ALABAMA WHEAT AND FEED GRAINS PRODUCERS PROJECT SUMMARY from YEAR 2014 CONTINUING PROJECT

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1 ALABAMA WHEAT AND FEED GRAINS PRODUCERS PROJECT SUMMARY from YEAR 2014 CONTINUING PROJECT TITLE: Evaluation of Effects of Foliar Fungicide Applications on Diseases of Wheat INVESTIGATOR: Dr. Kira L. Bowen Department of Entomology and Plant Pathology 209 Life Sciences Bldg Auburn University, AL FUNDS RECEIVED: $4,200 OBJECTIVE: To evaluate the efficacy of selected foliar fungicides on specific diseases of wheat at three locations in Alabama. Results: Plots of wheat were planted at four research units of the Alabama Agricultural Experiment Station. Cultivars were Pioneer 26R10 at TVREC in Belle Mina, Coker Oakes at SMREC in Crossville, AGS 2026 at PARU in Prattville, and AGS 2060 at GCREC in Fairhope. Fungicides included Stratego YLD, Absolute 500 SC (Bayer CropSciences), Tilt, Prosaro (Syngenta), Caramba, Priaxor and Twinline (BASF) and Aproach (DuPont). All trials included at least one scab treatment, as well as direct comparisons between differentially timed fungicide applications of Tilt and Twinline at all locations, Stratego YLD and Prosaro at Gulf Coast. Fungicide applications were made at Feekes stages 9 (flag leaf collar visible), 10 (ear swollen), and (beginning flower). At all four locations, Septoria and Stagnospora leaf and glume blotches were the predominant diseases with low to moderate intensity on non-treated plots. Leaf rust was noted on non-treated plots at minimal levels at Prattville and powdery mildew was seen at a low intensity at Gulf Coast. Stripe rust and scab were seen only at trace levels at all four locations. At northern locations (TVREC and SMREC), fungicides significantly affected leaf and glume blotch. Greatest reduction in disease was noted with Prosaro 421SC (6.5 fl oz per A), applied either at FS10 or FS10.51, and Stratego YLD (4 fl oz per A) at FS10 at both TVREC and SMREC; Tilt at FS10 did well at TVREC (see tables on accompanying pages). No significant differences in yields or test weights (TVREC) or 1000-kernel weights (SMREC) were noted with any fungicide applications. However, at TVREC, fungicides increased yield an average of 3.8%, while at SMREC, the yield increase over all fungicide treatments was 8.1%. Fungicide treatments did not significantly affect disease levels, yields or thousand-kernel weights in tests at Prattville and GCREC. However, at Prattville all fungicides tested tended to reduce blotch. Highest yields at Prattville were seen with FS10 applications of Stratego YLD and Twinline (see tables on next pages). At GCREC, a 10% increase in yield was seen with Absolute made at FS10.5. Tabular data follows for these four tests. Disease ratings and data analysis done by Dr. K.L. Bowen with assistance from undergraduate student, Andrea Nelson. 1

2 Tennessee Valley, Belle Mina, AL: Branson planted on 5 Nov 13. Fungicide applications made FS6 (jointing, 17 Apr), FS9 (23 Apr), FS10 (1 May), and FS10.51 (2 May). Powdery mildew, rusts, scab and BYD were observed at nil to trace levels. Stagnospora/Septoria blotch was reduced by all fungicide treatments and best treatments were Stratego YLD applied at FS6 followed by Prosaro at FS10.51, Stratego YLD and Tilt applied at FS10, and Prosaro at FS10 or FS While not significantly different from the control, most fungicide treatments improved test weight and improved yield. The highest yield was from plots treated with Tilt and Caramba applied at FS10. Stagnospora