90 STATE HORTICULTUEAL SOCIETY. 



ospores. If these be placed on the leaves of wheat, the characteristic 

 rust will be produced. 



Years ago it was the belief of farmers in England and in the older 

 states of this country, that if barberry bushes were near wheat fields 

 there would be a great amount of rust, and with our present knowledge 

 this can at once be accounted for. On the other hand, rust often appears 

 on wheat in the spring miles from any barberry plants. How can this be 

 accounted for? Repeated experiments have failed to produce rust by 

 sowing the spores on the leaves, and it has been found that all parts of the 

 plant, after the radicle has pushed its way an appreciable distance outside 

 the seed, were proof against infection in this way. 



It has also been found that if grain seeds are soaked in a fungicide 

 before they are planted, the amount of rust will be wonderfully reduced. 

 This has given rise to the theory that the teleutospores may be on the 

 seed wheat, and, germinating, infect the young wheat plantlet as the 

 radicle emerges. It is possible also that if the seed wheat came from 

 rusted plants, the mycelium might have been within, and only wanted 

 favorable conditions for development. However it may be accounted for, 

 there can be no question but that the barberry is unnecessary for the 

 reproduction of the rust, although it may and often does supply one 

 generation in the cycle. 



For the rust of our grains, spraying is out of the question. Soaking the 

 seeds in solution of sulphate of iron or sulphate of copper has been 

 practiced for many years and is quite effectual. Unless carefully done, 

 however, the vegetative power of the seed is lessened and a poor stand is 

 secured. Hence great care should be used. 



During the past two or three years the effect of heat in destroying the 

 spores has been tested and found even more effectual than the copper and 

 iron solutions. The experiments in this country were conducted by Prof. 

 Kelleeman of Kansas, and it was found that, by soaking the seed for 

 fifteen minutes in water at 132 degrees Fahrenheit, the spores were 

 destroyed and grain free from rust resulted. Care must be taken to 

 maintain a uniform temperature, as anything above this point will injure 

 the viability of the seed; and at even a few degrees below, the spores 

 would not be destroyed. 



Of the other injurious fungi, are the black-knot of the plum, the black- 

 rot of the grape, and others of this class commonly known as black fungi. 

 In the State Horticultural report for 1889 will be found descriptions and 

 illustrations of the black-knot, and it need not be repeated here. It may 

 be said, however, that whenever any fungi of this group are found, the 

 diseased plants should be gathered and burned. 



The spraying with arsenites, for our insect pests, is now becoming quite 

 common, and, with the new light that is each year being shed on the 

 subject of fungicides, it may be confidently predicted that the day when 

 fungicides will be freely used is not far off. 



If it is found that fungicides will answer as insecticides, the problem 

 will be greatly simplified. 



BLACK-KNOT IN PLUMS. 



The secretary read a letter from Mr. A. J. Knisely of Benton Harbor, 

 urging amendment of the yellows law so as to provide for inspection of 

 plum orchards for detection and destruction of black-knot. 



