利用中和後之亞磷酸溶液防治馬鈴薯與番茄晚疫病

Control of Phytophthora Late Blight of Potato and Tomato with Neutralized Phosphorous Acid

蔡志濃(Jyh-Nong Tsai) ； 安寶貞(Pao-Jen Ann) ； 王姻婷(Ien-Tien Wang) ； 王馨媛(Shin-Yuan Wang) ； 胡瓊月(Chyung-Yue Hu)

《台灣農業研究》 58卷3期 (2009/09) Pp. 185-195

https://doi.org/10.6156/JTAR/2009.05803.04

摘要

將亞磷酸(phosphorous acid, H3PO3)的水溶液以等重(1:1, w/w)的氫氧化鉀(potassium hydroxide, KOH)中和後配製成亞磷酸－氫氧化鉀中和液（neutralized phosphorous acid solution，簡稱NPA），來測定其對晚疫病菌(Phytophthora infestans)與晚疫病的抑制能力。在rye B培養基上，NPA於高濃度1000 mg/L下可以完全抑制所有供試菌株之菌絲生長與胞囊發芽；當濃度100 mg/L時，NPA對菌絲生長與胞囊發芽之抑制率分別為21.1%與69.9%；但在低濃度10 mg/L時，則完全無抑制作用。1999-2000年之田間實驗結果顯示，當病害初發生時，將濃度1000 mg/L之NPA噴施於馬鈴薯 ‘克尼伯’品種與番茄‘農友301’品種，每隔7天施用1次，連續2次後即可顯著降低晚疫病的罹病度，病害防治率分別為30.1%與36.8%，施用4次後防治率分別為65.2與58.3%。2004年冬季至2005年春季在農試所番茄試驗田進行3次試驗，1000 mg/L之NPA施用3次後，停用3星期，亦可明顯降低番茄（‘農友’與‘聖女’品種）晚疫病的罹病度40-60%，進而減緩病害之病勢進展。但在連續降雨季節，NPA在1000 mg/L的濃度下降低罹病度僅有20-40%，無法有效壓抑晚疫病。

關鍵字

亞磷酸 ； 晚疫病 ； 馬鈴薯 ； 番茄 ； 病害防治

並列摘要

The effect of the neutralized phosphorous acid solution (NPA) prepared with a simple method on suppression of Phytophthora infestans and control of potato and tomato late blight was evaluated. The proposed method involved dissolving phosphorous acid in water before adding equal weights of potassium hydroxide. NPA at a concentration of 1000 mg/L (a.i.) completely inhibited the mycelial growth and sporangial germination of P. infestans on rye B agar plates, while the inhibitory effects of NPA at lower concentration (100 or 10 mg/L) decreased dramatically. The inhibition rates of mycelial growth and sporangial germination of P. infestans at 100 mg/L NPA were decreased to 21% and 69.9%, respectively, and at 10 mg/L NPA down to 0%. When NPA at 1000 mg/L was foliar-sprayed to the plants of potato var. 'Kennebec' and tomato var. 'Known-you 301' for 2-4 times at 7 d intervals in the naturally infected fields in 1999-2000, the disease severity of Phytophthora late blight of both crops were significantly and effectively suppressed. The disease reduction by 2 applications and 4 applications were 30.1% and 65.2%, respectively, for potato late blight, and 36.8% and 58.3%, respectively, for tomato late blight in comparison with the control. Application of NPA at 1000 mg/L for 3 times every 6 weeks was also effective in suppression of tomato late blight, and thereby delay disease progress in the fields during the winter-spring seasons of 2004-2005. The disease severity of both tomato varieties 'Known-you 301' and 'Sen-nyu' were 40-60% less than those without spray in the dry periods, whereas NPA treatments were only 20-40% less than controls during continuous rain.

並列關鍵字

Disease control ； Phosphorous acid ； Phytophthora late blight ； Potato ； Tomato