490 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



from the j^eriplieiy, allowing as little as possible to fall to tlie ground 

 and permitting each spray particle to adhere. It is best done in the 

 cool of the day, and, where possible, in calm and cloudy weather. 

 With one-hfth of the time and material now ex^jended in California 

 the sjn-aying should be successfully done, so that three sprayings at 

 proper intervals will be cheaper and far more satisfactory than only 

 one as ordinarily conducted. In this particular neither Mr. Coquil- 

 lett's nor Mr, Koebele's experiments are entirely satisfactory, as we 

 were so far from the field while they were being carried on as to 

 render any special direction of them impossible. Both strove for the 

 practically impossible, viz, the destraction of all insects by a single 

 application. Mr. Koebele's estimate of the cost of the kerosene wash 

 is also too high, as he used it much stronger than necessary. The 

 resin compounds may doubtless be used to advantage in connec- 

 tion with the kerosene emulsions; but anything which will give per- 

 manence and preventive character to the wash will add greatly to 

 its value. Without going into details as to reasons, we would there- 

 fore recommend the addition to every 50 gallons of the kerosene-soap 

 wash, made after the usual formula, 3 ounces of arsenious acid. 

 Though the arsenical preparations are mainly effective against man- 

 dibulate insects, by poisoning through the stomach, they have also 

 more or less effect by contact, and we are strongly of the opinion 

 (which we hope soon to verify) that this combination, for the first 

 time recommended, will give the spray more lasting effect, and that 

 the few insects which escape the direct spray will be destroyed as 

 they subsequently leave their protecting retreats or hatch from eggs 

 and" crawl about the tree. As a means of arresting the growth of the 

 black-mold (which is, however, only the indirect consequence of the 

 Coccid), so troublesome an accompaniment of the leery a, a small pro- 

 Xjortion of sulphate of copper might also be added. 



Just as there is now a great wastage of time and material in drench- 

 ing a tree, so the spraying nozzle most in vogue in California is also 

 wasteful. That most commonly used is the San Jos6 nozzle, in which 

 the water is simply forced through a slightly flaring terminal slit in 

 a more or less direct and copious jet. The force and directness of the 

 spray give this nozzle its popularity under the mistaken spraying 

 notions which prevail, and to this we must add the fact that, being 

 a patented contrivance, it is well advertised and on the market. 



The cyclone nozzle has not yet had proper trial to impress its ad- 

 vantages, having scarcely been knovni prior to the experiments of 

 Messrs. Coquillett and Koebele. That made and sold by G. N. Milco 

 is patterned in size and aperture after that which we designed to spray 

 from near the surface of the ground. What is wanted for an orange 

 grove or for trees is a bunch of nozzles of twice the ordinary size 

 and capacity, the size of the outlet to be regulated by the force of 

 the pump. There is no form of nozzle so simple and so easily ad- 

 justable to all purposes. We strongly recommend a bunch of four 

 nozzles of twice the ordinary size and thickness, one arranged so as 

 to have the outlet distally or at one end of the piping (which may be 

 ordinary gas-pipe) and the other three on branches, so that the outlet 

 is at right angles, each about an inch below the other, and so placed 

 that they are separated by one-third the circumference of the main 

 pipe. Such a bunch, with apertures properly adjusted to the occa- 

 sion, worked from the center of the tree, will envelop it in a perfect 

 hall of floating mist, which in a very short time will imbue all acces- 

 sible parts. For tall trees a more forcible direct spray might be sent 



