last planting times were 12 and 10 C, respectively. The mean high tem- 

 perature during the first month after planting was 3^ G in the first 

 planting time, 32 G in the second planting time, and JO G in the third 

 planting time. 



Amendment with the antagonists reduced significantly (? 0.05) the 

 mean incidence of disease (Table l). The analysis of varience also 

 showed that the inoculum density of the pathogen and the pathogen 

 inoculum density-antagonist interaction significantly affected disease 

 incidence. The mean disease incidence at the highest inoculum density 

 of the pathogen when the antagonists were not added was five times 

 greater than the mean incidence of disease at that inoculum density 

 when antagonists were added. 



The population density of the pathogen decreased with time in soils 

 amended with antagonists and increased with time in nonamended soils 

 (Fig. 8). In soils amended with antagonists in the first planting, the 

 pathogen decreased from 600 propagules per gram of soil 3 w ^ after 

 planting to 200 propagules per gram of soil 19 wk after planting. In 

 nonamended soils the pathogen population increased from 1000 propagules 

 per gram of soil 3 w k after planting to 53000 propagules per gram of 

 soil 19 wk after planting. Similar results occurred in each of the 

 plantings . 



In both amended and nonamended soils, the populations of antagonists 

 decreased until 11 wk after planting, and began to increase 15 wk after 

 planting (Fig. 9). The increase, however, in amended soils was approxi- 

 mately four times as great as in nonamended soils. The population of 

 Trichoderma spp. usually was much higher in amended than in nonamended 

 soils. Aspergillus ochraceus was not isolated from nonamended soils, 

 but was present during the entire season in amended soils. 



