個別報告論文
人工光型植物工場産の野菜に対する不安度に影響を及ぼす要因
―福島県内JA直売所を事例として―
2016 年 52 巻 4 号 p. 235-240
詳細
2016 年 52 巻 4 号 p. 235-240
2011年の福島原発事故に起因する土壌汚染や風評被害が深刻な地域では，外部環境の影響を受けずに野菜を周年栽培できる人工光型植物工場に注目が集まっている．しかし，工場野菜に対する消費者意識や評価に関する研究はほとんどない．本研究では，福島県内JA直売所の利用者に対してアンケート調査を実施し，工場野菜に関する知識の程度および不安度を測定するとともに，不安度に影響を与える要因を分析した．その結果，管理された環境で安定生産が可能なことはよく理解されている一方，土を使わない栽培法や製品の安全性に関する知識は乏しいことがわかった．また，工場野菜に対する不安度は全体的に低いものの，栄養や味に関して不安に思う人が相対的に多く，工場野菜の質に関する知識が乏しい人ほど不安度が高い傾向が見られた．被災地の農業再生のためには，セミナーや教育，試食等を通じて，消費者の次世代施設園芸に関する理解を深めていく必要がある．
Radioactive contamination of farmland and harmful rumors caused by 2011 nuclear accident are main obstacles to restore agriculture in Fukushima and surrounding region (Agriculture, Forestry and Fishery Department of Fukushima Prefecture, 2012). To overcome this issue, increasing attention has been paid to plant factories using artificial light (hereafter PFAL) where leafy vegetables can be produced year round without being affected by the external environment, such as the atmosphere or the soil outside (Kozai, 2013). Vegetables produced at PFALs are pesticide-free and nutritious; and this is also a reason why PFALs are expected to contribute to the restoration of agriculture in the region.
Since PFALs have been more frequently covered by the media in recent years, there has been increasing recognition of their products among consumers. However, the cultivation system and overall quality of vegetables produced at PFALs are not yet well-understood. Some consumers still feel a strong resistance to growing vegetables without natural sunlight or soil. It seems that they feel anxious about the nutritional value and/or taste of vegetables produced at PFALs in particular (Mitsubishi UFJ Research and Consulting Co. Ltd., 2013). For continued development of the plant factory industry and agricultural restoration in the region, it is necessary to improve not only the cost performance of PFALs (Yamori et al., 2014) but also consumers’ image of these products. Therefore, it is indispensable to identify the factors that influence consumers’ impressions about PFAL vegetables.
As Kurihara et al. (2014) points out, there is still insufficient marketing information regarding PFAL vegetables. They explore consumers’ attitude toward PFAL vegetables in Chiba Prefecture, Japan. More recently, Yano et al. (2015) attempt to reveal consumers perception of PFAL vegetables by conducting a questionnaire survey in Saitama Prefecture, Japan. Thus far, however, the level of consumers’ understanding about PFALs has not been considered in the literature.
The objectives of this study are to: (1) measure the current level of consumers’ understanding of and the degree of anxiety about PFALs and their products, and (2) identify factors influencing this anxiety level. A questionnaire survey was carried out at a farmers’ market run by JA Tozai Shirakawa1 in Fukushima, where vegetables were indeed produced at PFALs and sold; and a total of 135 valid responses were obtained. To measure the level of understanding, 12 true-or-false questions were included in the survey. Such true-false test has been widely used in the literature, for example, to measure the knowledge of radiation and analyze the factors influencing people’s or students’ anxiety (Kunugita, 2008; Suzuki, 2014). In this study, participants were asked about the degree of anxiety concerning sanitation, attached substances, and nutritional value/taste of vegetables produced at PFALs. Statistical methods were used to summarize data and analyze the link between anxiety level and certain variables.
A total of 143 visitors to the JA farmers’ market “Miryokumanten Monogatari” in Fukushima on June 19 and 20, 2015 were asked to complete the questionnaire survey (135 valid responses).
