VINEYARD EVALUATION OF A RECYCLING TUNNEL SPRAYER

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1 VINEYARD EVALUATION OF A RECYCLING TUNNEL SPRAYER G. Ade, G. Molri, V. Rondelli ABSTRACT. This rticle presents the results of field trils of n ir-ssisted tunnel with recycling system for the liquid tht is not retined y the leves. Its chrcteristics nd performnce, in terms of distriution qulity nd losses to the soil, were compred with conventionl ir-lst. The trils were done in vineyrd trined to spur-pruned cordon t two growth stges using fully rndomized experimentl design. The results show tht losses to the ground with the tunnel were less thn 5% of the spryed liquid in oth growth stges, which re much lower thn those of conventionl s. The mount of liquid retined y the leves ws out 87% of tht distriuted in oth stges. Biologicl tests crried out during the seson showed no significnt difference etween the s in terms of efficcy. The overll results point out tht the tunnel using this type of ir-circultion system requires much less chemicl product nd shows higher environmentl sustinility in comprison with conventionl ir-lst s. Keywords. Deposit, Losses, Recycling, Sprying,. In vineyrds, pesticides re common nd necessry tool to protect the vines ginst diseses, insects, mites, nd fungi ttcks tht would otherwise destroy or dmge the grpes. The chemicls should e pplied in such wy tht they cn interct effectively with the pest or disese. Trditionlly, spry ppliction hs delivered sufficient quntity of wter to thoroughly wet the plnt, ut over the yers mny reserches hve demonstrted tht when lrge spry volume is used, significnt proportion of the liquid ends up not on the trget plnt ut on the ground or in the tmosphere, where it is potentil pollutnt (Viret et l., 2003). More thn 25 yers go, Mtthews (1979) stted tht ppliction efficiency could e improved y not ttempting to wet the whole trget ut selecting the optimum droplet size to increse the mount of spry dhering to the plnt. Vrious pproches hve een used to increse the uniformity of spry deposition. Pneumtic s with high-velocity ir strems to produce nd trnsport spry droplets throughout the cnopy hve een used in vineyrds with reduced volumes of wter nd chemicls (Bker, 1984). Another wy of incresing ppliction efficiency hs een to move the ir-liquid outlets closer to the leves in order to minimize the effect of environmentl conditions y shortening the pth of the spry to rech the plnt (Pezzi nd Ade, 1999). However, lortory nd field reserch hs demonstrted tht the mjor prolems in orchrd nd vineyrd spry pplictions remin spry drift nd pesticide runoff (Fox et l., 1998). Axil-fn mistlower s, lmost exclusively used for sprying orchrds nd vineyrds for severl decdes, generte lrge rdil spry plume, which is poorly trgeted Article ws sumitted for review in June 2005; pproved for puliction y the Power & Mchinery Division of ASABE in Novemer The uthors re Giorgio Ade, Associte Professor, Giovnni Molri, Resercher, nd Vld Rondelli, Resercher, Deprtment of Agriculturl Economics nd Engineering (DEIAgr), University of Bologn, Bologn, Itly. Corresponding uthor: Giovnni Molri, DEIAgr, University of Bologn, vi G. Fnin 50, 40127, Bologn, Itly; phone: ; fx: ; e-mil: giovnni.molri@unio.it. for modern intensive trining systems where tree height rrely exceeds 2.0 m, even where nozzles re imed t the tree (Cross, 1991). Another pproch to improve spry ppliction hs een the design of tunnel s to recover nd recycle the spry droplets tht fil to deposit on the trget. Enclosing the spry plume in tunnel hs een recognized s wy to prevent the spry not deposited on the tree from escping s drift or contminting the soil (Hogmire et l., 1995). prototypes were studied in the erly 1980s in Itly (Svi, 1996) nd Polnd (Ber, 1984). Trils on this type of equipment without ir ssistnce