. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. APPENDIX. 403 can be applied without damajje to trees. (2) All wild plum trees in the woods through a hop-g-rowing- country should be destroyed. (3) The hop vines should be either burned or thoroughly drenched with kerosene emul- sion as soon after the crop is harvested as possible with a view of killing the males, and thus preventing the impregnation of the females. If these measures are carefully followed, comparative exemption from lice may con- fidently be e
. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. APPENDIX. 403 can be applied without damajje to trees. (2) All wild plum trees in the woods through a hop-g-rowing- country should be destroyed. (3) The hop vines should be either burned or thoroughly drenched with kerosene emul- sion as soon after the crop is harvested as possible with a view of killing the males, and thus preventing the impregnation of the females. If these measures are carefully followed, comparative exemption from lice may con- fidently be Fig. .'i—Tho ITop Phint-louse, male—enlarged. At the present time it is too late for preventive work, and the only thing which can be done to lessen the damage to the crop is to destroy the lice upon the vines by spraying with an insecticide mixture. Such spraying can, with care, be made quite effective, and the individual hop grower will have the satisfaction of knowing that whatever work he does upon his own yard will not be thwarted by the carelessness of neighbors, as during the summer the lice can not migrate except bj^ crawling from one yard to another. Substances to be used—Of all the different substances experimented with in 1888 none gave better satisfaction than properly prepared kerosene emul- sions and fish-oil soaps. FORMULA FOR KEROSENE EMULSION'. Cheap kerosene 8 pints Water 4 pints Soap OA pound Dissolve the soap in the water and add (boiling hot j to the kerosene. Churn the mixture by means of a force-pump and spray-nozzle for five or ten minutes. The emulsion, if perfect, forms a cream which thickens upon cooling, and should adhere without oiliness, to the surface of glass. Dilute one part of the emulsion with twenty-five parts of Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the orig
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