Table 1 summarizes the individual characteristics of survey respondents. More than 80% of our respondents were from Fukushima Prefecture; 19.3% from Shirakawa City, and 63% from other regions in Fukushima; and 17.8% from outside the Fukushima Prefecture. Also, the majority of the respondents were female (nearly 80%), belonged to the middle age group (aged 40–59) or the old age group (aged 60 or above), and were high school or junior/technical college graduates. It seemed that mainly local people came to the shop or the restaurant at the farmers’ market.
| Characteristic (n=135) | n | % | |
|---|---|---|---|
| Gender | Female | 107 | 79.3 |
| Male | 28 | 20.7 | |
| Age (years) | 29 or younger | 5 | 3.7 |
| 30–39 | 12 | 8.9 | |
| 40–49 | 20 | 14.8 | |
| 50–59 | 34 | 25.2 | |
| 60–69 | 50 | 37.0 | |
| 70 or older | 14 | 10.4 | |
| Residence | Shirakawa city | 26 | 19.3 |
| Other in Fukushima | 85 | 63.0 | |
| Other | 109 | 17.8 | |
| Children | 0 | 95 | 70.4 |
| 1 | 21 | 15.6 | |
| More than 2 | 19 | 14.1 | |
| Education | College/university | 12 | 8.9 |
| Junior/tech. college | 48 | 35.6 | |
| High School or less | 75 | 55.6 | |
| Occupation | Housewife | 47 | 34.8 |
| Full-time worker | 45 | 33.3 | |
| Other | 43 | 31.9 | |
| Knowledge of PFALs | Purchased or seen | 57 | 42.2 |
| Learned by TV, conversation or other | 65 | 48.1 | |
| Never heard of | 51 | 37.8 | |
Source: Questionnaire survey.
1) Multiple answers for “Knowledge of PFALs”.
Concerning the prior knowledge of PFALs and their products, roughly 40% of the participants had never heard of “vegetables grown at PFALs” and 60% had prior knowledge; 57 participants had purchased or seen the products at stores and 65 participants mentioned that they had learned them through TV (n=36) and daily conversation (n=16) and other means, such as newspapers.
(2) Data analysisThe questionnaire used in this study comprises three main parts: a) participant’s personal characteristics, presented above; b) the measurement of participant’s understanding of PFALs and their products, using 12 true-or-false questions (Table 2); the respondent selects one answer for each question from “true”, “false” or “I don’t know”; and c) the self-evaluation of the degree of anxiety concerning sanitation, attached substances, and nutritional value/taste of vegetables produced at PFALs, using a 5-point Likert scale: 1=Confident; 2=Rather Confident; 3=Neutral; 4=Rather Anxious; 5=Anxious. For parts a) and b), we do not provide any information on PFALs in order to avoid learning bias. Meanwhile, we explain that vegetables are grown indoor using artificial lighting and hydroponic techniques in PFALs for part c) so that we can explore the respondents’ anxiety level for PFAL vegetables under the condition that all participants receive explanations about the correct cultivation methods in PFALs.
| Questions | Answer | Correct Answer Rate | |||
|---|---|---|---|---|---|
| Overall (n=135) | Purchased repeatedly (n=24) | Learned from TV (n=36) | |||
| Q1 | Crops are unaffected by weather or season | ○ | 90% | 96% | 89% |
| Q2 | Rich soil is used in the facility | × | 19% | 13% | 28% |
| Q3 | Can increase nutritive values such as Vitamin by controlling the nutrient solution | ○ | 76% | 71% | 83% |
| Q4 | Necessary to wash vegetables before cooking | × | 41% | 50% | 33% |
| Q5 | Being washed repeatedly prior to shipment, the products (vegetables) have little nutritional value | × | 60% | 67% | 56% |
| Q6 | Workers do not touch vegetables with bare hands at all through production to shipment | ○ | 34% | 46% | 25% |
| Q7 | The products have poor nutritional value due to lack of exposure to natural sunlight | × | 66% | 75% | 67% |
| Q8 | PFALs should be built on land suitable for agriculture | × | 50% | 38% | 56% |
| Q9 | Harvested vegetables are packaged inside the PFAL | ○ | 70% | 71% | 72% |
| Q10 | Does not have to use pesticides at all | ○ | 64% | 75% | 67% |
| Q11 | Workers have no dress code when entering the grow room | × | 79% | 75% | 75% |
| Q12 | A very small portion of vegetable should be removed when using it | ○ | 78% | 100% | 75% |
Source: Questionnaire survey.