Yield Test weight (lbs) Foliar treatment (formulation/a) Appl. Stage blotch x (bu/a) Non-treated control a Stratego YLD y (2 fl oz) fb FS 6 fb z FS d Prosaro y 421SC (6.5 fl oz)... Tilt y (3 fl oz)... FS ab Twinline y (8 fl oz)... FS abc Caramba y (14 fl oz)... FS abc Prosaro y 421SC (6.5 fl oz)... FS cd Stratego YLD y (6.5 fl oz)... FS d Tilt y (3 fl oz)... FS cd Twinline y (8 fl oz)... FS abc Caramba y (14 fl oz)... FS bcd Prosaro y 421SC (6.5 fl oz)... FS cd Tilt y (3 fl oz)... FS ab Twinline y (8 fl oz)... FS abc P = x 0 to 10 scale; 0 = no disease, 10 = severe disease; rated 5/16/14. y Plus 0.125% Induce (v/v). z fb = followed by. Prattville AGS2026 planted on 10 Oct FS9 applications done on 31 March, FS10 on 8 Apr, and FS10.51 on 17 Apr Mar. Diseases rated 8 May. Harvest date, 18 Jun Disease levels were low; no differences observed due to treatment kernel weight and yield: no significant differences due to treatment. However, Absolute 500SC treatments numerically improved 1000-k wt and several treatments numerically improved yield compared to non-treated control. Fungicide, rate/a Application Leaf rust y Septoria blotch x 1000 Kernel wt time (g) Yield (bu/a) Control Aproach w, 9 fl oz FS Priaxor w, 4 fl oz.. FS Tilt w, 3 fl oz.. FS Twinline w, 8 fl oz... FS Absolute 500SC w, 8 fl oz.. FS Aproach w, 9 fl oz.... FS Stratego YLD w, 2 fl oz FS Twinline w, 8 fl oz.... FS Tilt w, 3fl oz.. FS Absolute 500SC w, 4 fl oz. FS Stratego YLD w, 2 fl oz FS P-value y 0 to 100% scale; 0 = no disease, 100 = severe disease; x 0 = no disease, 9 = severe disease; w plus 0.125% non-ionic surfactant (Induce). 2

3 Sand Mountain, near Crossville, AL: Oakes was planted on 27 Oct 13. Fungicide applications made at FS6 (24 Mar), FS10 (29 Apr) and FS (2 May). No to trace levels of powdery mildew, rusts, scab and BYD were observed. Stagnospora (~Septoria) blotch was reduced by all but one fungicide treatment; best treatments were Stratego YLD applied at FS10 and Prosaro applied at FS10 or FS Although not statistically different from the non-treated control, many treatments reduced kernel weight. Three treatments reduced yield compared to the control. Although not statistically different from the control, Prosaro applied at FS10 and Caramba applied at FS10.51 had 15% higher yields than the control. Foliar treatment (fl. oz./a) Appl. Stage Leaf and Glume Blotch x 1000-kernel wt (g) Bushels per acre Nontreated Ab Caramba (14) y.. FS Bcd FORTIX (4) y... FS Abcd FORTIX (5) y... FS Bcd Prosaro 421SC (6.5) y.. FS Cd Quilt Xcel (3) y. FS Abcd Stratego YLD (4) y... FS Cd Twinline (8) y... FS Abcd Caramba (14) y. FS A Prosaro 421SC (6.5) y.. FS D Quilt Xcel (3) y FS Abc Twinline (8) y.. FS Abc Priaxor (2) y fb x Caramba (14) y FS5-7 fb FS A Priaxor (14) y fb Caramba (14) y FS5-7 fb FS Bcd Stratego (2) y fb Prosaro 421SC y (6.5) FS5-7 fb FS Abcd P = x 0 = no disease, 9 = severe disease; y plus 0.125% non-ionic surfactant (Induce); z fb = followed by Gulf Coast AGS 2026 planted 12 Nov 2013; foliar fungicides were applied at Feekes' stage (FS) 9 on 30 Mar; FS10, 27 Mar; and FS10.5, 10 Apr. No rusts were noted; powdery mildew was found at low levels. Septoria leaf and glume blotches were noted at low to moderate intensity. No significant differences in disease levels among treatments kernel weights did not significantly differ among treatments. Yield was improved with several treatments; highest yield seen with Absolute 500SC at FS Appl. Powdery Septoria Foliar treatment (formulation/a) Stage mildew y blotch y Yield (bu/a) Non-treated control bcd 34.7 Absolute 500SC z (4 fl oz)... FS bc 35.8 Aproach z (9 fl oz)... FS ab 35.4 Priaxor z (4 fl oz)... FS cd 36.0 Prosaro 421 SC z (4 fl oz)... FS ab 35.3 Tilt z (3 fl oz)... FS abc 34.6 Twinline z (8 fl oz)... FS ab 35.4 Absolute 500SC z (4 fl oz)... FS abc 35.0 Aproach z (9 fl oz)... FS bcd 34.0 Prosaro 421SC z (6.5 fl oz)... FS bc 35.1 Stratego YLD z (2 fl oz)... FS d 34.4 Twinline z (8 fl oz)... FS bcd 36.1 Tilt z (3 fl oz)... FS bc 34.5 Absolute 500SC z (4 fl oz)... FS a 35.8 Stratego YLD z (4 fl oz)... FS bcd 35.1 P = y 0 to 10 scale; 0 = no disease, 10 = severe disease; z Plus 0.125% Induce (v/v) Kernel wt (g) 3

4 2014 PROJECT Summary Alabama Wheat and Feed Grains Committee Continuing project. TITLE: Evaluation of Disease Response on Small Grain Cultivars in Alabama (continuing project) Investigator: Dr. Kira L. Bowen, Plant Pathology Funds received: $4,000 Objective 1: To evaluate a number of small grain varieties for their reaction to specific diseases at several locations throughout the state. Results: Up to thirty-seven (37) soft red winter wheat cultivars were evaluated as part of small grain variety trials at seven research centers and experiment fields across Alabama. In addition, up to seven oat cultivars were evaluated at each of seven locations. Disease evaluations were done during April and May 2014, about Feekes stage 11.2 (soft dough). Locations were: Tennessee Valley Research Center (REC) in Belle Mina, Sand Mountain REC in Crossville, Plant Breeding Unit in Tallassee, Prattville Experiment Field, Brewton Research Unit, Gulf Coast REC in Fairhope and Wiregrass REC in Headland. In general, disease pressure was low in variety trials throughout the state in the spring of 2014, lower than in However, substantial powdery mildew intensity was noted in variety trials at Belle Mina, Crossville, Headland and Fairhope; usually this disease is not found as spring weather warms and humidity decreases. At two of these locations, Progeny 357 was among the varieties with the highest powdery mildew. Leaf rust was found on very few varieties in all trials; stripe rust was not seen anywhere. While leaf and glume blotch was generally low, a few varieties, particularly at northern locations, developed high blotch intensity. Lower blotch levels were consistently observed on AGS 2038 and SY Harrison. Fusarium head blight (=Scab) was consistently found on all varieties at Belle Mina, but most varieties had only trace levels of scab. A few varieties at Fairhope and Crossville, presumably those with earlier flowering dates, were seen with high levels of scab. Varieties that consistently had lowest levels of scab included Baldwin, Progeny 185 and Terral On oats cultivars, up to moderate levels of Helminthosporium leaf spot were noted at southern and central locations. Crown rust was seen only at Headland. At northern sites, little disease developed on the oats varieties in tests. Disease ratings for small grain cultivars are presented in the on-line publication Performance of Wheat Varieties in Alabama, Objective 2. To collect rust samples to be sent to the Cereal Disease Laboratory (St. Paul, MN), in order to monitor races of rust present especially for the virulent wheat stem rust type Ug99, for which resistance is not widely known. Results: Leaf and stripe rust samples were sent to St. Paul. No word on results has been received. A potentially devastating disease and emerging of wheat (= blast caused by Magneporthe oryzae) was also watched for in all plots.

