. The American florist : a weekly journal for the trade. Floriculture; Florists. igog. The American Florist. 69. WHITE KILLARNEY GROWING AT THE SCARBOROUGH RANGE OF THE F. R. PIERSON CO., TARRYTOWN-ON HUDSON, N. Y. Dr. W. E. Hinds in May. 1900, re- ported tlie results of some tests for tlie suppression of greenhouse thrips in wliicli lie used .155, .2 and .31 grams of potas- sic cyanide to 30 cubic feet with excel- lent results. This is using the gas at the rate of one ounce of cyanide to to feet in an all-night fumigation. All the thrips were killed in his tests. It will be seen t
. The American florist : a weekly journal for the trade. Floriculture; Florists. igog. The American Florist. 69. WHITE KILLARNEY GROWING AT THE SCARBOROUGH RANGE OF THE F. R. PIERSON CO., TARRYTOWN-ON HUDSON, N. Y. Dr. W. E. Hinds in May. 1900, re- ported tlie results of some tests for tlie suppression of greenhouse thrips in wliicli lie used .155, .2 and .31 grams of potas- sic cyanide to 30 cubic feet with excel- lent results. This is using the gas at the rate of one ounce of cyanide to to feet in an all-night fumigation. All the thrips were killed in his tests. It will be seen that the results were quite different, for, in one case, from one- fifth to one-third ounce of cyanide gave positive results, while in the other three ounces failed to kill thrips. In Circular 37 of the United States Di- vision of entomology it is stated that Scott, McGowan and Meteor carnations withstood one-tenth gram of 98 per cent cyanide per cubic foot for 15 minutes without injury. This is a little over three ounces per 1,000 feet although we must not fail to consider that the time for the exposure is very short. "This will kill about 90 per cent of the plant lice but will not kill ; Since the use of hydrocyanic acid gas has passed the experimental stage in the repression of cucumber insects it was decided that some tests should be made as to its value in killing thrips. Three con- nected houses each 15x300 feet, of the short roof type, were offered us for a test with the gas. There were one and three-fourths houses in young plants 12 to 18 inches in height, and one and one- fourth houses of large bearing plants. The old plants were infested with white fly and all the plants were completely covered with thrips. Even the blossoms were filled with thrips. Twenty-five staminate flowers picked in various parts of the house yielded 81 specimens of thrips. The pistillate flowers were ap- parently as badly infested and the failure of the plants to set fruit was a
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectfloriculture, bookyea