suggested the importnce of introducing ir-ssisted systems (Rndll, 1971; Hle, 1978; Brzee et l., 1981). In the 1990s, ir-lst tunnel s with hydrulic nozzles (Brldi et l., 1993) nd pneumtic tunnel s (Brldi et l., 1994) were tested in orchrds nd vineyrds nd produced encourging results in terms of reduction of losses to the soil, lthough they proved to e unstisfctory with regrds to penetrtion nd uniformity of coverge. s with rdil or cross-flow fns were therefore designed, nd different irflow positions were tested to otin etter cnopy distriution nd reduce losses y drift nd runoff (Peterson nd Hogmire, 1995; Hogmire nd Peterson, 1997). The opposite direction of the spry in this type of tunnel produced reduction of spry penetrtion into the cnopy, which ws ssocited with lower ir velocity in the center of the chmer (Holownicki et l., 1995). In 1992, tunnel for orchrd crops, developed with the contriution of the Deprtment of Agriculturl Economics nd Engineering (DEIAgr) of the University of Bologn, ws uilt using xil fns to otin n internl ir circultion, nd the prototype ws tested on tll pech trees, demonstrting its performnce in penetrting the cnopy nd recovering the off-trget droplets (Ade nd Pezzi, 2001). These encourging results susequently led to the development of new tunnel prototype designed to e mtched to the shpe nd dimension of the vines (Molri et l., 2005). The prototype hs een designed using computtionl fluid dynmics (CFD) simultion in order to develop Trnsctions of the ASAE Vol. 48(6): Americn Society of Agriculturl Engineers ISSN

2 more compct mchine tht cn reduce losses to the soil to elow 5% nd give uniform distriution on the cnopy, with forwrd speed comprle to tht of conventionl ir-lst s. This reserch investigted the efficcy nd spry deposits of the tunnel in comprison with n xil-fn in vineyrd. Losses to the soil nd recycling efficiency were lso determined to check the performnce of the tunnel prototype. MATERIALS AND METHODS THE VINEYARD Tests were conducted in 2004 on Sngiovese vineyrd in centrl Itly, with spur-pruned cordon trining system, row spcing of 3.0 m, nd horizontl cordon 1.0 m high. Two growth stges were considered in the tril: onset of the vegettive period on 11 My 2004, nd full lef development on 19 July 2004 (fig. 1). The vineyrd chrcteristics nd environmentl conditions in oth stges re reported in tle 1. TEST SPRAYERS The recycling tunnel developed t the DEIAgr of the University of Bologn in ws compred in 2004 with conventionl xil-fn in vineyrd spry ppliction. The tunnel (fig. 2) ws composed of two verticl concve shields mounted on triled crrier on which memrne pump, 400 L cpcity tnk, constnt pressure regultor, nd hydrulic motor for operting the fns were fitted. The shields enclosed the trget plnt on oth sides nd were connected y roof on the upper side of the chmer, while the lower closures of the shields cted s collectors for the liquid intercepted y the wlls, which ws re-circulted to the tnk y mens of two pumps. Shield distnce ws hydruliclly djustle nd during the tril ws set to 760 mm in oth stges. The shields were 1660 mm long nd 1700 mm high, nd the djustment ws set to spry folige trget from 900 mm to 2400 mm. The shields nd roof were of fierglss. One 600 mm dimeter xil fn ws plced long the verticl xis of ech shield, suitly supported nd powered y hydrulic motor. Ech fn produced n ir strem ddressed to verticl oom with four hydrulic flt-fn nozzles, spced 0.30 m prt. In the vineyrd trils, ech fn produced n irflow rte of 2.9 m3/s nd men ir velocity of 7.0 m/s t the nozzles, s ssessed in previous trils (Molri et l., 2005). The reciprocl position of the shields ws hydruliclly djustle to fit the system to the thickness of the cnopy during the spry ppliction. The specific setting of the fns gve internl ir circultion imed t confining the spry