SECRETARY'S REPORT. 17 



crop is seriously diminished or nearly annihilated that its effects are ade- 

 quately realized, and the community awake to its importance. 



The respiratory organs are first affected. Spots of an orange or hrown hae 

 appear on the leaves of a young wheac plant, and then upon the straw, in 

 consequence of which the stem is stunted, and the blossom and grain ill 

 developed. On these mildewed patches, various minute fungi abound, of the 

 kind called puccinia, signifying thick, from the crowded arrangement of their 

 clusters. It seems to be a well established fact, that fungi principally affect 

 decaying or diseased vegetation, and that innumerable millions of them float 

 every where in the atmosphere, and pervade the soil, awaiting fivorable cir- 

 cumstances for their development, each one so extremely minute that it can 

 circulate in the sap, or penetrate the finest breathing pores of plant or tree. 



The theory is therefore plausibla, that the wheat plant becomes debilitated 

 by some predisposing cause or causes resulting either from a deficiency of its 

 nesessary constituents in the soil, from too great dilution of its food, from 

 irregular supply, from disorder to the respiratory organs, or from suspension 

 of evaporation by a low temperature and continued wet weather when the 

 plant has taken up a maximniii of moisture, thus stopping the circulation, 

 cutting off the supply of food and nutrition, altering and stagnating the jui- 

 ces, and inducing decay in certain parts which henceforth become a fertile 

 soil for parasitic growths. Assuming then, that disease has begun on account 

 of one or more of these causes, or a complication of them, we can the more 

 easily comprehend how these infinitesimal mushrooms can flourish in unhealthy 

 structure. When the plants begin to be mildewed, the fungi grow just within 

 the openings of their pores, soon destroy their vitality, and bursting through 

 the tissues of their cuticles, cover them with myriads of orange, brown, or 

 black spores, often running into one another, and forming long parallel lines 

 of dense clusters. They seem to exert a chemical influence on the juices of the 

 infested plants, and mechanically interfere with their circulation by intercept- 

 ing the sap that would otherwise nourish the wheat. Hence the mildewed 

 grain never comes to perfection, but shrivels up and yields a disproportionate 

 amount of bran. Thus it has been found by accurate inrestigations to lose 

 from 30 to 75 per cent, of flour. Rain, fogs and mists, which are known to 

 contain more ammonia than the atmosphere, favor the prevalence and spread 

 of mildew, while heat and dry weather counteract it. Light, sandy and cal- 

 careous soils are most liable, clayey most exempt. Enclosed valleys are more 

 subject to it than exposed hills. Among the remedies for mildew, may be 

 recommended clean culture, and supplying the land with all the substances 

 essential to the health and vigor of the plant. If draining were extensively 

 practiced, it would tend to prevent those unwholesome fogs which are a pro- 

 lific source of fungoid vegetation. 



Bearded wheat should be selected for seed, because its cuticle is of firmer 

 texture, and offers greater resistance to the entrance of the fungus than the 

 bald varieties. Steeping it in various mixtures of brine and lime water will 

 not prevent the disease. It will only destroy the germinating power of the 

 fungus on the grain, but will have no influence on that which pervades the 

 air and soil. As the application of salt and lime is destructive to the whole 

 mushroom family, it will be more effectual to sow the surface of the land 

 infested with mildew with from two to six bushels of salt to the acre in the 

 autumn, and the same quantity of freshly slaked lime in the spring. This 

 treatment invigorates the crop, and destroys maggots and worms. Early 

 sown wheat may mature and escape before the ravages of the disease begin. 

 Mildew has been arrested by sprinkling the plants affected with a solution of 

 salt and water, in the proportion of one pound to a gallon. Dusting them 

 with powdered charcoal is said to produce the same effect. It neutralizes 

 ammonia, which is one of the most eflacient agents in promoting a fungus 

 growth. 



Rust in wheat resembles mildew, but is not so injurious, though it does 



