Abstract: In order to reveal characteristics of source and sink,source2sink relationship,and the effect of source and sink on grain yield,find out the restrictive factors of grain yield,a study was conducted with three hybrids (Jingdan28, Zhengdan958,Nongda108) in four plant density (4. 5 × 10plant/ ha,6. 0 × 10plant/ ha,9. 0 × 10plant/ ha) under lim2 ited light and heat conditions. The results showed that the population total leaves area and the dry matter production ca2 pacity increased with the increase of plant density,but the population total leaves area decreased rapidlyfrom 30th day af2 ter silking under high density condition ( 9. 0 × 10plant/ ha). Increasing the plant density was an effective approach to increase the total leaves area and grain yield by decreasing the leaves senescence from 30th days after silking and increas2 ing the dry matter production capacity. The grain numbers per ear and grain weight decreased with the density increased, while the ear numbers,grain numbers per ear and the maximum potential sink capacity per unit area increased and was 16.7 % - 103 %,4. 7 % - 87 % and 8. 4 % - 73 % higher of the high density (9. 0 × 10plant/ ha) than those of the other treatments respectively. Increasing the plant density was an effective to obtain a larger sink capacity and higher grain yield. The sink2source ratio decreased gradually with the plant density increased. Under high plant density,both source and sink had effect on the formation of grain yield,but sink was the major restrictive factor. Increasing planting density with enlarging sink capacity and strengthening source was the key approach to obtain high grain yield of summer maize in Hebei Province.

Key words: Summer2maize( Zea mays L. ), Sink2source relationship, Planting density, Grain yield

CLC Number: 

• S14