Table of Content

10 August 1992, Volume 13 Issue 04

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THE MODEL OF WEIGHTED MULTIPLE REGRESSION FOR YIELD PREDICTION

Tang Zhicheng Sun Han(Meteorological Institute of Jiangsu Province)

1992, 13(04):  24-28. 

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According to the relationship between agronomical characteristics and yield formation, for two kinds of multiple regression models (i. e. successive addition and multiplication), the weighted coefficient of each stage having influnce on yield was respectively given out, based on which and the fitting accuracy of submodel of each stage, two kinds of improved multiple regression modles were established, with elimination of the weakness of general multiple model.

A STUDY ON RELATIONSHIPS BETWEEN THE CONDITIONS OF SUN-LIGHT, TEMPERATURE AND ACCUMULATION OF DRY-MATTER AND GRAIN WEIGHT OF WINTER-WHEAT

Liu Donghai Cheng Liyong Huo Shirong(Xizang Institute of Agricultural Sciences)

1992, 13(04):  40550-405. 

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Through covering sun-light made the light intensity, temperature (the highest, the lowest temperature, diurnal range and ground temperature), and humidity changing, dry-matter, grain weight, stem and leaf were also changed. Therefor, this paper analysed the effects of sun-light and temperature on accumulation of dry-matter. The results are as follows: With increasing of intensity of sun-light the accumulation of dry-matter increased, the relations between them are linearlly positive; The increase of temperature could make the photosynthetic intensity increasing. When the temperature was above 21℃, the photosynthetic intensity sharply decreased; the size of diurnal range was no certain relation with accumulation of dry-matter; The relations among ground temperature and dry- matter above ground, accumulation of grain weight were obviously positive. The more the humidity increased, the more the grain weight decreased, the relations between them were linearlly negative.

EFFECT OF SOIL MOISTURE ON PHOTOSYNTHETIC RATE OF WINTER WHEAT

Du Baohua Lu Xuedu(Institute of Agrometcorology Chinese Academy of Agricultural Sciences)

1992, 13(04):  40766-407. 

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This paper describes the response of the photosynthetic rate of winter wheat on soil moisture according to the experiment in pot and field during the flowering and filling stage. The results are as follows. 1. Optimal soil moisture for leaf's photosynthetic rate is 70%-80% of field capacity, and the photosynthetic rate is more sensitive to low soil moisture than to high soil moisture. 2. Soil drought strengthens the Photosynthetic Midday Rest, and irrigation can relieve it. 3. The photosynthetic rate increases significantly when watered after soil drought, and watering at the low limit of optimal soil moisture is most effective for the photosynthetic rate.