臺中東勢地區梨赤星病發生之調查

Survey of Pear Rust Disease in Dongshi, Taichung

沈原民(Yuan-Min Shen) ； 林大淵(Da-Yuan Lin) ； 趙佳鴻(Chia-Hung Chao) ； 洪挺軒(Ting-Hsuan Hung)

《臺中區農業改良場研究彙報》 133期 (2016/12) Pp. 57-69

摘要

梨(Pyrus pyrifolia)是臺灣中部地區的重要經濟果樹，本研究在臺中市主要梨產地東勢區進行梨赤星病(Gymnosporangium asiaticum)田間調查。梨赤星病的中間寄主是龍柏(Juniperus chinensis)，東勢區內計有1,279株龍柏，換算當地龍柏密度每平方公里為11株，公營部門的龍柏數量多於私人所有。東勢區內的龍柏在梨赤星病冬孢子成熟期普遍帶有梨赤星病的冬孢子堆。臨近新種植龍柏的梨園，調查距離龍柏5~60 m的範圍，梨樹與龍柏愈近，梨赤星病的罹病率及每葉平均病斑數愈高。在另一個梨園，4月份台中一號梨罹染梨赤星病的狀況低於台中二號梨，由於台中一號梨的萌芽時間晚，葉片可能因此避開病害感染。梨葉施用殺菌劑下，梨赤星病的罹病率與嚴重度較低。於2011~2016年，調查東勢兩個梨園內梨赤星病的罹病率與嚴重度，並換算病害發生進程下之面積(AUDPC)，同一果園內橫山梨與台中二號梨的AUDPC在多數年度差異不顯著，6年當中兩果園梨赤星病的AUDPC在2013年最低、2016年最高，2月至3月是東勢區梨赤星病大量感染的高風險期，此期間大量降雨可能導致梨赤星病發生嚴重。

關鍵字

梨赤星病 ； 膠銹菌屬 ； 銹病 ； 果樹病害 ； 植物病害管理

並列摘要

Pear (Asian pear; Pyrus pyrifolia) is an important fruit tree in central Taiwan. Field survey of pear rust caused by Gymnosporangium asiaticum was carried out in Dongshi, a main pear production area in Taichung. 1279 junipers (Juniperus chinensis), an alternate host of pear rust, was enumerated in Dongshi, which represented a juniper density of 11 plants/km^2 in the region. Distribution of junipers in public sector exceeded other location categories in number. Junipers in Dongshi generally harbored telia of pear rust during the period of teliospores maturation. A pear orchard near a newly grown juniper plantation was investigated. Within a range of 5 m - 60 m, pear rust incidence and average lesion numbers per leaf increased with decrease of distance between pear trees and junipers. In another pear orchard, pear cultivar Taichung No.1 had lower pear rust infections than pear cultivar Taichung No. 2 in April. Late budburst date of pear cultivar Taichung No.1 is suggested to result in disease avoidance. Comparison of pear rust of pear trees under management and pear trees without fungicide treatments, the pear leaves treated with fungicides showed lower disease incidences and severities. During 2011-2016, pear rust disease incidences and severities were investigated in two pear orchards in Dongshi. Area under disease progress curve (AUDPC) values of pear cultivar Hengshan and pear cultivar Taichung No.2 grown in the same orchard was not significantly different in most of the years. Among the 6 years, pear rust AUDPC values of the two orchards were lowest in 2013 and highest in 2016. Large rainfall amounts in February and March, the time period that pear rust has a risk to increase drastically in Dongshi, were likely to lead to severe pear rust infection.

並列關鍵字

pear rust disease ； Gymnosporangium ； rust disease ； fruit tree diseases ； plant disease management