5 2014 PROJECT Report Alabama Wheat and Feed Grains Committee TITLE: Proof of concept of aflatoxin accumulation in corn over a growing season. PRINCIPLE INVESTIGATORS: Dr. K.L. Bowen, bowenkl@auburn.edu Dept. Entomology and Plant Pathology 209 Life Sciences Bldg. Auburn University, AL Funding received: $3200 OBJECTIVE: To evaluate corn for aflatoxin content at intervals following silking. Approach: Corn cultivar Pioneer 33V14 was planted at three dates (1 Apr, 21 Apr, and 12 May). Full silk for the first planting date (PD1) was 30 May; kernels on which aflatoxin assays could be done had developed by 22 June. At day intervals, 10 ears were randomly collected from each planting date and individually assayed for aflatoxin content. By 15 Aug, all corn was full dent and sampling was terminated. Ears were dried, shucked, and grain was ground for aflatoxin assays. RESULTS Aflatoxin was below detectable limits for all planting and sampling dates before 15 Aug. Ears sampled on 15 Aug., had aflatoxin contents that averaged 24, 22, and 400 ppb for PD1, 2 and 3, respectively. Average maximum and minimum daily temperatures were 3+ F warmer (max/min = 91.8/72.3 F) over the 14 days preceding silk date for PD3 compared to averages for PD1 and PD2 (88.3/67.2 F and 88.5/69.6 F, respectively). In addition, rain (> 0.10 inches in 24 hrs) occurred with greater frequency prior to silk in PD1 and PD2 than in PD3. These results support preliminary observations from other studies (i.e., Bowen, unpublished) that weather conditions near silk stage are important relative to aflatoxin contamination.

6 Wheat and Feed Grain Committee Project Report for 2014 Project Title: Reproduction of the peanut root-knot and cotton root-knot nematodes on commercial field corn varieties and impact of this nematode on corn yield Project PI: A. K. Hagan Award: $3,000. Objectives: 1. Monitor the reproduction of the cotton root-knot (Meloidogyne incognita) nematode on selected commercial corn varieties. 2. Assess the impact of Counter 20G insecticide/nematicide application rate on corn yield and control of root knot nematode. 3. Compare the performance of VOTiVO and Avicta Duo corn nematicide seed dressings with Counter 20G for the control of cotton root knot nematode and assess their impact on corn yield Trials designed to assess the impact of the soil insecticide/nematicide Counter 20G as well as the nematicide seed dressings VOTiVO and Avicta Duo Corn on root knot nematode juvenile populations and corn yield was conducted at two AAES research units. In a study at the Brewton Agricultural Research Unit, stand count was not impacted by either the insecticide seed dressing Poncho 600 or Cruiser FS6, nematicide seed dressings VOTiVO or Avicta Duo Corn, or granular insecticide/nematicide Counter 20G. While a similar root knot nematode reproductive ratio was noted for all insecticide and nematicide seed dressing treatments, a 60% reduction in root knot nematode reproduction was obtained with the Counter 20G-treated than noninsecticide/nematicide-treated corn. Plant dry weight was not impacted by either the insecticide or nematicide seed dressings but the biomass of the Counter 20G-treated corn, which were noticeably larger and greener, was higher compared with the non-insecticide/nematicide-treated control. The Poncho 600/VOTiVO and Poncho 600 seed dressings plus an in-furrow application of Counter 20G resulted in a significant yield gain of 20 bu/a on 150 bu/a irrigated corn, which is valued at $80 to $100 per acre, when compared with either of those insecticide or nematicide seed dressing treatments alone. In contrast, yield response with Cruiser FS6 and Avicta Duo Corn seed dressing alone or in combination with the Counter 20G insecticide/nematicide infurrow treatment was similar. While seed dressing insecticide and nematicide treatments had no impact on cotton root knot nematode reproduction, ring nematode reproduction was significantly lower for the insecticide seed dressing Cruiser FS6-treated seed than the insecticide seed dressing Poncho 600 as well as the nematicide seed dressing Avicta Duo Corn and Poncho/VOTiVO. The insecticide and nematicide seed dressings did not impact stand density but the Counter 20G-treated corn had a higher stand count than the non-treated control. Plant root, top, and total plant biomass were similar for the Cruiser FS6 and Poncho 600 insecticide and Avicta Duo Corn and Poncho/VOTiVO nematicide seed dressings. In contrast, significant increases in root, top, and total plant biomass were noted for Counter 20G-treated corn as compared with the non-treated control. In addition to the significant increases in plant biomass

7 of 30% and a yield gain of 13 bu/a were recorded for the Counter 20G-treated corn than for the non-treated control. In these and an additional study, the nematicide seed dressings have shown no impacted the reproduction of the corn root knot nematode nor have provided significant yield gains in the presence or absence of this nematode. In contrast, Counter 20G insecticide/nematicide has and continues to consistently provided yield gains in the range of 10 to 20 bu/a in corn established in fields with resident populations of the cotton root knot nematode Meloidogyne incognita Race 3.

