The estimated ex ante economic impact of Bt cowpea in Niger,Benin and Northern Nigeria

Genetically modified (GM) crops could increase economic growth and enhance living standards in Africa, but political issues have slowed the use of biotechnology. This is the first study that assesses the potential impact of GM crops in Africa while considering the preferences of producers and consumers towards GMOs as well as the income and price risks they face. The study uses a choice experiment to estimate the ex ante economic impact of a novel technology, Bacillus thuringiensis (Bt) cowpea, on producers and consumers in Benin, Niger and northern Nigeria. The experiment involves the simulation of a market transaction similar to those in open air markets in West Africa. During the market simulation, respondents are informed about the advantages and disadvantages, including health risks, of Bt cowpea. The results from the study suggest that cowpea growers and consumers in Benin and northern Nigeria prefer Bt to conventional cowpea for health safety reasons. The results estimate that social welfare in Benin, Niger and northern Nigeria would increase by at least US$11.82 per capita annually with Bt cowpea, if seed sectors are operating smoothly. With inefficiencies in seed sectors and the potential for cowpea acreage increase, the estimated social welfare increase in the region would be about US$1.26 per capita annually.     

蔬菜农药残留检测中质量控制的要点研究

近年来食品安全问题尤其是蔬菜中的农药残留问题,得到了社会的普遍关注。为了确保人们购买到安全放心的蔬菜,就要对蔬菜中的农药残留量进行科学合理的检测,但是在实际的检测过程中,其检测结果会受到多种因素的影响。本文对蔬菜农药残留检测的误差来源进行分析,并在此基础上,提出了具有一定针对性的检测质量控制要点,有助于获取良好的检测精度,对从事相关检测工作的技术人员具有一定的借鉴意义。     

Bt Cotton,Pesticide Use and Environmental Efficiency in Pakistan

There is a broad literature on the impact of Bt cotton adoption in different countries, but few studies have explicitly looked at environmental and health effects from an economic perspective. We analyse the impact of Bt cotton on environmental efficiency in Pakistan, using farm survey data and a doubly heteroskedastic stochastic production function framework. Negative environmental and health effects of chemical pesticide use are quantified with the environmental impact quotient. Bt‐adopting farms have higher cotton yields, while using lower pesticide quantities and causing less environmental damage. Bt farms are both technically and environmentally more efficient than non‐Bt farms. Bt adoption increases environmental efficiency by 37%. Achieving the same reduction in negative environmental and health impact without Bt would cost conventional cotton farmers US$ 54 per acre in terms of foregone yields and revenues (7% of total revenues). Extrapolating this shadow price of the technology's health and environmental benefits to the total Bt cotton area in Pakistan results in an aggregate value of US$ 370 million. These benefits are in addition to the profit gains for Bt‐adopting farmers. Our results suggest that Bt technology can contribute to sustainable agricultural development.     

Pesticide Productivity and Transgenic Cotton Technology: The South African Smallholder Case

This paper empirically investigates how the productivity of pesticide differs in Bt versus non‐Bt technology for South African cotton smallholders, and what the implications for pesticide use levels are in the two technologies. This is accomplished by applying a damage control framework to farm‐level data from Makhathini flats, KwaZulu‐Natal. Contrary to findings elsewhere, notably China, that farmers over‐use pesticides and that transgenic technology benefits farmers by enabling large reductions in pesticide use, the econometric evidence here indicates that non‐Bt smallholders in South Africa under‐use pesticide. Thus, the main potential contribution of the new technology is to enable them to realise lost productivity resulting from under‐use. By providing a natural substitute for pesticide, the Bt technology enables the smallholders to circumvent credit and labour constraints associated with pesticide application. Thus, the same technology that greatly reduces pesticide applications but only mildly affects yields, when used by large‐scale farmers in China and elsewhere, benefits South‐African smallholder farmers primarily via a yield‐enhancing effect.     

Ecosystem impacts of pesticide reductions through Bt cotton adoption

This article examines the ecosystem impacts of transgenic Bt cotton technology resulting from reduced chemical pesticide use. Employing unique panel data from smallholder farmers in India, negative environmental and health effects of pesticide use are quantified with the environmental impact quotient (EIQ), with and without Bt technology. An environmentally sensitive dynamic production function is estimated, treating the environmental risk of pesticide toxicity as an undesirable output in the production process. Negative externalities are significantly lower in Bt than in conventional cotton. The reduction in EIQ through Bt technology adoption has increased from 39 per cent during 2002–2004 to 68 per cent during 2006–2008. Bt adoption has also contributed to higher environmental efficiency. Environmental efficiency is influenced by the quality of Bt technology: high‐quality Bt seeds are associated with higher environmental efficiency than lower‐quality seeds.     

