紅龍果濕腐病及煤煙病之發生與預防

The Severity and Prevention of Pitaya Wet Rot Disease and Pitaya Sooty Mould Disease on Pitaya Fruits

葉士財(Shih-Tsai Yeh) ； 尤澤森(Irvan-Prawira Julius) ； 謝慶昌(Ching-Chang Shiesh)

《臺中區農業改良場特刊》 131號 (2016/04) Pp. 71-88

摘要

紅龍果進行去除雄蕊及花瓣，配合清除落花及落果對紅龍果濕腐病(Gilbertella. persicaria)之預防效果，白肉紅龍果(Hylocereus undatus Britt. & Rose)在去花蕊及花瓣 配合清園處理，第9天後幼果濕腐病罹病率為4.7%，與對照處理7.5%呈顯著性差異，去花蕊及花瓣後於果實採收期第9天後之罹病率為2.5%，也與對照處理4.8% 呈顯著性差異。紅肉紅龍果(Hylocerus polyrhizus(Weber) Britt. & Rose)去花蕊及花瓣後9天(清園)處理及(無清園)處理，幼果罹濕腐病，其罹病率分別為8.8、12.3%，對照無處理 為21.3%，呈顯著性差異。果實採收期之濕腐病發病情形，去花蕊及花瓣(清園)處理，其罹病率為6.8%，與對照無處理12.8%呈顯著性差異。有無去花蕊及花瓣，在紅肉及 白肉紅龍果幼果或成熟果皆以上層果罹病率最低。下層果罹病率最高，罹病率皆超過6成。於室內篩選得克利(Tebuconazole)、免得爛(Metiram)、波爾多(Bordeaux mixture)及枯草桿菌(Bacillus sp.)等4種藥劑，可完全抑制紅龍果濕腐病病原菌絲之生長。紅龍果煤煙病(Phaeosaccardinula javanica)發生在半翅目(Hemiptera)害蟲所分泌排泄蜜露所寄生感染，以乾旱季節受發生率偏高，被害處出現暗褐色至黑褐色的覆蓋污物，此種污物 由煤煙病菌絲塊所形成，惟阻礙莖部光合作用與呼吸作用，應防治害蟲即可降低為害。

關鍵字

紅龍果 ； 濕腐病 ； 煤煙病 ； 殺菌劑 ； 套袋

並列摘要

In Taiwan, pitaya fruit is one of the economic crops. However, Taiwan is hot and humid climate country which leads to rapid spread of the diseases. Two of many diseases that often occur in pitaya plant orchard are pitaya wet rot by Gilbertella. Persicaria and pitaya sooty mould by Phaeosaccardinula javanica. The objective of this study is to investigate the occurrence and prevention of these diseases. The prevention of pitaya wet rot diseases by removing the petals and stamens showed that the disease severity of Hylocereus undatus Britt. & Rose young fruits at day 9 was about 4.8% while the disease severity without removing the petals and stamens (control) was about 7.5%. Furthermore, the disease severity of Hylocereus undatus Britt. & Rose fruits 9 days after harvest showed that removing petals and stamens treatments (2.5%) had lower disease severity than non-removing petals and stamens (4.8%). The disease severity of Hylocerus polyrhizus (Weber) Britt. & Rose young fruits 9 days after removing the petals and stamens with or without cleaning the orchard were about 8.8% and 12.3% while control treatment was about 21.3%. The disease severity of Hylocerus polyrhizus (Weber) Britt. & Rose fruits 9 days after harvest showed lower disease severity in removing petals and stamens treatment (6.8%) than control (12.8%). Either young or mature fruits of Hylocerus polyrhizus (Weber) Britt. & Rose and Hylocereus undatus Britt. & Rose showed the lowest disease severity when the fruits are grown in higher parts of plant while the disease severity of pitaya fruits which grow at lower parts of plants showed above 60%.In vitro fungicide screening showed that Tebuconazole, Metiram, Bordeaux mixture and Bacillus. sp are able to inhibit pitaya wet rot phatogen (Gilbertella. Persicaria). Pitaya sooty mould happens when the Hemiptera insects secrete nectar which causes the infection by Phaeosaccardinula javanic. This phenomenon usually happens during dry season. The infection area usually appear dark brown to black color dirt cover resulting the inhibition of plant photosynthesis and respiration. Therefore, prevention or management of Hemiptera is needed in order to prevent Pitaya sooty mould occurrences.

並列關鍵字

pitaya fruitsl ； pitaya wet rot ； pitaya sooty mould ； fungicide