within the spce covered y the cnopy until it ws cptured y the shields nd sl collectors, s hd een demonstrted in the previous study sed on CFD simultion (Molri et l., 2005). The overll tunnel width could e hydruliclly collpsed ehind the tnk for trnsporttion. In the trils, the tunnel prototype ws compred with conventionl ir-lst without ir conveyors nd fitted with 900 mm dimeter fn, which ws driven y the power tke-off vi gerox, llowing two trnsmission rtios. The ir-lst hd memrne pump nd constnt pressure regultor. During the trils, the fn Tle 1. Vineyrd chrcteristics nd environmentl conditions. First Stge Second Stge Tril dte Temperture ( C) Reltive humidity (%) Wind speed (m/s) Lef re index (m2/m2) Vegettive period (Eichorn nd Lorenz, 1977) 11 My < inflorescence swelling 19 July < erry touch First Stge Second Stge Figure 1. The vineyrd in the two growth stges Figure 2. The prototype tunnel in the first growth stge. TRANSACTIONS OF THE ASAE

3 Active Nozzles per Side Air-lst 2 Nozzle Type Msotti [] Teejet VS [] The numers indicte disc nd core dimensions. Tle 2. Spryer settings. First Growth Stge Pressure (r) Volume Spryed (L/h) Forwrd Speed (km/h) Active Nozzles per Side Second Growth Stge Nozzle Type Msotti [] Teejet 8003VS Pressure (r) Volume Spryed (L/h) Forwrd Speed (km/h) Figure 3. Position nd distnce of the sprying nozzles with respect to vines for the two growth stges. produced flow rte of 5.6 m 3 /s. The ir-lst ws fitted with 12 hydrulic hollow-cone nozzles divided on two hlf ooms. The nozzles hd different orifice dimeters ccording to the verticl distriution on the vines. Both s were connected to 55 kw trctor, nd constnt forwrd speed of 6 km/h ws mintined during ll tretments. Tle 2 reports the settings used during the vineyrd tretments, nd figure 3 illustrtes the position nd distnce of the sprying nozzles in respect to the vines. The ir-lst volumes were those typiclly used in the region for the two growth stges of the vines. DEPOSITION MEASUREMENTS Tretments were pplied to plots mde of nine rows, 30 m long, nd the smples were collected in stretch 2 m long in the middle of the centrl row. With the ir-lst, ll the nine rows were treted, while with the tunnel, only the centrl row ws treted. Four replictions were mde, otining fully rndomized experimentl design. Replictions were reciproclly seprted y four untreted rows to void ny interference etween tretments. Trtrzine, registered food dye (Neelikon Food Dyes nd Chemicls, Ltd., Bomy, Indi), ws used to quntify spry deposition ecuse this trcer cn e esily nd completely recovered from rtificil nd nturl trgets (Pergher, 2001). The spry deposit on the cnopy ws ssessed y distriuting wter solution of the dye nd picking leves from different prts of the vine. In the first tril, 30 leves were collected per vine from single zone on oth sides of the plnt ecuse the cnopy ws poorly developed, s detiled in figure 4, while in the second tril, ech vine cnopy ws divided into twelve zones, nd eight leves collected per zone. The deposit on the ground ws determined using sheets of sorent pper s rtificil collectors. The collectors were rectngulr in shpe, with dimensions of m nd height of 0.03 m (Whtmn No. 4, W&R Blston, Ltd., Brentford, U.K.). To prevent contct with the ground, the ppers were fixed to wooden frmes nd distriuted s detiled in figure 5 so s to cover the two inter-rows djcent to the smpled row. After tretment, when the spry hd dried, the leves nd pper trgets were collected in seprte leled plstic gs. In the lortory, known mount of distilled wter ws dded to ech g, nd the solution sornce for the dye ws mesured using spectrophotometer (Smrt Spectro SLM2000-EX2, LMotte Co., Chestertown, Md.). Dye deposits were quntified nd expressed s L/cm 2 of lef re Figure 4. Cnopy zones for spry deposit ssessment in the two growth stges. The zones re identified with the letters to f. The dimensions of the zones re reported in meters. Leves collected in zones with sme letter were considered single smple. Vol. 48(6):

