Abstract
Recently, tomato and eggplant baterial wilt caused by Pseudomonas solanacearum has caused serious damage in farmers fields. In this paper, physical, chemical, cultural, biological and integrated control were tested for tomato and eggplant bacterial wilt in heavily infested fields. In the control of tomato bacterial wilt, a susceptible variety, Toko-K and Momotaro showed 100% wilt with or without chloropicrin, but the moderately resistant variety Zuiei suppressed disease incidence under the same conditons. Wilt percent of Momotaro grafted with MATE, BF-Okitsu 101 or BFNT-R were 80%, 93.3% and 50%, respectively with chloropicrin treatment in 50 days after transplanting. Non-grafted plants had a very low percent (0-30%) of wilt. Especially, Kagemusha had excellent suppressivenss when grafted to Momotaro. Physical control with root-proof sheet, and chemical control with chloropicrin had good suppression in the early stage of crop growth, but the suppression did not continue to the late stage of plant growth. Treatment of charcoal compost fixed with Bacillus subtilis and Actinomycetes to the nursery soil and planting hole slightly decreased disease incidence. Treatment with the VA mycorrhizal fungi, Gigaspora margarita or Glomus sp. did not suppress disease incidence when applied alone, but when combined with charcoal compost the control was better. Integrated control combining physical (root-proof sheet), charcoal compost with antagonists, and chemical (chloropicrin) showed 10% wilt using the moderately resistant variety, Zuiei, but in the same conditions, the susceptible variety, Toko-K were 100% wilted. In the control of eggplant bacterial wilt, resistance of the varieties Kokuyo, Senryo-2, Tunonasu, Hiranasu, Torvum vigour and Tiwan-Naga were checked. The former 3 varieties showed 100% wilt, but the latter 2 varieties had no wilt. From these results, the strain of the pathogen of this field seemed to be race II . Kokuyo grafted with Meet and Karehen had 15% and 35% wilt respectively, but non-grafted plants did not wilt. Physical control (root-proof sheet) alone or chemical control (chloropicrin) alone were tested for eggplant bacterial wilt. Kokuyo when grafed with Meet had 90-100% with or without chloropicrin treatment. But when combined both treatments resulted in a decreased wilt percentage. The conclusions of these studies indicated it is necessary to develop integrated control fitted to the pathogen density in a particular field and more studies are needed on the infection mechanisms of these diseases.