2020年周口市市售蔬菜农药残留状况调查与分析

目的:调查分析2020年周口市所售蔬菜中有机磷类、氨基甲酸类、拟除虫菊酯类农药残留情况.方法:分别对2020年第二季度和第三季度周口市各蔬菜售卖点进行抽样,运用气相色谱法对各类蔬菜中3大类农药进行检测.结果:共检测蔬菜137份,检出含有农药残留的蔬菜19份,农药超标的5份,137份蔬菜农药残留检出率排序为鳞茎类>茄果类...     

Impacts of price and exchange rate policies on pesticide use in the Philippines

Pesticide prices can influence producer decisions to apply pesticides as opposed to nonchemical means of pest control. Those prices are are turn influenced by price and exchange rate policies. The effective rate of protection for nine pesticides commonly applied to vegetables in the Philippines was calculated to determine whether government policies are creating incentives or disincentives to adopt more integrated pest management methods. Calculations found that direct price policies, primarily through an import tariff, tax pesticide use while an overvalued exchange rate subsidizes pesticide use. The net effect is a 6 to 8% pesticide subsidy. This subsidy results in economic surplus gains to vegetable producers and consumers when negative externalities associated with pesticide use are not accounted for. However, recent analysis of human health effects of pesticide use on rice in the Philippines demonstrates that these externalities can be substantial.     

Valuing financial,health, and environmental benefits of Bt cotton in Pakistan

Data from a farm survey and choice experiment are used to value the benefits of Bt cotton in Pakistan. Unlike previous research on the economic impacts of Bt, which mostly concentrated on financial benefits in terms of gross margins, we also quantify and monetize health and environmental benefits associated with technology adoption. Due to lower chemical pesticide use on Bt cotton plots, there are significant health advantages in terms of fewer incidents of acute pesticide poisoning, and environmental advantages in terms of higher farmland biodiversity and lower soil and groundwater contamination. Farmers themselves value these positive effects at US$ 79 per acre, of which half is attributable to health and the other half to environmental improvements. Adding average gross margin gains of US$ 204 results in aggregate benefits of US$ 283 per acre, or US$ 1.8 billion for the total Bt cotton area in Pakistan.     

气相色谱法在蔬菜中农药残留检测的实验研究

目的:了解气相色谱法在蔬菜农药残留检测中的应用情况.方法:文章依据随机抽样原则抽取5份样品,将样品切碎后匀浆粉碎,并经超声提取处理.利用HP-5弹性石英毛细管柱,测定了样品中残留的有机磷农药、氨基甲酸酯农药含量.结果:在0.01～1.00μg·mL-1加标浓度下,有机磷农药具有良好的线性关系,回收率为85.0％～100...     

2020年河北省蔬菜监督抽检数据分析

目的:分析2020年河北省市场监督管理局发布的蔬菜监督抽检数据。方法:下载2020年河北省市场监督管理局发布的食品抽检相关通告,从蔬菜品种、蔬菜细类、不合格蔬菜检出详情及不合格项目等方面进行分析。结果:1199批次蔬菜10个蔬菜品种中,检出62批次不合格,平均不合格率为5.17%。鳞茎类蔬菜、芽菜类蔬菜等不合格率较高,不合格突出的蔬菜细类为韭菜、豆芽、芹菜等,不合格项目主要为农药残留,且禁用农药残留占总不合格项次的50%。结论:河北省蔬菜质量安全水平相对较好,但低于全国平均水平,超剂量使用农药、违规使用禁用农药仍是蔬菜质量安全的主要问题,仍需加强韭菜、豆芽、芹菜等高风险蔬菜的监管力度。     

Consumer preferences for GM food and other attributes of the food system

While qualitative surveys regarding consumers' attitudes about gene technologies and their application to food production are plentiful, quantitative studies are less so. The present paper reports choice modelling methods to examine the conditions under which Australian consumers are willing to purchase genetically modified (GM) foods, if at all, and examines those preferences within the context of the food system as a whole. This allows us to compare consumer attitudes towards gene technology to consumer preferences for other features of the food they consume. The results of the choice modelling analysis suggest consumers require a discount on their weekly food bill before they will purchase GM food. Gene technology using animal as well as plant genes was found to be more objectionable to respondents than that using plant genes alone, especially among women. Age seems to affect the preferences for a certain type of food, with older people generally more accepting of the use of gene technology.     

