棉花生长发育与产量潜力的模拟

SIMULATION ON GROWTH AND POTENTIAL YIELD OF COTTON CROP

根据1989年高产栽培试验结果,修改作物生产潜力模拟模型L1D的作物参数,用于棉花生长与潜在产量的模拟。结果表明,用该模型模拟1988与1989年棉花总干物重、总叶重及叶面积系数,模拟值与实测值接近且趋势一致;皮棉产量的模拟值与实际值也较吻合,能反映气候生产力的差异,证明L1D模型在棉花生长和潜在产量模拟中的有效性。

The L1D model developed by Penning de Vries was adapted with some parameters re- placed by cotton's to simulate growth and potential yield of cotton crop. The replaced parame- ters were adjusted to fit the experiment data on cotton variety Zhongmian 12 collected in 1989 season, including (1) DRCV, DRCR, DRVTT and DRRTT relevant to cotton growth and development; (2) PLMTT, PLETT and PLMX related to photosynthesis; (3) CALVT, CASTT and CASST concerned with partitioning of carbohydrates; (4) LLVT and LRTT linked with senescence of leave and roots; and (5) WSD, WPC and RLW added to initialize the modified model. In addition, flowering stage was defined as DS equal to 1.0, boll opening as DS equal to 1.6 and completed development as DS equal to 2.0. It was also defined that the cotton stops growth at a temperature below 0℃. The output of the adapted model was compared with data observed in 1988 and 1989 sea- sons. The modified model simulated the trend of the total dry matter weight, leaf weight and leaf area index, especially for cotton planted before April 20th. It underestimated those param- eters above-mentioned for cotton planted after April 25, possibly because of the higher plant density. Lint yield was also consistent with that produced by model in 1989, but it was overes- timated in 1988, which could be attributed to the cloudy weather and frequent rainfall prevail- ing in July and August in that year. Except for the development stages, the partitioning of carbohydrate was also affected by the density, microclimatic environment, and shedding of squares--bolls etc. which have not been taken into consideration in the adapted model. Some more parameters should be further modified to make the L1D model more applicable for cotton crop, as the characteristics of growth and development of cotton are quite different from those of rice, wheat or corn.