荔枝密闭园和间伐园主要病害发生情况比较

回缩间伐是荔枝密闭园改造的一个有效措施,但改造后的病害发生情况尚未见有报道。为给荔枝密闭园改造提供病害防控方面的理论依据,本研究分别于荔枝花穗期、小果期、果实成熟期和冬梢期,在国家荔枝龙眼产业技术体系荔枝密闭园改造示范园,对4个荔枝品种于密闭园和间伐园发生的主要病害种类、病害危害程度进行了两年的调查。调查数据统计分析结果显示,间伐园与密闭园所发生的主要病害在种类上无差异,但各物候期间伐园的平均总病叶率、果实成熟期的平均总病果率均低于密闭园,其中3个品种的差异达到显著水平;从花穗期至果实成熟期,密闭园和间伐园的病害危害程度均逐渐升高,在果实成熟期达到最高峰,进入冬梢期时又有所下降;调查还表明对密闭园进行回缩间伐改造有利于荔枝病害管理,改造后果园的病害防治重点时期为花穗期至果实成熟期。

Comparison of the occurrence of the main diseases in the thinned and un-thinned litchi orchards

Tree thinning and branch pruning were considered to be the two effective treatments in modifying litchi high-density orchard, but the effect of thinning and pruning on disease occurrence has not yet been reported. In order to provide theoretical basis for disease control in the modification of high-density orchard, the occurrence and infection degree of main diseases of four litchi cultivars were separately investigated in the period of flowering, small fruit, fruit maturing and winter shoot in the thinned and un-thinned orchard in 2012 and 2013. The statistical results indicated that there was no noticeable difference in the types of main diseases between the thinned and un-thinned orchard, however, both the average total diseased leaf rate in all phenological phases investigated and the average total diseased fruit rate in fruit maturing period in the thinned orchard were lower than that in the un-thinned orchard with significant difference in the three litchi cultivars. Meanwhile, from flowering to fruit maturing period, the infection degree in both thinned and un-thinned orchard rised regularly and peaked in the fruit maturing period, and then decline in winter shoot period. The results also showed that thinning and pruning facilitated the orchard disease management, and the period of flowering to fruit maturing was critical to disease control.