herbicid strategi reduc nutgrass cyperu rotundu l densiti cotton gossypium hirsutum introduct spp identifi charl 1991 second import weed australian product infest 79 new south wale properti 15 area 21 000 ha weed problem primarili attribut report field densiti 20004000 tubersm2 correspond reduct lint yield 92 1995 grower tradition attempt control msma interrow cultiv incrop infallow strategi rel ineffect control repeat applic glyphos gave effect suggest appli earli season follow mid late occur interv longer 4 week tuber produc shoot emerg hauser 1962 indic inclus norflurazon enhanc suppress research success rang altern herbicid 1963 control amitrol eptc 24d note asynchron tuber difficult erad holt al chernicki watkin 1992 shortterm phytotox johnson 1975 observ good bentazon perfluidon grichar imazethapyr anderson dunford 1969 limit bensulid w k vencil per comm degre methazol fomesafen lactofen fluometuron diuron best gener come combin keelei 1973 costa applebi 1976 obrigawitch 1980 c esculentu prometryn atrazin metolachlor halosulfuronmethyl newer evalu registr australia activ somervail encourag glyphosatetrimesium combin ethephon studi experi test develop propos treatment assess develop materi method detail site experi 1 overlai wilona warren 31 48s 147 59e alluvi soil ph 67 5 water surfac 74 07 m mckenzi 2 norwood more 291 26s 149 47e grei crack clai 73 treatment alloc pseudorandom design start averag heavili infest lightli plot base visual estim autumn residu halflif 180 dai humburg 19891 overlai previous treat 3 posit farm histori 6 paloma premer 55e 001 mol cacl2l randomis complet block design applic sampl situat commerci flood irrig field irrig schedul neutron probe insect pressur twice weekli insecticid necessari bed maintain minim disturb trifluralin 12 aiha 05 26 august 18 1993 09 band hill sow nitrogen anhydr ammonia 118 nha juli 104 waterrun urea 50 decemb cv cs plant 13 kgha sicala vi 16 14 june 03 7 octob trifiuralin 11 ailha 27 pendimethalin 04 april 160 250 respect 189 siokra l23 10 annual spring core plot taken top centr row 70 mm diamet 150 deep count wash 20 long row wide handheld boom width deliv 100 lha 200 kpa nozzl preplant incorpor depth lilliston roll finger cultiv direct nozzl sprai novemb tractormount curtain sprayer agral 60 nonion surfact sulfometuron 02 025 volum harvest central pick singl picker seed record subsampl process gin assess gin percentag comparison seventeen tabl block 9 replic 28 23 1994 viabil glasshous subsampl place sandpeat moss pot mix seedl trai 35 120 seven replic high low initi impact efficaci compar preemerg 199293 postemerg compris addit 199394 reduc afallow popul fallow ad paddock graze sown oat number occas month regularli cultiv establish 1988 continu site graze period twelv 2m 19 septemb 1989 1990 30 25 statist analys data analys poisson model genstat two dimension trend remov column effect core weight loge offset prior covari analysi convert standard error freedom contrast specif comparison reml maximum error differ mean sed signific level rainfal season 350 262 fig untreat rose 278 increas 1903 4389 7194 contrast benfures fell 1931 repres 96 drop highest 1488 consist januari reduc postharvest did consist v compar larg decreas 8 addit percentag averag 418 417 effect show 63 improv increas 317 315 2wai interact term 556 311 2250 367 year initi lower remain differ particular time 815 1029 lowest 87 86 aboveaverag yield receiv extra greater reduct 441 fewer averag declin 1342 310 final 95 91 84 89 80 significantli overal 378 582 47 dimethenamid suifometuron affect 374 06 434 lower 438 total 1989juli figur progress ester discuss examin level multipl success support find zandstra 1974 doll piedrahita 1982 observ kill veget shoot quickli emerg again attach consequ expos receiv subleth dose possibl inadequ transloc incomplet chase 1979 account 5fold compar unstress plant humid moisturestress 1985 decreas plant ag anecdot evid indic giyphos cold stress young opportun appli result longterm popul achiev glyphosatebas program irrig advers weather condit demand make appli optimum delai prevent canopi closur allow grow uncheck remaind time overcom improv combin benefit factor contribut appar inconsist activ moistur declin event irregular basi wet cover dry belowaverag fig addition crop fulli insuffici like case wetter full experi consecut improv previou norflurazontr ad report support concentr react came suspens mix excel outstand undergo evalu regist drop develop similar halosulfuron superior 4treatment safe remain option crop system imazapyr rate situat higher 1015 act asa steril give better elimin isol patch clean practic poor 1417 rate 0056 0038 46 effect rainf larg seri summer largest influenc 4454 657 strong neg relationship end appar third plant result pronounc declin highli p0001 lack respons explain competit probabl lighter infest occur 1123 tubersim2 vigour growth rapid north temperatur warmer 130c 290c daili minimum octob31 taller rapidli shade conclus us remain andor reduc difficulti crop sensit encount presow activ grow earlier safeti narrow window consist combin ideal