Consumer's Fresh Produce Food Safety Practices: Outcomes of a Fresh Produce Safety Education Program

Authors

  • Amanda R. Scott,

    1. Author Scott is with Dept. of Nutrition and Food Science, Texas AgriLife Extension Service, Texas A&M System, 223 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Author Pope is with Dept. of Agricultural Leadership, Education, and Communications, Texas AgriLife Extension Service, Texas A&M System, 148 Scoates Hall, MS 2116, College Station, TX 77843-2116, U.S.A. Author Thompson is with Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM301, Houston, TX 77030, U.S.A.; previously with Texas AgriLife Extension Service, Texas A&M University System, 352 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Direct inquiries to author Scott (E-mail: arscott@ag.tamu.edu).
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  • Paul E. Pope,

    1. Author Scott is with Dept. of Nutrition and Food Science, Texas AgriLife Extension Service, Texas A&M System, 223 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Author Pope is with Dept. of Agricultural Leadership, Education, and Communications, Texas AgriLife Extension Service, Texas A&M System, 148 Scoates Hall, MS 2116, College Station, TX 77843-2116, U.S.A. Author Thompson is with Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM301, Houston, TX 77030, U.S.A.; previously with Texas AgriLife Extension Service, Texas A&M University System, 352 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Direct inquiries to author Scott (E-mail: arscott@ag.tamu.edu).
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  • Britta M. Thompson

    1. Author Scott is with Dept. of Nutrition and Food Science, Texas AgriLife Extension Service, Texas A&M System, 223 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Author Pope is with Dept. of Agricultural Leadership, Education, and Communications, Texas AgriLife Extension Service, Texas A&M System, 148 Scoates Hall, MS 2116, College Station, TX 77843-2116, U.S.A. Author Thompson is with Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM301, Houston, TX 77030, U.S.A.; previously with Texas AgriLife Extension Service, Texas A&M University System, 352 Kleberg Center, Mail Stop 2253, College Station, TX 77843-2253, U.S.A. Direct inquiries to author Scott (E-mail: arscott@ag.tamu.edu).
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Abstract

ABSTRACT:  The Centers for Disease Control and Prevention estimate that there are 76 million cases of foodborne disease annually. Foodborne disease is usually associated with beef, poultry, and seafood. However, there is an increasing number of foodborne disease cases related to fresh produce. Consumers may not associate fresh produce with foodborne disease or recognize that these foods require safe handling. To address this learning need, a 1-h educational program was developed and evaluated. Extension agents in 69 Texas counties presented the program to participants. Most participants (n = 2651) were female (89.5%), Caucasian (60.5%), and over age 55 (62%). Participants completed a traditional pretest and then a retrospective posttest at conclusion of the program to assess knowledge, attitudes, and behaviors related to fresh produce safety. Participants' behaviors and attitudes were assessed using a 5-point scale. To measure the longer-term impact of the program, a follow-up telephone survey was conducted among a random sample (n = 426) of participants. Repeated measures ANOVA, t-tests, and eta-squared were used to determine significant differences. Immediate posttest results indicated improved knowledge and attitudes regarding specific fruit and vegetable safety recommendations. Long-term improvement was also noted for food safety behaviors, but not for overall food safety attitudes. The results suggest that this educational program is an effective tool to teach consumers about safe handling of fresh produce.

Introduction

Foodborne disease is a serious and costly issue in the United States (USDA/ERS 2007b). In fact, the Centers for Disease Control and Prevention (CDC) estimate that foodborne diseases cause approximately 76 million illnesses, 325000 hospitalizations, and 5000 deaths each year (Mead and others 1999, 2000). Certain population groups such as infants and young children, pregnant women, immunocompromised individuals, and elderly people over age 65 have an increased risk of foodborne disease when exposed to contaminated food.

While not traditionally associated with transmission of foodborne diseases, fresh fruits and vegetables have recently been linked to several outbreaks. Specific examples include Hepatitis A contamination of green onions (USFDA 2003) and Salmonella infections resulting from contaminated Roma tomatoes (CDC 2005). Additionally, E. coli O157:H7 outbreaks have been linked to fresh spinach (USFDA 2007b) and shredded iceberg lettuce (USFDA 2007a). More recently, a Salmonellosis outbreak was reportedly linked to fresh jalapenos grown and harvested in Mexico (USFDA 2008).

