Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . the chaffto infect the plants that develop from the kernels. After the spores have lodged in the chaff they re-main there until the oats are planted. Then they ger-minate by sending out little tubes, which enter theyoung plant through the first leaf-sheath. These tubesare only able to gain access to the plants during a veryshort period of the growth of the latter. After the oatshave pushed out the second leaf the danger of infectionby smut is past. When the
Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . the chaffto infect the plants that develop from the kernels. After the spores have lodged in the chaff they re-main there until the oats are planted. Then they ger-minate by sending out little tubes, which enter theyoung plant through the first leaf-sheath. These tubesare only able to gain access to the plants during a veryshort period of the growth of the latter. After the oatshave pushed out the second leaf the danger of infectionby smut is past. When the germinating tube has enteredthe plant it sends out branches in all directions, pene-trating the stem and all its parts, thus forming the 187 188 PUKGI AND FUlfGICIDES mycelium, or vegetative portion of the fungus. As theoats plant grows this mycelium also develops, takingpossession of all the new tissues of the host, and form-ing within the head a mass of thick threads. Thesethreads eventually produce vast numbers of spores, sousing themselves up in the operation that they becomegelatinous, and finally altogether disappear, leaving. g FIG. 78. SMUT SPORES GEllMIXATIKG. MAGNIFIED. nothing but the jjowdery mass of spores, which areblown about to infect other plants, and thus begin anewthe cycle of existence. The smut mycelium usually produces no peculiareffect upon its host-plant early in the season. Infestedplants are seldom distinguishable from healthy ones THE LOOSE SMUT 189 until it is nearly time for the oats to blossom. Thencomes a sudden change; the spores develop rapidly, andare dry, powdery masses before the plants are throughblooming. When one of the branches of a stoolingplant is infested, the others from the same root usuallyare also, a result of the entrance of the smut so soonafter the seed germinates. It sometimes happens thatonly a part of the spikelets of a head are attacked, and,according to Kellerman and Swingle, ^^in a few casessmutted heads have been collect
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpathoge, bookyear1896
