Progress 10/01/00 to 06/30/07
Outputs
Annual studies during the project period have focused on management of major insect pests on newly released commercial peanut cultivars. Of particular focus has been thrips/tomato spotted wilt(TSW) management. In-furrow insecticides aldicarb and phorate were also compared to untreated peanuts of each cultivar for their impact on thrips populations and subsequent TSW. Impact on other insects such as leafhoppers and three-cornered alfalfa hoppers(TCAH) was also studied. During the term of this project studies were conducted at the Wiregrass Research and Extension Center(WREC) in Headland, AL and the Gulf Coast Research and Extension Center(GCREC) in Fairhope, AL. Results indicate the cultivar Georgia Green, which comprised about 70% of the producer acreage in Alabama in 2000 and has declined to about 40% by the year 2006, has had increased incidence of TSW during this time. As a result yields have been negatively impacted as well. Newer cultivars such as Ga-02C, Ga-03L,
AP-3 and others that we evaluated have significantly less TSW than the older cultivars such as Georgia Green. Studies with in-furrow insecticides continue to show that phorate generally reduces TSW levels in all cultivars and that phorate and aldicarb provide significant seedling protection from thrips damage. Aldicarb has also had reduced three-cornered alfafa hopper damage compared to phorate or untreated peanuts. In 2005 Carver and Ga-01R had significantly less leafhopper damage than Georgia Green, Ga-02C and AP-3 peanuts at the WREC study location. Also, Ga-02C had significantly less TCAH damage than Georgia Green, ANorden, or Ga-01R peanuts. In 2006 studies at WREC were also conducted evaluating foliar insecticides for efficacy against corn earworms, fall armyworms and granulate cutworms. Steward and Tracer insecticides were effective in controlling cutworms and corn earworms. Tracer was effective in controlling fall armyworms. Two experimental compounds provided superior (>95%)
control of all species present. Labelled pyrethroid insecticides were only effective in controlling the corn earworms present. Studies were conducted at WREC and at Plant Breeding Unit in Tallassee evaluating in-furrow and foliar insecticide sprays for leafhopper/TCAH contol on Ga-03L peanuts. Due to hot,dry weather during season insect populations were too low to make valid comparisons.
Impacts
Data generated by the insecticide X cultivar studies are used to update and validate the peanut spotted wilt risk index. This is a multi-state tool that extension and research scientists in Georgia, Florida, and Alabama utilize to assist peanut growers in managing TSW. Evidence from period 2000-2006 indicate the overall succuss of the index as growers have significantly changed their production practices and adopted results of studies and changes made to the risk index. Based upon surveys of grower's peanut fields and research plots located across the state TSW levels have declined where TSW index recommendations are being followed. As the cultivar Georgia Green is replaced in acreage by cultivars like AP-3 and Ga-03L, TSW incidence levels should remain low. Since it takes 2-3 years for sufficient quantities of seed to become available, the shift to more TSW resistant cultivars is a somewhat slow process and is an evolving process as 3-4 new cultivars are released each
year. The impact of evaluating and identifying cultivars that have insect and disease resistance and high yields is significant due to the economics of production. In 2007 peanut growers should plant an estimated 160,000 acres. Acreage of AP-3, Ga-02C, Ga03L should continue to increase and Georgia Green acreage decrease to about 30% of planted acreage. Because of decresed TSW incidence and resultant yield increases the newer resistant cultivars would provide an increase in revenue to growers of about $2.5 million dollars in Alabama alone.
Publications
- Campbell, H. L., J. R. Weeks, A.K. Hagan, and L. Wells. 2006. Evaluation of Absolute and JAU 6476 for control of peanut diseases in southeast Alabama, 2005. Fungicide and Nematicide Tests 61: 45.
- Weeks, J.R. and H.L. Campbell, H. L. Wells, and Pegues, M. 2006. Evaluation of peanut cultivars for suitability in pest management systems. Proc. Am. Peanut Res. Ed. Soc. 37:80.
- Campbell, H. L, J.R.Weeks, A.K. Hagan,and M. D. Pegues. 2006. Evaluation of Peanut Cultivars for Suitability in Pest Management Systems in Southwest Alabama, GCREC. In Peanut Control Field Trials, 2005: Standard Fungicide Trials. Hagan,A. K., K.L. Bowen, and H. L. Campbell, eds., Entomology and Plant Pathology Departmental Series No. 9B. March 2006. Al Ag Exp.St. pp43-44.