8 Wheat and Feed Grain Committee Project Report for 2014 Project Title: Management of southern rust and other diseases in early and double crop corn. Project PI: A. K. Hagan Award: $6000. Objectives: 1. Evaluate the efficacy of registered fungicides for the control of southern rust and northern corn leaf blight (NCLB) on disease susceptible and resistant corn lines. 2. Evaluate alternative fungicide application timing on disease severity and corn yield. 3. Develop fungicide treatment programs for the control of southern rust on double crop corn. 4. Compare the efficacy of novel or experimental fungicides with registered fungicides for rust and NCLB control in corn. 5. Assess the reaction of corn varieties to southern rust and other diseases. 6. Establish sentinel plots to monitor the spread and development of southern rust in corn. In 2014, southern rust extensively damaged corn across the southern tier of counties in Alabama. Heaviest damage was observed in Baldwin and Mobile Counties where near complete blighting of the ear leaf was observed. Yield gains in Alabama and Georgia fungicide trials of up to 80 bu/a suggest that producer that did not apply a fungicide or did not apply an efficacious fungicide suffered southern rust related losses of upwards of $400 per acre in irrigated corn. In a variety trial at the Gulf Coast Research and Extension Center (GCREC), southern rust was observed at GS VT and disease development accelerated at GS R2. All varieties suffered 60 to 80% ear leaf blighting by GS R6 (black layer), however, significant differences in rust ratings were observed among varieties. The severe southern rust ear leaf blight noted on Pioneer 1690R was matched by that on the Pioneer 1690YHR isoline as well as Pioneer 2088R and Pioneer 2088YHR isolines, Pioneer 2023YHR, DKC and DKC isolines, DKC and DKC isolines, and DKC Similarly lower rust ratings for Pioneer 1498YHR and Pioneer 1498HR isolines were noted for eight additional varieties. With the exception of DKC and DKC-67-88, the remaining isoline pairs had similar rust severity ratings. Yields recorded for DKC were higher compared with all varieties except for Pioneer 1690R and Pioneer 1690YHR, both of which had significantly higher rust ratings than the former variety. Fungicide selection, application number and timing were assessed in trial at GCREC. While significant differences in rust severity were observed between fungicide treatments, highest disease ratings were recorded for the non-treated control. Most effective southern rust control was obtained with two applications of Quilt XCEL, Headline AMP, and Stratego YLD at GS VT and R2. When applied on the same schedule, Fortix proved as effective in controlling southern rust as the latter but not two former fungicide programs. While less efficacious than the above treatments, single V6 and VT applications of Headline AMP as well as 4 and 5 fl oz rates of Fortix also reduced rust severity below values recorded for the nontreated control but the effectiveness of the single V6 applications was limited. When compared with the non-treated control, significant reductions in rust severity were also obtained with single applications of Fortix and Headline AMP tank mixtures with the herbicide Glyphos (generic

9 glyphosate) herbicide as well as Glyphos alone. When compared with the non-treated control, significant yield gains were obtained with the VT fb R2 Quilt XCEL, Headline AMP, and Stratego YLD programs as well as single VT applications of both rates of Fortix as well as the V6 Headline AMP and Fortix programs. In a concurrent study of similar design at GCREC, two application GS VT fb R2 Priaxor, Quilt XCEL, Stratego YLD, Headline AMP, and Aproach fb Aproach Prima programs gave equally effective control of southern rust. Although less efficacious than the two former fungicide programs, significant reductions in rust severity were also obtained with the two application GS V6 fb R2 Quadris fb Quilt XCEL and GS V6 fb VT Aproach fb Aproach Prima programs when compared with