Effcets Of Sowing Period And Density On Summer Sorghum Growth And Yield

Jinza30 and Xiaza7 which are suitable for summer sowing in precocious mature area of Shanxi province are used as test materials and the study also separated test. The sowing period test is carried out in agriculture station of Shanxi Agriculture University during june,2013, which varieties are Jinza30 and Xiaza7,studing they growing development and yield through 5 sowing periods. The density test is carried out in agriculture station of Shanxi Agriculture University during june,2014, using the single factor randomized block design, which variety is Jinza30. Researching its growing development and yield through 5 planting density.The results of two tests showed that:1 Sowing period test1) With the delay of sowing period that the Jinza30 and Xiaza7 growth days reduced. The correlation analysis to the temperature during the growing period and growth period showed:the growth period and the accumulated appeared significant positive correlation, the growth period appeared positive correlation with minimum temperature and negative correlation with highest temperature and average temperature.2) The height and the stem diameter of 30 and Xiaza7 all along with the sowing period delay showed first increasing and then decreasing, and the sowing period had significant difference. The stem node number also appeared the same result, but the sowing period had no significant difference.3)The influence on leaf age and visible leaf of Jinza30 and Xiaza7 all appeared gradually reduced through the sowing period delay. With the delay of sowing period, two varieties leaf area index reduced, and the relationship between sowing period and maximum leaf area index is monadic linear. The result indicated sowing late could cut down the photosynthetic efficiency of the green leaf area of summer sorghum.4)The sowing period effects the summer sorghum on yield reached extremely significant level that two varieties’yield are decreased with the sowing period; Sowing period effect the summer sorghum on the spike number had significant difference which decreased following the sowing period delay, and the spike number of Jinza30 more than Xiaza7. The sowing period also effects the summer sorghum on 1000 grain weight reached significant level that they 1000 grain weigh are decreased following the sowing period.2 Density test1)The whole growth duration of Jinza30 lengthened with the planting density increased. The least whole growth duration are 97days which planting density is 9million strains/hm2 and the most whole growth duration are 99 days that density is 18 million strains/hm2.2)The sowing period effect Jinza30 on height reached extremely significant level,the plant height increased fist and then decreased with the density enlarged. The stem diameter is also influenced by density reached significant level, which diameter of stem taper with the increase density. The effect of density on stem node number reached significantly, and the stem node number increased with the density gradually less.3)The leaf age increased with the density decreased, and the leaf area index first increased then felled with the increase of density. Maximum leaf area index and the density showed a downward opening parabola relationship during different density, the highest value of maximum leaf area is in the 9 million strains/hm2.4)Yield of Jinza30 is influenced by density reached extremely significant level, which during the different density is 15.75 million strains/hm2> 18 million strains/hm2> 13.5 million strains/hm2> 11.25million strains/hm2>9 million strains/hm2;Spike number increased by the density enlarged, but the grain number and 1000grain weight all cut down with the density increased.