Effects Of Gibberellin And Potassium Fertilizer On Spring Wheat Growth,Yield And Seeds Vigor

In order to provide theory support to the planting of spring wheat,Xinchun 31 was selected as test object,using split experiment design.The K（amounts of potassium）of the main area was divided into 3levels which are K₀(0 kg·hm^-2),K₁₈₀(180 kg·hm^-2)and K₃₆₀(360 kg·hm^-2).The G（amounts of Gibberellin on foliage）of split area was divided into 5 levels,which are G₁(0 g·hm^-2),G₂(8 g·hm^-2),G₃(16 g·hm^-2),G₄(24 g·hm^-2)and G₅(32 g·hm^-2).The effects of potassium application and gibberellin on spring wheat growth,yield and seeds vigor were studied.The main conclusions were come into as follows:First,gibberellin had no significant effect on the dynamics of spring wheat population,but it had significant effect on plant height,plant biomass,internode length,spike length and stem diameter.With the amount increase of gibberellin application,plant height,plant biomass,panicle length,internode length and stem diameter presented increasing first and then decreasing trend,which reached the maximum at G₄ level.The effect of potassium application on panicle length had no significant effect,but for wheat population dynamics,plant biomass,panicle length and stem diameter,it had significant effect.With the increase of potassium application amount,the above indexes all presented increasing first and then decreasing trend,which reached the maximum at K₁₈₀ level.Second,the leaf area,leaf area index（LAI）and SPAD of spring wheat were significantly affected by gibberellin and potassium fertilizer application.With the increase of gibberellin and potassium fertilizer application,leaf area,LAI and SPAD presented increasing first and then decreasing trend,which LAI（x）and yield（y）can be fitted to the quadratic curve equation:y=-60.267x²+1249.8x（R2=0.9433,r=0.9602）.Third,the grain weight of spring wheat increasing presented a“S”curve model,the grain weight growth was slow at the beginning and the end of grain filling time,but it was the fastest in between.Wheat dry matter accumulation was fitted well with Logistics equation,which fit（R²）were between 0.9857-0.9989,which showed the grain filling process quite well.Forth,with the advance of crop fertility after flowering,the grain dry matter accumulation showed a gradual upward trend,while the leaf,stem and panicle dry matter accumulation showed a decreasing trend after the first increase;accumulation of potassium of leaves and stems presented a decreased trend;the accumulation of potassium of panicle was increased first and then decreased,while the accumulation of potassium in grain increased gradually.Both got the largest value under the combination of K₁₈₀ and G₄level.Potassium accumulation in stem sheath with grain yield can be fitted to a quadratic function:y=-0.106x²+50.643x+535.18,with fit R2=0.8691 and a correlation coefficient of 0.9299.Fifth,the effects of gibberellin and potassium application on the seed vigor of spring wheat were significant,which could obviously improve the seeds germination rate,germination potential,germination index,vigor index,fresh weight,dry weight,seedling length,root length and the number of roots,while the conductivity of the immersion solution of spring wheat seeds was negatively correlated to the vitality of seeds.Artificial accelerated aging can reduce the seed vigor rapidly.Under the application of potassium180 kg·hm^-2 and gibberellin 24 g·hm^-2,the seed germination is still higher than that of other treatments after 8 days of aging.Application of a certain amount of potassium fertilizer and gibberellin can improve the seed vigor of spring wheat.The results showed that when the potassium application was 180 kg·hm^-2 and the amount of gibberellin was 24 g·hm^-2,both the spring wheat growth and development could be promoted,the grain yield could be increased and the seed vigor could be kept at a high level at the same time.