Study On Characteristics Of Growth And Development And Yield Of Spring Wheat Under Low Density

Three typical cultivars of spring wheat largely grown in Hei Longjiang provincewere selected and field experiments were conducted at carnpus trial field and xiangfang experiment station of Northeast Agricultural University under five density. Theexperirnent was used p1ot design and basic seedling was set separately 6.0, 4.5, 3.0,1 .5, 0.75 million stem per hm2.The characteristics of growth and deve1opment and thediscipline of yield and yield components under low density were studied. Theexperiment was expected to reduce basic seed1ing properly in good cultivated area ofHei Longiiang province, and to utilize tiller of spring wheat partly or big spike havingmore grains.The study was wished lo provide the foundation of theory which reducingcost of production and increasing yield of spring wheat grown Hei Longiiangp rovi nce.The results were as followstl At the density of 3.0 mi1lion stem per hm2 Long Fu 10 and Dong Nong l22had high yield,and at the density of 4.5 million stem per per hm2 Long mai 26 alsohad high yield. But each cultivar had different proper density.2 The yield components of different cultivars had difference under low growndensity.Long Fu 10 planted 3.0million stem per hm2 had 4.22 million spike per hm2,36.3grain per spike, 43.6g 1000 grain weight; Long Mai 26 planted 4.5 million stemper hm2 had 4.88 mi1lion spike per hm2, 35.9grain per spike, 40.8g l000 grainweight;Dong Nong 122 planted 3.0million stem per hm2 had 3.78 million spike per hm2,40.6grain per spike, 40.1g 1000 grain weight. With the reduce of density, Long Fu10can gain yield by the increase of the number of earbearing ti11er and grainweight,and Long Mai 26 can acquire yield by the increase of grain weight,and DongNong 122 can have high yield by the increase of the number of grain and earbearingtiller.3 With the reduce of density, the number and percentage of earbearing tillerincrease. The number of earbearing tiller of Long Fu 10, Long Mai 26 and Dong Nong1 22 increase from 0. 1, 0.03, 0. 1 7 million stem per hm2 to l .76, l .25. I .26 million stemper hm2 each. The percentage of earbearing tiIler of Long Fu l0, Long Mai 26 and2002DongNong 122 increase from 5.8%, 0.8%, 10.1% to 55.3%, 49.4%, 58.3% each.4 The number of available spikelet and grain per spike and grain weight per spike of tiller were improved with the reduce of density, and were the negative correlation with the density. With the reduce of density, the grain weight per spike of tiller of Long Fu 10, Long Mai 26 and Dong Nong 122 each increase from 0.25g, 0.4g, 0.36g to 1.367g, 1.482g , 1.62g; the number of grain per spike of tiller of Long Fu 10, Long Mai 26 and Dong Nong 122 each increase from 6, 15.6, 10 to 38.5, 44.3, 39.2; the number of available spikelet per spike of tiller of Long Fu 10, Long Mai 26 and Dong Nong 122 each increase from 4, 10.3, 9 to 16.9, 16.8, 14.7 .5 The growing time increase with the reduce of density. Long Fu 10 prolonged five days ,but Long Mai 26 and Dong Nong 122 prolonged 2-3 days.