Results of Insect Control Evaluations on Corn, Sorghum and Cotton in Texas Coastal Bend Counties

Transcription

1 Results of Insect Control Evlutions on Corn, Sorghum nd Cotton in Texs Costl Bend Counties Texs Coopertive Extension, Dr. Edwrd Hiler, Vice Chncellor nd Director, The Texs A&M University System, College Sttion, Texs

2 FOREWORD This report contins summry of pplied reserch/demonstrtion projects conducted by Texs Coopertive Extension deling with the mngement of rthropod pests in the Costl Bend Counties of Texs in It includes work with corn, sorghum, nd cotton. Experiments were conducted with commercil griculturl producers in coopertion with county Extension gents, county row crop committees, griculturl consultnts, nd gribusiness compnies. Eight of the experiments were conducted t the Texs Agriculturl Experiment Sttion t Corpus Christi. The objectives of these studies were to find more cost effective wys to mnge pests nd to identify res tht require more study. Costl Bend frm coopertors re cknowledged for providing lnd, equipment, lbor, time, ides, nd other ssistnce in support of these projects. The results obtined will be of benefit to ll griculturl producers. Trde nmes of commercil products used in this report re included only for better understnding nd clrity. Reference to commercil products or trde nmes is mde with the understnding tht no discrimintion is intended nd no endorsement by the Texs A&M University System is implied. Reders should relize tht results from one experiment my not represent conclusive evidence tht the sme response would occur where conditions vry. This report contins clcultions of dded return over tretment costs bsed on numericl differences in yield. It must be kept in mind tht the returns ttributed to tretment re not bsolute, i.e. the yield differences my hve been the result of other vribles not ssocited with the tretment. The reder should lwys consider the sttisticl nlysis nd dt from multiple tests over spce nd time in mking judgements concerning the economic returns. If you hve comments or questions bout the reports contined herein, contct: Roy D. Prker Professor nd Extension Entomologist Texs A&M University Agriculturl Reserch & Extension Center Agnes Corpus Christi, Texs (361) telephone (361) fx r-prker1@tmu.edu

3 TABLE OF CONTENTS CORN Evlution of Insecticides for Control of Mexicn Corn Rootworm (Golid County)... 1 Evlution of Insecticides for Control of Soil Insect Pests in Corn (Whrton County)... 3 Seed nd Grnulr Insecticide Comprison on Corn (Nueces County)... 6 Comprison of Trnsgenic B.t. nd Non-Trnsgenic Pioneer Corn Hybrids for Effectiveness on Mexicn Corn Rootworm (Golid County)... 8 SORGHUM Effect of Row Spcing nd Plnt Popultion on Sorghum Production (Sn Ptricio County) Row Spcing nd Plnt Popultion Effects on Sorghum Grown Under Irrigtion (Sn Ptricio County) Row Spcing nd Plnt Popultion Effects on Sorghum Production (Refugio County) Evlution of Asgrow A571 nd Deklb DK54 Sorghum Hybrids Grown on Two Row Spcings t Three Popultion Levels (Whrton County) Rection of Sorghum Hybrids to Counter, Cruiser, nd Gucho Systemic Insecticides (Nueces County) Comprison on Sorghum of Seed nd In-Furrow Applied Insecticides (Nueces County) Insecticide Seed Tretments on Sorghum (Lvc County) Comprison of Systemic Insecticides on Sorghum (Bee County) COTTON Seed nd In-Furrow Systemic Insecticide Evlution on Cotton (Nueces County).. 41 Comprison of Temik Rtes for Effectiveness in Controlling Insect Pests nd Impct on Yield (Bee County)... 44

4 Comprison of Seed nd In-Furrow Applied Systemic Insecticides on Cotton (Colordo County) Evlution of Insecticides for Control of Aphids in Cotton (Nueces County) Flehopper Control on Okr Lef nd Stndrd Lef Cotton with Orthene (Nueces County) Comprison of Insecticides for Control of Bollworm nd Tobcco Budworm on Non-Trnsgenic nd Trnsgenic B.t. Cotton Cultivrs (Nueces County) Evlution of Trnsgenic Cotton Cultivrs (Nueces County) Boll Weevil Numbers in Pheromone Trps in Nueces nd Sn Ptricio Counties Compring Yers Before nd During the Current Erdiction Progrm... 69

5 EVALUATION OF INSECTICIDES FOR CONTROL OF MEXICAN CORN ROOTWORM Hernndez Frms, Golid County, 2001 Roy D. Prker nd Brin D. Ynt Extension Entomologist nd County Extension gent, respectively Corpus Christi nd Golid, Texs SUMMARY: Prescribe, clothinidin, Counter, Aztec, nd Regent were evluted for effectiveness in controlling Mexicn corn rootworm. No sttisticl differences were detected in plnt stnds, root dmge rtings, or yield. Root dmge rting even in the untreted corn ws low, but numericlly, untreted corn hd the gretest dmge level. OBJECTIVE: The field study ws estblished to compre grnulr (Counter nd Aztec), seed tretment (clothinidin nd Prescribe), nd liquid (Regent) insecticides for effectiveness in controlling Mexicn corn rootworm. MATERIALS/METHODS: Pioneer 3167 hybrid corn ws plnted ner the Sn Antonio River on Riverdle Rod northwest of Golid, Texs on Mr 12, 2001 with n 8-row John Deere 2 vcumeter plnter delivering 22,000 seed/cre. Tretments were rrnged in rndomized complete block design in 4-row by 1,100 ft plots with rows on 38-inch centers nd 3 replictions. Corn hd been grown on the site during the previous 5 yers. The cly soil (3% snd, 72% cly, 25% silt) hd ph of 6.6 nd orgnic mtter content of 1.5%. Soil moisture for plnting ws excellent nd soil temperture ws 67 F t the 4-inch depth. Fertilizer nlysis pplied ws nd herbicide consisted of Accent 75% i (0.14 oz/cre) + Bnvel 7.64 lb i/gl (3.0 oz/cre) pplied when corn ws bout 12 inches tll. Grnulr insecticides were bnded over the open seed furrow, Regent ws pplied with Redbll Microtube (pink tubes) pplictor in totl volume of 5 gp t 42 psi, nd seed tretments were pplied by Gustfson Compny. Tretments were ssessed by (1) counting the number of plnts on ft row in ech of the center two rows in ech plot on Apr 16, (2) digging 6 plnts from the center 2 rows in ech plot on My 9 for root dmge rting using the Iow Stte University 6 ctegory system (1 = no visible dmge up to 6 = 3 or more nodes of roots destroyed), nd (3) hrvesting entire plots with commercil mchine on Jul 28. Corn weights were djusted to stndrd t 15% moisture. RESULTS/DISCUSSION: Tretments hd no sttisticl effects on plnt stnd, root dmge rting, or yield (Tble 1). Mexicn corn rootworm numbers were low s indicted by the root dmge rting in untreted corn. Adverse effect on yield t this dmge level (2.17) is not considered likely. Mexicn corn rootworm pressure ws so low tht little informtion ws obtined from the study. 1