the non-treated control. Single VT applications of Headline AMP and Aproach Prima, and the 2 and 4 fl oz rates of Stratego YLD also significantly reduced rust intensity below the non-fungicide treated control. Rust intensity ratings for the single GS V6 applications of 2 and 4 fl oz of Stratego YLD and non-fungicide treated control were similar. When compared with the non-fungicide treated control, significant yield gains of up to 80 bu/a were obtained with the GS VT fb R2 Priaxor, Quilt XCEL, Stratego YLD, Headline AMP, and Aproach fb Aproach Prima programs as well as GS V6 fb VT Aproach fb Aproach Prima program and single GS V6 application of 4 fl oz of Stratego YLD. Yields for the remaining single application GS V6 and VT programs along with GS V6 fb VT Quadris fb Quilt XCEL program did not significantly differ from the non-fungicide treated control. In the corn variety trials conducted at the Brewton Agricultural Research Unit, rust severity, while significant, was lower than was observed at the GCREC. Significant differences in southern rust severity, test weights, and yield were noted among the corn varieties. Equally high rust ratings were recorded for the Pioneer 1690R and Pioneer 1690YHR, Pioneer 2088R and Pioneer 2088YHR, and DeKalb and DeKalb isolines along with Pioneer 2023BVT and Pioneer 1319HR. With the exception of Pioneer 1498R and Pioneer 1498YHR, no significant differences in rust severity were noted between any isolines. Southern rust severity was similarly low on the tropical corn Pioneer 30F35HR as well as DeKalb 62-08, Pioneer 1498YHR, and Northrup King 78S The isolines Pioneer 1184R and Pioneer 1184HR along with DeKalb and DeKalb produced the highest test weights, Pioneer 30F35HR and Pioneer 2088R had the lowest test weights. Pioneer 1319HR and Pioneer 2088YHR had higher test weights than their respective non-bt isolines, Pioneer 1319R and Pioneer 2088R. In addition to the highest test weights, the isolines Pioneer 1184R and Pioneer 1184HR produced higher kernel yields than all other varieties except for DeKalb Lowest yields were noted for Pioneer 30F35HR tropical corn. Severe rust development was also seen in a late planted corn fungicide study at the Brewton Agricultural Research Unit in a study designed to compare the efficacy of two application VT fb R2 programs for a number of registered fungicides. The combination of late planting and frequent showers through early August favored rapid southern rust development. The Headline 2.09SC and Quilt XCEL proved more effective than the other fungicides in controlling southern rust. Though less efficacious than the latter fungicide programs, Headline AMP and Priaxor also gave a high level of southern rust control. With the exception of Tilt 3.6E, all fungicide programs had lower southern rust ratings than the non-fungicide treated control. When compared with the non-fungicide treated control, all fungicide programs except for Tilt 3.6E and Muscle 3.6F significantly increased yield. Equally high yield gains of up to 57 bu/a were obtained with the fungicide programs that gave superior disease control, Headline 2.09SC, Quilt XCEL, Priaxor, and Headline AMP. Overall, the poor performance of the inexpensive generic fungicides Tilt (propiconazole) and Muscle (tebuconazole) was very disappointing while the efficacy of several name-brand fungicide

10 products was excellent. Southern rust was not observed in an early corn variety trial conducted the at the Field Crops Unit at the E. V. Smith Research Center. While DeKalb DKC produced the highest kernel yields, an additional 11 varieties had statistically similar yields. Lowest yields were noted for the 135 day tropical corn Pioneer 30F35HR. Other varieties with similarly low yields to the latter variety included Northrup King 77P 3111, Northrup King 78S- GT, Northrup King 78S-3111, DKC 68-05, DKC 67-86, DKC 65-17, DKC 67-58, Pioneer 2088R, Pioneer 2088YHR, and Pioneer 1319R. Varieties with Bt traits did not produce higher yields when compared with their non-bt isoline.

