Pesticide Note

North Carolina Cooperative Extension Service
North Carolina State University



Pesticide Note Number 7
ENT/pia-7
May 1997

Insect Management by North Carolina Peanut Growers in 1995




Stephen J. Toth, Jr., Extension Pesticide Impact Assessment Specialist

Rick L. Brandenburg, Extension Peanut Entomology Specialist


Caution!
The information and recommendations in this Note were developed for North Carolina and may not apply in other areas.




Introduction

North Carolina ranked fourth nationally in the production of peanuts in 1995, accounting for 10 percent of U. S. production (Meadows 1996). Peanut growers in the state produced 347 million pounds of peanuts on 144,000 acres in 1995. The value of the peanuts produced in North Carolina in 1995 was estimated at $103 million in 1995.

Pest problems confronting peanut growers in North Carolina include insects and mites. Foliar insect pests of North Carolina peanuts include thrips, leafhoppers, corn earworms, fall armyworms and spider mites (Brandenburg 1996). Feeding below the soil surface, the southern corn rootworm is also a pest of peanuts. Growers in the state employ a variety of chemical and nonchemical pest management practices to manage these insects and mites.

A mail survey of peanut growers in 13 North Carolina counties was conducted in March and April of 1996 to determine the pest management practices used by the growers on the 1995 peanut crop. Insect and mite management practices used by survey respondents in 1995 are reported with results from a similar grower survey conducted for the 1988 crop (Toth et al. 1994).


Survey Method

Bertie, Bladen, Chowan, Edgecombe, Gates, Halifax, Hertford, Martin, Nash, Northampton, Perquimans, Pitt and Washington counties were selected for inclusion in the survey of peanut growers in North Carolina (Fig. 1). Mailing lists of peanut growers were received from the respective county offices of the North Carolina Consolidated Farm Services Agency. Approximately 1,200 individuals were selected randomly from the county mailing lists for participation in the survey. The number of individuals selected in each county was equally proportional to the total acres planted to peanuts and the number of growers in the county. County Extension agents reviewed the mailing lists for accuracy and eliminated from the lists those individuals who were not active peanut growers.

A total of 1,036 peanut growers in the selected counties were contacted by mail a maximum of three times in March and April of 1996, following methods described by Christenson (1975) and Dillman (1978). The information contained in survey questionnaires returned by peanut growers was compiled and analyzed in the Department of Entomology at North Carolina State University.

Figure 1

Fig. 1. North Carolina counties participating in mail survey of peanut growers. Hatching denotes counties in which peanut growers were surveyed.


Results and Discussion

Peanut Production. A total of 605 (58%) of the peanut growers surveyed responded. Of the respondents, 558 planted 53,767.52 acres of peanuts in 1995. The remaining respondents did not produce a peanut crop. Peanut growers responding to the survey harvested 52,724.17 acres of peanuts in 1995. The average yield of those growers reporting their yields was 2,505.82 pounds per acre. A total of 144,000 acres of peanuts were harvested in North Carolina in 1995 (Meadows 1996). The statewide average yield of peanuts in 1995 was 2,410 pounds per acre.

Insect and Mite Pests of Peanuts. Nearly all peanut fields are vulnerable to thrips damage; thus, growers frequently use a preventative, at-planting, in-furrow application of an insecticide for thrips. Sixty-two percent of survey respondents applied insecticides for thrips in 1995 (Fig. 2). Preventative insecticide treatments are likewise used to manage Southern corn rootworms. However, this insect is rarely a problem on light, sandy soils; thus, less acreage needs to be treated. Almost 40% of peanut growers used insecticide for the Southern corn rootworm. Corn earworms are easily monitored through scouting and thresholds for their treatment are available which reduces insecticide applications for this insect. Thirty-eight percent of growers responding to the survey applied insecticides for corn earworms in 1995. The percentage of peanut growers treating for spider mites in 1995 (41% of survey respondents) was much higher than normal. The weather during the 1995 growing season was relatively hot and dry, conditions which are conducive to high populations of spider mites. Fall armyworms and leafhoppers were each treated with insecticides by 30% of survey respondents, while aphids and wireworms were each treated by 19% of these growers.

Figure 2

Fig. 2. Insects and mites for which insecticides and miticides were applied by peanut growers in 1995. Bars indicate the percentage of growers reporting the respective insects and mites.

Insecticide and Miticide Use. Temik was the most frequently used insecticide during planting to manage thrips and other insects on peanuts in 1995 (65% of the acreage), followed by Thimet (19%), and Di-Syston (7%) (Fig. 3). Temik use decreased slightly, while Thimet use increased slightly from 1988. Di-Syston use remained the same. Orthene was applied to 2% of the acreage during planting in 1995; it was not labeled for use on peanuts in 1988.

Figure 3

Fig. 3. Insecticides applied during planting of peanuts to manage insects (i.e., thrips, leafhoppers, aphids, and wireworms). Bars indicate the percentage of peanut acreage treated in 1995 (dark) and 1988 (hatched) (Toth et al. 1994) with the respective insecticides.

There was a notable shift in the foliar insecticides applied to manage early-season thrips and leafhoppers from 1988 to 1995 (Fig. 4). The percentages of acres treated with Asana and Orthene were 15% and 11%, respectively, in 1995 (increases in the use of these insecticides from 1988). Sevin and Lannate were applied to 5% and 4%, respectively, in 1995 (decreases in their use from 1988). Pydrin, used on almost 10% of the peanut acreage in 1988, was not used in 1995. These changes in the insecticides used on early-season insects in peanuts reflects the insecticides available to growers in 1988 and 1995 and an increase in cotton acreage in the state since 1988 (similar insecticides are used on both crops).

