Evaluation method of leaf blade porosity in different growth periods of crops

The invention relates to an evaluation method of leaf blade porosity in different growth periods of crops. The method is characterized in that an area which is encircled by four strains of crops arrayed in certain row spaces and strain spaces is selected as a calculated area of the colony leaf blade porosity of community according to the characteristic of the crop community; crop leaf blades are abstracted into a shape similar to the leaf blade according to the shape characteristic of the crop leaf blade and corresponding abstraction simplification on the community plants is carried out simultaneously; the leaf blade porosity along a plant direction is determined according to a requirement to calculate a cross section, i.e., different position heights of the community plants, and a first layer, a second layer, a third layer, a fourth layer or more layers and the like are respectively marked from the tops of the crop plants to the bottoms of the crop plants; by calculating overlapping parts of the leaf blade area projected to all layers, the leaf blade porosity of each of the layers is further evaluated, so that the leaf blade porosity of the community plants in different positions can be obtained. According to the evaluation method disclosed by the invention, by evaluating the leaf blade porosity of the community plants, a reference can be provided for choosing pesticide application spray parameters in different growth periods of the crops, so that the effective utilization rate of the pesticides is improved, and the pollution of pesticides to the ecological environment is reduced.