- Campbell, H. L, J. R Weeks, A. K. Hagan, and L.W. Wells. 2006. Evaluation of Peanut Cultivars for Suitability in a Pest Management System in Southeast Alabama, WREC.In Peanut Control Field Trials, 2005: Standard Fungicide Trials. Hagan, A. K., K.L. Bowen, and H. L. Campbell, eds., Entomology and Plant Pathology Departmental Series No.9B. March 2006. Al Ag Exp.St. pp. 41-42.
- Hagan, A.K., H. L. Campbell, J. R. Weeks, and M. D. Pegues. 2006. Impact of Crop Rotation on the Occurrence of Diseases and Nematodes in Corn, Cotton and Peanut in Southwest Alabama, GCREC. In Peanut Disease Control Field Trials, 2005: Standard Fungicide Trials. Hagan, A.K., K. L. Bown, and H. L. Campbell, eds. Entomology and Plant Pathology Departmental Series No. 9B. March 2006. Al. Ag. Expt. St. pp. 51-53.
- Hagan, A.K., J. R. Weeks, K. L. Bowen, C. D. Monks, D. P. Delaney, W. R. Goodman, H. L. Campbell, and. S. P. Nightengale. 2006. Influence of Cropping Sequence on Diseases and Nematodes and the Yield of Peanut, Cotton, and Corn, and in Central Alabama, PBU. In Peanut Disease Control Field Trials, 2005: Standard Fungicide Trials. Hagan, A.K., K. L. Bown, and H. L.Campbell, eds. Entomology and Plant Pathology Departmental Series No. 9B. March 2006. Al. Ag. Expt. St. pp. 54-56.
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Progress 01/01/05 to 12/31/05
Outputs
In 2005 studies were conducted at the Wiregrass Research and Extension Center (WREC) in Headland and at the Gulf Coast Research and Extension Center (GCREC) in Fairhope to evaluate new peanut cultivars for evidence of resistance or tolerance to thrips, leafhoppers, foliage feeding worms, tomato spotted wilt (TSW), peanut leafspots, and/or southern stem rot. Insecticides, aldicarb and phorate applied as granular formulations, were applied in furrow on each cultivar to compare their efficacy to untreated (UTC) peanuts. Both at-planting insecticide treatments gave significantly better thrips control on all cultivars compared to the UTC. Leafhopper populations at WREC were low to moderate. In mid-August evaluations of leafhopper damage were made by subjectively rating whole plots visually as to hopperburn severity. At GCREC populations were moderate to high. Visual ratings of all plots were also made at GREC in mid- August. At WREC, cultivars Ga O1R and Carver had very
low damage from leafhopper. Cultivars AP-3, Ga 03L, ANorden, and Tifrunner rated as low to moderate damage and cultivars Georgia Green, Ga 02C had medium hopper damage. In-furrow insecticide treatments of aldicarb reduced hopper damage in all cultivars. At GCREC, Ga 01R had very low hopper damage. Cultivars AP-3, Tifrunner and C 99R had low to medium hopper damage and Georgia Green, Ga 03L, Ga 02C, and ANorden had moderate hopper damage. Aldicarb insecticide in-furrow, at planting reduced hopper damage on all peanut cultivars-but only marginally. Over the top foliar insecticide applications were necessary to keep prevent excessive damage. There were differences among cultivars for TSW infected plants. At WREC, AP-3, Ga 01R and Tifrunner had significantly lower incidence of TSW than Georgia Green, ANorden, Carver cultivars. Ga 02C and Ga 03L had intermediate TSW incidence. At GCREC, AP-3, Ga 03L and Tifrunner had significantly less TSW than other cultivars. Georgia Green and ANorden
had significantly higher TSW incidence than all other cultivars. Other foliar insects did not reach treatable levels at either study site.
Impacts
Because of increased incidence in Alabama of tomato spotted wilt(TSW) in the most commonly grown cultivar, Georgia Green, results of these studies will help producers evaluate potential newer cultivars such as AP-3 and Ga 01R as replacements. In 2005 in Alabama TSW average incidence was reported at approximately 15% on the 217,570 acres of peanuts planted. Based upon our cultivar studies, when growers shift to these new cultivars with reduced risk of TSW incidence could be reduced to below 5% on average. This should result in an estimated yield increase of 400 lbs/Acre across our 200,000 acres of peanuts or $71.00/acre. Selection of leafhopper tolerant cultivars for growers with a history of severe hopperburn damage would also save an average of 1.5 insecticide sprays on approximately 20% of our peanut acreage. Extension pest management specialists will utilize these data in area peanut production meetings prior to 2006 planting season to encourage Alabama peanut
growers to begin to shift to more pest resistant or tolerant cultivars.
