+bx(x is the natural logarithm of cottonseed and y is the natural logarithm of fiber dry weight per boll,a is intercept and b is regression coefficient for the linear equation)."b" of the cotton bolls bloomed on Jul 25 was significantly declined under low-nitrogen or high-nitrogen treatment,fiber strength also decreased correspondingly. "b" of the cotton bolls bloomed on Sep 10 has a little difference between high-nitrogen treatment and medium-nitrogen treatment,but significantly higher than low-nitrogen treatment,and the indices of fiber length,strength and uniformity showed similar trends too.All the results indicated that the larger "b" is,the more favorable to form high fiber quality.
|