Study On The Control Of Watermelon Bacterial Fruit Blotch By Seed Treatment

Bacterial Fruit Blotch(BFB)is a serious quarantine disease that occurs on melons,watermelons and other cucurbit plants.This disease is a typical species-borne bacterial disease,and its pathogen is Acidovoorax citrulli(Ac).The pathogens spread by attaching to the seeds,and can also survive on the soil and other natural media to infect again the seeds sown in the next growing season.This experiment studied the antibacterial effects of different fungicides on acidophilus watermelon,the purpose is to screen out suitable drugs,to prepare a seed coating agent that can prevent and control BFB and at the same time prevent external pathogens from re-infecting seeds.Provide reference for seed treatment to prevent and control BFB.The main research results of this paper are as follows:1.Flat colony counting effect of different medicamentsThe study screened 25 drugs using the fat colony counting method,found that 8 kinds of agents compared with sterile water CK had significant differences in antibacterial effect.That is 80,000mg/L 8%Kasugamycin-Benziothiazolinone WG;5000mg/L,2500mg/L,1250mg/L of the Fungicide No.1 AS;300mg/L,150mg/L 3%Benziothiazolinone WP;3000mg/L、1500mg/L 0.3%Tetramycin AS;50000mg/L,25000mg/L 5%Kasugamycin-Zhongshengmycin WP;2000mg/L 25%Oligose Ethylicin ME;100000mg/L,50000mg/L 80%Ethylicin EC and 10×106mg/L,40×105mg/L,20×105mg/L Pseudomonas fluorescensDP..2.The effect of different medicaments on the germicidal effect and germination of watermelon contaminated fungusTreat the seeds with the 8 effective medicaments obtained by the above screening,and then use the plate to count the amount of bacteria carried.The less the number of colonies,the better the sterilization effect.Among them,the above concentration of bactericide Fungicide No.1 AS,25%Oligose Ethylicin ME,3%Benziothiazolinone WP and 100000mg/L 80%Ethylicin EC treated the infected seeds with 0 colonies.It shows that these four medicamentshave a bactericidal effect on contaminated seeds.By measuring the germination of seeds after the treatment,it was found that the germination rate of CK was 63%and the vitality index was 1.07.The germination rate and vitality index of the bacteria-infected seeds treated by the fungicide Fungicide No.1 AS and 25%Oligose Ethylicin ME CK is low;Compared with CK,100000mg/L 80%Ethylicin EC treatment increased by 14%,and the vitality index increased by 1.08;300 mg/L、150 mg/L 3%Benziothiazolinone WP treatment compared with CK,the germination rate increased by 37%,34%,and the vitality index increased by 2.21.,1.66,indicating that these two medicaments not only produce bactericidal effects,but alsohave obvious growth-promoting effects on seeds.3.The control effect of 3%Benziothiazolinone suspension seed coating agent on the bacterial fruit blotchAccording to the preparation principle of seed coating agent,the active ingredient must be insoluble in water,and finally,the preparation of pyridoxone into 6%pyridoxone suspension,found that its antibacterial rate of Ac reached 80.51%which can be used as the active ingredient of the suspension seed coating agent.Mix the thiophene suspending agent and the inactive seed coating agent in different proportions.It is found that the ratio of drug species(the ratio of drug to seed coating agent)of 1:1 has fast film formation and strong stability,and finally a 3%Benziothiazolinone suspension seed coating agent is obtained.The safety performance,film formation,and other performance indicators of its application on seeds were tested,and the results were all qualified.Therefore,the prepared 3%Benziothiazolinone suspension seed coating agent can be used in the following tests.Set up 4 treatments.According to the statistics of the incidence of watermelon seedling growth,it was found that the four treatments were effective in preventing bacterial fruit spot disease of cucurbits.Among them,treatment 2had the best control effect,which reduced the incidence of CK2 by 35.56%and the control effect was 87.26%;Followed by treatment 3,compared with CK2,the incidence rate was reduced by 34.45%,and the control effect was 83.02%;compared with CK2,the incidence rate of treatment 4 was reduced by 28.89%,and the control effect was 67.43%.In summary,the method of treating seeds with medicament makes the prevention and control effect of coating treatment after the seeds reach pathogen-free is better.At the same time,the 3%Benziothiazolinone suspension seed coating agenthas a certain effect on preventing and controlling bacterial fruit spot of cucurbits and at the same time blocking the re-infection of pathogenic bacteria.In order to explore whether the coating treatment would inhibit the growth of seedlings.The cotyledon length,cotyledon width,plantheight,stem thickness,fresh weight and dry weight of watermelon seedlings after treatment 1,treatment 2,treatment 3,CK1 and CK2 treatments were measured.The results showed that the strong seedling index was:treatment 3>treatment 1>treatment 2>CK1>CK2,but there was no significant difference between treatment 1,2,3 and CK1.It can be seen that the coating treatment of contaminated fungus seedshas no inhibitory effect on the growth of seedlings.In summary,In order to effectively reduce the acidophilic bacteria carried by watermelon seeds,we use 3%Benziothiazolinone to treat the seeds to keep the seeds in ahealthy state,and then use 3%Benziothiazolinone suspension seed coating agent for coating is a more preferable choice.This will not only keep the seedshealthy,but also promote seed germination and seedling growth.