6 ACKNOWLEDGMENTS: BASF, Byer, Aventis, nd Gustfson Compnies re cknowledged for their support. Mrk Kelling, Aventis, is thnked for his ssistnce in test estblishment. Apprecition is expressed to the Hernndez fmily for providing lnd, equipment, nd lbor for conducting the study. Tble 1. Comprison of insecticides on corn for effect on Mexicn corn rootworm, Hernndez Frm, Golid County, TX, Insecticide & formultion Rte Plnts (1000's/cre) Root dmge rting Yield (bu/cre) Prescribe 600F 1.36 mg AI/seed Clothinidin 600F 1.25 mg AI/seed Counter 20CR 6.0 oz/1000 ft Aztec 2.1 G 6.7 oz/1000 ft Regent 4SC 3.29 oz/cre Untreted LSD (P = 0.05) NS NS NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Iow Stte University 1-6 rting scle: 1 = no dmge up to 6 = 3 or more nodes of roots destroyed. 2

7 EVALUATION OF INSECTICIDES FOR CONTROL OF SOIL INSECT PESTS IN CORN A. J. nd Tony Kutch Frm, Whrton County, 2001 Dn D. Fromme, Roy D. Prker, nd Richrd L. Jhn Extension Agent-IPM, Extension Entomologist, nd Count Extension Agent, respectively Whrton, Corpus Christi, nd Whrton, Texs SUMMARY: Cpture (T-bnd nd in-furrow), Counter (T-bnd), nd clothinidin nd Prescribe (seed tretments) hd no effect on corn plnt stnd. All insecticide tretments except the Cpture T-bnd tretment hd significntly lower plnt dmge rtings thn the untreted corn 15 dys fter plnting (DAP). All insecticide tretments hd lower dmge rtings thn the untreted corn 22 DAP. Clothinidin hd the lowest plnt dmge rting on both inspection dtes but it ws not sttisticlly better thn other insecticides. Cpture (T-bnd) treted corn hd significntly greter numbers of chinch bugs thn ll other tretments on the first inspection dte (22 DAP). Fourteen dys lter, chinch bug numbers in both Cpture tretments were sttisticlly the sme s in untreted corn; none of the insecticide tretments differed sttisticlly. All tested insecticides provided root protection from the Mexicn corn rootworm s indicted by root dmge rting; numericlly, the clothinidin tretment exhibited the lest dmge. OBJECTIVE: This corn test ws conducted to compre the effectiveness of grnulr infurrow pplied nd seed tretment insecticides on soil insect pests. MATERIALS/METHODS: Midlnd 798 hybrid corn ws plnted Apr 5, 2001 t 22,216 seed/cre on silty cly lom soil (8% snd, 64% silt, 28% cly, 1.3% orgnic mtter, ph 7.6) est of Igo, TX next to FM rod 1096 on lnd frmed by A.J. nd Tony Kutch. A 2- row John Deere MxEmerge model 7100 reserch plot plnter with seed boxes spced on 38-inch centers ws used to plnt the test. Tretments were rrnged in 2-row by 42 ft plots in rndomized complete block design with 4 replictions. Corn hd been plnted on the site for 8 yers. Soil conditions t-plnting consisted of moist soil with dry crust nd 70 F soil temperture t 4-inch depth. Fertilizer ws 500 lb of nd herbicide ws Bicep II 2.67 lb i/gl (1.6 pt/cre). The plot ws hnd weeded twice during the testing period. Grnulr Counter nd Cpture were pplied in T-bnd with stndrd John Deere 6-inch bnders nd bnders were oriented prllel with rows for the in-furrow tretments. Tretments were ssessed by (1) counting estblished plnts on ft row on ech of the 2 rows in ech plot on Apr 20, (2) ssigning visul plnt dmge rting (1 = no dmge up to 5 = stunting, uneven plnt growth, yellowing nd thin stnd) 15 nd 22 DAP, (3) counting the number of chinch bugs round 5 plnts per plot 22 nd 36 DAP (plnts 3

8 were 24 inches tll 36 DAP), nd (4) digging 2 plnts from ech row of plots (4 totl) on My 24 for root dmge nlysis using the Iow Stte University six ctegory system (1 = no visible dmge up to 6 = 3 or more nodes of roots destroyed). RESULTS/DISCUSSION: Tretments hd no mesurble effect on plnt stnd estblishment (Tble 1). There were differences in plnt dmge rtings with greter dmge in untreted nd Cpture (T-bnd) treted corn 15 DAP. Seven dys lter (22 DAP) ll insecticide tretments hd sttisticlly lower dmge thn did the untreted corn. Clothinidin hd the lowest plnt dmge rting on both dtes. Chinch bugs present 22 DAP were significntly greter in the Cpture T-bnd plots; none of the other tretments were sttisticlly different. By 36 DAP, chinch bug numbers in Cpture tretments were no different from the untreted corn. Dmge by Mexicn corn rootworm lrve ws sttisticlly greter in untreted corn thn in ny of the tretments. The clothinidin tretment hd numericlly the lowest dmge from Mexicn corn rootworm, but it ws not sttisticlly lower thn the other insecticides. ACKNOWLEDGMENTS: We extend thnks to Terry Mize, FMC Agriculturl Products nd Terry Pitts, Gustfson Compny for supporting this project. Apprecition is expressed to the Kutch fmily for providing lnd for this study. 4

9 Tble 1. Comprison of insecticides for effect on chinch bug nd root dmge by Mexicn corn rootw Kutch Frm, Whrton County, TX, Insecticide & formultion Appliction Rte method Plnts (1000's/cre) b Plnt d. rting c Chinch bugs/5 plnt 15 DAP 22 DAP 22 DAP 36 DA Cpture 1.5G 8.0 T-bnd b 2.38 b Cpture 1.5G 8.0 In-furrow bc 2.56 b 2.5 b 5.3 Counter 15G 8.0 T-bnd bc 1.94 bc 2.0 b 1.8 b Clothinidin 600F 1.25 Seed trt c 1.25 c 0.5 b 1.3 b Prescribe 600F 1.34 Seed trt bc 1.88 bc 0.5 b 0.8 b Untreted b 7.3 LSD (P=0.05) NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Rte for grnulr tretments expressed in oz formulted product per 1000 row ft nd rte for see in mg AI/seed. b Averge of two counts (13.75 ft row ech) mde on 4/20. c Plnt dmge rtings rnge from 1 = no dmge up to 5 = stunting, uneven plnt growth, yell Counts represent the verge of 3 redings. DAP = dys fter plnting d Corn ws 24 inches tll on 5/11. e Iow Stte University 1-6 dmge rting scle: 1 = no dmge up to 6 = 3 or more nodes of roots d

