INTEGRATED MANAGEMENT OF POWDERY MILDEW OF GERBERA UNDER POLYHOUSE CONDITION IN ARUNACHAL PRADESH Sunil Kumar, Krishna S. Tomar, R.C. Shakywar* and M. Pathak College of Horticulture and Forestry, Central Agricultural University, Pasighat-791102 (A.P.) *E-mail: rcshakywar@gmail.com ABSTRACT: Powdery mildew caused by the fungus Erysiphe cichoracearum DC. is a common disease of gerbera grown in Indian conditions. Fungicidal and varietal trial was conducted at Instructional farm, Department of Floriculture, College of Horticulture and Forestry, Central Agricultural University, Pasighat, during April 2011 to March 2012. In fungicidal disease management, least disease severity (5.23%) was observed in spray of wettable sulphur @ 2.5g/l of water followed by Carbendazim @ 2g/ l of water foliar spray (7.23 %). Whereas, the unprotected treatment showed highest disease severity (65.30 %). The highest number of flowers m -2 / year (195.00) and number of suckers / plant / year (6.60) were also recorded in wettable sulphur @ 2.5g/l of water foliar spray. Powdery mildew symptoms were first observed on the leaves of the varieties viz. Pia, Rionegro and Tecala on 30 th day after planting. In Manizales, Teresa and Galileo powdery mildew incidence was started only after 38 days of planting. On the other varieties Figaro, Marinila and Palmira powdery mildew incidence was started only after 68 days of planting. Palmira variety showed resistance to powdery mildew with per cent disease index of 9.27% at the end of 160 days after planting followed by Figaro and Marinila with PDI of 9.73% and 10.23%, respectively. Variety Teresa showed moderately resistant reaction (24.57 %) against powdery mildew infection. Varieties Pia and Tecala were highly susceptible to powdery mildew throughout the experiment which showed per cent disease index of 65.30% and 54.27%, respectively. Other varieties like as Galileo (34.73%), Manizales (46.93%) and Rionegro (49.67%) showed susceptible reaction to powdery mildew infection. Keywords: Disease, gerbera, fungicides, powdery mildew, screening, variety. Gerbera (Gerbera jamesonii Bolus ex. Hooker F.), belongs to the family Asteraceae, is a popular flower throughout the world. Many people enjoy by growing this flower in gardens or large containers (Tjia et al., 14). It has demand as cut flower and also as an ornamental potted plant gaining importance in the world market and has a very good export potential because of its graceful appearance, hardiness and ability to withstand during transportation and long shelf life (Latha and Suresh, 9). The tremendous variability in gerbera with reference to flower colour, shape and size makes it more useful for cut flowers, bouquet and decoration in marriage and landscaping in gardening (Aswath and Survay, 2). Apart from domestic consumption it has got export potential also. Claims have been made that from 30-70 % of the potential lasting quality of cut flowers is determined at harvest (Halevy and Mayak, 5). In India, gerbera is mainly grown in North Eastern States, Karnataka and Maharashtra (Aswath and Rao, 1). Gerbera is susceptible to a variety of pests and diseases. Powdery mildew is one of the most destructive fungal diseases of gerbera causing significant economic losses under poly house conditions. It is caused by two fungal species viz. Erysiphe cichoracearum DC and Podosphaera fusca (Fr.) S. Blumer. They are the obligate parasite (they live always living matter) and can affect all parts of the plants. Powdery mildew is easy to identify since to noticeable white spots or powder like appearance or white patches appear on the upper and lower surfaces of the leaves or flowers. These spots are enlarge to form a white, powder like mat, which can spread to stems and flowers also (Moyer and Peres, 11). This disease reduced plant growth and lesser flower quality which contribute to economic losses. Severely infected leaves turn pale yellow or brown and the plants eventually die. Some environmental conditions like high relative humidity (80-95%), moderate HortFlora Research Spectrum, 2(2): 130-134 (April-June 2013) ISSN : 2250-2823 Received : 6.4.2013 Accepted : 04.5.2013 Author's Copy Not For Commercial Use