Studies On The Development The Biological-organic Fertilizer With Prevention And Control Erwinia Carotovora Function

Soft rot is one of the most popular three soil-borne diseases in Chinese cabbage production in our country. At present, although several integrated agricultural measures including disease-resistant varieties, chemical pesticides and biological control et al.,are taken to control this disease, it could not be controlled thoroughly, because each measure has some limitations or weaknesses in practices. In the study, highly effective antagonistic strains were screened from the in-situ soils and introduced into organic fertilizer increase.It can improve and restore the ecological environment of soil, enhance the abilities of cabbage suppressing plant diseases, reduce the use of fertilizers and chemical fungicides, reduce the influence on the environment in agricultural production. The results are as follows:(1)The pathogenic bacteria of Chinese cabbage soft rot were isolated from the disease trains in cabbage plants from Henan Province cabbage field.(2) After isolation and purification,24 bacterial strains were obtained from the in-situ soil, and only 2 bacterial strains named BRJ1 and BRJ2 had apparent antagonistic effect to Erwinia carotovora.(3)The experiment of fermentative condition of the antagonistic strains indicated that BRJ1 and BRJ2 were aerobic bacteria; the logarithm time of growth for BRJ1 were 0～8h, the growth pH was acid or neutral and the growth temperature were 15～35℃; for BRJ2 the logarithm time of growth were 4～13 h, pH ranged 4.5～9.5,the optimum temperature was 32℃.When the common fermentation be processed, the pH should be a neutral environment, the temperature should be controlled at 32℃and regular turning were required in order to provide their oxygen demand when the common fermentation be processed.(4) The experiment of the biological-organic fertilizer in the secondary fermentation process indicated that there had not significant heating process, the moisture content was 40～50%, pH was 6～7.The result of microbe count showed that the content of bacteria in biological-organic fertilize was 2.53 times more than the comparison. When secondary fermentation process finished, the index of the seed germination of the comparison organic fertilizer and the biological-organic fertilizer were bigger than 50%.It shows that the fertilizer has been stable and harmless and can be used in the field experiment.(5) The results of field experiment showed that the bio-organic fertilizer could promote the growth of Chinese cabbage obviously, but has little effect on certain specific enzymes activity. The bacterial content in the filed executed with bio-organic fertilizer was significantly higher than the comparison, but laterly the number of bacteria decreased rapidly which indicated the antagonistic strains and indigenous soil microorganisms in competition, thus affecting its colonization. The soft rot had not occurred because of the influences of factors such as weather in this field experiment. Therefore, the effect to control the soft rot of cabbage using this fertilizer and needs...