. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. ASCOMYCETES 247 originates, and the asci to which it gives rise obtain room for com- plete development either by forcing the separation of the cells in the center of the cellular body or by dissolving some of these. The mature perithecium consists of a flask-shaped structure, the mouth of which projects, along with the tissues which inclose it, slightly beyond the general level (Fig. 106, b). Within the neck of this perithecium are to be found many periphy- ses. The mature asci are
. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. ASCOMYCETES 247 originates, and the asci to which it gives rise obtain room for com- plete development either by forcing the separation of the cells in the center of the cellular body or by dissolving some of these. The mature perithecium consists of a flask-shaped structure, the mouth of which projects, along with the tissues which inclose it, slightly beyond the general level (Fig. 106, b). Within the neck of this perithecium are to be found many periphy- ses. The mature asci are long-clavate. Each ascus contains eight filiform spores, averaging 60-70 fi in length, which issue from the tip of the ascus and readily germinate in water (Fig. 106, c). Control. Proper precautions in the selec- tion of the grain seed, together with thorough preparation of the land, obviate any danger in the case of rye. When detected in the har- vested product, the sclerotia must be shaken out or the product discarded. When ergot appears in abundance on grasses in the pas- ture, either the animals must be taken off until the ergot falls, or, where possible, the grass may be mowed with a machine the blade of which may be set high. In the latter case subsequent raking may be unnecessary. In the central West, ergot is not uncommon on the chief pasture crop, blue grass (Poa pratensis). This may not be ergot of rye, for besides that species, two ergot-producing fungi have been reported on Poa, Claviccps microcephala (Wallr.) Tul. and Claviceps setulosa (Quel.) 1 A disease of rice known as green smut is well developed in the rice-growing regions of Japan and Louisiana. The effect of the fungus is conspicuous (Fig. 107), although only a few grains in a head are affected. The disease has every appear- ance externally of being a smut. Brefeld (Unters. a. d. Gesammtg. d. Myk. 12: 194) and others have studied this form. Brefeld has studied also more particularly a related specie
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Keywords: ., bookauthorduggarbe, bookcentury1900, bookdecade1900, bookyear1909