4 (33.7 C, 31% reltive humidity), with the tunnel djusted s in the vineyrd tretments ut operting it in sttic condition in the sence of cnopy so s to recover nd recycle the mximum quntity of spryed liquid. The tunnel prototype ws kept sprying for 50 min, nd smple ws collected every 10 min from the tnk. Trtrzine ws used to quntify the spry concentrtion in the tnk using the solution sornce for the dye s mesured y the spectrophotometer. Figure 5. Disposition of sorent ppers on the ground. nd pper trget re. The lef re for ech smpled lef ws mesured using lef re meter (model 3100, Li-Cor, Inc., Lincoln, Ne.). In order to compre spry deposits, the distriuted volumes were normlized to the volume spryed y the prototype tunnel in the second stge. The results were nlyzed using ANOVA nd Student-Newmn- Keuls tests, fter verifying the homogeneity of the vrinces using the Brtlett test (Sttistic, Stt Soft, Inc., Tuls, Okl.). During ech tunnel tretment, the liquid recovered y the side wlls nd recycled into the tnk ws mesured y collecting it in 10 L tnk specilly fitted on the. Another mesurement ws crried out on the tunnel in order to verify if the concentrtion of the liquid spryed chnged during the tretment due to evportion of the liquid recycled into the tnk. The tril ws done on 19 July BIOLOGICAL INVESTIGATION An investigtion ws crried out on the two s in order to verify the iologicl efficcy of the tunnel recycling system in comprison with the conventionl ir-lst. This ws done on the sme rndomized plots on which the deposit ssessment ws performed, treting ll the rows of the plots nd covering the complete cycle of tretments for Plsmopr viticol nd Botrytis cinere. The plots of untreted vines were otined y covering 5 m lengths of the smple rows with polythene sheets. These smples were distriuted in the rndomized locks to e used s references to determine tretment efficcy. The volumes, chemicls, nd dte of ech tretment re reported in tle 3. As regrds P. viticol, 100 leves per repetition were collected on 19 July The percentge of dmged surfce ws mesured on ech lef in the lortory, nd the leves were divided into six dmge clsses. The sme procedure ws followed for B. cinere, ut in this cse 50 grpes per repliction were collected on 23 Septemer 2004 nd the percentge of grpe surfce dmged ws determined, seprting the grpes into six dmge clsses (tle 4). The dt were sttisticlly nlyzed with the sme softwre used for the spry deposits. Tle 3. Tretment dte nd volume distriuted in the complete cycle of tretments. Concentrtion Volume Rte (L/h) Dte Chemicl Disese (g/l) Spryer Air-Blst Spryer 29 April Mncoze Plsmopr viticol My Mncoze Plsmopr viticol Dinocp Uncinul nector My Mncoze Plsmopr viticol My Mncoze Plsmopr viticol Dinocp Uncinul nector June Mncoze Plsmopr viticol Dinocp Uncinul nector June Mncoze Plsmopr viticol Dinocp Uncinul nector June Flufenoxuron Loesi otrn Ciprodinil nd fluidioxinil Botrytis cinere July Copper Plsmopr viticol Dinocp Uncinul nector July Copper Plsmopr viticol Dinocp Uncinul nector July Copper Plsmopr viticol Dinocp Uncinul nector August Copper Plsmopr viticol August Chlorpyrifos Trgioni vitis August Ciprodinil nd fluidioxinil Botrytis cinere TRANSACTIONS OF THE ASAE