1) “Purchased repeatedly” means that the respondents have purchased PFAL vegetables more than three times.
2) Soil is rarely used in the PFALs. Water hydroponic system is used in the most existing PFALs.
First, the correct answer rates of the true-false test are calculated. In addition, for reference, the correct answer rates for those who had purchased vegetables produced at PFALs repeatedly (more than three times) and for those who had learned PFALs from TV are also computed, though the sample size is quite small for these groups. This enables us to assess how well consumers understand the PFALs and their products.
Next, we calculate the means of the degree of anxiety for sanitation, attached substances, and nutritional value/taste of PFAL vegetables, respectively. Analysis of variance (ANOVA) is, then, performed to determine whether the means are statistically different. If the ANOVA result shows that there is a significant difference in the means, multiple comparisons between all pair-wise means should be performed to find how they differ. We used three methods proposed by Bonferroni, Šidák, and Holm. From these analyses, we can find what consumers worry about.
Finally, multiple regression analysis (OLS) is performed to investigate the factors that affect the anxiety level. The scores of anxiety levels concerning three aspects are summed up in order to grasp the participants’ overall anxiety level toward PFAL vegetables and that total score is used as a dependent variable. The independent variables used are prior knowledge of PFALs (1=“purchased or seen” and/or “learned by TV, conversation or other for knowledge of PFALs in Table 1, 0=otherwise), individual characteristics of the respondents, and dummy variables indicating whether or not the respondent correctly answers each true-or-false question (i.e., 1=correct; 0=wrong or I don’t know). Other factors that can potentially influence consumers’ anxiety level regarding PFAL vegetables are considered; for example, the respondent’s interest or custom.
The correct answer rates of 12 true-or-false questions regarding PFALs are shown in Table 2.
Questions having low correct answer rates (less than or equal to 50%) were Q2, Q4, Q6 and Q8. These indicate that the respondents do not know a great deal about “soilless and automated production systems” and “safety of PFAL vegetables.” Besides, approximately one-third of the respondents did not give the right answers for questions about the use of pesticides and nutritional value of the products (Q5, Q7 and Q10).
By contrast, questions having high correct answer rates (greater than 75%) were Q1, Q3, Q11, and Q12. These results mean that the participants do understand that “PFALs enable the stable production of vegetables under carefully controlled environments,” and “vegetables produced at PFALs are easier to use for cooking.”
For questions 1, 4, 6, 10 and 12 concerning the characteristics of the products mainly, the correct answer rates of the respondents having purchased vegetables produced at PFALs repeatedly were slightly higher than those of other groups. Additionally, for questions 2, 3, and 8 concerning the soilless production system, the respondents who had learned PFALs from TV were more likely to give the right answers. However, the differences were not significant, except for Q12.
Overall, it seemed that many participants had the image of “traditional greenhouse cultivation” rather than “closed plant production system.” There is still room to improve the recognition and understanding of PFALs and their products.
(2) The degree of anxietyThe means of the degree of anxiety concerning sanitation, attached substances, and nutritional value or taste are presented in Table 3. Three mean values are less than 2, meaning that the degree of anxiety regarding PFAL vegetables is, on the whole, low. Among these, however, the respondents were relatively more likely to anxious about nutritional value/taste of the products.
| The mean degree of anxiety | Mean | SD |
|---|---|---|
| Sanitation | 1.237 | 0.535 |
| Attached substances | 1.444 | 0.719 |
| Nutritional value or taste | 1.793 | 0.939 |
Source: Questionnaire survey.
1) The anxiety level was measured on a 5-point Likert scale: 1=Confident; 2=Rather Confident; 3=Neutral; 4=Rather Anxious; 5=Anxious.