Publications
- Bostick,J., K.L. Bowen, H.L.Campbell,D.W.Gorbet,B.E.Gamble, A.K.Hagan, M.D. Pegues, J.R.Weeks, and L.W. Wells. 2005. Peanut Disease Control Field Trials, 2004. Entomology and Plant Pathology Dept. Series No. 8, July 2005. Ala. Ag. Expt. Station. pp.67-70 and 73-74.
- Weeks, J.R., H.L. Campbell, L.W. Wells,and M.D.Pegues. 2005. Evaluation of Peanut Cultivars for Suitability in Pest Management Systems. Proceedings of Am. Peanut Res. and Ed. Society.37:81.
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Progress 01/01/04 to 12/31/04
Outputs
In 2004 eight peanut cultivars at the Wiregrass Research & Extension Center(WREC) in Headland, AL and eight at the Gulf Coast Research & Extension Center(GCREC) in Fairhope, AL. were evaluated for thrips damage,tomato spotted wilt virus(TSWV) incidence,and the impact of other foliage feeding insects. Each peanut cultivar was treated with aldicarb or phorate granular insecticide in the furrow at 1.0 lb a.i./ Acre, or left untreated for control comparison. Cultivars evaluated at WREC were: Georgia Green, Ga02C, Ga02R, C3424, AP-3, C99R, DP-1, and Carver. At GCREC the same cultivars were evaluated with the exception that ANorden was included instead of Carver. Aldicarb-treated peanuts of all the cultivars at both locations had significantly less thrips damage than phorate-treated peanuts and phorate-treated peanuts had significantly less than the untreated peanuts. Aldicarb and phorate-treated cultivars had significantly lower TSW final incidence than did the untreated
peanuts. C3424 cultivar had greater thrips damage at the 30 day visual assesment than did other cultivars. Foliage feeding caterpillars and leafhopper populations were not significantly high enough to make comparisons of cultivars or insecticides during the 2004 season.
Impacts
As new cultivars become available to peanut growers they need to know how to manage the major insect and disease pests and how the tolerance or susceptibility to these pests can help them plan for more efficient and cost effective peanut production. Growers in southeast Alabama where insect and disease pressure is greater due to poor crop rotation will have help with some of these new cultivars the ability to achieve high yields with less costs. Management of tomato spotted wilt, leafspot, white mold, leafhoppers and possibly foliage feeders by cultivar selection offers reduced risk of damage and yield loss and reduced costs to manage these important pests.
Publications
- Yang, H.,P.Ozias-Akins, A.K. Culbreath, D.W. Gorbet, J.R. Weeks, B. Mandal, and H.R. Pappu. 2004. Field Evaluation of Tomato Spotted Wilt Virus Resistance in Transgenic Peanut (Arachis Hypogaea). Plant Disease 88: 259-264.
- Weeks, J.R. and L.C. Campbell. 2004. Impact of Various Cover Crops in a Minimum Tillage Production System on Insect Pests, Diseases, Nematodes, and Yield of Peanut. Proc. Am. Peanut Res. Ed. Soc. 36: 72.
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Progress 01/01/03 to 12/31/03
Outputs
Two studies conducted at the Wiregrass Research and Extension Center at Headland, AL in 2003 evaluated 4 pest management strategies on eight peanut cultivars. Cultivars evaluated were Georgia Green, Andru II, Carver, ANorden, C-99R, Hull, DP-1,and Georgia 01R. Temik 15G and Thimet 20G in-furrow, Orthene 75SP as a hopper-box treatment all provided satisfactory control of thrips compared to untreated peanuts of all eight cultivars. Tomato Spotted Wilt tospovirus levels of all cultivars at season end were below 15% by counting hits/row feet. Thimet 20G treatments in Carver, AndruII, ANorden cultivars had reduced TSW hits compared to the untreated peanuts. At planting insecticide treatments did not significantly affect leafhopper damage. GA 01R had significantly reduced potato leafhopper damage (hopper burn) compared to C-99R, DP-1, and Hull cultivars. DP-1 had significantly higher leafhopper damage than all other cultivars. Peanut yields were influenced by early leafspot
defoliation. Andru II had significantly greater defoliation than Georgia Green, ANorden and Carver. In the late maturing cultivars, C-99R and Hull had significantly higher leafspot defoliation than DP-1 or GA 01R.
