Pesticide Note

North Carolina Cooperative Extension Service
North Carolina State University



Pesticide Note Number 3
ENT/pia-3
February 1995

Pest Management in the Production of Agricultural Crops in North Carolina




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

H. Michael Linker, Extension Integrated Pest Management Specialist


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




Introduction

A series of mail surveys of North Carolina growers was initiated in 1989 by the North Carolina Cooperative Extension Service to determine pesticide use patterns on economically important crops in the state. The surveys completed to date have provided data on the use of pesticides and other pest management practices on field (cotton, peanuts and flue-cured tobacco), fruit (apples) and vegetable (cucumbers, potatoes and sweetpotatoes) crops. These data have been provided to the U. S. Department of Agriculture's National Agricultural Pesticide Impact Assessment Program to address current and emerging pesticide issues and to support Extension initiatives, including integrated pest management.

Growers in North Carolina use a variety of methods, including cultural and chemical, to manage pests on field, fruit and vegetable crops. Pest management practices reported by North Carolina apple, cotton, cucumber, peanut, potato, sweetpotato and tobacco growers responding to mail surveys conducted from 1989 to 1993 are presented.


Survey Method

Mail surveys of selected apple, cotton, cucumber, peanut, potato, sweetpotato and tobacco growers in North Carolina were conducted by the North Carolina Cooperative Extension Service from 1989 to 1993 following methods described by Christenson (1975) and Dillman (1978). Questionnaires developed for each of the grower surveys were mailed from the county extension centers accompanied with letters signed by the respective county agricultural extension agents. The response of growers to the surveys ranged from 43 percent by cucumber growers to 68 percent by cotton growers, with a mean response rate of 54 percent (Table 1). The number of acres of agricultural crops planted and harvested statewide in North Carolina and by those growers responding to the mail surveys are contained in Table 2.


Table 1. Response of North Carolina growers to mail surveys conducted by the North Carolina Cooperative Extension Service.

Agricultural Crop (Year)Date Survey ConductedQuestionnaires MailedQuestionnaires ReturnedPercent Returned
Peanuts (1988)May 198950327855
Potatoes (1989)February 1990965759
Tobacco (1989)May 19901,27169755
Cucumbers (1990)January 199193540443
Apples (1990)February 199160028347
Sweetpotatoes (1991)February 199294045048
Cotton (1992)February 19931,11575568
TOTALS1989 - 19935,4602,92454


Table 2. Acres of agricultural crops planted and harvested statewide in North Carolina (Watson 1989, 1990, 1991, 1992, 1993) and by growers responding to the mail surveys.

Agricultural Crops (Year)North CarolinaSurvey Respondents
Acres PlantedAcres HarvestedAcres PlantedAcres Harvested
Peanuts (1988)155,000153,00017,128---
Potatoes (1989)17,70017,00012,201---
Tobacco (1989)---266,70013,978---
Cucumbers (1990)31,30030,70013,68013,680
Apples (1990)---15,0007,2476,007
Sweetpotatoes (1991)31,00030,00025,52724,602
Cotton (1992)380,000377,000155,640151,556


Results and Discussion

Scouting. According to survey respondents, the scouting of crops for insects, weeds and plant diseases was predominately performed by the grower, a family member or employee, except in cotton where a professional scout was utilized by 50 percent of the growers (Fig. 1). Professional scouts were used by 24 and 16 percent of potato and apple growers, respectively. For each crop, the percentage of growers reporting their crop was not scouted was less than 10 percent. These results suggest that growers recognize the importance of scouting their crops for pests; however, the results do not reveal the quality of the scouting.

Figure 1

Fig. 1. Scouting for weeds, insects and diseases. Bars indicate the percentage of North Carolina growers reporting their crop was scouted by themselves, family member or employee (dark), and/or professional scout (hatched). Light bars indicate percentage of growers not scouting.

Pesticide use. Results from the surveys indicate the largest percentages of growers using herbicides were those growing field crops and potatoes (Fig. 2a). Over 90 percent of the peanut, potato, tobacco and cotton growers reported herbicide use. Insecticides were used extensively on all of the crops, except on cucumbers where only 34 percent of growers reported insecticide use (Fig. 2b). Cucumber beetles and pickleworms are significant pests of cucumbers in North Carolina; however, pickleworms are rarely found on the spring cucumber crop (the majority of the acreage produced in the state) (Toth et al. 1994). Greater than 60 percent of the survey respondents growing tobacco and sweetpotatoes used nematicides, while about 35% of peanut and cotton growers treated for nematodes (Fig. 2c). Only 17 percent of potato growers reported the use of a nematicide, which is surprising due to the popularity of Temik for management of nematodes. Evidently, potato growers were sensitive to the fact that some buyers did not want to buy Temik-treated potatoes in 1989 (Toth et al. 1993). The manufacturer suspended Temik use on potatoes following the 1989 season because of residue concerns. Fungicide use was greatest among apple (93 percent), peanut (90 percent) and tobacco (82 percent) growers (Fig. 2d). Cotton growers heavily depended on growth regulators (86 percent) and defoliants (83 percent). Approximately 48 percent of apple growers used rodenticides in their orchards, while 11 percent of potato growers applied a vine desiccant to their crop to facilitate harvest.

Figure 2a

Figure 2b

Figure 2c

Figure 2d

Fig. 2. Pesticide use by North Carolina growers. Bars indicate the percentage of peanut, potato, tobacco, cucumber, apple, sweetpotato and cotton growers using a) herbicides, b) insecticides, c) nematicides and/or d) fungicides.