10 SEED AND GRANULAR INSECTICIDE COMPARISON ON CORN Texs Agriculturl Experiment Sttion, Nueces County, 2001 Roy D. Prker Extension Entomologist Corpus Christi, Texs SUMMARY: Insect pests were not detected, no differences were found in plnt dmge, nd Cruiser treted corn hd the lowest plnt stnd counts t ll 3 rtes evluted. Plnt stnds were sttisticlly or numericlly lower in Cruiser plots thn the other two insecticide tretments. OBJECTIVE: The test objective ws to evlute the effects of Cruiser nd Force ST (seed tretment) on chinch bug, southern corn rootworm, nd other pest insects. MATERIALS/METHODS: Corn ws plnted Mr 9, 2001 on the Meney Annex of Texs Agriculturl Experiment Sttion t Corpus Christi. A reserch plot cone plnter set on 38- inch centers ws used to plnt the 2-row by 40 ft long plots. Tretments were rrnged in rndomized complete block design with 4 replictions. The soil with good plnting moisture ws cly lom (50% snd, 26% silt, 24% cly) with 1.4% orgnic mtter t ph of 8.0. Cotton hd been plnted on the site in the previous seson. Herbicide consisted of Atrzine 4L (1.0 qt/cre) + Dul II Mgnum 7.64 lb i/gl (1.0 pt/cre) which ws brodcst on Mr 9. Fertilizer nlysis ws Tretments were evluted by (1) counting the number of plnts on ft row on ech of the 2-row plots on My 3 nd (2) ssigning plnt dmge rting bsed on: 1 = no dmge up to 5 = stunting, uneven plnt growth, yellowing, nd thin stnd. RESULTS/DISCUSSION: Rinfll ws not sufficient to produce corn in this experiment nd insect pests were not detected during the study. There were not differences in plnt dmge rtings mong tretments but there were differences in plnt stnds (Tble 1). Cruiser treted corn hd noticebly lower numbers of plnts which might hve indicted phytotoxic effects hd it not been for improved stnds s the Cruiser rte incresed. Additionl evlution should indicte whether Cruiser cuses phytotoxic effects on corn. ACKNOWLEDGMENTS: Thnks re extended to Brd Minton, Syngent Crop Protection, for grnt support in conducting this study. 6

11 Tble 1. Evlution of seed tretment nd grnulr insecticides on corn, Texs Agriculturl Experiment Sttion, Nueces County, TX, Insecticide & Appliction formultion Rte method Plnts (1000's/cre) b Plnt dmge rting c Cruiser 5FS 1.27 ST 14.1 c 1.4 Cruiser 5FS 2.55 ST 16.5 bc 1.5 Cruiser 5FS 5.10 ST 17.9 b 1.3 Force TX200CS 4.0 ST Counter 20CR 6.0 IFG Untreted 17.3 bc 1.6 LSD (P = 0.05) NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Rtes for seed tretments (ST) expressed in oz/cwt seed nd rte for Counter in-furrow grnule (IFG) expressed in formulted grnulr product per 1000 row ft. b Averge of two counts on ft row from ech row of the two row plots on 5/3. c Plnt dmge rtings rnge from 1 = no dmge up to 5 = stunting, uneven plnt growth, yellowing, nd thin stnd. 7

12 COMPARISON OF TRANSGENIC B.t AND NON-TRANSGENIC PIONEER CORN HYBRIDS FOR EFFECTIVENESS ON MEXICAN CORN ROOTWORM Hernndez Frms, Golid County, 2001 Roy D. Prker nd Brin D. Ynt Extension Entomologist nd County Extension Agent, respectively Corpus Christi nd Golid, Texs SUMMARY: Evlution of trnsgenic corn event expressing proteins from B.t. strin PS149B1 from Pioneer Hi-Bred Interntionl demonstrted high degree of effectiveness ginst Mexicn corn rootworm lrve when compred to the negtive isoline. Although Pioneer is not plnning to commercilize this event becuse of poor gronomic chrcteristics, seed ws vilble to provide n erly indiction of protein ctivity ginst Mexicn corn rootworm. The PS149B1 event, however, exhibited smller, generlly unthrifty plnt growth compred to the negtive isoline. The crop ws destroyed before tsseling. OBJECTIVE: The experiment ws conducted to chrcterize the level of root protection from Mexicn corn rootworm in trnsgenic corn expressing proteins from B.t. strin PS149B1 compred to the negtive isoline. Although Pioneer is not plnning to commercilize this event becuse of poor gronomic chrcteristics, seed ws vilble to provide n erly indiction of protein ctivity ginst Mexicn corn rootworm. MATERIALS/METHODS: The corn comprison ws plnted ner the Sn Antonio River on Riverdle Rod northwest of Golid, Texs on Mr 16, 2001 with 2-row John Deere 7100 plnter equipped with reserch cone plnters. All seeds provided by Pioneer were plnted in 2-row by 20 ft plots in rows spced 38 inches prt. Tretments were rrnged in rndomized complete block design with 4 replictions. Corn hd been grown on the site during the previous 5 yers. Soil ws cly (3% snd, 72% cly nd 25% silt) with ph of 6.6 nd orgnic mter content of 1.5%. Soil moisture for plnting ws dequte nd soil temperture ws 70 F t the 4-inch depth. Plots were destroyed on My 9 before tsseling. Tretment effects were compred by (1) counting the number of plnts on ft row on ech of the 2 rows in ech plot on Apr 16, (2) ssigning plnt vigor rting (1 = rpid growth nd even plnt stnd up to 5 = stunted growth, smll leves nd uneven stnd) 31, 42 nd 56 DAP (dys fter plnting), nd (3) digging 5 plnts t rndom from ech plot on My 2 nd gin on My 9 for Mexicn corn rootworm dmge evlution using the Iow Stte University 1-6 dmge rting scle: 1 = no dmge up to 6 = 3 or more nodes of roots destroyed. 8

