Show CONTROL OF ALFALFA WEEVIL WEE BY SPRAYING POISON OVER FIELDS Prepared by br the United States Department of Agriculture Farmers In regions newly Infested by the alfalfa weevil will be Interested Interest Interest- ed in knowing that an unusually effective effective ef ef- ef- ef fecU e method of control has been worked out by the United States Department Department Department De De- De- De of ot Agriculture Specialists of ot the department say that rarely has any method of Insect control been so thoroughly safeguarded against failure fail fall ure tire as weevil alfalfa spra spraying It has been tested every season for seven years tears The cost rost of the operation operation- about 1 an acre acre Is is trifling compared with the he returns and no farmer furmer In the territory infested or threatened can afford to overlook it the specialists say There is no control measure however which can be applied advantageously advantageously advantageously this late in the season Effective Ef Ef- Effective work must be be delayed until next spring Control ol by Poison Polson Spry Spray Control Is effective by spraying poison polson pot poi son over O the fields so that It will cover the growing parts on which the weevils mostly feed Arsenate of lead and ond of zinc have been mostly used but other recommended recommend recommend- ed for orchard spraying are thought to be about as good There is practically practically cally no danger of burning the foliage of alfalfa and therefore the range rane of ot suitable poisons Is larger than In fruit fruit- tree spraying Arsenate of lead Is said ead to be everything considered the best poison polson to use principally because It sticks to the le lepes es more readily and costs less than Ti most ost of the others The poison Is 11 weighed or measured at the rate of two pounds of powder or four tour pounds of ot commercial paste for each gallons of water Is stirred with a little water atel in a pall until It becomes a thin paste without lumps Is diluted and strained into the sprayer tank Two pounds of laundry laundry laundry laun laun- dry soap for each gallon should be added In order to make the liquid stick to the leaves properly The dry powdered form torm of the poison polson Is better better than the paste There is no danger of stock being poisoned by hay cut from sprayed fields where the poison poi pol son Is applied at a rate of not greater than Ithan gallons of ot spray mixture per acre Simple Outfit Sufficient The essentials of the spraying outfit are Bre A truck ruck or other vehicle a tank with an agitator to keep the poison polson from settling to the bottom a pump a pressure gauge an engine and pumpIng pumpIng pump pump- I Ing ng Jack unless the pump Is to be driven by hand a strainer a n pipe for distributing the liquid from the pump end and nd as many nozzles as are required by the capacity of the pump These essentials may all be contained In a barrel pump barrel pump outfit carried In a l wagon The pump must be capable of delivering delivering delivering ering four-fifths four of ot a gallon gullon or more morea a IT and maln maintaining a pressure of ot at least 75 pounds If the pressure Is 18 less than that the mist spray will not be fine enough to prevent the liquid from gathering in drops an and running to the ground Instead of ot dryIng dryIng dry dry- Ing lag on the tops of the plants The number of ot nozzles used should be bo sufficient to take up the capacity of the pump At the average walkIng walking walking walk walk- ing gait gnit of a team each nozzle should deliver tenths nine-tenths of a n gallon a it min min- ute Therefore a pump of nine nine gal gallon gal gal- lon capacity per minute will supply ten nozzles each of which covers a n a strip two feet wide By y an nn arithmetIcal arithmetical ical teal calculation of the cubical content content content con con- tent of the pump cylinder clInder nun and the number of strokes the capacity ca- ca of the outfit can be determined The spray should be applied at the rate of ot gallons of at spray mixture per acre Nearly any kind of spraying outfit can enn be adopted adapted for this purpose however However How How- ever modern orchard spray outfits are usually designed to give a comprehensively lively small flow and high pressure and are less suitable for alfalfa spraying praying than the older pumps pumps with larger cylinders cylinder and longer strokes designed ned for tor larger flow and lower pressure The spraying outfit should be mounted mount mount- ed on the wagon or other vehicle used so that the nozzles will be about two feet above the tops of ot the alfalfa plants Four gallon 50 barrels with an engine and anti pump mounted on an ordinary wagon or or for tor a pump hand-pump outfit an express wagon and fewer barrels constitute a satisfactory out out- fit A paddle piddle dasher or some other form of agitator must be provided to keep the liquid stirred A strainer of mesh 20 brass or bronze screen should be fitted to