重庆地区茶树病害种类及武夷菌素对茶病的田间控制效果

Survey of tea Diseases in Chongqing and the Efficiency of Disease Control with Wuyiencin Under Field Conditions

2005-2007年调查重庆主要茶叶种植区、县茶树病害的发生情况,共查明病害16种,分布频率较高(F>42)的有云纹叶枯病、煤污病、地衣病、轮斑病、炭疽病、白星病和藻斑病等,其中以前4种病害发生最普遍,发病分布频率和病植株率分别达到70%和30%以上,而以云纹叶枯病和轮斑病对茶树的危害最严重.武夷菌素是产自于不吸水链霉菌(Strepromyces ahygroscopicus)的一种无毒性生物杀菌剂,测定该药剂在田间条件下对重庆当地主要茶树叶部病害的防治效果,采用原药的600倍液并按15 L/667 m2的用量对茶树叶面喷雾2次.以对照病叶率计算武夷菌素对茶树云纹叶枯病(Colletotrichum cameliae)、轮斑病(Pesalotiopsis theae)和其它叶斑病的防效,分别为71.33%,65.38%和87.78%;而按病害严重度计算分别为61.02%,77.08%和79.01%7.经统计学显著性测验表明,武夷菌素对这些茶树病害的相对防病效果与多菌灵的病害控制效果没有显著的差异(p>0.05),但处理与对照茶树病害的病叶率和病情指数的差异都达到了极显著水平(p<0.001),这表明武夷菌素对茶云纹叶枯病和轮斑病具有很好的控制效果,可以代替多菌灵在茶叶生产中应用.

A disease survey was performed on tea crops in 9 counties of Chongqing, China and 16 leaf diseases were diagnosed and recorded. These tea diseases were leaf blight （Collectortichum cameliae）, gray blight （ Pestalotiopsis theae ） , sooty blight （ Neoca pnodium theae ） , lichinosis （ Barbella pendula , Drummondia sinensis , Parmelia cetrata , etc. ）, anthracnose （ Colletotrichum theae-sinensis ） , white scab （Elsinoe leucospila ） , Phyllosticta leaf spot （Phyllosticta theae ） , Gray mold （ Botrytis cinerea ） ,alga red rust （Cephaleuros virescens）, red leaf spot （Phoma theicola）, root-knot nematode （Meloidogyne spp. ）, bud blight （ Ph yllosticeta gemmiphliae ） , sclerotial blight （ Sclerotium rol f sii ） , blister blight （ Exobasidium vexans）,shoot withering （Diplodia theae-sinensis） and copper blight （Guignardia camelliae）. The first four were the commonest diseases present; the distribution frequency and prevalence of the four diseases reached over 70 % and 30 %, respectively. The leaf blight and gray blight were the most damaging diseases in tea orchards of these counties. Wuyiencin is a none-toxic mycofungicide derived from Streptomyces ahygroscopicus var. wuyiensis. A field experiment was conducted to test the efficiency of wuyiencin in controlling tea diseases. Recordings in the experimental tea fields before wuyiencin sprays showed that the percentages of diseased leaves （PDL） of leaf blight, gray blight and other leaf spot diseases were 38.42%, 13.53 % and 54.82%, disease severities （DS） were 8.65%,5.74% and 7.44%, respectively. Two sprays with wuyiencin （concentration 16.7 mg/L and dosage 25 L/667 m^-2） were applied twice on June 18 and July 2, 2006. The intensities of leaf diseases were recorded 18 days following the last spray. In the treated plots, the PDL were 12.81%, 6. 12% and 10.37%, and the DS were 5.27%,1.96% and 2.07%, respectively for the three kinds of diseases; but in the CK plots the PLD were increased to 44.68%,17.68% and 84.84%,the DS to 13.52%, 8. 55% and 9.86%, respectively. Based on PLD and DS data in the CK crops, the relative efficiencies of leaf diseases control by wuyiencin were 61.02%-87.78%. Statistic analysis showed that these disease control effects were all extremely significant （p〈0. 001）. However, analysis also showed that the disease control achieved by wyjiencin was not significantly different from that by standard fungicide carbendazim （p〉0. 05）. This result indicates that wuyiencin can be applied to replace carbendazim in controlling leaf diseases in tea fields.