An attempt to control of the soft rot of Chinese cabbages [Brassica chinensis] with avirulent strain of Erwinia carotovora subsp. carotovora
1996
Togashi, J. (Yamagata univ., Tsuruoka (Japan). Faculty of Agriculture) | Suzuki, T. | Namai, T.
The present study was carried out to confirm the effect of avirulent strain (AS) of E. carotovora subsp. carotovora on the control of the soft rot of Chinese cabbages in a field with reference to the spraying time and frequency of AS. Chinese cabbages (Matsushima-kohai Shin No.6) was sown on April 28 (spring sowing) and August 8 (summer sowing), 1994 at the Farm of our Faculty. AS (T-9-1) was grown in broth for 24 hours at 2 degrees C and the cell suspensions were sprayed to Chinese cabbages at an intervals of 7 days before occurrence of the soft rot. Agricultural chemical Z-Bordeaux and sterile deionized water were used as control. Control effect was calculated from susceptibility index and protective value. In spring sowing, control effect depended more largely on the spraying time than the frequency and spraying in initial stage of disease development showed the better performance to control. In summer sowing, susceptibility indexes in spraying AS were higher than those in control and the control effect was not found. The soft rot bacteria isolated from the field were identified as E. carotovora subsp. carotovora. However, a ratio of sensitivity isolates to bacteriocin-like substance produced by AS varied with the sampling time of isolate and the method of bacteriocin-sensitive test. It is necessary for raising the control effect for the soft rot of Chinese cabbages by AS to study the behaviour of the organism on chinese cabbages and bacteriocin-typing of indigenous soft rot bacteria in a field
Показать больше [+] Меньше [-]