Effect Of Irrigation And Boron Fertilization On Seed Yield And Quality Of New Strains Of Alfalfa And Sainfoin In Hexi Region

Alfalfa and sainfoin are high-quality legume forage in China,with a wide planting area and a high demand for seeds.Irrigation not only increases seed production and improves seed quality,but also extends the useful life of seed producing fields.Boron fertilizer can promote pollen grain germination and improve fruit set and set rate.However,there are still problems of low seed yield and poor quality in China,and the effects of irrigation and boron fertilization in alfalfa and sainfoin seed production have not been reported.This study focused on irrigation and boron fertilizer technology for new strains of alfalfa and sainfoin seed production,and explored the effects of different irrigation frequency(2,3,4 and 5 times)and boron fertilizer concentrations(0,0.3%,0.6%and 0.9%)on plant height,seed yield and yield components,and seed quality of new strains of alfalfa and sainfoin.The results are as follows:(1)The frequency of irrigations significantly affected the plant height of new strains of alfalfa and sainfoin,while the concentration of boron fertilizer had no significant effect on the plant height of both.With the increase of irrigation frequency,the plant height of new strain of alfalfa showed a gradual increase,with the maximum height of 135.1 cm under 5 irrigations,which was 16.37%higher than the control;the plant height of new strain of sainfoin showed a trend of increasing and then decreasing,with the maximum height of 150.1 cm under 4 irrigations,which was 59.85%higher than the control.(2)The frequency of irrigation,boron fertilizer concentration and the interaction between them significantly affected the seed yield of new strains of alfalfa and sainfoin.With the increase of irrigation frequency and boron fertilizer concentration,the seed yield of new strain of alfalfa showed a trend of increasing and then decreasing,and the highest yield was 935.00 kg/hm~2 under 3 irrigations and 0.6%boron fertilizer concentration,which was 321.55%higher than the control;the seed yield of new strain of sainfoin showed the same trend as that of new strain of alfalfa,and the highest yield was 1205.75 kg/hm~2 under 4 irrigations and 0.6%boron fertilizer concentration,which was 111.90%higher than the control,which was 111.90%higher than the control.(3)The frequency of irrigation,boron fertilizer concentration and the interaction between them significantly affected inflorescences/stem,florets/inflorescence,and pods/inflorescence in both new strains of alfalfa and sainfoin.Seed yield of both new strains of alfalfa and sainfoin was positively related to effective stems/plant,florets/inflorescence and pods/inflorescence,with pods/inflorescence contributing the most to seed yield of both.(4)The frequency of irrigation and the concentration of boron fertilizer significantly affected the hard seed rate of new strain of alfalfa,with the increase of irrigation,the hard seed rate of new strain of alfalfa showed a trend of decreasing and then increasing,and the lowest rate was 58%under 4 irrigation,which was 4.92%lower than the control;the trend of boron fertilizer concentration was consistent with the frequency of irrigation,and the lowest rate of hard seed was 57%under 0.3%boron fertilizer concentration,which was 6.56%lower than the control.The frequency of irrigation and boron fertilizer concentration significantly affected the germination rate of new strains of alfalfa and sainfoin,with the increase of irrigation frequency,the germination rate of both new strains of alfalfa and sainfoin showed a trend of increasing and then decreasing,with the highest germination rate of 36%and 77%under three irrigations,which was 24.14%and 11.59%higher than the control;the trend of boron fertilizer concentration was consistent with the frequency of irrigation,with the highest germination rate of new strains of alfalfa under 0.3%boron fertilizer concentration,which was 6.45%higher than the control,and the highest germination rate under 0.6%boron fertilizer concentration was 78%,which was 11.43%higher than the control.In summary,this study preliminarily determined that the optimal irrigation frequency for new strain of alfalfa seed production is 3 times,and the boron fertilizer concentration is 0.6%.The optimal irrigation frequency for new strain of sainfoin seed production is 4 times,and boron fertilizer concentration is 0.6%,which provided the theoretical basis for the efficient production of new strains of alfalfa and sainfoin.