Effects Of Seed Dressing With Trichoderma Longifolia On Kidney Bean Growth And Rhizosphere Soil Enzyme Activitie

Trichoderma is a kind of fungus widely distributed in soil.Studies have found that most Trichoderma strains can induce plant resistance,promote plant growth and improve crop yield.In recent years,the research on Trichoderma in crops is mostly focused on melon,pepper and other crops,and less on legumes,especially kidney beans.In this study,kidney bean "baishak" was used as the test variety to explore the effects of Trichoderma longibrachiatum on the growth of kidney bean and rhizosphere soil through seed dressing,so as to provide a theoretical basis for the application of Trichoderma longibrachiatum in kidney bean and related crops.Samples were taken at the seedling stage,the first flowering stage,the pod setting stage and the mature stage during the growth of kidney bean to determine the growth characteristics,yield,dry matter accumulation and rhizosphere soil enzyme activity of kidney bean.1.The results showed that when the seed dressing amount of Trichoderma longibrachiatum was 1%(Y1),the emergence time of kidney bean was the best,and the emergence time of this treatment was 105.6 h;Compared with 0%(YCK),the seed dressing amount of 1%(Y1)shortened the seedling emergence time by 24 h,increased by 18.52%,while the seed dressing amount of 4%(Y4)did not perform well in the seedling emergence time,indicating that the treatment with low dosage of Trichoderma longibrachiatum could significantly shorten the seedling emergence time of kidney beans,while the treatment with high dosage Trichoderma longibrachiatum could inhibit the seedling emergence time of kidney beans.2.In the early flowering stage of kidney bean plant height,the treatment of 3%(Y3)of Trichoderma longibrachiatum could significantly increase the plant height and root length of kidney bean.In the pod setting stage,the treatment of 4%(Y4)of seed dressing had the most significant effect on promoting the growth of dry and fresh root weight of kidney bean.The SPAD value of kidney bean leaves was the highest at the first flowering stage,and there was a significant difference between 0%(YCK)and 3%(Y3)seed dressing(p<0.05);The SPAD value of kidney bean leaves at pod setting stage was the best under 4%seed dressing(Y4);The SPAD value of kidney bean at mature stage was significantly lower than that at pod setting stage,and showed a trend of first increasing and then decreasing with the increase of Trichoderma longibrachiatum dosage.It can be seen that Trichoderma longibrachiatum seed dressing has a certain promoting effect on the growth of kidney bean.3.The yield of kidney bean was the best when the seed dressing amount was 3%(Y3),and the average yield could reach 29.49 g/pot,which was 23.29%higher than that of 0%(YCK);The average yield of 4%(Y4)seed dressing was 28.39 g/pot,which was 18.69%higher than that of 0%(YCK),indicating that an appropriate amount of Trichoderma longibrachiatum had a certain yield increasing effect on kidney beans.4.Under the treatment of Trichoderma longibrachiatum seed dressing,the protease activity in the rhizosphere soil of kidney bean first increased and then decreased with the increase of dosage,urease first decreased and then increased,sucrase first weakened and then stabilized and then increased,dehydrogenase as a whole increased and then weakened,acid phosphatase as a whole weakened and then enhanced,and catalase as a whole remained stable.The mature stage showed a trend of increasing first and then decreasing.Trichoderma longibrachiatum seed dressing could improve the soil activity in the rhizosphere of kidney bean,but the increase of enzyme activity would be weakened if the dosage was too high or too low.The appropriate dosage of Trichoderma longibrachiatum and kidney bean was 3%～4%.5.The absorption of nutrients by kidney beans as a whole showed that the absorption of total N,total P and total K by grains was significantly higher than that by plants,while the absorption of total Ca by plants was higher than that by grains.Through the seed dressing experiment of Trichoderma longibrachiatum and kidney bean,it was found that when the seed dressing amount was 3%(Y3),the amount of nutrients absorbed by the plant was the best.