附錄PlantProtectionAbstractThecardsontheuppersurfacewereblue,says[JohnHowell].Inmanycases,cardsonthelowerleaveswerenotcoveredaswell."Ifgrowerswanttocheckoutcoverageinanykindofcrop,theycangetthesecardsfrommachinerydealers,"saysHowell."Itisagreatwaytodeterminewhatkindofspraycoverageyouaregetting.Wetestedallthesesprayersat4milesanhourand2milesanhourandwediditwiththedifferenttypesofsprayers."[Headnote]Increaseyieldsbymakingsureyourpumpkinandsquashcropsareadequatelycoveredwithacropprotectant.OVERtheyears,diseasepressureonpumpkinsandwintersquash,especiallyintheNortheast,hasbecomemoresevere.Morethan30yearsago,thesecropswerenottypicallysprayedwithfungicidesorinsecticidesbecauseitsimplywasn'tnecessary.Diseaseandinsectpressurewasn'tthatsignificant-backthen.Fastforwardtoabout15yearsago,andthingswerebeginningtochange.AccordingtoJohnHowell,retiredextensionvegetablespecialistattheUniversityofMassachusetts,asdemandforthesecrops,especiallypumpkinsforHalloween,increased,sodidproductionandthespreadofplantdisease,particularlyblackrot.Theresultwasthatsprayingbecameanecessity."Growersdidn'twanttodrivethroughtheirfieldswithasprayerbecausetheywouldsquashafewsquash,andpumpkins,"saysHowell."Wehadtoconvincethemthatlosingafewplantsthiswaywasbetterthanlosingmuchmoretodisease."SprayerVs.SprayerAccordingtoHowell,mostgrowersusehigh-pressurevolumesprayerstoapplyinsecticidesandfungicidestorowcrops.Someuseairblastsprayersandlow-volumeunits.Frompastresearchsprayinginsecticidesandfungicidesonpumpkinsandsquash,Howelllearnedthatnoneofthesprayertypesworkedaswellastheywouldhavelikedthemto.Low-volumeandairblastsprayersfellshortinbeingabletosuccessfullypenetratethecanopyandachievegoodleafcoverage.Low-volumesprayers,saysHowell,aretypicallyusedtosprayherbicidesdirectlyonthesoil,soapplyingproducttoplantleavestopreventdiseaseisn'tthemaingoal.Theairblastunits,helearned,haddifficultygettingcoverageundertheplantcanopy.Ofthethreetypes,thehigh-pressurevolumesprayersprovidedthebestcoveragetoplantleaves."Theyalldidagoodjobontheuppersurfacesoftheupperleaves,"heexplains."However,youalsowanttobeabletogetthelowerleavesthatarelowerinthecanopyandtheundersidesofthoseleaves,aswell.Ithinkslowlymoregrowersarebecomingmoreawareofthisissuewithspraycoverage."Duringhisresearch,Howellemployedtheuseofwater-sensitivecards.Theseyellowcardswereclippedonthetopupperleavesofplantsandonleaveslowertotheground.Waterwassubstitutedforacropprotectantsoresearcherscouldwalkthroughthefieldsaftertheplantsweresprayed.Cardsthatgotwetturnedblue.Thecardsontheuppersurfacewereblue,saysHowell.Inmanycases,cardsonthelowerleaveswerenotcoveredaswell."Ifgrowerswanttocheckoutcoverageinanykindofcrop,theycangetthesecardsfrommachinerydealers,"saysHowell."Itisagreatwaytodeterminewhatkindofspraycoverageyouaregetting.Wetestedallthesesprayersat4milesanhourand2milesanhourandwediditwiththedifferenttypesofsprayers."Usingahigh-pressuresprayerfilledwithwater,theseyellowwatersensitivecardsturnedbluewherewaterdropletshitthem.Thetopcard?ineachcolumnisfromanupperleaf,topsurface.Thesecondcardisfromanupperleaf,underside;thethirdcardisalowerleaf,topsurface;andthefourth(lowest)cardisfromcloverleaf,underside.Itwasdifficulttoachievegoodcoverageontheundersidesofleaves.Howelladdsthatsprayingpumpkinsandsquashareparticularlychallenging,thankstotheamountoffoliagethatneedstobecovered.Researchersalsoareusingwater-sensitivecardstotestthecoverageoffungicidesandinsecticidesonothercrops,suchassweetcorn,hesays.[Sidebar]UseTheRightNozzleJOHNHowell,aretiredvegetableextensionspecialistattheUniversityofMassachusetts,saysgrowersshoulduseahigh-pressuresprayerontheirpumpkinandsquashplantsandtheyshoulduseasolid-conenozzle.Mostsprayers,hesays,comewithhollow-conenozzles."Asolidconehasanarrowerangleandtendstopushthespraymaterialfurtherintothefoliage,"heexplains.Healsotellsgrowerstonotexceedspeedsof2milesperhourwhensprayingbecauseittakestimetopushthespraymaterialdownintothecanopy."Ifyouaretravelingtoofast,youwon'tgetgoodpenetrationofthefoliage,"hesays."Youhavetogivethesolutiontimetogetdownintothefoliageasyoupassoverthecrop."Anglingthenozzlealsohelps.Onmostboomorhigh-pressuresprayers,growerscanloosentheclampsontheboom,andangleitabout15to20degreesforwardasopposedtofacingitstraightdown.Bysettingthenozzleonanangle,ittendstostiruptheleavesalittlebitandaidsinthepenetrationofthecanopy,saysHowell.植物保護(hù)摘要在上表面的卡是藍(lán)色的，說[約翰豪厄爾]。在許多情況下，在下部葉卡也沒有涉及?！叭绻N植者想看看在任何一種作物的覆蓋面，他們可以從機(jī)械經(jīng)銷商那里得到卡片，“豪威爾說?！按_定你正在用什么樣方式來噴涂覆蓋面這是偉大的。我們在4英里的時速和2英里的時速測試所有這些噴霧器，我們用不同類型的噴霧器來測試。通過確保你增加南瓜和西葫蘆作物涵蓋量，來增加作物保護(hù)劑的產(chǎn)量。多年來，尤其是在東北，疾病對南瓜、冬瓜的壓力變得更加嚴(yán)重。30多年前，這些作物通常不噴灑殺菌劑或殺蟲劑，因為它根本沒有必要。病蟲害壓力并不顯著。當(dāng)時的情況?？焖倩氐酱蠹s15年前，事情開始發(fā)生變化。據(jù)約翰豪威爾——一位退休的常識淵博的麻省理工大學(xué)的蔬菜專家，他認(rèn)為，隨著這些作物，尤其是萬圣節(jié)南瓜的需求的增加而加速了植物疾病的傳播，特別是黑腐病。其結(jié)果是，噴灑農(nóng)藥成為必然。“種植者不希望駕駛一個攜帶噴霧器的機(jī)械駛過自己的田地，因為他們會損失幾個南瓜，”豪威爾說?！拔覀儽仨氄f服他們，通過這種方式失去幾個南瓜，比被一些植物的疾病奪去更多的南瓜要好?！辈煌瑖婌F器的比較據(jù)豪威爾介紹，大部分種植者通過用高壓噴霧器噴灑殺蟲劑和殺菌劑來保護(hù)中耕作物。有的用鼓風(fēng)噴霧機(jī)和低容量噴霧器。，豪威爾了解到，從過去的南瓜和西葫蘆噴灑殺蟲劑和殺菌劑的研究來看，噴霧器類型沒有一次達(dá)到他們預(yù)期的效果。低容量噴霧器和鼓風(fēng)噴霧機(jī)沒有能夠成功地滲透，實現(xiàn)良好的葉冠層覆蓋。豪威爾說，低容量噴霧器通常用于在土壤上直接噴灑除草劑，使植物葉片應(yīng)用產(chǎn)品，以防止疾病，但不是主要目標(biāo)。他還了解到，鼓風(fēng)噴霧機(jī)很難作用到樹冠覆蓋下的植物。在這三種類型中，高壓容量噴霧器對植物的葉子起到了最好的覆蓋效果?！八袊婌F器都對葉子上表面的效果不錯，”他說。“不過，你也希望能夠使較低的葉片，在樹冠較低處，同樣有很好的效果。我想慢慢地越來越多的種植者會意識到噴霧覆蓋這個問題?！痹谒难芯恐?，豪威爾采用了水敏卡。這些黃色卡片被夾在植物的葉子的上表面和下表面。對保護(hù)者來說，水是