Williams news., 1922-06-30


 I fit. A paddle, dasher, or some other
 form of agitator must be provided to
 keep the liquid stirred. A Strainer O1
 2O-mesh brass or bronze screen should
 be fitted to the opening through which
 the water enters the tank and an
 other over the outlet leading to the
 pump. The parts of the pump in which close fitting is required should be ot brass, bronze, porcelain, or some other substance less rapidly cOrroded by the chemicals than iron and steel. All commercial spray pumps are built in this way, but pumps which were in tended for other purposes should be refitted when used for spraying.
 An engine-driven outfit must have a relief valve near the pump, permit ting the surplus flow to return to the tank. The pump must have an air pressure chamber large enough to keep the flow steady and insure even distribution of the poison. Even pres sure, indispensable for uniform spread of the poison, cannot be maintained without pressure gauge. This gauge should be attached to the pres sure chamber or near it and at a dis tance from relief-valve and nozzles.
 The boom or pipe which carries the nozzIes and supplies them with liquid from the pump is made of twO-foOt pieces of one-hah inch galvanized iron pipe joined by ITS, each of which af lords an opening for the attachment of q nozzle. The boom is connected with the pump by a one-half inch pressure hose. The boom should be supported by a piece of timber, two by four, clamped or hinged to the truck
  wired to it. Plain misty nozzles- without strainerS or other complica- tions, should be used.
 Spray in Warm Weather.
 The best time for spraying is at point of weevil infestation--from one to two weeks before the first crop is ready for cutting, when the young larvae become so numerous that they completely destroy the growing tips. After that point is reached the weevils, if left alone, consume the leaves until nothing is left but the woody fbers. If spraying is done at this time the crop recovers quick ly. Spraying yearly in the spring sometimes entirely prevents damage, but it is uncertain. On the other hand, plants sprayed after they were en- tirely stripped of their foliage have been able to recover and bloom, but this allows destruction to go too far and makes recovery too slow.
 Spraying at the turning point'' not only protects the first crop but con- fers an even larger benefit on the sec ond crop, which sprouts and grows without delay, and no treatment of the stubble is necessary.
 Stubble spraying, after the cutting of the first crop, has been successfully done, but it requires getting into the field immediately after cutting and a much larger quantity of liquid is re- quired than if it were applied to the first crop. Stubb1e spraying, there fore, is advised only when earlier spraying has been impossible.
 Spraying should be done, if possible, at the beginning of a warm spell. The weevils do not feed so voraciously in cool weather.
 There are other control measures, but none of them promises much more unless applied before or immediately after the first cutting. One method is to pasture the alfalfa field until most of the eggs and young larvae have been destroyed. Another is to use the alfalfa as a soiIing crop, cutting 1t green two or three times during the season. These methods, however, must be practiced before the turning point of infestatiOn, as after that time he weevils destroy the plants so com l oletely that there is not enough growth 1 for either pasture or SOiling. Another l method is to cultivate the field with | a harrow other implement, imme- | 1iately after the first cutting, in such | way as to cover the field with a dust l mulch, thus exposing the entire sur | face of the field to the sun and kill | nS most of the weevils. In some in- 1 stances. the second crop has been pro- -ected by dragging the stubble, while 1 t is still wet from irrigation. with i he land leveler or the clod breaker. This causes the insects to perish by them in the mud, but it is aa----nful> to the soil and is, not recon nended.