A model for annual plant growth which takes account of mutual shading of leaves has been developed. By using the gradient method, optimal allocation pattern of photosynthates between vegetative and reproductive parts has been calculated. The optimal pattern is to allocate at first all photos. nthates to vegetative parls( 1st period), and then to both vegetative and reproductive parts (2nd period), and at last all to reproductive parts (3rd period). This pattern differs from those published before in which a...