Figure 4

Fig. 4. Insecticides applied to manage early-season insects (i.e., thrips and leafhoppers) in peanuts. Bars indicate the percentage of peanut acreage treated in 1995 (dark) and 1988 (hatched) (Toth et al. 1994) with the respective insecticides.

The use of Lorsban and Dyfonate as preventative applications for Southern corn rootworm management in peanuts increased from 1988 to 1995 due to growers' perception of the insect's threat to peanut yields and the lack of an ability to detect or predict the occurrence of the pest in a timely manner. Lorsban and Dyfonate were applied to 56% and 8% of the acreage treated in 1995, respectively (Fig. 5). Mocap and Thimet use was very limited due to their shorter residual activity compared to Lorsban and Dyfonate.

Figure 5

Fig. 5. Insecticides applied at mid season to manage southern corn rootworms in peanuts. Bars indicate the percentage of peanut acreage treated in 1995 (dark) and 1988 (hatched) (Toth et al. 1994) with the respective insecticides.

A notable shift in insecticides and miticides used to manage late-season insects and spider mites in peanuts in 1988 and 1995 was observed. Asana and Lorsban use increased significantly from 1988 to 1995, Lannate and Sevin use declined during the same period, and Orthene use remained the same (Fig. 6). Some of the insecticides used in 1988 are no longer available to peanut growers (Azodrin, Nudrin and Pydrin) which explains many of the changes in insecticide use patterns from 1988 to 1995. Other changes appear to be the result of grower preference.

Figure 6

Fig. 6. Insecticides and miticides applied to manage late-season insects and spider mites in peanuts. Bars indicate the percentage of peanut acreage treated in 1995 (dark) and 1988 (hatched) (Toth et al. 1994) with the respective insecticides and miticides.

The use of the miticide Comite was significantly higher in 1995 than 1988 due to the enhanced likelihood of spider mite outbreaks resulting from the hot and dry weather in 1995. Twenty-one percent of the peanut acreage was treated with Comite in 1995 compared to less than 2% of the acreage in 1988. The use of Sevin, which has been associated with outbreaks of spider mites in peanuts, declined in 1995.

Nonchemical Pest Management Practices. Peanut growers were asked to indicate on the survey questionnaire the nonchemical pest management practices they used in 1995. Over 99% of the peanut growers responded that they rotated the fields on which they planted peanuts as a means of pest management. Cotton, corn and tobacco were the predominate crops they rotated with peanuts.

Approximately 91% of the growers responded that they or a family member scouted their peanut fields for weeds, insects, mites or diseases. Almost 9% indicated that an employee scouted their crop, while 11% claimed that a professional scout or consultant performed this service. Less than 1% of the respondents reported that their peanut crop was not scouted. Peanut fields were scouted for leafhoppers (64% of survey respondents), thrips damage (77%), corn earworms (65%), spider mites (80%), and lesser corn stalk borers (31%). Fifty-one percent of the growers used action thresholds for insects and mites for deciding if or when to apply insecticides or miticides to their peanut crops.


Literature Cited

Brandenburg, R. L. 1996. Peanut Insect Management. In 1996 Peanut Information. AG-331. North Carolina Cooperative Extension Service, Raleigh, NC. 83 pp.

Christenson, J. A. 1975. A procedure for conducting mail surveys with the general public. J. Community Development Society 6(1): 135-146.

Dillman, D. A. 1978. Mail and Telephone Surveys: The Total Design Method. John Wiley and Sons, New York. 325 pp.

Meadows, B. C., ed. 1996. 1996 North Carolina Agricultural Statistics. Publication No. 185. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 132 pp.

Toth, S. J., Jr., J. E. Bailey, R. L. Brandenburg, G. A. Sullivan, A. C. York, and H. M. Linker. 1994. Peanut Pest Management: A Survey of Pesticide Use by North Carolina Peanut Producers. AG-498. North Carolina Cooperative Extension Service, Raleigh. 20 pp.


Acknowledgments

The following county extension directors and agents are acknowledged for their valuable participation in the mail survey of peanut growers: William J. Griffin (Bertie County), Van Alphin (Bladen County), Mike Williams (Chowan County), James R. Pearce (Edgecombe County), Wayne T. Nixon (Gates County), Arthur Whitehead, Jr. (Halifax County), Byron L. Simonds (Hertford County), Kent Yarborough (Martin County), James D. Stephenson (Nash County), Keith Cox (Northampton County), Lewis W. Smith, Jr. (Perquimans County), Samuel N. Uzzell (Pitt County) and Frank C. Winslow (Washington County). Also acknowledged are Dudley Lameck and the following extension specialists for their help in planning the survey and designing the survey questionnaire: Jack E. Bailey (Plant Pathology), H. Michael Linker (Crop Science), Gene A. Sullivan (Crop Science), and Alan C. York (Crop Science). Appreciation is extended to the North Carolina Consolidated Farm Services Agency for providing mailing lists of growers. Finally, Rebecca Osborne is recognized for preparation of grower survey materials and entry and compilation of survey data. This research was supported by the National Agricultural Pesticide Impact Assessment Program, Extension Service, United States Department of Agriculture, under project 95-EPIX-1-0222.


Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by the North Carolina Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical. For assistance, contact an agent of the North Carolina Cooperative Extension Service in your county.




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Web page last modified on July 15, 1998 by Stephen J. Toth, Jr.