5 Dmge Clss Tle 4. Dmge clsses for leves nd grpes. % Dmge on Lef % Dmge on Grpe >70 >70 RESULTS AND DISCUSSION The mount of deposit on the leves nd ground is the focus for evluting the test results. Informtion on the deposit mde it possile to clculte the losses into the tmosphere s the difference etween the liquid spryed nd tht found on the ground, on the leves, or recycled (y the tunnel ). Tle 5 reports the lnce of the distriution for the two s in the two stges. Losses were less thn 5% in oth growth stges nd were unlikely to e influenced y vegettion density. However, the size of the plnts gretly ffected the ground losses of the conventionl ir-lst. In fct in this cse, ground losses decresed from 49.3% in the first stge, with lef re index (LAI) of 0.72, to 27.0% in the second stge, with n LAI of The difference in the ground losses etween the ir-lst nd the tunnel were evident. The tunnel lmost entirely recycled the product not cptured y the folige. Only 1.7% of the liquid spryed in the first test nd 6.6% of tht in the second ws not recovered. This represents, regrdless of mesurement errors, the mount of product dispersed in the eril environment y the tunnel. There ws definitely more drift with the conventionl ecuse the liquid not recovered on either the plnts or on the ground in the first nd second test ws 12.8% nd 11.3%, respectively. The higher mount of liquid not recovered y the tunnel in the second stge might e explined prtly y the higher temperture fcilitting evportion of the liquid in contct with the shields nd prtly y vine size nd lef density. Figure 6 shows how different it is for the tunnel, owing to the effect of recycling, to define the deposit on the plnt s function either of wht the nozzles dischrge or of wht the effectively distriutes on the field, sutrcting the volume recovered y the shields. It cn e oserved tht the mount of liquid deposited on the leves with respect to tht effectively distriuted ws out 87% in oth stges for the tunnel nd 37.9% in the first stge nd 61.7% in the second for the ir-lst. To compre the distriution qulity of the different s in terms of deposits, the volume rte of the tunnel in the second stge ws ssumed s reference. Considering figure 7, which shows the deposits on the cnopy normlized in this wy, it cn e noted tht in oth stges the Air lst Air lst First Stge dischrged spry distriuted spry Percent Second Stge dischrged spry distriuted spry Percent Figure 6. Deposit on the leves for the two s in the two stges, expressed s percentge of the liquid dischrged nd tht distriuted over the field. Air lst Air lst First Stge Deposit ( L/cm 2 ) Second Stge Deposit ( L/cm 2 ) Figure 7. Men deposit on the leves for the two s in the two growth stges. The error rs report the stndrd devition. The differences re significnt t P = in the first stge nd P = in the second stge. Spryer Tle 5. Liquid deposited on the leves, on the ground, recycled y the tunnel, nd dispersed, expressed s percentge of the totl spry. The percentges re clculted s n verge of the four replictions. SD is the stndrd devition. First Growth Stge Second Growth Stge Liquid on Liquid on Liquid Liquid on Liquid on Liquid Liquid Leves Ground Recycled Leves Ground Recycled Dispersed % SD % SD % SD (%) % SD % SD % SD Liquid Dispersed (%) Air-lst Vol. 48(6):

6 Air lst Deposit ( L/cm 2 ) high medium low Ground deposit ( L/cm 2 ) 3.0 First stge Air lst Distnce (m) Air lst Deposit ( L/cm 2 ) outside inside Figure 8. Deposit on the leves in the second growth stge. The letters indicte the significnce, within ech, reported in tle 6. differences etween the two s were highly significnt, with higher vlues for the tunnel system. Anlysis of the lloction of the deposits on the cnopy in the second test (fig. 8, tle 6) shows etter uniformity for the tunnel, where no significnt differences were found etween levels. All equipment showed good penetrting cpcity of the cnopy, with no differences found etween the two depths considered. With reference to figure 4, the heights re identified s follows: high (zones, d), medium (zones, e), nd low (zones c, f), nd the depths re: outside (zones,, c), nd inside (zones d, e, f). The nlysis of losses to the soil, reported in figure 9, shows very low vlues ll long the profile considered for the tunnel