河北省苹果果实黑点病的发病规律及药剂防控研究

 近几年,河北省苹果产区苹果果实黑点病大面积发生。该病害在河北省的流行规律以及时空分布尚不清楚,给病害防控带来挑战。2018年对河北省不同市区的4个果园分别进行黑点病调查,并对其在苹果树上的空间分布以及发生时间进行动态监测,开展田间药剂防效试验。结果表明:苹果果实黑点病在7月中下旬开始出现明显症状,果树中层内膛病果率较高,上层外膛病果率较低;套袋苹果的萼洼处发病率较高,以黑点型症状为主;不套袋苹果的果面发病率较高,以晕斑型症状为主;‘斗南'、‘富士'品种的发病率较高,‘中秋王'、‘乔纳金'品种的发病率较低。田间药剂防效试验表明,50%异菌脲1 500倍液防效最好,防治效果均达54%以上。其次为10%多抗霉素1 000倍液,而80%代森锰锌600倍液、10%吡唑醚菌酯1 500倍液防效较低。研究结果可为河北省苹果果实黑点病的综合防控提供理论支持。

Studies on the incidence and chemical control of apple black spot disease in Hebei Province

In recent years, a large area of apple fruit black spot disease has occurred in the apple cultivation regions of Hebei Province. Spatial and temporal distribution of disease epidemics in Hebei Province are still unclear, which brings great challenges on the prevention and control of the disease. In 2018, four apple orchards in Hebei Province were investigated for black spot disease, where the spatial distribution and occurrence time on apple trees were dynamically monitored, and the field control experiments were carried out. The results showed that the symptoms of apple fruit black spot emergency on mid-to-late July, with a higher number of diseased fruits in the middle layer of the fruit tree and a lower number of diseased fruits in the upper outer canopy. In bagged apples, the incidence of calyx depression was higher, and mainly, the symptoms exhibited as black spots. Among the unbagged apples, the incidence on the fruit surface was higher, mainly with halo-type symptoms. Also, the disease incidence in ‘Dounan' and ‘Fuji' varieties was higher, while it remained lower for ‘Mid-Autumn King' and ‘Jonagold'. In field control effect experiments, 50% iprodione with 1 500 dilution showed the best control effect and 10% polyoxin with 1 000 dilution showed lower control effect. While 80% mancozeb with 600 dilution and 10% pyraclostrobin with 1 500 dilution showed a lowest control effect. This study can provide theoretical support for the comprehensive prevention and control of apple fruit black spot.