Crown limitation and its causing interaction between crown and roots in sorghum

Analysising the relationship between root and crown by using different corwn limiting treatments for the same genotype, the result indicated that if only one leaf and no leaf remained in single plant according to leaf order, the limited photosynthesis production is distributed coordinately to roots, stems and ears, with only a little competition between ears and roots and two varieties showed the same trend. In the paper, if the amount of photosynthesis production accumlating in roots relected by root unit weight, the root unit weight and root activity varied with remained leaf of different leaf order, with marked negative correlation between root unit weiht and root activity. There is no basis to reflect root activity by using root weight. Root is a high activity sink organ is sorghum, and even no photosynthesis production supplied by crown, the root did not die at once, on the contrary, crown can be regenerated by root through the consumption of reserved production, and the root kept high activity.