Overall, the number of outbreaks associated with fresh produce food items has increased in recent years (Buck and others 2003; Sivapalasingam and others 2004). A review of outbreaks of foodborne disease from 1973 through 1997 revealed that 190 outbreaks were associated with fresh produce resulting in 16058 illnesses and 8 deaths. In fact, the total proportion of produce-related outbreaks rose from 0.7% in the 1970s to 6% in the 1990s (Sivapalasingam and others 2004). Additional data indicate that between 1990 and 2005 approximately 713 outbreaks of foodborne illness were related to produce resulting in over 34000 cases of illness. In fact, the number of produce outbreaks in this same time period exceeded numbers for the individual categories of beef, dairy, and poultry. Reported cases of foodborne illness related to produce were also higher than other commodity categories (CSPI 2007).

Current nutrition recommendations for consumers promote consumption of fruits and vegetables as part of a balanced diet and to prevent some chronic diseases (USDHHS 2005). Recent data indicate the availability of fresh fruits to consumers has increased 26% and fresh vegetables 29% between 1970 and 2005 (USDA/ERS 2007a). However, Americans continue to consume fewer fruits and vegetables than recommended (Guenther and others 2006). From a food safety standpoint, consumption of fresh produce could pose a unique risk. Specifically, when fruits and vegetables are consumed raw, there is no kill step in which pathogens are eliminated. Rather, pathogen load is most often reduced by adequate washing, proper storage, and avoidance of cross-contamination.

Many consumers are not familiar with safe food handling recommendations for fresh produce. Results of a national mail survey with consumers indicated that 50% of respondents reported “no special requirements” for bagging fresh produce at the grocery store, 35% did not wash melons, 23% stored meat above other foods in the refrigerator, and 50% did not wash their hands before handling fresh produce (Li-Cohen and Bruhn 2002).

The purpose of our study was to evaluate the effectiveness of an educational program designed to help consumers reduce their risk of foodborne disease from fresh fruits and vegetables.

Materials and Methods

Educational program

The program followed recommendations of the U.S. Food and Drug Administration and covered 4 major concepts relating to fresh produce safety: selecting and purchasing produce; proper storage; proper methods to wash produce; and safe methods to serve them (USFDA 2000, 2005). Educational efforts were targeted to consumers responsible for food preparation in their home and focused on the following specific program objectives:

  • • To increase awareness about the risks of foodborne disease
  • • To increase safe handling of fresh produce at the grocery store or market
  • • To increase safe storage of fresh fruits and vegetables in the home
  • • To increase adequate washing of fresh fruits and vegetables
  • • To increase safe handling when serving fresh produce

The educational program was reviewed and then piloted by 2 Family and Consumer Sciences (FCS) extension agents in the field. Following the pilot, all FCS agents were given the opportunity to implement the program with 69 Texas counties ultimately participating.

County extension agents were asked to conduct the program with captive audiences within their respective county during the months of February to August. Pre-scripted lesson plans, visuals, handouts, teaching supplies, and pre-numbered evaluation instruments were provided to the extension agents. Pre-numbered copies of evaluation materials made it possible to match pre- and post-project data. Spanish-language materials and surveys were available. Agents were instructed to follow the lesson plan as written and to implement all activities in the curriculum. Participants received a refrigerator thermometer and vegetable brush for their participation in the study.

Administration

We administered a short 3-item pretest to all participants before the start of the program (n = 2651) to assess their knowledge of produce food safety. We also gathered demographic data. At the end of the program, participants completed the same knowledge assessment.

Immediately following the program, participants were asked to rate their attitudes and behaviors before and after participating in the lesson. We chose to use a retrospective posttest because of the reported benefits of this method in evaluating changes in the behavior of participants (Raidl and others 2004; Betz and Hill 2006). Both pre and retrospective post-questionnaires were administered by county extension agents.

