Williams news., 1922-06-30

(Prepared by the United States Department
 of Agriculture.}
 Farmers in regions newly infested by the alfalfa weeviI will be interest ed in knowing that an unusually eff fective method of control has been worked out by the United States De partment of Agriculture. Specialists of the department say that rarely has any method of insect control been so thoroughly safeguarded against fail ure as alfalfa-weevil spraying. It has been tested every season for seven years. The cost of the operation about $1 an acre-is trif1ing compared with the returns, and no farmer in the territory infested or threatened can afford to overlook it, the specialists say. There is no control measure, however, which can be applied advan- .ageously this late in the season. Elf fective work must be delayed until next spring.
 Control by Poison Spray.
 Control is effective by spraying poi son over the fields so that it will cover the growing parts on which the weevils mostly feed. Arsenate of lead and arsenite of zinc have been mostly used, but other arSenicalS recommend ed for orchard spraying are thought to be about as good There is practi cally no danger of burning the foliage of alfalfa, and therefore the range of suitable pOiSons is larger than in fruit tree spraying ArSenate of lead is said to be, everything considered, the best poison to use, principally because it sticks to the leaves more readily and costs less than most of the others.
 The poison is weighed or measured at the rate of two pounds of powder or four pounds of commercial paste for each 100 gallons of water, is stirred with a little water in pail until it becomes a thin paste without Jumps, is diluted and strained into the sprayer tank. Two pounds of laun- dry soap for each gallon should be added, in order to make the liquid stick to the leaves properly. The dry, powdered form of the poison is better than the paste There is no danger of stock being poisoned by hay cut from sprayed fields where the poi son is applied at a rate of not greater than 100 gallons of spray mixture per acre.
 Simple Outfit Sufficient.
 The essentials of the spraying outfit are: A truck or other vehicle, tank with an agitator to keep the poison from settling to the bottom, pump, a pressure gauge, an engine and pump ing jack, unless the pump is to be driven by hand, strainer, pipe for distributing the liquid from the pump. and as many nozzles as are required by the capacity of the pump. These essentials may all be contained in a barrel-pump outfit carried in a, wagon. The pump must be capable of deliv- ering four-ffths of a gallon or more
 
 of at least 75 pounds. If the pressure is less than that, the mist spray will not be fine enough to prevent the liquid from gathering in drops and running to the ground instead of dry ing on the tops of the plants. < The number of nozzles used should be sufficient to take up the capacity of the pump At the average walk ing gait of a team, each nozzle should | deliver nine-tenths of a gallon a min ute Therefore, a pump of nine-gal | lon capacity per minute will supply | ten nOzzles, each of which covers a | strip two feet wide. By an arithmet- ica1 calculation of the cubicaI con- tent of the pump cylinder ana the | number of strokes per minute, the ca pacity of the outfit can be determined. | The spray should be applied at the l rate of 100 gallons of spray mixture i per acre.
 Nearly any kind of spraying outfit | can be adopted for this purpose. How ever, modern orchard spray outfits are | designed to give a comprehen- sively small flow and high pressure, | and are less suitable for alfalfa | than the older pumps with | larger cylinders and longer strokes, | designed for larger flow and lower pressure.
 The spraying outfit should be mount | ed on the wagon or other vehicle used | so that the nOzzleS will be about two | feet above the tops of the alfalfa | plants. Four 50-gallon barrels with an engine and pump mounted on an ordinary wagon. or, for a hand-pump | OH tfit,- aH- .eNpreSs~.swa gon- and d- -feWer barrels constitute a satisfactory out