the opening through which the water enters the tank and anether another another an an- other ether over the outlet leading to the pump The parts palts of the pump In which close fitting Is required should be of ot brass bronze porcelain or some other substance less rapidly corroded by the chemicals than iron and steel All commercial spray pumps are built bunt In Inthis Inthis inthis this wa way but pumps which were Intended intended intended in In- tended for other purposes should be refitted when used for spraying An engine-driven engine outfit must have havea a relief valve near the pump permitting permitting permit permit- ting the surplus flow to return to the tank The pump must have an air- air pressure chamber large enough to keep the flow steady and Insure even distribution of the poison polson Even pressure pressure pressure pres pres- sure Indispensable for uniform spread of the poison polson cannot be maintained without a pressure gau gauge e. e This gauge should be attached to the pressure pressure pressure pres pres- sure chamber or near It and at a n distance dis tance from valve relief and nozzles The rhe boom or pipe which carries the nozzles and supplies them with liquid from the pump is made of two-foot two pieces of at one half Inch galvanized Iron Ironpipe Ironpipe ironpipe pipe Joined b by Ts T's each of which affords affords af nf af- af fords an nn opening for the attachment of a nozzle The boom Is 18 connected with the pump by a one-half one Inch pressure hose The boom should be supported by a piece of timber two b by four clamped or hinged to the truck with the boom stapled bolted or wired to It Plain misty nozzles without ut strainers or other complications Ions should be us used Spray In Warm Weather The best time for spraying Is at what the specialists call the turning point of weevil from infestation infestation from on onto one oneto oneto to two weeks before the first crop l Is ready for tor cutting when the young young larvae become so numerous that they completely destroy the growing tips tipa After that point Is reached the weevils If It le left t alone consume the leaves until nothing Is left but the woody fibers libers If It spraying Is dons done at this time the crop recovers quick ly Iy Spraying yearly early in the spring sometimes entirely prevents damage but it Is uncertain On the other Land plants sprayed after the they were entirely en stripped of their foliage hav been able to recover and bloom but this allows destruction to go too far fai farand and makes recovery too slow Spra Spraying at the turning point not only protects the he first crop but confers confers con con- fers an even een larger lorger benefit on the second second sec see ond and crop which sprouts and grows without delay and no treatment of the stubble Is necessary Stubble spraying after tho the cutting of ot the first crop has been successfully done but It requires getting Into tho the field Immediately after cutting and a much larger quantity of ot liquid is required required required re re- re- re than thun if it were applied to the first crop Stubble spraying therefore therefore there there- fore Is advised only when earlier spraying has hns been Impossible Spraying should be done if It possible at the beginning of a warm spell The weevils do not feed so voraciously in cool weather anti and If the poison polson Is applied apPlied applied ap ap- plied at the beginning of ot a cool spell It may become largely Impotent before the weevils resume feeding freely When spra spraying is done under favor favorable able weather conditions most of ot the weevils are killed within four tour or five days t There are other control measures but none of them promises much more unless applied before or immediately after otter the first cutting One method Isto isto Is la lato to pasture the alfalfa field until most of the eggs and young larvae larvae- have been destroyed Another Is to use the alfalfa as ns a soiling crop cutting It green two or three times during the season These methods however must be practiced before the turning point of ot Infestation as after that time the we weevils vlIs plants so c com completely cow rn- rn that there is not enough growth for Cor either pasture or soiling Another method Is to cultivate the field with witha a harrow or r other implement Ira Imme me mediately dintel after utter the first cutting In such nay any v. v ny as to cower cover the field with a lust dust mulch thus exposing the entire surface sun sur face tace of at the field to the sun and killing kill ing big most of the w weevils In some Instances In In- stances the s second ond crop MX 69 been protected protected pro pro- by drugging dragging the stubble while It Is still wet from irrigation with tho the land leveler lecler or tho the l Jod breaker This causes the Insects 0 o perish b bj embedding them In the nad but It 1 if 11 I harmful mended wended to the soil and Ui Iw not lot 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