Impacts
As new cultivars become available to peanut growers they need to know how to manage the major insect and disease pests and how the tolerance or susceptibility to these pests can help them plan for more efficient and cost effective peanut production. Growers in southeast Alabama where insect and disease pressure is great due to poor crop rotation will have with some of these new cultivars the ability to achieve high yields with less costs. Management of tomato spotted wilt, leafspot, white mold, leafhoppers and possibly foliage feeders by cultivar selection offers reduced risk of damage and yield loss and reduced costs to manage these important pests.
Publications
- Weeks, J. R.and W. Birdsong. 2003. Thrips Control on Bollgard and Non-BT Cotton Varieties. Proceedings of 2003 Beltwide Cotton Conferences, National Cotton Council. pp. 1056-1059.
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Progress 01/01/02 to 12/31/02
Outputs
Studies conducted in 2002 evaluated Tracer, Steward and Intrepid insecticides for control of foliage feeders in peanuts. Tracer and Steward both received federal labels for use on peanuts since July 2002. Tracer and Steward provided significantly better control of beet armyworms and loopers than commercial standards- Karate and Lannate. Numbers of granulate cutworms were too low to evaluate efficacy of either of these products. Intrepid demonstrated excellent residual in controlling velvetbean caterpillar near the end of the growing season. No significant defoliation from VBC occurred 30 days after treatment. Defoliation studies were conducted at Wiregrass and Gulf Coast Research & Extension Centers to establish thresholds for peanut defoliators. However, continued non-infestation in research plots resulted in no useful data collected. In 2003 studies will again be conducted in an effort to evaluate and validate our current threshold levels.
Impacts
Research data generated aided in the labelling of Tracer insecticide in 2002. Studies conducted in two locations also provided information to make extension recommendations for 2003. These insecticides will enable peanut growers to effectively control beet armyworms, fall armyworms, and soybean loopers in peanuts.
Publications
- Campbell, H. L., J.R. Weeks, A.K. Hagan, and B. Gamble.2002. Impact of Strip-Till Planting Using Various Cover Crops on Insect Pests and Diseases of Peanuts. In E. van Santen (ed.) Making Conservation Tillage Conventional: Building a Future on 25 years of Research. Proc. of 25th Annual Southern Tillage Conference for Sustainable Agric. Ala. Agric. Expt. St., Auburn, University Special Report No. 1: pp 161-164.
- Mason, C., J.R.Weeks,L. Campbell. 2002. Producer Awareness of Damage Due to Leafhopper and Three Cornered Alfalfa Hoppers. Proc. Amer. Peanut Res. and Ed. Society. 34: 52.
- Weeks, J. R., A.K. Hagan, L. Campbell, and L. Wells. 2002. Evaluation of Georgia Green and C99R peanut cultivars for Thrips and Nematode Damage, Southern Stem Rot,Tomato Spotted Wilt Tospovirus Incidence, and Peanut Yield and Quality. Proc. Amer. Peanut Res. & Ed. Society 34: 34.
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Progress 01/01/01 to 12/31/01
Outputs
Studies were conducted in 2001 on peanut to evaluate novel insecticides for thrips/TSWV management. Surround WP @ 25lb./100 gal. Spray, Neem oil in a 2% spray, and Hot Pepper Wax @ 8 oz./gal of spray were evaluated with traditional in-furrow insecticides Temik 15G and Thimet 20G @ 1.0 lb. Ai/Ac. These 'novel' insecticides neither reduced thrips damage to peanuts nor Tomato spotted wilt incidence to peanuts. However, Thimet 20G @ 1.0 lb. Ai/A. when applied alone or in combination with any of the foliar insecticides reduced thrips damage and TSWV compared to the untreated peanuts. A significant yield increase of 800-850lbs./acre of peanuts also resulted from the Thimet treatments. Another study in 2001 was conducted evaluating leafhopper and three cornered alfalfa hopper damage to peanut. Plots comparing Karate treated peanuts to untreated peanuts showed significant reductions in insects and plant damage, and resulted in increased peanut yields of 800 lbs/Acre. Limited
data was taken to correlate insect numbers and plant damage with yield increases. Additional data will be required in future studies to be able to establish economic treatment levels.
Impacts
During a time when peanut growers are having a financial crisis and the government program is drastically changing,current research that can be adopted quickly and easily will enable many Alabama growers to sustain their farming operation. Increased yields on a per acre basis will be important in allowing them to be competitive in the market. Increased emphasis on scouting and identifying insect pest will be stressed to peanut growers as the means of applying this new technology.
Publications
- No publications reported this period
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