紅龍果莖潰瘍病菌之殺菌劑篩選及紫外線抑制效果

Study on the Fungicide Screening and Ultraviolet-C Irradiation Efforts for Inhibiting Neoscyralidium dimidiatum

葉士財(Shih-Tsai Yeh) ； 謝慶昌(Ching-Chang Shiesh)

《臺中區農業改良場研究彙報》 127期 (2015/06) Pp. 1-14

摘要

紅龍果莖潰瘍病（Neoscytalidium dimidiatum）為紅龍果最主要的病害，可為害紅龍果嫩莖及果實，嚴重時會造成組織腐爛，影響商售價值。本病目前尚無推薦藥劑防治，以植物保護手冊之紅龍果炭疽病推薦藥劑做PDA平面篩選，結果以62.5%賽普護汰寧（Cyprodinil+Fludioxonil）水分散性粒劑1,500倍、25.9%得克利（Tebuconazole）水基乳劑1,000倍及80%免得爛（Metiram）水分散性粒劑500倍稀釋液效果最好，可達百分之百抑制菌絲生長效果。本菌菌絲以PDA培養基培養於30℃溫度培養箱，第3天即可長滿直徑90 mm培養皿，如果採UV-C60W照射，距離在24 cm，以照射30分鐘效果最佳，其第2天菌落直徑為24.1±0.6 mm，與對照31.3±0.3 mm呈極顯著性差異。而莖潰瘍病病菌孢子以UV-C 60W照射，距離在35 mm照照射10分鐘、30分鐘及60分鐘，皆可完全抑制孢子發芽。

關鍵字

紅龍果 ； 莖潰瘍病 ； 殺菌劑篩選 ； 紫外線

並列摘要

Pitaya Stem Canker is one of the major disease in pitaya. The symptom occurred in young stems and fruits,and further more, the infected lesion will turn into brown or black spots and ruinned the tissue. Unfortunately, there is still no offical recommended treatment for controlling pitaya Stem Canker disease. Thus, the purpose of this research is to investigate the effect of fungicides and UV-irradiation on Pitaya Stem Canker pathogen (Neoscytalidium dimidiatum) through observing the mycelia growth on potato dextrose agar (PDA). The results showed that 62.5% Cyprodinil+Fludioxonil (1500 x dilution), 25.9% Tebuconazole (1000 x dilution) and 80% Metiram (500 x dilution) are 100% inhibitory. On UV-C 60W exposure at 24 cm from PDA for 30 min has the best effencicy, the mycelium diameter is about 24.1±0.6 mm comparing to control (31.3±0.3 mm). Using 253.7 nm UV-C 60W irradiation at 35 mm distance for 10 min, 30 min and 60 min are able to inhibit spore germination.

並列關鍵字

pitaya ； pitaya stem canker pathogen (Neoscytalidium dimidiatum) ； fungicide screening ； UV-irradiation