International Journal of Plant Pathology1996-0719xxxx-xxxxKnowledgia Review10.3923/ijpp.2015.48.57ArafatK. H.2201562Powdery mildew caused by Erysiphe necator is the most serious diseases of grapes in Egypt and the world. Conidia of Uncinula necator are formed in a wide range of climatic conditions. Fungal growth, conidia formation and germ tube formation are mainly influenced by temperature. The prediction of occurrence of powdery mildew disease is one of the important processes in the fight against disease and reduces the losses of direct and indirect. Average temperatures which are obtained from meteorological stations located in places in Egypt and through the cultivation of grapes were possible to determine the month will be higher and lower rate of germination of conidial spores (GR), Penetration Rate (PR), reduction in the germination rate due to presence of liquid water on the host surface (GRM) and reduction in the number of conidia produced per day due to the presence of liquid water in the host (SRM). Studied were in the three Governorates viz. Alexandria, Giza and Aswan where it was getting on average temperatures for a period of fifteen years earlier and the application of equations of growth rate and the rate of penetration of the conidial spores of the fungus that causes conidia for white powdery mildew. The aim of this work improve control of powdery mildew disease by improving timing of biological control agents and soft fungicides sprays and possibly reducing the need for fungicide sprays during the growing season. Reducing fungicides application will also reduce exposure of the environment as well as farm workers and consumers to harmful pesticide residue. Fewer sprays also mean a lower consumption of fuels and lower labor costs which further reduces input costs and thereby increases the economic margin for grape growers. This is the first research study done in Egypt to study the effect of environmental conditions on the powdery mildew disease of grape.]]>Berger, R.D. and J.W. Jones,198575792797Blaise, P.A. Arneson and C. Gessler,198771574578Chellemi, D.O.,19901990Delp, C.J.,195444615626FAO.,20102010Fessler, C. and H.H. Kassemeyer,1995Uncinula necator.]]>346364Oehlert, G.W.,20101st Edn.,Pages: 600Pages: 600Mackenzie, D.R.,198165394399Rumbolz, J. and W.D. Gubler,2005Erysiphe necator.]]>54535548Sall, M.A.,198070338342Stummer, B.E., I.L. Francis, T. Zanker, K.A. Lattey and E.S. Scott,2005116676Waggoner, P.E. and J.G. Horsfall,19691969Willocquet, L., D. Colombet, M. Rougier, J. Fargues and M. Clerjeau,1996102441449Bendek, C.E., P.A. Campbell, R. Torres, A. Donoso and B.A. Latorre,2007Erysiphe necator.]]>5522532Braun, U., R.T.A. Cook, A.J. Inman and H.D. Shin,20022002pp: 13-55pp: 13-55Calonnec, A., P. Cartolaro, C. Poupot, D. Dubourdieu and P. Darriet,2004Uncinula necator on the yield and quality of grapes (Vitis vinifera) and wine.]]>53434445Campbell, P., C. Bendek and B.A. Latorre,2007Erysiphe necator) outbreaks on grapevines in relation to cluster development].]]>34511, (In Spanish)Carroll, J.E. and W.F. Wilcox,20039311371144Chellemi, D.O. and J.J. Marois,1991Uncinula necator.]]>75455457Gadoury, D.M., R.C. Seem, A. Ficke and W.F. Wilcox,200191948955Gadoury, D.M., R.C. Seem, R.C. Pearson, W.F. Wilcox and R.M. Dunst,200185137140Jarvis, W.R., W.D. Gubler and G.G. Grove,20022002pp: 169-199pp: 169-199Kast, W.K.,199752230231Madden, L.V. and F.W. Nutter Jr.,199517124137Pearson, R.C. and D.M. Gadoury,19921992