“Shanyou 63",the Veriety With the Largest Cultivated Area in China Ⅲ.the Photosynthetic Characteristics and Solar Energy Utilization Efficiency

The cultivated ar ea of“Shany ou63"has been kept the first in China since 1986.The average cultivated area one year is 4.67 million hectare,about 22%of the area of indica zone in China and particularly 27.1% in 1990.The cult ivated area of shanyou 63 also reached 4.47 million hectare in 1996,nearly 4-5 t imes that o f the seco ndar y one fo r the past 11 years.It is cultivated all over the indica cultiv ated zone from 17°36′N to 37°49′N and fr om 100°36′E to 121°56′E.It has been cultivated 52.67 millio n hectare and increased by about 58.5 billion kg grain from the year 1986 to 1996.A ccor ding to the national regional yield trial,it incr eased 1.1t grain perhectare com-paring with CK.General grain yield was 7.5t to 9tper hectare and the highest was 13.9tper hectare.T his paperint roduces the photo synthetic charac teristics of Shany ou 63:low light compen- satio n point,hig h lig ht sat ur ation point and high net photo synthesis efficiency of flag leaf.This re- search also indicates that the photo synthetic character istics and the group solar energy unitilization efficiency of Shanyou 63 are different in different cultivated seaso ns,differ ent soil types and fer- tiliser levels and differ ent plant density.In order to bring its photosynthetic potentiality into full play and to achieve high yield,suitable so wing and plant ing season,cultiv ated density and fertilizer application level should be studied in the different zones.