Evaluation of the longer-term impact of the program involved a follow-up telephone survey conducted with a sample of 426 participants 3 mo after pre- and post-data collection ended. Longer-term follow-up data were matched with retrospective posttest questionnaires. Follow-up telephone surveys were completed by the Public Policy Research Inst. (PPRI) at Texas A&M Univ. Prior to live data collection, PPRI conducted training on the instrument and interview procedures to help ensure reliability of data and consistency among callers. The Texas A&M Univ. Institutional Review Board approved all protocols for this study (protocol nr 2003-0386).

Questionnaires

Demographics and knowledge As described previously, a series of questions related to participant demographics (gender, ethnicity, age, highest education level, and income level), as shown in Table 1, were included in the pretest. In addition, 3 knowledge questions were administered on the pretest and retrospective posttest (Table 2).

Table 1—.  Frequency analysis of selected demographic variables of participants completing a fruit and vegetable safety educational program.
Demographic variableNumber of participants (%)
Gender (n = 2521)
 Male 265 (10.5)
 Female2256 (89.5)
Ethnicity (n = 2415)
 African American 253 (10.5)
 American Indian 32 (1.3)
 Asian American 31 (1.3)
 Caucasian1461 (60.5)
 Hispanic American 564 (23.4)
 Other 74 (3.0)
Age in years (n = 2510)
 Under 24150 (6.0)
 25 to 34 266 (10.6)
 35 to 44248 (9.9)
 45 to 54 291 (11.6)
 55 to 64 436 (17.4)
 Over 651119 (44.5)
Highest education level (n = 2390)
 Some high school 368 (15.4)
 High school graduate 825 (34.5)
 Some college 713 (29.8)
 College graduate 332 (13.9)
 Post-college graduate152 (6.4)
Annual household income (n = 1541)
 Less than $15000 443 (28.7)
 $15000 to $24999 317 (20.6)
 $25000 to $34999 200 (13.0)
 $35000 to $49999 237 (15.4)
 $50000 to $74999 204 (13.2)
 $75000 and over140 (9.1)
Table 2—.  Numbers and percentages of participants (matched pre and post) answering knowledge questions correctly at entry and exit from program.
Knowledge questionPretest nr (% correct)Posttest nr (% correct)P
  1. Note: Answer choices in bold indicate the correct answer.

Fresh fruits and vegetables should be washed with:
 a. Bleach and water   
 b. Vinegar and water   
 c. Soap and water   
 d. Running water only1637 (69)2168 (92)<0.001
Cutting boards and kitchen utensils should be sanitized with:
 a. Hot soapy water   
 b. Disinfectant spray   
 c. A mixture of bleach and water1244 (53)1794 (77)<0.001
 d. Hot water only   
The refrigerator should be kept at:
 a. 55 degrees F   
 b. 50 degrees F   
 c. 45 degrees F   
 d. 40 degrees F1397 (59)2250 (96)<0.001

Attitudes and behaviors The retrospective posttest and follow-up questionnaires included 18 scaled items: 7 attitude and 11 behavior items. Four of the 7 items related to the specific program objectives; the other three were related to awareness of risks of foodborne disease (Table 3). Participants responded to the attitude questions on a 5-point Likert scale: (1 = strongly disagree to 5 = strongly agree). The instrument also contained 11 behavior items related to the specific program objectives on a 5-point rating scale (1 = never; 2 = occasionally; 3 = sometimes; 4 = frequently; 5 = always).

Table 3—.  Mean retrospective pretest, posttest, and 3-mo follow-up scores for participants' attitudes toward foodborne illness and fresh fruit and vegetable safety (n = 426).
Attitude statementAPretest M ± SDPosttest M ± SDFollow-up M ± SD
  1. Note: For each item (row), means not sharing a letter are statistically significantly different.

