. Elementary principles of agriculture; a text book for the common schools. a stalk. Two germinating SHOWS a SpOrO 01 thespores (a, b) piercing the epidermis, and j. x ur i j. • j. the threads penetrating the cells of the potatO blight germmat- leaf. Highly magnifieoT • i n rni n . mg on a leaf. The firstthread soon enters the plant and absorbs the moistureand food substance of the potato leaf. It soon forms acrop of spores, sometimes in only a few days. Thesespores are blown to otherplants, and soon a wholefield will be blighted by thefungus. Most species of fungigrow on only one kind ofplant
. Elementary principles of agriculture; a text book for the common schools. a stalk. Two germinating SHOWS a SpOrO 01 thespores (a, b) piercing the epidermis, and j. x ur i j. • j. the threads penetrating the cells of the potatO blight germmat- leaf. Highly magnifieoT • i n rni n . mg on a leaf. The firstthread soon enters the plant and absorbs the moistureand food substance of the potato leaf. It soon forms acrop of spores, sometimes in only a few days. Thesespores are blown to otherplants, and soon a wholefield will be blighted by thefungus. Most species of fungigrow on only one kind ofplant. The fungus thatcauses grape mildew () does not grow on anyother kind of plants butgrapes. The fungus thatcauses the blasting of theears and tassels of corn(corn smut) grows only oncorn. The fungus that causesthe smut of oats never at- tacks corn. However, the Fig. 90. Downy mildew of grape fungus that produces the tu/r^ gonldTophores ^beaTiSf «,,^4. ^^ ^-^^.X «l ^ 1 gonidia, also intercellular myce- rust on grains also attacks uum. After Fungus Diseases of Plants 151 barberry bushes. A number of fungi known as rustshave more than one host-plant. The yellow rust ofapple leaves is the same fungus that produces the so-called cedar apples on cedar trees. 218. Not All Fungi Cause Disease. Some fungi are veryuseful, like the little bacteria that gather the free nitro-gen of the air for beans and clover plants; the yeast,used in making bread, and in making wines and fungi are quite large, as the mushrooms and puff-balls. Certain kinds are highly esteemed as table deli-cacies, and are cultivated. Some species of mushroomsshould not be eaten because they are poisonous. 219. Preventing Fungus Diseases. There is no curefor the fungus diseases in plants. Prevention is the onlysafeguard against loss from parasitic fungi. This isaccomplished in four ways: (a) Treating the Seeds with substances that destroythe disease-causing germs, as scab in pota
Size: 1271px × 1967px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
