Effects Of Leaf Ages,Seedling Trays And Hill Distances On Yield And Quality In Rice

With rice variety Shendao 47 as entry,the experiment was conducted with three leaf ages(small seedling-early transplanting,normal transplanting and large seedling-late transplanting),tow seedling trays(hole tray and flat tray)and three hill distances(13cm,20cm and 27cm)to study the effects of different leaf ages,seeding trays and hill distances on dry matter production characteristics,physiological characteristics,population growth,yield and yield formation and quality in rice.The results showed that:1.Effects of leaf ages,seedling trays and hill distances on dry matter production characteristics of rice(1)Leaves per shoot,Culm and sheath per shoot,dry matter weight of per stem at full heading and maturity stage were large seedling-late transplanting>normal transplanting>small seedling-early transplanting;Dry matter weight of population at jointing and full heading stage were normal transplanting>small seedling-early transplanting>large seedling-late transplanting.The dry matter weight at maturity stage was normal transplanting>small seedling-early transplanting>large seedling-late transplanting,the difference was significant.Phase accumulation of dry matter of normal transplanting at full heading to maturity stage was the highest.(2)Between tow seedling trays,leaves per shoot,Culm and sheath per shoot,exportation and exportrate,dry matter weight of per stem and population at transplanting,jointing and full heading stage with hole tray were higher than those with flat tray.Dry matter weight of per stem at maturity stage,phase accumulation of dry matter at full heading to maturity stage with flat tray were higher.Accumulation of dry matter with flat tray was much more in later period.(3)Besides exportation of leaves per shoot,leaves per shoot,culm and sheath per shoot,exportation,exportrate,dry matter weight of per stem increased with the increase of hill distance.Dry matter weight of population at jointing and full heading stage,phase accumulation of dry matter at transplanting to jointing and jointing to full heading stage decreased with the increase of hill distance.Dry matter weight of population at maturity stage and phase accumulation of dry matter at full heading to maturity stage with 20cm hill distance were the highest.2.Effects of leaf ages,seedling trays and hill distances on physiological characteristics of rice(1)SPAD,net assimilation,net photosynthetic rate,stomatal conductance,transpiration rate were large seedling-late transplanting>normal transplanting>small seedling-early transplanting;Leaf area index,photosynthetic potential were small seedling-early transplanting>normal transplanting>large seedling-late transplanting.Population growth rate of normal transplanting was the highest at full heading to maturity stage;Light transmittance rate at 60cm from the base between leaf ages was significantly different,which was normal transplanting>small seedling-early transplanting>large seedling-late transplanting.(2)Between tow seedling trays,leaf area index,photosynthetic potential,pre-population growth rate with hole tray were higher than those with flat tray.Late population growth rate,SPAD,net assimilation,net photosynthetic rate,stomatal conductance,transpiration rate and light transmittance rate with flat tray were higher.(3)SPAD,net photosynthetic rate,stomatal conductance,transpiration rate and lighttransmittance rate increased with the increase of hill distance.With the increase of hill distance,leaf area index of jointing,full heading,maturity and photosynthetic potential of jointing to full heading and full heading to maturity decreased,the difference was significant.Population growth rate at full heading to maturity stage with 20cm hill distance was highest.3.Effects of leaf ages,seedling trays and hill distances on the growth characteristic and yield in riceThe stems and tillers of unit area in all stages were small seedling-early transplanting>normal transplanting>large seedling-late transplanting and hill distance 13cm>20cm>27cm,and those of hole tray were more than those with flat tray.Productive panicle rates was large seedling-late transplanting>normal transplanting>small seedling-early transplanting.With hill distance increasing,productive panicle rate increased,productive panicle rate of flat tray was higher than that of hole tray.Seedling qualities of hole tray was better than flat tray.Normal transplanting was easy to gain more seed-setting rate and 1000-grain weight,effective panicles and spikelets per panicle were not the highest,but the structure of panicles and grains was coordinated with each other,the yield of normal transplanting was higher significantly than that of large seedling-late transplanting and small seedling-early transplanting.The yield with 20cm hill distance was the highest,10.78t/hm2,which was much higher than that with 13cm hill distance and 27cm hill distance.It was easy to gain more effective panicles with hole tray,but to obtain more spikelets per panicle,seed-setting rate and 1000-grain weight with flat tray,to reach higher yield.Among the 18 combinations,under the condition of normal transplanting and 20cm hill distance both flat tray and hole tray obtained higher yield,the difference between them was not significant and were higher significant than other combinations,the yield were 10.90t/hm2 and 10.83t/hm2 respectively.They were the better combinations.4.Effects of leaf ages,seedling trays and hill distances on rice quality(1)The effects of leaf ages on milling quality and fatty acid content were not significant.Appearance quality of small seedling-early transplanting was the best.The difference of chalky grain rate among leaf ages was significant.Among three leaf ages,the protein content of small seedling-early transplanting was significantly higher than that of normal transplanting and large seedling-late transplanting,the protein content of normal transplanting and large seedling-late transplanting were not significant.Appearance,taste,taste value and quality evaluation value of large seedling-late transplanting were the best.(2)There was no significant difference in milling quality,appearance quality and nutritional,edible quality between the two seedling trays.Appearance and taste with flat tray were better,taste value and quality evaluation value were higher.Taste quality with flat tray was better.(3)Brown rice rate and milled rice rate increased firstly and then decreased with the increase of transplanting hill distance.Head rice rate increased with the increase of transplanting hill distance,and the difference was significant.With the increase of transplanting hill distance,chalky rate and chalkiness decreased firstly and then increased.Appearance quality with 20cm hill distance was better.There was no significant difference in the ratio of grain length to width among the three transplanting hill distance.With the transplanting distance increased,the fatty acids content increased;Amylose content with 20cm hill distance was the highest.Appearance and taste with 27cm hill distance were better.Taste value and quality evaluation value increased with the increase of the transplanting hill distance,and the taste value was higher than the quality evaluation value,and taste quality with low density was better.