. Circular. Insect pests; Insect pests. HOW TO CONTROL THE PEAR THRIPS. 23. commercial tobacco extract No. 1, which is a (hirk, almost viscous liquid containing per cent nicotine, at the rate of 1 to 75; or tobacco extract No. 2, which is a light-colored liquid containing 40 per cent of almost nonvolatile nicotine at the rate of 1 to 1,500, or a fraction more than a pint to a 200- gallon tank. This form of the nicotine has been highly efficient and will in all probability be more satisfactory than the former. By reason of its greater concentration the handling and transportation charges w
. Circular. Insect pests; Insect pests. HOW TO CONTROL THE PEAR THRIPS. 23. commercial tobacco extract No. 1, which is a (hirk, almost viscous liquid containing per cent nicotine, at the rate of 1 to 75; or tobacco extract No. 2, which is a light-colored liquid containing 40 per cent of almost nonvolatile nicotine at the rate of 1 to 1,500, or a fraction more than a pint to a 200- gallon tank. This form of the nicotine has been highly efficient and will in all probability be more satisfactory than the former. By reason of its greater concentration the handling and transportation charges will be much less; also, the nicotine contained in this ])reparation is much less vola- tile, thus allowing the use of a smaller amount of actual nicotine in the dilu- tion, as it remains an active killing agent for a longer time on the trees. In Santa Clara County greater dilutions than these have been found to be satisfactory, due most likely to different climatic conditions, evapo- ration there being much less at this time than in the interior counties where the atmosphere is drier. Grow- ers in the Santa Clara Valley are advised to use the 3 per cent distillate-oil emulsion, with tobacco extract No. 1 added at the rate of 1 to 100 or tobacco extract No. 2 at the rate of 1 to 2,000. These recommendations hold for all thrips sprayings, for both adults and larva3 and on all varieties of deciduous fiaiits attacked by the pear thrips. No or- chards should be sprayed, however, when the trees are in full bloom. All spraying for adults should be done before the blos- soms appear and spraying for larva^ after a large ])roportion of the ])etals have fallen. In the prune orchards of Santa Clara Valley deep fall plowing and cross-])low- ing has proved a valuable and profita- ble aitl in controlling tlie thri])s. Those who can do so are strongly advised to irrigate their orchards in September or October, and when the soil is in proper condition plow with disk plows to a depth of 7 or Fig
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsectp, bookyear1904
