枇杷灰斑病的發生與其對果實損失的評估

The Occurrence of Pestalotiopsis eriobotryicola in Loquat and Effects on Yield and Quality of Fruits

10.6956/BTDAIS.199506.0059

劉添丁(Tien-Ding Liu)

枇杷 ； 灰斑病 ； 損失評估 ； Loquat ； Pestalotiopsis eriobotryicola ； loss assessment

臺中區農業改良場研究彙報

47期（1995 / 06 / 01）

59 - 66

繁體中文

灰斑病為枇杷主要病害之一。灰斑病菌（Pestalotiopsis eriobotryicola）胞子發芽最適溫度為20~28℃，菌絲生長為24~28℃。本省枇杷栽培多分佈在中海拔山麓地帶，1～4月及10～12月平均氣溫在20℃以下，灰斑病菌胞子發芽及菌絲生長受到抑制，田間發病少。5～9月平均氣溫在25～29℃間，適合本病菌之生長，田間發病趨於嚴重。罹病率在10%以下時，果實肥大期的每一枝條葉片數一般可保持15片，開花率達80.5%，每穗果實重144.3g，糖分達11.45度（°Brix），屬生育正常範圍內。隨著罹病率的增加，由於罹病葉片提早黃化落葉，枝條葉片數隨之減少，開花率因而減低。當罹病率達50%時，果實肥大期每一枝條僅保存6個葉片，開花率降低為57.5%，果粒較小，每穗果實重量僅約86.8 g，果實糖度為9.9度。

Pestalotiopsis eriobotryicola is one of the major diseases occurred in loquat. The most appropriate temperature for spore germination of P. eriobotryicola was at 20~28°C, and for mycelium growth was at 24~28°C. The loquat mostly grown at slopeland and mountainous areas in Taiwan. During Jan. to April and Oct. to Dec. when the monthly mean temperatures below 20°C, the spore germination and mycelium growth of P. eriobotryicola was inhibited, and the disease occurred very rare. However, the disease became severe, when the temperature was favorable to mycelial growth of the pathogen at 25~29°C from May to September. When the disease severity was below 10% during enlargement stage of the fruit, the plants were able to have 15 leaves in each branch, 80.5% of blooming rate, and produce 144.3g of fruit weight per cluster with 11.45 °Brix of the sugar content. However, when the disease severity was more than 50%, the plants defoliated prematurely, had less leaves and blooming rate in each branch and produced 86.8 g of fruit weight per cluster with 9.9 °Brix of the sugar content.