  2. Attitude scale: 1 = strongly disagree to 5 = strongly agree. M = mean, SD = standard deviation.

  3. AInstructions to participants: “Please circle the ONE number that best tells how you feel about each statement ….”

I believe foodborne illness caused by bacteria on food is a problem.4.23 ± 0.70a4.75 ± 0.51b4.29 ± 0.62a
I believe foodborne illness caused by bacteria on fresh fruits and vegetables could be a problem.4.23 ± 0.70a4.75 ± 0.51b4.29 ± 0.62a
I believe foodborne illness can occur if fresh fruits and vegetables are handled unsafely.4.36 ± 0.68a4.83 ± 0.39b4.35 ± 0.56a
How fresh fruits and vegetables are handled while grocery shopping is important to keep them safe to eat.4.09 ± 0.78a4.77 ± 0.45b4.41 ± 0.60c
Proper storage of fruits and vegetables can keep them safe to eat.4.28 ± 0.63a4.78 ± 0.47b4.42 ± 0.57c
Washing whole fruits and vegetables can help keep them safe to eat.4.34 ± 0.66a4.77 ± 0.52b4.46 ± 0.54c
I can reduce the risk of foodborne illness by washing and sanitizing areas where foods are prepared.4.44 ± 0.65a4.85 ± 0.35b4.53 ± 0.55a
Total attitude scale mean4.29 ± 0.52a4.78 ± 0.33b4.39 ± 0.41c

Two food safety extension specialists reviewed the instruments for content validity while 2 county extension educators reviewed the items for face validity. Exploratory factor analysis as well as internal consistency reliability (Cronbach's alpha) indicated that the attitude and behavior items factored on 2 separate scales. These 2 factors accounted for 52% of the variance. Internal consistency reliability of the attitude and behavior factors was 0.89 and 0.87, respectively.

Statistical analysis

Data analysis included repeated measures analysis of variance (ANOVA) between retrospective pretests, posttests, and follow-up data for attitude assessment while a t-test was used to determine differences between the retrospective pretests and the follow-up for behavioral items. All data were analyzed using SPSS 15.0 (SPSS, Inc., Chicago, Ill., U.S.A.); the alpha for our study was set at 0.05. Practical significance or effect size was analyzed using variance accounted for (η2). Practical significance was defined as η2≥ 16, or at least 16% of the variance accounted for (Kline 2004).

Results and Discussion

Participant characteristics are shown in Table 1. Results revealed that the majority of participants (60.5%) were Caucasian. Half of the participants reported completing at least some college while almost half earned less than $25000 annually (Table 1). Importantly, many of the participants (44.5%) were over age 65 and therefore at an increased risk for foodborne illness based on their age (USDA/FSIS 2006b).

Participant knowledge gain

Results of knowledge questions showed an increase in immediate knowledge gain between pretest and posttest, suggesting that the educational program was successful in improving food safety knowledge of participants (Table 2). At program entry, only 24.4% of the participants answered all 3 items correctly. After the program, 75.6% of the same participants answered the questions correctly (P < 0.001).

Participant improvement in attitudes

Overall, participants' attitudes regarding fresh produce food safety were statistically and practically significantly different between the time points, with an average attitude rating of 4.29 (SD = 0.52), 4.78 (SD = 0.33), and 4.39 (SD = 0.41) on the retrospective pretest, posttest, and follow-up, respectively (Table 3). Post hoc analysis indicated that attitudes were statistically (P < 0.001) and practically (η2= 0.49) significant. However, at the 3-mo follow-up, gains above pretest levels were modest (P = 0.005, η2= 0.02). Specifically, there were improvements in attitudes related to safe handling of fresh produce at the grocery store or market and proper storage and washing of fresh fruits and vegetables (Table 3).

Participants' improvement in behavior

At follow-up, participants' overall food safety behaviors significantly improved compared to retrospective pretest levels, being both statistically (p<.001) and practically (η2= 0.16) significant. Improvements in behaviors were found related to all areas. Table 4 indicates participants' reported behaviors before the program and at the 3-mo follow-up.

Table 4—.  Mean retrospective pretest and 3-mo follow-up scores for participants' behavior related to fresh fruit and vegetable food safety (n = 426).
Behavior itemAPretest M ± SDFollow-up M ± SDP
  1. Note: Behavior scale: 1 = never; 2 = occasionally; 3 = sometimes; 4 = frequently; 5 = always; M = mean; SD = standard deviation.

