THE EFFECT OF SEED AND SOIL APPLIED SYSTEMIC INSECTICIDES ON APHIDS IN SORGHUM Txs Agriulturl Exprimnt Sttion, Nus County, 2000 Roy D. Prkr Extnsion Entomologist Corpus Cristi, Txs SUMMARY: Grnug, yllow sugrn pi n orn l pi numrs wr onsir to low onomilly mging lvls trougout t sson. Sttistil irns wr not oun in t-plnting instii trtmnt or plnt stn, ovrll inst mg or yil. Numrilly, owvr, mor sorgum ws prou y ll svn instii trtmnts ompr to t untrt sorgum, ut tis inrs ws rltivly smll (149 l/r). OBJECTIVES: T xprimnt ws stlis to ompr s n soil ppli systmi instiis on sorgum or t on inst psts n impt on yil. MATERIALS/METHODS: Crgill 839 yri sorgum (Conpt III trt) ws plnt 2 Mr 2000 on t Mny Annx o t Txs Agriulturl Exprimnt Sttion t Corpus Cristi. A rsr plot on plntr ws us to s t 4 row (38-in ntrs) y 30 t long plots. W intn to plnt 5 s/row t ut n up wit mu grtr sing rt. T xprimnt ws rrng in rnomiz omplt lok sign wit 4 rplitions. Plnting onitions onsist o xllnt soil moistur, 74.1 F soil tmprtur t t 3-in pt n 80 F ir tmprtur. Soil t t sit ws ly lom (50% sn, 26% silt, 24% ly) wit 1.1% orgni mttr n soil ph o 8.1. Cotton n plnt on t sit in t prvious sson. Furn 4F ws ppli into t s urrows troug singl 8002 E nozzl orint wit t row t 7.88 gp totl volum, 40 psi n 3.25 mp. Countr 20CR ws ppli wit ltri rivn Gny oxs quipp wit stnr Jon Dr 6-in nrs. Atrzin 4L (1.5 qt/r) ws rost on y tr plnting. Frtilizr onsist o 100-14-0 + 0.6 Zn/r. A totl o 7.64 ins o rin ws riv uring t growing sson. Trtmnt ts wr ssss y (1) ounting t numr o plnts on 13.75 t row on on o t ntr rows in plot on 1 Apr, (2) ssigning visul mg rting to plot on 1 Apr, wit 1 = no mg up to 5 = stunt, ying, yllow plnts or unvn plnt stn, (3) ounting grnug (GB) n yllow sugrn pi (YSA) numrs on 10 lowr lvs n stimting orn l pis (CLA) pr worl in plot on 20 Apr, 16 My n 23 My (i.. 49, 75 n 82 ys tr plnting) n (4) rvsting 10 rowt on o t two ntr rows (20 t totl) in plot on 28 Jun. Grin wigts wr susquntly just to 14% moistur. RESULTS/DISCUSSION: GB, YSA n CLA numrs wr onsir to low onomilly mging lvls trougout t sson (Tl 1-3). Sttistilly signiint irns wr not tt in GB numrs t 49 DAP, 75 DAP or or omin sson vrg t (Tl 1). At 82 DAP t Furn trt sorgum ontining signiintly mor GB tn otr trtmnts. Altoug rltivly low numrs wr ount 49 DAP, YSA popultions wr sttistilly lowr in t Guo n Ag 50% trt/untrt s mixtur trtmnts ompr to t Furn trtmnt (Tl 2). Ts rsults o not ppr to v n us y t instii trtmnts. YSA numr irns wr not oun on
ny otr insption nor wr signiint irns oun in t sson vrg numr t. CLA numrs wr lowr 49 DAP in Guo n Ag (100% s trt) trtmnt ompr to untrt n Furn trt sorgum (Tl 3). By 75 DAP Guo (50% trt/untrt s mixtur) trt sorgum ontin signiintly mor CLA tn ny otr trtmnt. No otr irns wr msur nor i strong trtmnt ts our; numrs wr simply too low to v signiint t. Sttistil irns wr not tt in plnt popultion, inst mg rting or yil (Tl 4). Numrilly, mor sorgum ws rvst in ll instii trtmnts ompr to untrt sorgum ut t irn ws smll (83-273 l/r). ACKNOWLEDGMENTS: Apprition is xprss to Novrtis Compny or support o tis il stuy. Tl 1. Comprison o s n soil ppli systmi instiis or t on grnug, Txs Agriulturl Exprimnt Sttion, Nus County, TX, 2000. Trtmnt Rt mto Applition Grnugs pr 10 lowr lvs 49 DAP 75 DAP 82 DAP Sson vg. Guo 480 FS 8.0 ST 0 82.5 0 27.5 Guo 480 FS 8.0 ST 0 32.3 0 10.8 Ag 5FS 5.1 ST 0 106.8 0 35.6 Ag 5FS 5.1 ST 0 59.0 0 19.7 Countr 20CR 3.0 IFGAP 0 94.0 0 31.3 Sorgum Gur 5.34 ST 0 68.3 0 22.8 Furn 4F 16.0 IFSAP 0 37.5 1.25 12.9 Untrt 4.25 15.3 0 6.5 LSD (P=0.05) NS NS NS P > F.0933.1186.0053.1303 Mns in olumn ollow y t sm lttr r not signiintly irnt y ANOVA (LSD). Formult rts r xprss s oz/wt s or ST, oz/1000 row-t or IFGAP n oz/r or ST = s trtmnt, IFGAP = in-urrow grnuls t plnting n IFSAP = in-urrow spry t plnting. A mixtur o 50% trt n 50% untrt s. Sorgum Gur is mixtur o 32.75% ptn n 16.6% linn. DAP = ys tr plnting or 20 Apr, 16 My n 23 My. T P > F is s on trnsorm [squr root (x + 1)] t vlus; it is inpproprit to list LSD vlus s on trnsorm t.
