Holb I J
Department of Plant Protection, University of Debrecen, Centre of Agricultural Sciences, P.O. Box 36, H-4015 Debrecen, Hungary.
Plant Dis. 2005 Jun;89(6):611-618. doi: 10.1094/PD-89-0611.
In a 3-year Hungarian study, the effectiveness of apple tree pruning as a management tactic for control of apple scab (Venturia inaequalis) was investigated on two susceptible (cvs. Jonagold and Mutsu), two moderately susceptible (cvs. Elstar and Idared), and two V resistant apple cultivars (cvs. Liberty and Prima) in three high-density organic apple orchards treated with copperand sulfur-based fungicide programs. The area under the disease progress curve (AUDPC) for leaf and fruit incidences was calculated to evaluate three winter pruning treatments (unpruned, weakly pruned, and strongly pruned). Strong pruning significantly decreased leaf scab on the susceptible and the moderately susceptible cultivars at all sites compared with unpruned ones. Moreover, for the cultivar Jonagold in all years and for the cultivar Mutsu in 2001, AUDPC values of strongly pruned trees were significantly lower at P = 0.05 compared with the weaklypruned trees. The effect of pruning on development of fruit scab was weaker than on leaf scab in all years and at all sites. For fruit scab incidence on susceptible cultivars, only strong pruning treatments decreased AUDPC significantly compared with unpruned treatments. The effects of pruning treatments on moderately susceptible cultivars were significant only in 2001 at all sites. Resistant cultivars showed no significant effect of pruning treatments on development of either fruit or leaf scab except for cultivar Liberty in 2001 at one site. Pruning resulted in no consistent difference in the apple tree canopy microclimate. However, strong pruning resulted in improved spray deposition in the tree canopy when applications were made with an airblast sprayer at midsummer. Results are compared with similar studies, and their biological interpretation is discussed.
在一项为期3年的匈牙利研究中，在三个采用基于铜和硫的杀菌剂方案处理的高密度有机苹果园中，对两个易感品种（乔纳金和陆奥）、两个中度易感品种（埃尔斯塔和艾达雷德）以及两个抗病苹果品种（自由和普丽玛），研究了苹果树修剪作为控制苹果黑星病（苹果黑星菌）管理策略的有效性。计算了叶片和果实发病率的病害进展曲线下面积（AUDPC），以评估三种冬季修剪处理方式（未修剪、轻度修剪和重度修剪）。与未修剪的相比，重度修剪在所有地点均显著降低了易感和中度易感品种的叶片黑星病发病率。此外，对于所有年份的乔纳金品种以及2001年的陆奥品种，重度修剪树的AUDPC值在P = 0.05时显著低于轻度修剪树。在所有年份和所有地点，修剪对果实黑星病发展的影响均弱于对叶片黑星病的影响。对于易感品种的果实黑星病发病率，与未修剪处理相比，只有重度修剪处理显著降低了AUDPC。修剪处理对中度易感品种的影响仅在2001年在所有地点显著。除了2001年在一个地点的自由品种外，抗病品种的修剪处理对果实或叶片黑星病的发展没有显著影响。修剪并未导致苹果树冠微气候出现一致差异。然而，在仲夏使用鼓风喷雾器进行喷施时，重度修剪改善了树冠内的喷雾沉积。将结果与类似研究进行了比较，并讨论了其生物学解释。