  2. AInstructions to participants: “Please circle the ONE number that best tells how often you did/do this activity …”

Separate fresh fruits and vegetables from raw meat in the shopping cart.3.97 ± 1.224.52 ± 1.06<0.001
Bag fresh fruits and vegetables separate from raw meat at grocery checkout.4.28 ± 1.083.56 ± 1.71<0.001
Keep fruits and vegetables separate from raw meat in the refrigerator.4.66 ± 0.714.91 ± 0.46<0.001
Use a thermometer to check refrigerator temperatures.2.97 ± 1.643.90 ± 1.46<0.001
Wash fresh fruits and vegetables even if the skin or rind is not eaten.3.89 ± 1.214.54 ± 0.84<0.001
Use a fruit/vegetable brush to scrub skins and rinds of firm fruits and vegetables.3.51 ± 1.393.70 ± 1.37 0.042
Wash fresh fruits and vegetables just before cooking or eating them.4.47 ± 0.844.76 ± 0.68<0.001
Refrigerate fresh fruits and vegetables that have been cut within 2 h.4.17 ± 0.944.49 ± 1.00<0.001
Wash and sanitize food preparation areas in the kitchen.4.40 ± 0.844.65 ± 0.68<0.001
Wash hands before handling fresh fruits and vegetables.4.35 ± 0.934.77 ± 0.60<0.001
Wash and sanitize cutting boards/utensils before preparing fresh fruits and vegetables.4.33 ± 0.974.69 ± 0.77<0.001
Total behavior scale mean4.10 ± 0.684.42 ± 0.48<0.001

Discussion

Consumers often fail to recognize their home environment as a potential source of foodborne disease and underestimate the frequency of serious consequences related to foodborne disease (Bruhn 1997). This may serve as a barrier to consumers making recommended behavior changes (Sammarco and others 1997; Redmond and Griffith 2003).

However, it is interesting to note that in our study consumers reported long-term improvement of behaviors but not attitudes. It is possible that this lack of change in consumer attitudes may be due to a ceiling effect, since most participants reported positive attitudes toward produce food safety before the program. Perhaps consumers felt overall that fruits and vegetables were safe to eat before the program and therefore this topic was not a high priority for them. However, one could surmise that consumer attitudes might change if an outbreak of foodborne illness linked to produce was noted in their community or if they were exposed to repeated and specific news and media messages about a produce outbreak. Although participants' overall attitudes related to the risks of foodborne illness remained practically unchanged in our study several months after the program, improvements in food safety behaviors were realized, and changes in these behaviors (USFDA 2000, 2005) are crucial to reducing the risk of foodborne illness from fresh produce regardless of lack of change in attitudes among consumers.

One objective of this educational program was to improve safe handling of fresh produce at the grocery store or market. Results indicated that participants reported separating fresh produce from raw meats in their grocery cart as well as bagging fresh produce separate from raw meat at the checkout counter. Other studies have shown that half of consumers surveyed report “no special requirements” for bagging fresh produce at the grocery store (Li-Cohen and Bruhn 2002).

Proper home storage of fruits and vegetables is an important topic related to both quality and safety. For purposes of this study, storage recommendations were targeted toward increasing the safety of produce items via prevention of cross-contamination of fresh produce in the refrigerator, as suggested by previous research (Li-Cohen and Bruhn 2002). We noted significant, long-term behavior changes in this area. Consumers reported positive changes in use of a refrigerator thermometer in the home (Table 4) and also reported long-term knowledge gains related to the proper temperature of the refrigerator (Table 2) which are important for safe storage of foods.

Participants in our study reported a significant increase in washing fresh produce, including washing fresh fruits and vegetables with running water even if the skin or rind is not eaten (Table 4). In a previous study, 60% of consumers reported that they washed fruits and vegetables to remove germs and bacteria to improve their safety. In the same survey, 6% of consumers reported that they did not wash fruits and vegetables because these foods were safe without washing (Li-Cohen and Bruhn 2002). Medeiros and others (2001) suggest that messages concerning washing of fresh produce should be included in food safety education programs as “it is the only method to reduce pathogen load on fresh produce.” Additionally, washing fresh produce before eating was identified as an important behavior to prevent cross-contamination (Hillers and others 2003) although it cannot guarantee prevention of foodborne illness.

