The Penetration And Physiological Characteristics Of Corn And Soybean Seed Coating Of Pyraclostrobin And Azoxystrobin

Currently,many studies of strobilurin fungicides show that such fungicides can promote the growth of crops.However,it’s rarely reported that the penetration and physiological characteristics about strobilurin fungicides seed coatings on corn and soybean seeds.In this paper,the strobilurin fungicides of pyraclostrobin and azoxystrobin were selected to study its penetration on the seeds of corn and soybean by making the flowable concentrate for seed coating and establishing the high performance liquid chromatographic method of corn and soybean samples.In addition,different coating concentrations were set up to investigate the effects of the two fungicides on the germination of corn and soybean seeds.The analysis of the corn and soybean seed coating finds that the content of fungicide in corn and soybean seeds were gradually increased with the increase dose of seed coating.After 20 hours of cultivation,the average content of pyraclostrobin was 8.59 mg/kg in corn seed of which was coated at 1:5000 ratio seed coating agent of pyraclostrobin.And the average content of azoxystrobin was 2.06 mg/kg in corn seed of 1:5000 ratio seed coating agent with azoxystrobin after the same incubation time.The average content of pyraclostrobin and azoxystrobin was 7.67 mg/kg and 1.20 mg/kg in soybean seed which was coated at 1:5000 ratio seed coating agent after 12 hours of cultivation.This indicated that the seed coating of pyraclostrobin showed a good penetrability.After 7 days of growth,the content of pyraclostrobin in corn seeds,seedlings and roots were higher than those in soybean seeds,seedlings and roots,which indicated that the seed coating of pyraclostrobin was easier to penetrate the corn seeds than to soybean seeds.It was also studied that the effects of different coating treatments on corn and soybean seed activity and seedling growth.It was found that the coated corn and soybean seeds in the coating dose range of active ingredient and seed ratio at 1:20,000 ~1:2000,could improve the seedling rate of the seeds and stimulate the elongation of the roots of corn and soybean.Comparing with the contrast,it was increased that the seed germination potential,germination index,vigor index as well as the seedling of plant height,root length and fresh weight at the low concentration treatment(1:20,000 and 1:10,000)seed coating of pyraclostrobin and azoxystrobin on corn and soybean seed.It also increased the corn and soybean seedling leaf chlorophyll content and soluble sugar content,improved the seed vigor and seedling root activity of corn and soybean.All of this could accelerate the growth of plants.However,there was a tendency to delay seed germination and seedling growth in the high coating dose treatment(1:2000)of soybean seed.