Effects Of Difference Seedlings Number Per Hill On Tiller-earing And Yield Of Mechincal-transplanting Rice

The field experiment with split plot design was carried out in2011with indica hybrid rice Gangyou725as the material, which was applied in large area in Sichuan Province.The experiment included two transplanting patterns(mechanical transplanting and hand transplanting),two rice seedling ages(30days and40days after sowing). and three basic seedling density(l,3and5seedlings per hill).The tiller emerging rate,earbearing rate on each position of main stem and yield of mechincal transplanting rice were investigated.Rescults showed as following:1The SPAD value, activity of GS and nitrogen content in function leaf performed as1seedling>3seedlings>5seedlings.The activity of GS was significantly and positively correlated with nitrogen content in28days after transplanting by machine.The activity of GS was significantly and positively correlated with the tiller increasing number,the ear number per plant and the earbearing tiller percentage in28,35,42days after transplanting.With the activity of GS improving, the tiller increasing number,the ear number per plant and the earbearing tiller percentage increased in the same stage.2In heading and maturity stage,the single stem weight was heaviest as1seedling,which took the second place as3seedlings.The stem weight per unit area was heavier in30seedling days than in40seedling days in heading stage.The total leaf area and the top-three leaves area increased with the number per hill increasing. The efficient leaf area rate performed as3seedlings>5seedlings>1seedling. When seedling age prolonged from30to40days,the amount and the percentage of dry matter accumulation after silking decreased.3The position3/0,4/0,5/0and6/0had higher tiller emerging rate of mechanical transplanting rice,and4/0,5/0,6/0reached a hundred percent.With the number per hill increasing,the number of the position and the tiller emerging rate reduced.When seedling age prolonged from30to40days,the tiller number of2/0,3/0,7/0decreased.But the tiller number of4/0,5/0,6/0changed little.4In the stage of40days after sowing,the tiller arbearing rate reduced with tiller position raise,when the rice transplanted by machine as1,5seedlings per hill.The tiller arbearing rate increased then decreased as3seedlings per hill.The tiller number of2/0,3/0as3seedlings lower than as1,5seedlings,and higher than5seedlings but lower than1seedling of5/0,6/0.In the stage of30days after sowing,the tiller arbearing rate reduced with tiller position raise,4/0was highest as5seedlings and higher than as1,3seedling.When the seedling age prolonged from30to40days, The tiller arbearing rate of4/0,5/0reduced,but increased of2/0,3/0as1,3seedlings. The tiller arbearing rate of all position reduced as5seedlings.5The roductivity contribution of2/0to4/0increased with the number per hill increasing, as the main contribution position reached to the percentage40%as3,5seedlings.The percentage of roductivity contribution higher than4/0reached40%,as the main contribution position as1seedling. The roductivity contribution of2/0to4/0and main stem in30seedling age was higher than in40seedling days.6The number of grain per panicle increased then decreased with the tiller position higher.4/0,3/0The maximum appeard at4/0,3/0and the minimum at highest position.The theoretical ear weight per plant decreased with the number per hill increasing.In the stage of40days after sowing,the theoretical ear weight per unit area increased with the number per hill increasing,and the highest weight was1.36kg/m2as5seedlings per hill.The highest weight was1.38kg/m2as3seedlings per hill in the stage of30days.7The tiller arbearing rate of crop colony was highest as3seedling per hill,and had significant level between the different treatment. The tiller arbearing rate of crop colony in30seedling age was3%higher than in40days seedling age. The grain yield was highest as5seedling,and the grain yield was higher in40seedling age than in30days seedling age.Compared with transplanting by machine,the grain yield was higher transplanting by hand.The grain yield was highest on the treatment of5seedlings per hill.In conclusion,compared with the treatment of3seedlings per hill transplanting by machine,the tiller arbearing rate of crop colony,tiller emergency rate and tiller arbearing rate of each position was higher,but transmission rate,LAI and efficient leaf area rate was lower in heading stage. Which was not positive to dry matter accumulation in filling satge.Though grain number per spike and the single panicle weight was higher,the dry matter accumulation and the ear number was lower.The grain yield was low.The tiller number was most in each stage as5seedlings per hill,and the dry matter accumulation was heavier in heading and mature stage.But tiller emergency rate and tiller arbearing rate of each position and the tiller arbearing rate of crop colony,the single stem weight in heading stage and dry matter accumulation in filling satge were lower, which was not conducive to further improve the yield.As3seedlings per hill,compared with the treatment of40days seedling age transplanting by machine,tiller emergency rate and tiller arbearing rate of each position was higher, the dry matter accumulation in heading,mature and filling satge was heavier in40days seedling age,also higher efficient leaf area rate and theoretical yield.So,the treatment of30days seedling age and3seedlings per hill could develop greater potential to improve yield.by suitable fertilizer operation for mechanical transplanting rice.