Tl 2. Comprison o s n soil ppli systmi instiis or t on yllow sugrn pi, Txs Agriulturl Exprimnt Sttion, Nus County, TX, 2000. Trtmnt Rt mto Applition Yllow sugrn pis pr 10 lowr lvs 49 DAP 75 DAP 82 DAP Sson vg. Guo 480 FS 8.0 ST 1.75 67.3 2.5 23.8 Guo 480 FS 8.0 ST 0.0 65.3 0.5 21.9 Ag 5FS 5.1 ST 6.25 99.0 0.0 35.1 Ag 5FS 5.1 ST 0.0 128.8 1.8 43.5 Countr 20CR 3.0 IFGAP 1.67 120.7 0.0 40.8 Sorgum Gur 5.34 ST 2.0 79.0 0.5 27.2 Furn 4F 16.0 IFSAP 7.5 92.0 0.8 33.4 Untrt 2.75 69.5 0.5 24.3 LSD (P=0.05) 6.761 NS NS NS P > F.0469.2866.0807.2966 Mns in olumn ollow y t sm lttr r not signiintly irnt y ANOVA (LSD). Formult rts r xprss s oz/wt s or ST, oz/1000 row-t or IFGAP n oz/r or ST = s trtmnt, IFGAP = in-urrow grnuls t plnting n IFSAP = in-urrow spry t plnting. A mixtur o 50% trt n 50% untrt s. Sorgum Gur is mixtur o 32.75% ptn n 16% linn. DAP = ys tr plnting or 20 Apr, 16 My n 23 My.
Tl 3. Comprison o s n soil ppli systmi instiis or t on orn l pi, Txs Agriulturl Exprimnt Sttion, Nus County, TX, 2000. Trtmnt Rt mto Applition Corn l pis/plnt worl 49 DAP 75 DAP 82 DAP Sson vg. Guo 480 FS 8.0 ST 0.25 1.25 0 0.5 Guo 480 FS 8.0 ST 1.33 13.75 0 5.0 Ag 5FS 5.1 ST 1.00 2.80 0 1.3 Ag 5FS 5.1 ST 3.25 1.25 0 1.5 Countr 20CR 3.0 IFGAP 2.33 0.0 0 0.8 Sorgum Gur 5.34 ST 3.25 0.0 0 1.1 Furn 4F 16.0 IFSAP 4.50 0.5 0 1.7 Untrt 7.00 0.0 0 2.3 LSD (P=0.05) 3.197 NS NS NS P > F.0011.1142.1388 Mns in olumn ollow y t sm lttr r not signiintly irnt y ANOVA (LSD). Formult rts r xprss s oz/wt s or ST, oz/1000 row-t or IFGAP n oz/r or ST = s trtmnt, IFGAP = in-urrow grnuls t plnting n IFSAP = in-urrow spry t plnting. A mixtur o 50% trt n 50% untrt s. Sorgum Gur is mixtur o 32.75% ptn n 16.6% linn. DAP = ys tr plnting or 20 Apr, 16 My n 23 My.
Tl 4. Plnt stn, ovrll inst mg rting n yil in sorgum wit s n soil ppli systmi instiis, Txs Agriulturl Exprimnt Sttion, Nus County, TX, 2000. Trtmnt Rt mto Applition Plnts (1000's/r) Ovrll inst mg rting Yil (l/r) Rturn $/r ovr untrt g Guo 480 FS 8.0 ST 96.0 2.0 4080-5.10 Guo 480 FS 8.0 ST 90.3 2.0 4146 0.17 Ag 5FS 5.1 ST 100.8 2.3 4152 Ag 5FS 5.1 ST 111.1 1.3 4059 Countr 20CR 3.0 IFGAP 122.0 1.7 4270-0.05 Sorgum Gur 5.34 ST 103.0 1.8 4129 3.05 Furn 4F 16.0 IFSAP 105.0 1.5 4184-3.65 Untrt 114.0 2.0 3997 LSD (P=0.05) NS NS NS g P > F.1338.1381.3223 Mns in olumn ollow y t sm lttr r not signiintly irnt y ANOVA (LSD). Formult rts r xprss s oz/wt s or ST, oz/1000 row-t or IFGAP n oz/r or ST = s trtmnt, IFGAP = in-urrow grnuls t plnting n IFSAP = in-urrow spry t plnting. A mixtur o 50% trt n 50% untrt s. Sorgum Gur is mixtur o 32.75% ptn n 16.6% linn. Sing rt ws too ig. Dmg rtings rng rom 1 = no mg up to 5 = stunt or ying yllow plnts n unvn plnt growt. Sorgum vlu s on $3.18/wt; osts inlu Guo 480FS ($1.20/l s t 6.0 l/r), Countr 20CR ($2.60/l), Sorgum Gur ($4.00/wt s t 6 l/r = $0.24/r) n Furn 4F ($65.00/gllon). Applition osts inlu Countr 15G n Furn 4F ($0.25/r), n Sorgum Gur plntr ox trtmnt ($0.05/r). Hrvsting n uling osts or xtr yil ov t untrt sorgum ws st t $0.65/wt. Ag is n xprimntl instii or wi ost s not n stlis