13 RESULTS/DISCUSSION: Differences between the trnsgenic corn events nd isoline were not found in plnt stnd but there were differences in plnt vigor nd root dmge rtings (Tble 1). The trnsgenic event exhibited slower growth, smller plnts, nd generl unthrifty ppernce during inspections 31, 42, nd 56 DAP; differences were significnt 42 nd 56 DAP. We were not ble to determine resons for the growth hbit observed. No diseses or insects ppered to be involved. Lter we noted tht root systems were lso smller but without pprent dmge in the trnsgenic event. The Mexicn corn rootworm infesttion ws modertely low in the test field but corn cultivrs exhibited significntly different root dmge rtings on My 2 nd the redings week lter (My 9) were not sttisticlly different t P = 0.05 with reding of P = Obviously, trnsgenic event expressing proteins from PS149B1 ws effective in providing high degree of protection from Mexicn corn rootworm lrve. ACKNOWLEDGMENTS: Thnks re extended to Pioneer Hybrid Interntionl, Hopkins Agriculturl Service, nd the Hernndez Fmily for their support in conducting the study. Tble 1. Comprison of trnsgenic B.t. nd non-trnsgenic Pioneer corn hybrids for effect on Mexicn corn rootworm dmge, Hernndez Frm, Golid County, TX, Corn hybrid Plnts (1000's/cre) Plnt vigor rting b Root dmge rtings b 31 DAP 42 DAP 56 DAP 5/2 5/9 Trnsgenic event b 1.35 Negtive isoline b 1.3 b LSD (P = 0.05) NS NS NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Plnts were counted on ft row in ech plot on Apr 16. b Plnt vigor rtings: 1 = rpid growth nd even plnt stnd up to 5 = stunted growth, smll leves nd uneven stnd. DAP = dys fter plnting. c Iow Stte University 1-6 dmge rting scle: 1 = no dmge up to 6 = 3 or more nodes of roots destroyed. 9

14 EFFECT OF ROW SPACING AND PLANT POPULATION ON SORGHUM PRODUCTION Robert Brlow Frm, Sn Ptricio County, 2001 Jeffrey R. Stpper, Roy D. Prker, Gry N. Odvody, nd Lwrence L. Flconer County Extension Agent, Extension Entomologist, Reserch Plnt Pthologist, nd Extension Economist-Mngement, respectively Sinton nd Corpus Christi, Texs SUMMARY: Only the highest plnt popultions on 38-inch rows were slightly less thn the trget popultions. Plnt height ws generlly shorter in the 19-inch row spcing tretments. Insect numbers were low nd no differences were observed. Very dry conditions previled during the lst hlf of the seson, chrcol rot ws incresed, nd yield potentil ws gretly reduced. Plnt lodging from chrcol rot ws not sttisticlly different mong tretments, but there ws numericl trend for more lodging s row spcings incresed. Grin yields were not sttisticlly different between ny tretments. Net dollr vlue over seed cost ws generlly better for lower plnt popultions, especilly t 48,000 plnts/cre. However, the exception ws t the 38-inch row spcing where plnt popultions were lower thn those trgeted. More ttention should be pid to seeding rtes becuse seed tretments like Concep nd Gucho cn substntilly increse seed costs. We did not observe the significnt dvntge for 19-inch row plntings tht ws found in 2000 on this frm. OBJECTIVE: The field study ws estblished to compre the effects of row spcing nd plnt popultion on insect numbers, sorghum growth chrcteristics, incidence of chrcol stlk rot, gronomic performnce, nd economic returns. MATERIALS/METHODS: Deklb DK52 hybrid sorghum seed (pproximtely 15,000 seed/lb) ws plnted Mr 16-17, 2001 on the Robert Brlow Frm southest of Sinton, Texs, on 19-, 30- nd 38-inch row spcings t trget popultions for ech row spcing of 38, 48, 68, nd 88 thousnd plnts/cre. Trget popultions from plnted seed ssumed germintion nd estblishment rte of 90%. The 12 tretments (row spcings nd plnt popultions) were rrnged in rndomized complete block design with 3 replictions in 15-row (19-inch plnting) nd 8-row (30- nd 38-inch plntings) by 2,640 ft plots. All tretments were plnted flt (no beds). The 19- nd 38-inch row spcing tretments were plnted using John Deere MxEmerge model 7100 vcuum ir plnter equipped with 15 plnter boxes spced on 19-inch centers. The 38-inch row spcing tretments were chieved by closing the seed drop on every other seed hopper beginning with the second box on the plnter. The 30-inch row spcing tretments were plnted with n 8-row John Deere MxEmerge Plus Vcumeter Plnter. The Victori cly soil (ph 7.9) ws 67 F t the plnting depth nd moisture ws excellent. Cotton hd been plnted on the test site the previous seson. Fertilizer pplied ws Frontier herbicide (6 10

15 lb i/gl) ws pplied by ir t 19.2 oz/cre on Mr 15. All plots were cultivted once on Apr 27. A specil nrrow row cultivtor ws used on the 19-inch rows. Rinfll, mesured on the south end nd middle of the plots ws, 1.6 (My 7), 3.3 (My 21), nd 0.05 (My 21) inches, respectively, for totl of 4.95 inches during the growing seson. Tretment effects were determined by (1) counting the number of plnts on cre t 3 sites in ech plot on Apr 10, (2) estimting the number of yellow sugrcne phids nd greenbug s on 20 lower plnt leves in the center rows of ech plot on My 15, (3) mesuring plnt height on 10 consecutive plnts t ech of 3 loctions per plot on Jun 12, (4) estimting % lodging in ech plot by visul observtion on Jun 27, (5) determining chrcol rot infested plnts by hnd feel of 50 plnts (with confirmtion by stlk splitting) on ech of the center two rows in ech plot on Jun 27, nd (6) hrvesting 0.34, 0.24 nd 0.31 cres per plot for 19-, 30- nd 38-inch row spcings respectively from ll but outside rows in ech row spcing tretment with commercil combine on Jun 30. Grin weights were djusted to 14% moisture. Net grin vlue over seed cost ws clculted using $2.28/lb for plnting seed treted with Gucho nd Concep nd $3.18/cwt grin vlue. RESULTS/DISCUSSION: Field plnt popultions were reltively close to trget popultions except for the higher popultion on 38-inch rows (Tble 1). Plnt heights following heding were generlly greter s row widths incresed from 19- to 38-inches. In similr 1999 study no differences in plnt height nd row width were observed. Cultivtion of the 19-inch rows on Apr 27 ppered to be extremely close to plnts nd my hve influenced plnt height nd other production fctors (cultivtion nd no cultivtion s tretments re plnned for 2002). Yellow sugrcne phids nd greenbugs were the only insects present in sufficient numbers to consider for evlution nd no differences were observed (Tble 1). Numbers of greenbugs were very low cross ll tretments. Rinfll up to My 21 resulted in excellent growth nd good hed but lmost no dditionl rin ws received resulting in premture plnt deth nd chrcol rot. On Jun 27 (3 dys before hrvest) plnt lodging cused by chrcol stlk rot ws low with no sttisticl differences between tretments but there ppered to be trend for incresed numbers of lodged plnts s row spcing incresed. There lso ppered to be trend for more chrcol stlk rot (lodged nd nonlodged plnts) t the higher plnt popultions. Grin moisture t hrvest ws similr cross ll tretments nd there were no significnt differences in grin yield (Tble 2). The noted differences in bushel weights seemed to be rndom nd could not be ccounted for by row spcing or plnt popultion. Net dollr vlue over seed cost tended to be greter for the lower plnt popultions. Dollr returns in the 38-inch row trget popultions did not follow the trends observed in 19- nd 30-inch spcing tretments possibly becuse trget popultions were not chieved. 11