system, with no significnt differences within ech stge. Losses did not exceed the center of the inter-row, nd in the second stge they were reduced eneth the row, proly due to folige cpturing most of the spry. With the ir-lst, the deposit ws distriuted more evenly long the trnsverse profile nd ws significntly higher thn tht of the tunnel system (P < 0.001). The product concentrtion in the tnk cused y evportion during the circultion nd recycling incresed y 8% fter 30 min of opertion (fig. 10). Although this result ws otined in only one temperture nd reltive ir humidity condition, it demonstrted tht the increse in concentrtion inside the tnk might e not negligile, especilly with low volumes. This vlue cn nonetheless e considered s Vrile Tle 6. Anlysis of vrince test for height nd depth in the second growth stge. Air-Blst Spryer Fischer Vrince Rtio (F) Significnce (P) Spryer Fischer Vrince Rtio (F) Significnce (P) Height Depth Height depth Ground deposit ( L/cm 2 ) Second stge Air lst Distnce (m) Figure 9. Deposit of liquid on the ground in the two stges nd for the two s. The distnce is referenced to the smpled row. mximum tht is difficult to ttin, ecuse such poor vegettion conditions normlly occur in periods with much lower tempertures thn those in this tril. Figure 11 reports the results of the iologicl evlution, from which it cn e ssumed tht oth s could efficiently protect this crop from oth of the fungl diseses considered in the tril conditions. On the contrry, highly significnt differences were oserved for the untreted smple. CONCLUSIONS The results from the field trils show tht the tunnel with internl ir circultion nd liquid recycling produced very low losses to the ground, nd considering the smll mount of product not recovered, low vlues of drift losses. With the tunnel, the plnts cptured more thn 87% of the liquid distriuted in oth growth stges, showing tht cnopy density did not ffect this prmeter. The lmost complete recovery of the product not cptured y the folige is oviously of economic nd opertionl enefit. Increment of concentrtion Time (min) Figure 10. Vrition of concentrtion inside the tnk of the tunnel working in the sence of cnopy TRANSACTIONS OF THE ASAE

7 Clss of dmge Clss of dmge Not treted Not treted Air lst Air lst Plsmopr viticol Botrytis cinere Figure 11. Results of iologicl tests done for Plsmopr viticol nd Botrytis cinere on the leves nd grpes. The error rs report the stndrd devition. The differences re significnt t P = for P. viticol nd t P = 0.04 for B. cinere. With this type of, the volume rte ctully distriuted on the crop does not mtch the one resulting from the typicl clirtion prmeters of the s; the settings must thus e determined in tests focused on the reltionship etween deposits, equipment efficiency nd crop chrcteristics. According to the results of these trils, this system seems to provide firly good flexiility towrds folir density, ut further experiments re required to vlidte this. The nlysis of the deposits t different heights showed tht the tunnel, designed on the sis of computtionl fluid dynmics studies to optimize the shield shpe, gve good uniformity on the cnopy, thus confirming tht the irflow chrcteristics re fundmentl for chieving good result. Penetrtion within the cnopy did not differ for the two s, lthough this result could hve een ffected y the thinness of the row. Biologicl control of the two mjor pests of the vineyrd crop showed similrly good effectiveness for oth s t ll the settings dopted in the tests. This result ws chieved even though the product distriuted with the tunnel, due to the different volumes t the sme concentrtion nd the different frction of deposit on the leves, ws hlf the recommended dose tht ws pplied with the ir-lst. In the light of this, it would e interesting to investigte if this result should e