关键词: 苹果, 植物病害, 桔抗细菌, 生物防治

Abstract: Excavating the top buds (flower buds on the short fruit twigs and short middle branches and also the side buds on the short fruit twigs and short middle branches and also the side buds on middle long branches of three apple varieties golden delicious, Starking delicious and Qin-delicious, adopting the methods of organization differentiation and washing centrifuge, we discovered that there were Alternaria spp in buds scales of allthese three varieties, A. spp and its conidia carring ratio of Starking delicious was the highest in the three varieties. The A. spp carring and the quantity of conidia were the highest in the top buds on the short fruit twigs of the three varieties. All the conidia might germinate in the following spring as aninitial infecting source. The highest ratio of A. spp infecting fruits of these three varieties in the fields was of Starking delicious. This ratio had a plus interrelation to the quantity of A. spp and its conidi a carring in buds. Above results also showed that A. spp might overwinter by mycelia and conidia in buds of apple trees and then the buds of apple trees were one of the important A. spp overwintering place.

Key words: APPLE, PLANT DISEASE, ANTAGONISTIC BACTERIA, BIOTIC CONTROL