16 The significnt dvntge of 19-inch row plnting observed in 2000 study on the Brlow Frm ws not duplicted in this study. However, we believe cultivtion of the 19-inch rows my hve dversely ffected yields in tht row spcing compred to the 30- nd 38-inch spcings. We noted better dollr returns t the 48,000 plnt popultion trget except in the 38-inch spcing. The 48,000 plnt popultion trget in 2000 (ctul 46,000) provided significntly more return due to decresed seed cost. This greter economic return cn be ttributed, in prt, to seed tretments like Concep nd Gucho tht significntly incresed seed cost for the higher plnt popultions. ACKNOWLEDGMENTS: We thnk the Sorghum PROFIT Inititive Project funded by the Texs Legislture nd the Texs Grin Sorghum Producers Assocition for their support. Apprecition is expressed to Robert Brlow for his time, lnd, nd equipment in conducting this study nd Drwin Anderson, Plnters Coop t Odem for his ssistnce. Specil cknowledgment is given Bubb Thoms for grciously providing the trctor nd plnter for the 30-inch row tretments. 12

17 Tble 1. Row spcing nd plnt popultion effects on sorghum plnt height, phid numbers, nd chrcol stlk rot, Robert Brlow Frm, Sn Ptricio County, TX, Row spcing Plnts (1000's/cre) Plnt No./20 plnts height trget ctul (inches) YSA GB % lodging % chrcol rot infested plnts 19-inch e b e b de cde inch cde c bcd b bc b bc inch bcd bc bc b b LSD (P = 0.05) NS NS NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Trget seeding rtes were 42.2, 53.3, 75.6, nd 97.8 thousnd seed per cre with trget plnt stnd objectives of 38, 48, 68, nd 88 thousnd plnts per cre (90% germintion). b YSA = yellow sugrcne phid, GB = greenbug counts were mde on 5/15. 13

18 Tble 2. Row spcing nd plnt popultion effects in sorghum on grin production nd dollr returns, Robert Brlow Frm, Sn Ptricio County, TX, Row spcing Plnts (1000's/cre) trget ctul % grin moisture Bushel weight Yield (lb/cre) Net $ vlue over seed/hrvest cost b 19-inch bc b b bc inch b b inch b c bc LSD (P = 0.05) NS NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Trget seeding rtes were 42.2, 53.3, 75.6, nd 97.8 thousnd seed per cre with trget plnt stnd objectives of 38, 48, 68, nd 88 thousnd plnts per cre (90% germintion). b Seed ws Gucho nd Concep treted; the cost ws $2.28/lb t seed count of 15,000/lb nd totl cre cost ws bsed on seeding rtes provided in footnote. Hrvesting nd huling costs were figured t $0.65/cwt. Sorghum vlue ws bsed on $3.18/cwt. 14

19 ROW SPACING AND PLANT POPULATION EFFECTS ON SORGHUM GROWN UNDER IRRIGATION Clrence Chopels Frm, Sn Ptricio County, 2001 Jeffrey R. Stpper, Roy D. Prker, nd Lwrence L. Flconer County Extension Agent, Extension Entomologist, nd Extension Economist- Mngement, respectively Sinton nd Corpus Christi, Texs SUMMARY: The 19-inch row plnted sorghum produced significntly more grin thn 38- inch row plnting. It returned n verge of $30.24 more per cre net vlue over seed nd cultivtion cost compred with 38-inch row plntings. Similr results were obtined on the sme frm the previous 2 sesons. OBJECTIVE: This field experiment ws designed to evlute the effects of row spcing nd plnt popultion on insect numbers, plnt growth chrcteristics, nd other sorghum production fctors. MATERIALS/METHODS: Pioneer 83G66 hybrid sorghum seed (16,500/lb) ws plnted on Mr 8, 2001 on the Clrence Chopels Frm in western Sn Ptricio County on lnd with center pivot irrigtion system. Two row spcings (19- nd 38-inch) nd three trget plnt popultion tretme nts (65, 85, nd 105 thousnd) were rrnged in rndomized complete block design with 3 replictions. Plots were 1,320 ft long with 24 rows in the 19- inch row plots nd 12 rows in the 38-inch row plots. Trget plnt popultions for ech row spcing were 65, 85, nd 105 thousnd/cre. To chieve these popultions, 90% seed germintion rte ws used. The test ws plnted flt (no beds) with 12-row model 1720 MxEmerge plus vcumeter ir plnter; the 19-inch spcing ws chieved by plnting between the 38-inch rows. Soil t the site ws Victori cly, ph 8.0, nd conditions for seed germintion were fvorble. Cotton hd been grown on the site the previous seson. Fertilizer pplied ws Zn-2 S on 12/9/00. Herbicide ws Atrzine 90F (1.5 lb/cre). Only the 38-inch rows were cultivted. Rinfll ws mesured t the field site nd consisted of 0.05 (Mr 14), 1.6 (Mr 27), 2.0 (My 7), 1.0 (My 21), nd 0.6 (Jun 20) inches for totl of 5.25 inches during the seson. Irrigtion mounts nd dtes were 1.0 (Apr 29), 1.5 (My 23), 1.5 (Jun 8), nd 1.5 (Jun 17) inches for totl of 5.5 inches. Tretment effects were determined by (1) mesuring soil moisture levels with Wtermrk brnd sensors (red with Wtermrk soil moisture meter) buried t 12-inch depths in the following ctul plnt popultion tretments: 19-inch, 46,000 plnts; 19-inch 90,000 plnts; 38-inch, 73,000 plnts; nd 38-inch, 112,000 plnts, (2) evluting plnt popultions on Apr 10 by counting plnts on cre t 3 loctions in ech plot, (3) counting yellow sugrcne phids nd greenbugs on 20 lower leves in ech plot on Apr 28, (4) estimting the number of corn lef phids in totl of 20 plnt whorls/plot on Apr 28, (5) mesuring 15