restricted to high-performnce tunnel s with ir circultion systems, or if it could e extended to the simpler conventionl s, with cler environmentl nd economic enefits. A rise in concentrtion during tretment is to e expected with this type of. The mximum mesured (15% in 50 min) ctully refers to n unusul operting condition nd could e tolerted. For higher-precision tretments, the could e equipped with n uxiliry wter tnk. This type of tunnel, in which it is possile to predict with good precision where the liquid will e deposited, cn llow retention cpcity digrm to e determined more esily t different volume rtes nd growth stges thn with conventionl ir-lst. This would help to ccurtely determine the concentrtion of solution necessry to chieve given deposit of pesticide in every growth stge. Reserch progrms re eing considered for this purpose. ACKNOWLEDGEMENTS The uthors thnk Mr. S. Bertoni nd the technicins nd PhD students of the Deprtment for their help during the tests. REFERENCES Ade, G., nd F. Pezzi Results of field tests on recycling ir-ssisted tunnel in pech orchrd. J. Agric. Eng. Res. 80(2): Bker, G Plnt protection techniques in viticulture. KTBL Schrift. Drmstdt, Germny: Kurtorium fur Technik und Buwesen in der Lndwirtschft. Brldi, G., S. Bovolent, F. Pezzi, nd V. Rondelli Air-ssisted tunnel s for orchrd nd vineyrd: First results. In Proc. ENPP-BCPC 2nd Intl. Symp. on Pesticide Appliction Techniques, Alton, Hmpshire, U.K.: British Crop Protection Council. Brldi, G., S. Bovolent, F. Pezzi, nd V. Rondelli Performnce of prototype of tunnel on vineyrd crop. Proc. Giornte Fitoptologiche 1: Ber, B Primry trils with tunnel s for orchrd sprying. In Fruit Science Report 11: Skierniewice, Polnd: Reserch Institute of Pomology nd Floriculture. Brzee, R. D., R. D. Fox, D. L. Reichrd, nd F. R. Hll Turulent jet theory pplied to ir s. Trns. ASAE 24(2): Cross, J. V Ptterntion of spry mss flux from xil fn ir-lst s in the orchrd. In Air-Assisted Sprying in Crop Protection, BCPC Monogrph No. 46. Alton, Hmpshire, U.K.: British Crop Protection Council. Eichorn, K. W., nd D. H. Lorenz Phenologische Entwicklungsstdien der Ree. Nchrichtenl. Deut. Pflnzenschutzd. 29: Fox, R. D., R. C. Derksen, nd R. D. Brzee Air-lst/ir-ssisted ppliction equipment nd drift. In Proc. North Americn Conf. on Pesticide Spry Drift Mngement, Portlnd, Mine: University of Mine Coopertive Extension. Hle, O. D Performnce of ir jets in reltion to orchrd s. J. Agric. Eng. Res. 23(1): Hogmire, H. W., nd D. L. Peterson Pest control on dwrf pples with tunnel. Crop Protection 16(4): Hogmire, H. W., D. L. Peterson, K. C. Elliot, nd A. R. Collins s for dwrf pple trees. In Proc. Ntionl Conf. on Pesticide Appliction Technology, Guelph, Ontrio: University of Guelph. Holownicki, R., G. Duruchowski, nd A. Godyn Efficient spry deposition in the orchrd using tunnel with new concept of ir jet emission. Act Hort. 422: Mtthews, G. A Wht volume in spry is required? In Pesticide Appliction Methods, New York, N.Y.: Longmn. Molri, G., L. Benini, nd G. Ade Design of recycling tunnel using CFD simultions. Trns. ASAE 48(2): Pergher, G Recovery rte of trcer dyes used for spry deposit ssessment. Trns. ASAE 44(4): Peterson, D. L., nd H. W. Hogmire for dwrf fruit trees. Trns. ASAE 37(3): Vol. 48(6):

8 Pezzi, F., nd G. Ade Anlysis of the distriution on prototype of orchrd. Rivist di Ingegneri Agrri 30(1): Rndll, J. M The reltionship etween ir volume nd pressure on spry distriution on fruit trees. J. Agric. Eng. Res. 16(1): Svi, D Evoluzione delle ttrezzture. In Attrezzture per l Difes delle Pinte, Veron, Itly: Edizioni L Informtore Agrrio. Viret, O., W. Siegfried, E. Holliger, nd U. Risigl Comprison of spry deposits nd efficcy ginst powdery mildew of eril nd ground-sed sprying equipment in viticulture. Crop Protection 22(8): TRANSACTIONS OF THE ASAE