. Essay on the Hessian fly, wheat midge, and other insects injurious to the wheat crops [microform]. Wheat; Insects; Blé; Insectes. MILDEW. 41 common in clear and dry hot years; but when spring is wet, the finest fields of wheat run great hazard of being destroyed, by the mildew, which generally appears upon the breaking ou'- of the sun in the morning, after close and sultry weather, during which there has not been any ; M. Tillet ascribes mildew to a sharpness in the air in dry cloudy weather, which breaks the vascular tissue of the stfins and leaves, and makes them dis- charge a thi
. Essay on the Hessian fly, wheat midge, and other insects injurious to the wheat crops [microform]. Wheat; Insects; Blé; Insectes. MILDEW. 41 common in clear and dry hot years; but when spring is wet, the finest fields of wheat run great hazard of being destroyed, by the mildew, which generally appears upon the breaking ou'- of the sun in the morning, after close and sultry weather, during which there has not been any ; M. Tillet ascribes mildew to a sharpness in the air in dry cloudy weather, which breaks the vascular tissue of the stfins and leaves, and makes them dis- charge a thick oily juice of such a natu. - as to be changed by heat into a rusty powder. Other writers of the last century supposed it to bo a thick clammy vapour which settled upon the stems c: the grain and so stopping the pores as to pre- vent perspiration, and impeding the circulation of the sap. A modern writer, Mr. R. Somerville, iu a communication to the Board of Agricultuve, ascribes mildew to the attacks of insects introduced with the manure; these insects how- ever are found to be minute acari, which are almost always found upon decay- ing vegetable matter, and which in the case of mildew is thi follower and not the cause of the disease. The (rue origin of the Mihlcio has been found to be due to the regular para- sitic growth of the Fuccinia gmminis a fungous plant, belonging to the hypo- dermii division of the eutophyti class of coniomycetes. The name Fuccinia, is derived from a Greek work which .signifies "closely" or " thickly," and alludes to the crowded manner in which the minute fungi are packed in the tufts and patches in whicli they grow. When a stem of wheat begins to be mildewed, a number of ''.ark coloured spots will be seen under the epidermis, some of an orange hue, and others of a dark brown tinge; in a short time the outer cuticle is ruptured, and through the openings are protruded dark clusters of spores, amassed in dense, diffuse tufts, ofte
Size: 2005px × 1246px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade, booksubjectinsects, booksubjectwheat