20 height of 10 plnts in 3 loctions in ech plot fter blooming on Jul 12, nd (6) hrvesting 360 ft row of ech plot with commercil combine on Jul 3 (9 nd 18 rows of the 38-inch nd 19-inch row spcing tretments, respectively). Grin weights were djusted to 14% moisture. Net grin vlue over seed cost ws clculted using $0.958/lb for seed nd $3.18/cwt grin vlue. Hrvesting/huling costs were clculted t $0.65/cwt. RESULTS/DISCUSSION: Plnt stnds exceeded the trget by n verge of 8,000/cre except in the 19-inch row, 105 thousnd plnt stnd trget (Tble 1). An incorrect plnter sprocket rnge setting trget resulted in only 46,000 plnts/cre for tht tretment. Aphid numbers during the only outbrek for the seson were very low nd no sttisticl differences were found. There were lso no differences in plnt heights. Sttisticl differences were not found in grin moisture or bushel weight but significnt differences were found in the yield dt (Tble 2). The 19-inch row sorghum produced significntly more grin. It returned n verge of $30.24 more per cre net vlue over seed nd cultivtion cost compred with the 38-inch row plnting. Similr results were obtined on the sme frm the 2 previous sesons. Except for the mistke in seeding rte for the 19-inch, 105,000 plnt stnd trget, no differences were found in the respective plnt popultions within ech row spcing. ACKNOWLEDGMENTS: We thnk Clrence Chopels for use of lnd, equipment nd his time in conducting this experiment. We lso thnk the Sorghum PROFIT Inititive Project funded by the Texs Legislture nd Texs Grin Sorghum Producers Assocition for their support. 16

21 Tble 1. Aphid numbers nd plnt height in sorghum from row spcing nd plnt popultion tretments, Clrence Chopels Frm, Sn Ptricio County, TX, Row Plnts (1000's/cre) Number per 20 plnts c Plnt height spcing trget ctul YSA GB CLA (inches) d 19-inch b inch LSD (P = 0.05) NS NS NS NS P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Trget seeding rtes were 72.2, 94.4, nd thousnd seed per cre with trget plnt stnd objectives of 65, 85, nd 105 thousnd plnts per cre (90% germintion). b Proper setting on the plnter ws not mde resulting in lower thn trget plnt stnd. An estimted seeding rte of 47,200 ws clculted for this tretment where the proper plnter rnge ws not utilized. c YSA = yellow sugrcne phid, GB = greenbug, nd CLA = corn lef phid. Counts were mde when sorghum verged 20-inches tll (4/28). d Averge height of 30 plnts per plot (10 ech t 3 sites per plot). 17

22 Tble 2. Comprison of grin moisture t hrvest, bushel weight nd sorghum yields from row spcing nd plnt popultion tretments, Clrence Chopels Frm, Sn Ptricio County, TX, Row spcing Plnts (1000's/cre) trget ctul % grin moisture Bushel weight Yield (lb/cre) Seed & cultivtion cost $/cre c Net $ vlue over seed/hrvest cost d 19-inch b b inch c c c LSD (P = 0.05) NS NS 167 P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Trget seeding rtes were 72.2, 94.4, nd thousnd seed per cre with trget plnt stnd objectives of 65, 85, nd 105 thousnd plnts per cre (90% germintion). b Proper setting on the plnter ws not mde resulting in lower thn trget plnt stnd. An estimted seeding rte of 47,200 ws clculted for this tretment where the proper plnter rnge ws not utilized. c The seed cost ($0.958/lb) ws bsed on originl seeding rtes in footnote t 16,500 seed/lb for Pioneer hybrid 83G66. Cultivtion cost ws considered to be $6.00/cre nd only 38-inch rows were cultivted. d Net $ vlue bove seed, cultivtion, nd hrvesting/huling costs. Sorghum vlue bsed on $3.18/cwt. Hrvesting nd huling costs were figured t $0.65/cwt. 18

23 ROW SPACING AND PLANT POPULATION EFFECTS ON SORGHUM PRODUCTION Venture Frms, Refugio County, 2001 Michel L. Muldin, Roy D. Prker, nd Lwrence L. Flconer County Extension Agent, Extension Entomologist, nd Extension Economist- Mngement, respectively Refugio nd Corpus Christi, Texs SUMMARY: Row spcing hd little effect on sorghum production in this study. The yield difference ws only 117 lb/cre between the 20- nd 40-inch rows. OBJECTIVE: The field study ws conducted to compre the effects on sorghum production of 20-inch nd 40-inch row spcings t 3 plnt popultion levels. MATERIALS/METHODS: Deklb DK45 hybrid sorghum (14,000 seed/lb) tht ws Concep nd Gucho treted ws plnted Mr 20, 2001 on the Lmbert Rnch locted north of Refugio. The test ws plnted flt (no beds) with 24-row John Deere 1780 model plnter with seeding units spced on 20-inch centers. The 40-inch row spcing tretments were chieved by closing the seed drop on every other box on the plnter. Three trget plnt popultions of 48, 68, nd 88 thousnd/cre t both row spcings were rrnged in rndomized complete block design with 3 replictions. Plots were 12- or 6-rows for the 20- nd 40-inch spcings, respectively, nd ll plots were pproximtely 1000 ft long. Soil t the site ws hevy cly nd conditions for seed germintion were fvorble. Cotton hd been grown in the field during the previous seson. Fertilizer (N, P, K) ws plus 36 S. Atrex 4L (1 lb/cre) ws pplied for weed control. The test ws not cultivted. Tretment effects were mesured by (1) counting the plnts on 20 row ft t ech of 4 loctions in the center 4 rows in ech plot on My 2, (2) estimting the percentge plnt lodging in ech plot on Jul 7, nd (3) hrvesting cres of ech plot on Jul 12. Grin weights were djusted to 14% moisture. Net grin vlue over seed cost ws clculted using $2.28/lb for seed (Concep nd Gucho treted), $0.65 for hrvesting nd huling, nd $3.18/cwt grin vlue. RESULTS/DISCUSSION: Trget plnt popultions were not chieved nd there ws substntil vrition which my hve ffected the test outcome (Tble 1). Sttisticl differences were not found in plnt lodging, grin moisture, or bushel weight. There were differences in yields. Solid evidence of row spcing effect ws not observed, which my hve been confounded by vrition in plnt popultions. Overll, there ws only 117 lb/cre difference in grin yield between the 20- nd 40-inch row spcing tretments. Incresed seed costs due to the Concep nd Gucho resulted in just s good net dollr vlue over these costs t the lower seeding rtes. Four of the 6 row- spcing tests 19