11 Wheat and Feed Grain Committee Report for 2014 Project: Impact of crop rotation on diseases and nematode pests of corn, cotton, and peanut as well as on the economics of corn, cotton, and peanut production PI: A. K. Hagan Grant Award: $2,000. Objectives: 1. Assess the profit potential for cropping systems where corn, grain sorghum, pearl millet, and bahiagrass are rotated with peanut. 2. Determine whether corn contributes to the buildup of nematode pests of peanut and rotation partners. 3. Evaluate the impact of corn cropping frequency on the incidence of diseases, nematode pests, and yield of peanut. A crop rotation study which was established in 1988 at the Wiregrass Research and Extension Center in Headland, AL and consists of 34 different rotation patterns including crops such as bahiagrass, corn, grain sorghum, pearl millet, soybean, and cotton. The study area is heavily infested with the peanut root knot nematode. Beginning in 2009, a split plot design with rotation as the whole plot and peanut cultivar as sub-plots was used. Peanut cultivars Georgia-06G and Tifguard were planted in a randomized design within each rotation. Beginning in 2012, a similar split plot arrangement was added to cotton where the cotton variety Phytogen 499 and DPL Disease ratings, soil samples for nematode assay, and yield was taken from each peanut and cotton plot. All crops except for corn are maintained under a full irrigation program. Corn is considered rainfed. In 2014, the corn and sorghum plots were harvested with a standard grain combine, so no yields are available. The grain sorghum plots were heavily damaged by sugarcane aphid. While disease pressure was low, the severity of leaf spot diseases was lower in peanut cropped after 1 yr of corn, soybean, pearl millet, and cotton but not bahiagrass and grain sorghum than peanut behind peanut. Leaf spot ratings for peanuts following bahiagrass, corn, cotton, grain sorghum, pearl millet, and soybean did not significantly differ. When compared with continuous peanuts, stem rot incidence was equally high in peanut following all of the above crops. Stem rot incidence declined where peanut followed two years of corn, cotton, or a one year of each of these crops. With the notable exception of the pearl millet and soybean, yields for all of the above one year out rotation patterns were similar to continuous peanuts. Peanuts yields for the two year out rotation with corn and cotton but not pearl millet were 2000 to 2500 lb/a higher than one year out rotations with the same rotation partner.

12 2014 AWFGP Project Summary Title: Corn Disease Control: Will fungicide applications increase profitability when applied at V5 to V8 growth stage? Principal Investigators: Mark Hall, Extension Specialist Tyler Sandlin, Extension Agronomist One Fungicide Application On Irrigated Corn at V5 $35.75 loss/acre The Test had four plots that were treated at 7 a.m. May 14 with 2 ounces of Stratego fungicide per acre when the corn was V5 and four untreated plots. The treated corn yielded 7 bushels per acre less than the untreated. The corn sold for $3.50 per bushel. 7 bushels x $3.50 = $ oz Stratego = $ $4.50 application = $ Fungicide application loss/acre = - $ Two-Year Summary Fungicide application loss/acre = 2013 = 1 bushel 2014 = 7 bushels