Nonchemical Pest Management Practices. Cultural practices such as crop rotation and planting resistant crop varieties are used by North Carolina growers for the management of weeds, insects, nematodes and diseases. According to survey results, greater than 50 percent of potato, cucumber and cotton growers claimed to have rotated their crops as a means of pest management (Fig. 3a). Resistant crop varieties were planted by 35 percent of cotton (Fig. 4a) and 23 percent of sweetpotato growers (Fig. 4d).

Over 90 percent of cucumber, sweetpotato and cotton growers and nearly 70 percent of potato growers cultivated their fields for weed management (Fig. 3b). Eighty percent of cucumber growers reported that their crops were weeded by hand (Fig. 4b), 83 percent of potato growers practiced drag-off before their potato crop emerged to manage rapidly emerging weeds (Fig. 4c), and 52 percent of sweetpotato growers reworked their ridges (beds) prior to transplanting sweetpotato plants in an effort to manage weeds.

Pheromone and light traps were used by North Carolina growers for monitoring insect pests (Fig. 3c). Approximately 18 percent of apple growers used pheromone traps, the primary scouting procedure for the codling moth (Linker et al. 1991). Only 7 percent of sweetpotato growers (traps are for the sweetpotato weevil which is not currently established in state's sweetpotato production areas) and less than 1 percent of cucumber growers used pheromone traps (traps for pickleworm monitoring are not commercially available). Twenty-six percent of cotton growers and 1 percent of sweetpotato growers used light traps to monitor insects. Only a very small percentage of cucumber growers used a trap crop of squash to detect pickleworms. Likewise, few sweetpotato growers used seed baits in the soil to detect insects.

In an effort to combat insecticide resistance by the Colorado potato beetle (CPB), 85 percent of potato growers responding to the survey periodically changed insecticides and 16 percent utilized a CPB resistance monitoring kit. Nearly 75 percent of the apple growers pruned their trees to help manage insects and diseases. Economic thresholds were used by 39% of the growers to determine if pesticide treatments were necessary; 51% of apple growers reported using lower rates of pesticides as an integrated pest management strategy. Nematode samples were taken by 22 percent of cucumber growers, 28 percent of sweetpotato growers and 16 percent of cotton growers (Fig. 3d). A nematode sample provides information on the type and level of nematode populations in the soil which can assist the grower in determining if nematicide treatments are necessary. Approximately 70 percent of peanut growers used the leaf spot advisory, a weather-based advisory system available by telephone through the county extension centers which can help growers avoid unnecessary fungicide treatments for peanut leaf spot.

Figure 3a

Figure 3b

Figure 3c

Figure 3d

Fig. 3. Pest management practices used by North Carolina growers. Bars indicate the percentage of potato, cucumber, apple, sweetpotato and cotton growers using a) crop rotation, b) cultivation, c) insect traps and/or d) nematode sample.


Figure 4a

Figure 4b

Figure 4c

Figure 4d

Fig. 4. Pest management practices used by North Carolina growers. Bars indicate the percentage of growers using selected pest management practices on a) apples (dark) and cotton (hatched), b) cucumbers, c) peanuts (dark) and potatoes (hatched) and/or d) sweetpotatoes.


Literature Cited

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.

Linker, H. M., J. F. Walgenbach, T. B. Sutton, and M. L. Parker. 1991. Scouting Apples in North Carolina. North Carolina Agricultural Extension Service Publication V 1.1. 39 pp.

Toth, S. J., Jr., H. E. Duncan, D. W. Monks, K. A. Sorensen and L. G. Wilson. 1993. Potato Pest Management: A Survey of Pesticide Use and Other Pest Management Practices by North Carolina Potato Producers. AG-497. North Carolina Cooperative Extension Service, Raleigh. 20 pp.

Toth, S. J., Jr., C. W. Averre, D. W. Monks, J. R. Schultheis, and K. A. Sorensen. 1994. Cucumber Pest Management: A Survey of Pesticide Use and Other Pest Management Practices by North Carolina Cucumber Producers. AG-499. North Carolina Cooperative Extension Service, Raleigh. 20 pp.

Watson, D. D., ed. 1989. North Carolina Agricultural Statistics 1989. Publication No. 166. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 73 pp.

Watson, D. D., ed. 1990. 1990 North Carolina Agricultural Statistics. Publication No. 168. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 77 pp.

Watson, D. D., ed. 1991. 1991 North Carolina Agricultural Statistics. Publication No. 171. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 77 pp.

Watson, D. D., ed. 1992. 1992 North Carolina Agricultural Statistics. Publication No. 173. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 77 pp.

Watson, D. D., ed. 1993. 1993 North Carolina Agricultural Statistics. Publication No. 176. Agricultural Statistics Division, North Carolina Department of Agriculture, Raleigh, NC. 81 pp.


Acknowledgments

The authors gratefully acknowledge the specialists, county directors and county agricultural agents of the North Carolina Cooperative Extension Service that participated in the surveys of apple, cotton, cucumber, peanut, potato, sweetpotato and tobacco growers. The following organizations and companies are recognized for generously providing mailing lists of growers: North Carolina Agricultural Stabilization and Conservation Service, North Carolina Department of Agriculture, North Carolina Apple Growers Association, North Carolina Potato Association, North Carolina Sweetpotato Commission, Bick's Pickles (Sharpsburg, NC), Mt. Olive Pickle Company (Mt. Olive, NC), Nash Produce (Nashville, NC) and Vlasic Foods, Inc. (Bethel, NC). Anne Henderson, Allison Mains, Rebecca Osborne and Laura Steinbuch are acknowledged for their preparation of survey materials and data entry. Support for this research was provided by the National Agricultural Pesticide Impact Assessment Program, Extension Service, United States Department of Agriculture under the projects 90-EPIA-1-8033, 91-EPIA-1-0033 and 92-EPIX-1-0071.




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Web page last modified on August 14, 1996 by Stephen J. Toth, Jr.