Study On The Effects Of Several Bactericides And IBA Blebding Against Tobacco Bacterial Wilt

As continuous cropping on tobacco growing increases year by year, additionally species being single, harmful bacterial wilt of tobacco grows, which caused the general incidence rate of 10% to 30% or 70% to 80% when serious. In 2009, approximately 48.98 acres had been damaged by tobacco bacterial wilt, so had 5,145.300 kg in output and 105.5221 million yuan in output value. In April 2010 to August, according to the collection, isolation and identification of the tobacco having been infected by tobacco bacterial wilt in Qianjiang District of Chongqing, the hardest hit of tobacco wilt, and the antibacterial test on single dose and mixtures of pesticides on tobacco bacterial wilt, the main results are as follows:1. Pseudomonas solanacearum (Ralstonia solannacearum)'s isolation, culture and identification.Culture the Pseudomonas solanacearum isolated from the disease strains to the multiplication of Pseudomonas solanacearum. And keep it in sterile water. Then use TTC plate method and leaves in vitro method to identify the Pseudomonas solanacearum s pathogenicity. The results show that the isolated Pseudomonas solanacearum is with strong pathogenicity.2. The indoor virulence of single dose and mixtures of pesticides towards Pseudomonas solanacearum. Used the Oxford cup method to test the bacteriostatic efficacy of Agrostreptomycin, Ethylicin,Zhongshengmycin, Mancozeb and other 15 agents on the Pseudomonas solanacearum. And then through selection of the inhibition zone and transparency, screen the proper Agrostreptomycin and Ethylicin. Simultaneously, determined the EC50 of these two agents, which was 85.10 mg/L,42.23 mg/L, respectively. Besides, used the mixing proportion method to determine efficacy of the mixtures mixed by the proper Agrostreptomycin and Ethylicin. At the same time determined the largest tobacco bacterial wilt virulence of the mixtures. The results showed that when the proportion of mixture (Agrostreptomycin:Ethylicin) is just 1:1. inhibition rate was the highest and the efficiency risedup to 32.13%.Additionally, took the effects of growth regulator indole butyric acid (IBA) into account, combined the chemical control with tobacco bacterial wilt, so the active ingredient ratio which was 1/1 of Agrostreptomycin and Ethylicin was selected, while the content which was 10 mg/kg of IBA was added. Finally, processed it into granules.3. The determination of granules formulations and the effective test of product. Taking the factors of high labor intensity in the mountain area, water resources'lack. etc. into consideration, shape it into granules for convenience by using diatomaceous earth as the carrier, white carbon black as adsorbent and urea as the dispersant, polyvinyl alcohol (PVA) chose from polyethylene alcohol, dextrin, polyvinyl alcohol optimized paraffin as a binder. Making sure of granule formulation includes 7% Agrostreptomycin,7% Ethylicin,10% white carbon,5% urea,5% binder, 0.1% indole butyric acid (IBA) and about 66% diatomaceous earth.4. The indoor pot experiment on mixed pharmacy and granules. Choose proper Agrostreptomycin, Ethylicin, mixtures and home granules to conduct antibacterial test. After 24 hours' pharmaceutical treatment, inoculate tobacco with Pseudomonas solanacearum and verify the existence of hazard and efficacy in granules. Observations show that the granules make no adverse effect on tobacco and the control effect of pharmaceutical treatment on tobacco bacterial wilt was above 60% generally, of which indole butyric acid (IBA), Agrostreptomycin and Ethylicin controls best which is still 82.68% after inoculation 28days.Putting 1.5 g/strain controls best of the best in granules, which control effect reaches 74.29%. After inoculation 7 days, addition to 0.5 g/strain appearing diseased, the other treatments were not strain, which efficacy was 100%; after inoculation 14 days, the control effect of each treatment was in 76.19%-90.48%, of which 0.5 g/ strains and 1.0 g/strain were less effective, which control effect was 76.19%,78.57% respectively; after inoculation 21 days, the control effect of each treatment showing different degrees of decline, the control effect of each treatment is in 74.19%-90.32%, of which still 0.5 g/strains and 1.0 g/ strain shows the worst; after inoculation 28 days, all treatments showed the control effect of each treatment being in 62.86%-82.86%, of which Agrostreptomycin, Ethylicin and indole butyric acid (IBA) irrigating treatment shows the best control effect of 82.86%, while 14.1% Agrostreptomycin, Ethylicin and indole butyric acid (IBA) granules at 1.5 g/strain show the control efficiency of 74.29%. and there was no significant difference between the control effect of 1.5 g/strain and 1.0 g/strain which control effect was 71.43%. With the increasing amount of granules, the control effect on tobacco bacterial wilt gradually increased. What's more, the control effect of Agrostreptomycin, Ethylicin and indole butyric acid (IBA) irrigating treatment was better than granules' putting's.5. Mixed pharmacy and granules' field trials. After the irrigating treatment and pharmaceutical granules' putting together has been processed at a certain time, it showed that tobacco plants grows greenly and non-chemically. With the mixed pharmaceutical formulations' s irrigating treatment which included Agrostreptomycin, Ethylicin and indole butyric acid (IBA), it improved the disease resistance of tobacco plants to a certain extent, rised the control effect on tobacco bacterial wilt over 50%, postponed the disease severity and has a good effect on the weather fleck of tobacco, anthracnose and stem disease empty. With the increase of 14.1% of the granules'content, effect on tobacco bacterial wilt also increased. But the way putting 6 g/strains or 9g/strain had no significant difference with each other, so choosing the way putting 6 g/strains was much better, that was 90 kg/hm2, from the economics.