Spraying sugars, growth temperatures and N application levels change epiphytic lactic acid bacteria composition on Italian ryegrass

Lactic acid bacteria (LAB) naturally present on forage crops are responsible for the silage fermentation quality. However, there are few reports on the factors affecting the distribution of epiphytic LAB on the crops. Therefore, the influences of spraying sugars, growth temperatures and nitrogen application levels on the amounts and species of LAB on Italian ryegrass (Lolium multiflorum) were evaluated in this study. Spraying xylose, fructose, glucose, sucrose and galactose significantly increased (p < 0.05) the population sizes and species of LAB on Italian ryegrass. Spraying sucrose made Italian ryegrass epiphyte the most LAB. As for the effect of temperatures, Leuconostoc mesenteroides dominated on Italian ryegrass grown at 10 and 15°C, while Lactobacillus plantarum dominated at 20°C, and Weissella paramesenteroides dominated at 25°. The population sizes and species of LAB on Italian ryegrass were the most at 15°C. When N (0, 35, 70, 105, 140 or 175 kg/ha) was applied to Italian ryegrass, LAB population sizes and species were the most at N 35 kg/ha (p < 0.05). Lactobacillus plantarum was detected in all the treatments of Italian ryegrass except the growth temperatures of 10 and 25°C.