Effects Of Seeding Rate And Seedling Age On Seedling Quality And Yield Formation Of Bowl Mechanical-transplanting Rice

In order to find out the effect of sowing amount and seedling age on the quality and yield formation of rice seedling transplanted by bowl mechanical-trarsplanting rice,the experiment was carried out in Siqian village,Sansui County,Qiandongnan Prefecture,Guizhou Province in 2019.The experiment was designed with split area and two factors of seedling age?T?and seeding quality?Q?.The main area was treated with T and three seedling age levels were set with T1?60d?,T2?50d?and T3?40d?.The sub area was treated with Q and four were set Different sowing rates were Q1?2 grains per hole?,Q2?3 grains per hole?,Q3?4 grains per hole?and Q4?5 grains per hole?.The effects of seeding rate and seedling age on seedling quality,dry matter accumulation characteristics,nutrient absorption,population growth characteristics,photosynthetic characteristics and yield formation were studied.The test results are as follows:1.The effect of different sowing amount and seedling age on the quality of rice seedling transplanted by bowl mechanical-trarsplanting rice.The effect of seedling age on seedling quality was significant or extremely significant.With the decrease of T,the height of seedling,the height of leaf,the width of stem base,the dry weight of shoot and the ratio of root to crown decreased,the age of leaf and the area of leaf decreased first and then increased,the total root length,the surface area of root,the average diameter of root,the volume of root,the number of root tips and branches decreased first and then increased.With the increase of Q,the width of stem base decreased,while the area of leaf,the ratio of weight to height,the surface area of root and the number of branches of root were on the contrary.Taking12 agronomic indexes of rice seedling as the investigation object,the comprehensive quality of rice seedling was analyzed by the method of average membership function value.The results showed that the membership value of rice seedling was higher in T3Q4 treatment.2.The effect of different seeding rate and seedling age on the growth characteristics of the above ground part of rice transplanting in bowl mechanical-trarsplanting rice.With the decrease of T,plant height?jointing stage,booting stage?,leaf area index?booting stage?,dry matter accumulation,total amount?jointing stage,booting stage?,photosynthetic potential?jointing booting stage?,net assimilation rate?jointing booting stage?,crop growth rate?transplanting jointing stage,jointing booting stage?decreased,while stem tillering number?maturity stage?and leaf area index?heading stage?were opposite Trend:plant height?heading stage?,tiller number?jointing stage?,leaf area index?jointing stage?,total dry matter accumulation?heading stage?,photosynthetic potential?booting heading stage?,net assimilation rate?booting heading stage?,crop growth rate?booting heading stage?,plant height?mature stage?,tiller number?booting stage,heading stage?,total dry matter accumulation first increased and then decreased?mature stage?and crop growth rate?heading maturity?decreased first and then increased.The sowing rate had significant or extremely significant effects on tiller number,leaf area index,dry matter accumulation,photosynthetic potential,net assimilation rate and crop growth rate.With the increase of Q,plant height decreased at booting stage,plant height increased first and then decreased at heading stage,and leaf area index increased at jointing stage;with the increase of sowing amount,total dry matter accumulation?heading stage?,net assimilation rate?booting heading?,crop growth rate?booting heading?increased first and then decreased,while crop The growth rate?heading maturity?first decreased and then increased.3.The effect of different sowing amount and seedling age on the nutrient absorption of bowl mechanical-trarsplanting rice.With the decrease of T,the total accumulation in jointing stage?N,P,K?and heading stage?P?decreased.The total accumulation in heading stage?N,K?increased first and then decreased.The total accumulation in maturity stage?N,P,K?decreased first and then increased.With the increase of Q,the accumulation in jointing stage?N?and heading stage?K?increased first and then decreased.With the decrease of T,the accumulation of nitrogen and potassium?jointing-heading?increased first and then decreased,while the accumulation of nitrogen and potassium decreased first and then increased?heading-maturity?;with the decrease of T,the accumulation of phosphorus decreased?jointing-heading?,and the accumulation of phosphorus?heading maturity?was opposite.With the increase of Q,the accumulation of nitrogen and potassium?heading-maturity?decreased first and then increased,while the accumulation of phosphorus increased first and then decreased?heading-maturity?,and the accumulation of potassium increased first and then decreased?jointing-heading?.With the decrease of T,nitrogen,phosphorus and potassium in jointing stage?stem sheath?and maturity stage?stem sheath,leaf,ear?decreased first and then increased;nitrogen,phosphorus and potassium in jointing stage?leaf?and heading stage?stem sheath,leaf?,maturity stage?stem sheath?,and maturity stage?leaf?increased;nitrogen,phosphorus and potassium in heading stage?ear?increased At jointing stage?stem sheath,leaf?,heading stage?ear?,jointing stage?stem sheath?,heading stage?ear?,the potassium content decreased;at heading stage?stem sheath,leaf?,jointing stage?leaf?and heading stage?stem sheath,leaf?,the potassium content first increased and then decreased.With the increase of Q,nitrogen accumulation in jointing stage?stem sheath,leaf?and heading stage?stem sheath?,phosphorus accumulation in jointing stage?stem sheath?,heading stage?stem sheath?,maturity stage?ear?increased first and then decreased,potassium accumulation in jointing stage?leaf?,heading stage?stem sheath?,maturity stage?ear?increased first and then decreased,phosphorus accumulation in heading stage?ear?and maturity stage?ear?increased first and then decreased The nitrogen accumulation of stem and sheath decreased first and then increased.4.The effect of different sowing amount and seedling age on the photosynthetic characteristics of bowl mechanical-trarsplanting rice.With the decrease of T,the net photosynthetic rate?Pn?decreased first and then increased at jointing and booting stage,while Pn decreased gradually at heading stage.conductance to H₂O?Gs?and intercellular CO₂?Ci?decreased at jointing,booting and heading stages,transpiration?Tr?increased first and then decreased at booting stage With the decrease of T,SPAD value?jointing stage,booting stage?decreased,and SPAD value?heading stage?increased first and then decreased.With the increase of Q,Gs decreased first and then increased at jointing stage,but increased first and then decreased at booting stage,Ci increased at jointing stage,and decreased first and then increased at heading stage.The interaction of Pn?heading stage?,Ci?heading stage?,Tr?jointing stage,booting stage,heading stage?was significant or extremely significant.5.The effect of different seeding rate and seedling age on the yield and yield components of bowl mechanical-trarsplanting rice.With the decrease of T,the yield showed an increasing trend.Under T3 treatment,the yield could reach 8725.63 kg/hm².The yield of Q4 treatment was higher than other treatments,and the yield of Q4 treatment was 8491.58 kg/hm².T3Q4 had the highest yield,the highest yield was 9060.68kg/hm².With the decrease of T,the seed setting rate decreased,the total grain per panicle decreased first and then increased,the 1000-grain weight increased first and then decreased,and the number of effective panicles increased.With the increase of Q,the seed setting rate,total grain weight per panicle,1000-grain weight and effective panicle number had no obvious change rule,among which the seed setting rate,total grain weight per panicle and 1000-grain weight were the highest under Q1 treatment,while the effective panicle number was the highest under Q4 treatment.The number of effective panicles of interaction was very significant.Based on the indexes of seedling transplanter quality,aboveground growth characteristics,nutrient absorption,photosynthetic characteristics,yield and yield components and other indicators,within the treatment range set in this experiment,the suitable age for transplanting rice seedlings in this region is 40 days.The seeding amount is 5 grains,and the yield is 9060.68 kg/hm².