蒸氣消毒及溫水處理在作物病害上之應用

Abstract

蒸氣消毒及溫水處理乃利用高溫使生物細胞內的蛋白質凝固及酵素不活化，達到殺死生物之目的，可同時控制病害、地下害蟲、雜草問題，進而減少化學藥劑施用。蒸氣消毒應用時，必須考慮蒸氣溫度、處理時間、土壤水份含量、通氣性和其對土壤微生物相及土壤化學成份變化情形等因素。台灣示範推廣之蒸氣消毒處理方式可分為插入式、覆蓋式及耕耘式，應用於土壤及介質。蒸汽消毒的最佳條件為60-80℃處理30分鐘，以葵百合黃化病為例，連作田的葵百合發病率高達65.2%，在同一塊田分成土壤蒸氣處理(80℃、20分鐘及60℃、30分鐘)和對照組，結果蒸氣消毒處理均有利葵百合生育及病害防治，並提高切花品質及產量。利用蒸氣消毒回收再利用了罹白絹病及疫病的廢棄介質，椒草扦插後30天，蒸氣消毒處理使白絹病的罹病盆率由對照無處理的90%下降到0%，而疫病罹病盆率自67%下降到8%。此外，經土壤蒸氣消毒處理後，亦可達到防除雜草之目的。而溫水處理所以能有效抑制蔬果採收後病害發生的原因，乃是蔬果採收時田間已感染但潛伏或者是採收及處理過程新發生尚未外顯的病原菌通常僅位於採收後蔬果組織表面或者最外面數層細胞之間，較易受到熱能之影響，因此溫水處理對於採收後病害抑制的效果較能顯現。利用高溫水但短時間60℃/20 秒之溫水處理可以有效抑制或延緩檬果炭疽病及蒂腐病之發生，然而不同的芒果品種 對高溫忍受性都有些許不同，不能冀望所有果實都能適應同一處理條件，必須在大量處理前以少量果實進行測試後方能進行後續處理動作。 Steam disinfection and hot water treatment are used to kill living cells by making protein solid and inactivating enzyme with high heat. In the mean time, they can control the diseases, underground pests and weeds, so the use of chemical or peaticide is decreased. While applying steam disinfection, factors like steam temperature, steaming time, soil moisture and airiness, which affect soil microfloca and chemical ingredients. In Taiwan, the steam disinfection processes used by the farmers are poking, mulching and plowing systems. The best condition for steam disinfection is at the siol temperature between 60 and 80℃ for 30 minutes. Soil steam disinfection significantly controlled the lily yellowing disease and improved the quality of cut flowers 80℃ for 20 min. or 60℃ for 30min. The treated soil can last two continuous lily crops and solve lily monoculture problem. Steam disinfection can be used to recycle used medium. At 30 days after planting of Peperomia obtusifolia, steam disinfection decrease the diseased rate of southern blight and phytophthora rot , from 90% to 0%, and 67% to 8%, respectively. Besides, steam disinfection can also prevent kill weeds seeds. Hot water treatment can effectively reduce the postharvest diseaes due to latent infection in the out layer cells of the fruit. Mango anthracnose and stem-end rot diseases were reduced effectively by quick hot water treatment . However, it varied among mango varieties. Pretest for each variety is required.