24 conducted over the pst two sesons demonstrted significntly greter yields on the nrrow rows (19- or 20-inch compred with 38- or 40-inch rows). ACKNOWLEDGMENTS: We thnk the Sorghum PROFIT Inititive Project funded by the Texs Legislture nd the Texs Grin Sorghum Producers Assocition for their support. Wlt Frnke is cknowledged for equipment, interest, nd lbor donted to conduct the study. A specil thnks is extended to Tommy Bertling, Monsnto Compny, for his service during hrvest. Tble 1. Comprison of lodging, grin moisture t hrvest, bushel weight, nd sorghum yield from row spcing nd plnt popultion tretments, Venture Frms, Refugio County, TX Row spcing Plnts (1000's/cre) % trget ctul lodging % grin moisture Bushel weight Yield (lb/cre) Net $ vlue b 20 - inch c b bc inch bc bc LSD (P = 0.05) NS NS NS 252 P > F Mens in column followed by the sme letter re not significntly different by ANOVA. Trget seeding rtes were 53.3, 75.6, nd 97.8 thousnd seed per cre with trget plnt stnd objectives of 48, 68, nd 88 thousnd plnts per cre (90% germintion). b All seed ws Gucho nd Concep treted; the cost ws clculted t $2.28/lb t seed count of 14,000/lb with totl cost bsed on trget seeding rtes provided in footnote. Hrvesting nd huling costs were figured t $0.65/cwt. Sorghum vlue ws bsed on $3.18/cwt. 20

25 EVALUATION OF ASGROW A571 AND DEKALB DK54 SORGHUM HYBRIDS GROWN ON TWO ROW SPACINGS AT THREE POPULATION LEVELS Richrd Run Frm, Whrton County, 2001 Richrd L. Jhn, W. Jmes Grichr, Jr., Roy D. Prker, nd Lwrence L. Flconer County Extension Agent, Reserch Scientist, Extension Entomologist, nd Extension Economist-Mngement, respectively Whrton, Yokum, nd Corpus Christi, Texs SUMMARY: Both hybrids provided substntilly higher net dollr vlue over seed cost in the 20-inch plntings. Costs t the highest seeding rte tended to reduce dollr return. The intermedite plnt popultion produced the most income over seed nd hrvest costs. OBJECTIVE: The experiment ws conducted to mesure the effects on two sorghum hybrids grown on 20- nd 40-inch row spcings, ech t three plnt popultion levels. MATERIALS/METHODS: Asgrow A571 (pproximtely 12,000 seed/lb) nd Deklb DK54 (pproximtely 14,500 seed/lb) hybrid sorghum seed ws plnted Mr 21, 2001 on the Richrd Run Frm in west Whrton County bout 8 miles north of Louise on 20- nd 40- inch row spcings t 3 trget seed rtes of 45-50, 75-85, nd thousnd/cre. The hybrid, row spcing, nd seeding rte tretments were rrnged in rndomized complete block design with 4 replictions. Plots were 8 rows (20-inch plnting) nd 4 rows (40-inch plnting) by 50 ft. The test ws plnted flt (no beds) with Monosem vcuum ir plnter with seed boxes spced on 20-inch centers. The 40-inch tretments were chieved by rising lternte seed hoppers. The soil ws n Edn sndy lom with ph of 6.5. Rice hd been plnted on the site the previous seson. Totl fertilizer nlysis pplied in 2 pplictions ws Herbicide pplied ws lchlor (2.0 lb i/cre) + trzine (0.5 lb i/cre); subsequent weed pressure ws low. Plots were not cultivted. Rinfll fter plnting consisted of 0.77 (Mr), 0.65 (Apr), 3.8 (My), 1.31 (Jun), nd 3.7 (Jul) inches for totl of inches during the growing seson. Tretments were evluted by (1) counting the number of plnts on 10 row ft in ech plot on Apr 25, nd (2) hrvesting portions of plots with 5-foot heder combine on Jul 19. Grin weights were djusted to the 14% moisture stndrd. Net grin vlue over seed cost ws clculted using $2.12/lb for seed nd $3.18/cwt grin vlue. RESULTS/DISCUSSION: Trget plnt popultions were not chieved but some seprtion ws chieved (Tbles 1 nd 2). Seed cost incresed substntilly bsed on the verge trget seeding rtes. Grin yields in Asgrow A571 were significntly greter for 20-inch row spcing compred with 40-inch row spcing, except t the low popultion level (Tble 1). Net vlue over 21

26 seed nd hrvest/huling costs verged $126.65/cre in the 20-inch plntings nd $101.29/cre in the 40-inch plntings. Grin yield of Deklb DK54 in the 20-inch middle plnt popultion tretment ws sttisticlly greter thn the 40-inch low plnt popultion (Tble 2). The 20-inch yield ws numericlly greter t ll plnt popultion levels. Net vlue over seed cost verged $138.00/cre in the 20-inch plntings nd $126.62/cre in the 40-inch plntings. ACKNOWLEDGMENTS: Thnks re extended to the Sorghum PROFIT Inititive Project funded by the Texs Legislture nd Texs Grin Sorghum Producers Assocition for their support. Apprecition is expressed to Richrd Run for lnd, equipment, nd lbor, nd to Brd Minton, Syngent Compny, for providing hrvesting equipment. Tble 1. Evlution of Asgrow A571 sorghum hybrids t three popultions on two row spcings, Richrd Run Frms, Whrton County, TX, Row Plnts (1000's/cre) Yield Seed cost spcing trget ctul (lb/cre) ($/cre) b Net $ vlue c 20-inch b inch b b b Mens in column followed by the sme letter re not significntly different by ANOVA (P = 0.05). P > F vlue ws.0036; LSD = 890 lb. b Seed cost per cre ws bsed on the verge trget seeding rte t cost of $2.12/lb (Concep nd Gucho treted). Seed for Asgrow A571 ws clculted t 12,000/lb. c Net $ vlue over seed nd hrvesting/huling ($0.65/cwt) costs. Sorghum vlue ws bsed on $3.18/cwt. 22