To confirm this, we conducted the analysis of variance (ANOVA) and found that there was a statistically significant difference in the means (F=30.1, p<0.001). Accordingly, the Bonferroni pairwise comparisons were performed (Table 4) 2. The results show that the mean of anxiety level concerning nutritional value/taste is statistically significantly greater than those concerning attached substances and sanitation. Also, the mean degree of anxiety regarding attached substances is higher than that regarding sanitation.
| Multiple Comparisons | Mean Diff. (B-A) |
SE of Diff. | p-value | |
|---|---|---|---|---|
| The mean degree of anxiety concerning | ||||
| A | B | |||
| Sanitation | Attached substances | 0.21 | 0.07 | 0.013 |
| Attached substances | Nutritional value/taste | 0.35 | 0.07 | 0.000 |
| Sanitation | Nutritional value/taste | 0.56 | 0.07 | 0.000 |
The result of a multiple regression analysis with the total level of anxiety as the dependent variable is given in Table 5. The coefficients of (questions) dummy variables, Q3, Q7, Q10, and Q12 are negative, as expected; and they are statistically significant. It was found from these results that the respondents who answered Q3, Q7, Q10 and Q12 correctly had lower level of anxiety toward vegetables produced at PFALs. Thus, consumers’ anxiety about the products can be reduced by making them accurately understand the characteristics of PFAL vegetables, such as pesticide-free and high nutritional value.
| Explanatory variables | Coefficients (t-value) | |
|---|---|---|
| Q1 | –0.466 (–1.02) | |
| Q2 | 0.025 (0.07) | |
| Q3 | –1.323 (–3.96) | *** |
| Q4 | –0.372 (–1.32) | |
| Q5 | 0.213 (0.63) | |
| Q6 | 0.205 (0.68) | |
| Q7 | –0.608 (–1.86) | * |
| Q8 | 0.149 (0.51) | |
| Q9 | 0.381 (1.18) | |
| Q10 | –1.163 (–3.60) | *** |
| Q11 | –0.264 (–0.76) | |
| Q12 | –0.677 (–1.84) | * |
| Prior knowledge | 0.056 (0.20) | |
| Gender | 0.122 (0.33) | |
| Age | –0.013 (–1.07) | |
| Number of children | 0.030 (0.17) | |
| Education dummy | 0.306 (0.99) | |
| Housewife dummy | 0.117 (0.38) | |
| Constant | 7.785 (8.24) | *** |
| Adjusted R2 | 0.31 | |
1) Asterisk * and *** represent 10% and 1% significance level respectively.
2) Prior knowledge: 1=the respondent had some background information on PFALs; 0=otherwise.
3) Gender: 1=Female; 0=Male.
4) Education dummy: 1=university; 0=the rest.
5) Housewife dummy, 1=housewife; 0=the other.
Interestingly, the effects of individual characteristics of the respondents are not statistically significant. Also, prior knowledge does not affect the anxiety level. Thus, even though consumers know about PFALs, the anxiety level remains high if their understanding on nutritional value, pesticide usage or less vegetable waste is low. The results provide insight into ways to decrease consumers’ anxiety toward PFAL vegetables.
This paper measures the level of consumers’ understanding about PFALs as well as their products, and identifies factors influencing the anxiety level toward them in Fukushima, Japan.
The results show that consumers do understand “PFALs enable the stable production of vegetables under carefully controlled environments” and“PFAL vegetables are easier to use for cooking,” but that they hardly understand “soilless and automated production systems” and “safety of PFAL vegetables.” This indicates that it seems to be difficult for consumers to understand PFAL correctly, even where radioactive contamination has sparked worries about food safety, and PFAL vegetables are advertised and sold.
Although consumers’ anxiety level is low as a whole, they feel more anxious about nutritional values/taste compared to other aspects. We found that the higher the level of understanding about the quality of PFAL vegetables, the lower the degree of anxiety; for example, those who placed trust in “pesticide-free” or “high nutritional value” were more likely to respond “worry-free.” Other variables were not statistically significant. This implies that improving the level of understanding about PFAL vegetables through marketing (e.g., package design), seminars, or education would be of great importance for the further development of the plant factory industry. Consequently, this could accelerate agricultural restoration and activity in the areas affected by the 2011 disaster.
The limitation of this study was that the sample size was not so large and the sample collected was biased in that we asked people who visited the JA farmers’ market. Since they were expected to be more interested in food safety and have a knowledge of PFALs, the average anxiety level at that place might tend to be lower than those at other places. It would be important to collect more samples in various regions randomly to improve the reliability of data. Analyzing factors that affect consumers’ buying behavior toward PFAL vegetables is also a challenge to be tackled in the future. Notwithstanding, the findings in the current study give useful insights into ways to reduce consumers’ anxiety toward PFAL vegetables.
