番石榴為中部地區重要之經濟果樹,主要栽培品種有珍珠拔、世紀拔及水晶拔等三種。其生育期間主要發生病害有炭疽病(Colletotrichum gloeosporioides)、黑星病(Phyllosticta psidiicola)、瘡痂病(Pestalotia psidii)、立枯病(Myxosporium psidii)及煤煙病(Phaeosaccardinula javanica)等。其中以炭疽病、黑星病及瘡痂病為害果實最為嚴重。本試驗主要目的在於調查番石榴病害之發生消長,並進行防治藥劑篩選。於2003年選擇彰化縣二水鄉、社頭鄉及員林鎮等地區調查番石榴炭疽病、黑星病、瘡痂病及煤煙病之週年消長,結果顯示炭疽病主要發生於6~8月及10~2月。黑星病為7~10月,煤煙病則全年均有發生,主要發生月份為11~2月。田間藥劑篩選防治工作於2003年7月在二水鄉番石榴產區進行,防治對象為炭疽病及黑星病,供試品種為珍珠拔,供試藥劑包括25%克熱淨溶液800倍、75%四氯異苯腈可溼性粉劑600倍、44.2%克收欣水懸劑2,000倍、33.5%快得寧水懸劑1,000倍、24.9%待克利乳劑3000倍、40%邁克尼可濕性粉劑12,000倍、80%免得爛水分散性粒劑750倍及無藥劑處理等八種。結果顯示44.2%克收欣水懸劑、24.9%待克利乳劑3,000倍及33.5%快得寧水懸劑1,000倍對番石榴炭疽病皆有防治效果。於番石榴黑星病發生時,供試藥劑44.2%克收欣水懸劑2,000倍可有效防治炭疽病及黑星病的發生,另外75%四氯異苯腈可溼性粉劑600倍具有防治煤煙病的效果。
The guava is an important economic fruit in Taiwan. The major fruit diseases included anthracnose caused by Colletotrichum gloeosporoides, scab caused by Pestalotia psidii and black spot caused by Phyllosticta psidiicola. Only 23% Azoxystrobin SC was recommended to control the anthracnose. The occurrence of fruit diseases and their chemical control were studied during 2003 to 2004. Results showed that the peak occurrence of the anthracnose was June. to Aug. and Oct. to Feb. The black spot and sooty molds were occurred on Jul. to Oct. and Nov. to Feb. Seven fungicides including 25% Iminoctadine triacetate S at 1:800 dilution, 75% Chlorothalonil WP at 1:600 dilution, 44.2% Kresoxim-methyl SC at 1:2000 dilution, 33.5% Oxine-copper SC at 1:1000 dilution, 24.9% Difenoconazole EC at 1:3000 dilution, 40% Myclobutanil WP at 1:12000 dilution, 80% Metiram WG at 1:750 dilution were conducted for controlling guava anthracnose and nontreatment as a control. Results showed that 44.2% Kresoxim-methyl SC at 1:2000 dilution, 24.9% Difenoconazole EC at 1:3000 dilution, and 33.5% Oxine-copper SC at 1:1000 dilution had a better effect to the anthracnose. The 44.2% Kresoxim-methyl SC at 1:2000 dilution was highly effective against both anthracnose and black spot diseases. Furthermore, 75% Chlorothalonil WP at 1:600 dilution was to be effective for the control of the sooty mold.