27 Tble 2. Evlution of DK54 sorghum hybrids t three popultions on two row spcings, Richrd Run Frms, Whrton County, TX, Row Plnts (1000's/cre) Yield Seed cost spcing trget ctul (lb/cre) ($/cre) b Net $ vlue c 20-inch b b inch b b b Mens in column followed by the sme letter re not significntly different by ANOVA (P = 0.05). P > F vlue ws.0391; LSD = 953 lb. b Seed cost per cre ws bsed on the verge trget seeding rte t cost of $2.12/lb (Concep nd Gucho treted). Seed for DK 54 ws clculted t 14,500/lb. c Net $ vlue over seed nd hrvesting/huling ($0.65/cwt) costs. Sorghum vlue ws bsed on $3.18/cwt. 23

28 REACTION OF SORGHUM HYBRIDS TO COUNTER, CRUISER, AND GAUCHO SYSTEMIC INSECTICIDES Texs Agriculturl Experiment Sttion, Nueces County, 2001 Roy D. Prker Extension Entomologist Corpus Christi, Texs SUMMARY: Few observble impcts were found due to Counter, Cruiser, nd Gucho systemic insecticide use on sorghum hybrids. Low pest numbers llowed observtion of potentil phytotoxic effects on the tested hybrids. Consistent effects on plnt stnds were not observed lthough significnt differences were found in five hybrids. Counter nd Gucho seemed to dversely ffect plnt stnds in few hybrids. Six hybrids showed significnt heding differences due to tretment, with the Counter tretment heding erlier thn t lest one other tretment in five hybrids. Only one hybrid hd blooming rte differences. Yields vried significntly in four hybrids but, gin, consistent insecticide effects were not found. OBJECTIVE: The study ws conducted to determine the effect of Counter, Cruiser, nd Gucho on sorghum hybrids; to evlute their effectiveness in controlling insect pests; nd to mesure impct on yield. MATERIALS/METHODS: Sorghum hybrids (Concep III treted) were plnted Mr 14, 2001 on the Texs Agriculturl Experime nt Sttion t Corpus Christi. A reserch plot cone plnter set on 38-inch centers ws used to plnt the 2-row by 50 ft long plots. Seed ws prepckged by the Syngent Compny. The experiment ws rrnged in rndomized complete block with 4 replictions. Plnting conditions consisted of excellent soil moisture nd fvorble soil temperture. Cotton hd been plnted on the site the previous seson. Counter 20CR (3.0 oz/1000 ft row) ws pplied through electric driven Gndy boxes with stndrd John Deere 6-inch bnders. Atrzine 4L (1 qt/cre) plus Dul II Mgnum (7.64 lb i/gl) t 1 pt/cre ws brodcst over the test plot fter plnting. PENNCO iron (25% ferrous sulfte) t 1 gl/cre ws pplied on Apr 25 nd My 1. Fertilizer pplied ws Tretment effects were ssessed by (1) counting the number of plnts on ft row in both rows in ech plot on Apr 2, (2) estimting heding nd blooming rtes on My 21, nd (3) hrvesting ft from one of the two rows in ech plot on Jul 9 (24 plots were hrvested with two row plot combine). Grin weights were djusted for moisture to 14%. RESULTS/DISCUSSION: Counter, Cruiser, nd Gucho systemic insecticide use hd few observble impcts on plnt stnd, heding nd blooming rtes, or yield of the 18 hybrids (Tble 1). Pest insect numbers were extremely low for the durtion of the field study, 24

29 llowing for observtion of direct impct of insecticides on the hybrids. Two hybrids treted with Counter hd reduced plnt stnds compred with ll other tretments in 1 hybrid (J) nd ll tretments except Gucho in nother hybrid (O); Counter treted sorghum hd significntly better plnt stnd compred with the untreted plots in 1 hybrid (G). In 2 hybrids (P, R), Cruiser treted sorghum plnt stnds were significntly better thn 1 other tretment. Significnt differences occurred in heding rtes in 6 hybrids. Most notble ws erlier heding in Counter treted sorghum of 5 hybrids (D, H, I, K, L) compred with t lest 1 other tretment. Blooming rte ws significntly different in only 1 hybrid (K); Cruiser blooming rte ws slower thn Counter nd the untreted sorghum in tht cse. Sttisticlly significnt yield effects were observed in 4 hybrids (A, B, N, S), but no 1 insecticide ws consistently superior to nother. Three of the 4 cses of incresed yield involved n insecticide tretment being better thn the untreted control. ACKNOWLEDGMENTS: Apprecition is expressed to Syngent Compny for support of this field study. 25

30 Tble 1. Effect of insecticide tretments on sorghum hybrids, Texs Agriculturl Experiment Sttion, Nueces County, TX, Hybrid Insecticide & formultion Plnts (1000's/cre) heding % on 5/21 blooming Yield (lb/cre) A Gucho Cruiser b Counter b UTC b LSD (P=0.05) NS NS NS 640 P > F B Gucho b Cruiser b Counter UTC b LSD (P=0.05) NS NS NS 548 P > F C Gucho Cruiser Counter UTC LSD (P=0.05) NS NS NS NS P > F D Gucho b Cruiser b Counter UTC b LSD (P=0.05) NS NS NS 26

31 Tble 1. Continued. Hybrid Insecticide & formultion Plnts (1000's/cre) heding % on 5/21 blooming Yield (lb/cre) P > F E Gucho Cruiser Counter UTC LSD (P=0.05) NS NS NS NS P > F F Gucho Cruiser Counter UTC LSD (P=0.05) NS NS NS NS P > F G Gucho 70.8 b Cruiser 67.0 b Counter UTC 61.3 b LSD (P=0.05) NS NS NS P > F H Gucho b Cruiser b Counter UTC b LSD (P=0.05) NS 5.49 NS NS 27

32 Tble 1. Continued. Hybrid Insecticide & formultion Plnts (1000's/cre) heding % on 5/21 blooming Yield (lb/cre) P > F I Gucho b Cruiser Counter UTC b LSD (P=0.05) NS NS b NS P > F J Gucho 59.8 b Cruiser 67.5 b Counter 48.0 c UTC LSD (P=0.05) NS NS NS P > F K Gucho b 2739 Cruiser b 43.8 b 2442 Counter UTC LSD (P=0.05) NS NS P > F L Gucho b Cruiser b Counter UTC b LSD (P=0.05) NS NS NS 28