While participants in our study reported changing behaviors related to use of a vegetable brush to scrub firm produce, this was the smallest increase noted in behaviors, even though participants were given this item as an incentive for completion of the surveys (Table 4). Previous results indicate that only 4% of consumers use a vegetable brush to scrub whole melons and only 17% use a brush to wash whole carrots (Li-Cohen and Bruhn 2002). Similarly, data from the Partnership for Food Safety Education indicated that 49% of surveyed individuals were aware of the recommendation to use a vegetable brush, but only 42% reported always or usually using a scrub brush (PFSE 2006). These results suggest that additional innovative educational strategies beyond demonstrating how to scrub produce and providing a vegetable brush may be necessary to motivate consumers to use this food safety tool.

Proper washing of cutting boards, utensils, and food preparation areas after contact with raw foods such as meat, poultry, and fish is a key consumer behavior to the prevention of cross-contamination (Medeiros and others 2001). In an earlier study, 24% of consumers reported using only water to clean food preparation surfaces, with 5% reporting dry wiping with no water or solution (Li-Cohen and Bruhn 2002). Nearly 20% of respondents in the same study indicated rinsing knives with water only after cutting meat and before slicing fresh produce and 8% reported simply dry wiping the knife between foods. All of these behaviors could cause cross-contamination and result in foodborne disease. Consumers in our study reported improvements in behaviors related to washing and sanitizing food preparation areas and washing/sanitizing cutting boards/utensils before preparing fresh fruits and vegetables (Table 4).

If used properly, sanitizing solutions offer an added level of protection against the risk of foodborne disease (USDA/FSIS 2006a). Consumers reported knowledge gain (Table 2) related to identification of a mixture of bleach and water as a sanitizing method as suggested by the U.S. Food and Drug Administration (USFDA 2000, 2005). Given that over 40% of participants in this study could be considered at increased risk of foodborne illness, use of a sanitizing solution could be a valuable skill for them to adopt. At posttest, 77% of consumers were able to answer correctly as to what constitutes a sanitizing solution (Table 2). Furthermore, they reported washing and sanitizing food preparation areas, cutting boards, and utensils in their home kitchens (Table 4). However, no data were available on whether or not consumers in our study actually knew how to prepare the sanitizing solution correctly.

A unique food safety recommendation included in our educational program was to refrigerate fresh fruits and vegetables that have been cut within 2 h. According to survey data from the Partnership for Food Safety Education, 61% of consumers reported hearing or seeing this recommendation, with 75% reporting that they always or usually followed the 2-h rule for cut fruits and vegetables (PFSE 2006). Forty-four percent of participants in our study reported that they always followed this recommendation at pretest with a significant increase to 73% at the 3-mo follow-up.

Hand washing is another key behavior in the prevention of foodborne disease (Medeiros and others 2001). Long-term improvements related to washing hands before handling fresh fruits and vegetables were realized among participants. Forty-two percent of our study participants indicated that, before the program they did not always wash their hands before handling fresh produce. This is similar to other data showing 47% of individuals failed to wash their hands every time before handling fresh produce (Li-Cohen and Bruhn 2002). Following participation in our educational program, 84% of individuals at the 3-mo follow-up indicated that they always washed their hands before preparing fresh produce.

This study has several limitations. First, this study included the use of self-reported data in which participants may have over-reported behaviors perceived as positive (Stanton and others 1987). Additionally, participants answered the knowledge questions immediately before and after the program which may have influenced participant knowledge gain scores. Finally, there may have been a ceiling effect in regard to attitude measures as mentioned previously.

Conclusions

The results of this study suggest that this educational program was effective in improving knowledge and important behaviors related to food safety for fresh fruits and vegetables among consumer audiences.

Acknowledgments

This educational program was developed by Texas AgriLife Extension Service in conjunction with faculty from the Dept. of Nutrition and Food Science at Texas A&M Univ. The study was funded by the U.S. Dept. of Agriculture, Cooperative State Research, Education, and Extension Service, Initiative for Future Agriculture & Food Systems (IFAFS), grant number 00-52102-9637 under the direction of Principal Investigator, Suresh D. Pillai, Texas A&M Univ. Special thanks to the county extension agents that made implementation of this study a reality.

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