Potential impacts of Bt eggplant on economic surplus and farmers' health in India

In this article, the potential impacts of Bt eggplant technology in Indian agriculture are analyzed. Several proprietary Bt hybrids are likely to be commercialized in the near future. Based on field trial data, it is shown that the technology can significantly reduce insecticide applications and increase effective yields. Comprehensive farm-survey data are used to project farm-level effects and future adoption rates. Simulations show that the aggregate economic surplus gains of Bt hybrids could be around US$108 million per year. Consumers will capture a large share of these gains, but farmers and the innovating company will benefit too. As the company has also shared its technology with the public sector, Bt open-pollinated varieties might become available with a certain time lag. This would make the technology more accessible, especially for resource-poor farmers, entailing further improvements in welfare and distribution effects. The wider implications of the private–public technology transfer are discussed. Furthermore, the potential benefits for farmers' health resulting from reduced insecticide applications are examined, using an econometric model and a cost-of-illness approach. These benefits are worth an additional $3–4 million per year, yet they constitute only a small fraction of the technology's environmental and health externalities. More research is needed for comprehensive impact analysis.     

Measuring rural consumers’ willingness to pay for quality labels using experimental auctions: the case of aflatoxin‐free maize in Kenya

Aflatoxins are a common health hazard in tropical countries, especially in rural areas. New methods to reduce aflatoxin levels in food staples, as well as cheaper test methods, are being developed, but consumers’ willingness to pay (WTP) for these improvements is unknown. A survey was conducted with a representative sample of rural consumers (1,344 in total, 63% women) in all major maize‐production zones of Kenya. The survey included an experimental auction with maize products of different qualities. The results showed that many rural consumers were aware of aflatoxins, but few understood their health risks. Respondents were willing to pay a premium for maize tested for aflatoxins and labeled, but asked a high discount for maize that was visibly contaminated with moldy grain. The premium was higher for respondents with education and in regions with aflatoxicosis outbreaks. Knowledge of aflatoxins substantially reduced the overall WTP, but did not increase the WTP for tested maize. Welfare analysis indicates that mandatory testing would result in substantial benefits if the cost of testing can be lowered to below the premium.     

水果和蔬菜中农药残留检测技术研究进展

随着生活质量的不断提高,人们对食品安全的关注度也越来越高,要使果蔬等农副产品的安全性得到保证,需要对其农药残留状况进行全面监管。本文从农药残留检测发展现状入手,对涉及的检测技术及果蔬安全管控相关建议进行全面研究,明确果蔬农药残留检测技术的重要性,进而为打造绿色无公害农副产品提供助力。     

Estimating consumer willingness to pay for food quality with experimental auctions: the case of yellow versus fortified maize meal in Kenya

Biofortification of maize with provitamin A carotenoids is a new approach to the alleviation of vitamin A deficiencies in Africa. Unfortunately these varieties are yellow or orange, while consumers generally prefer white. Consumer willingness to pay for yellow and fortified maize was compared in experimental auctions in three regions in Kenya. The premium that consumers are willing pay for fortified maize (24%) was higher than the discount they require to buy yellow maize (11%), and in one zone consumers prefer yellow. Yellow color is, therefore, not an impossible obstacle for biofortified maize, although it would clearly be easier to introduce this maize first in regions where yellow maize is currently grown.     

Consumer Willingness to Pay for Low-Pesticide Fresh Produce in Taiwan

Willingness to pay (WTP) for reductions in health risk associated with consuming pesticide residues on vegetables are estimated using the contingent valuation method with in-person interviews of married females in Taiwan. Estimated median WTP for 25 per cent, 50 per cent and 90 per cent reductions in the risk of developing cancer from consuming pesticide residues on a popular Taiwanese vegetable, bok choy, are estimated as 46 per cent, 56 per cent and 75 per cent of the current price of bok choy, respectively. WTP is significantly related to the scope or magnitude of the risk reduction, although it varies less than proportionately to the risk increment. WTP is also significantly related to measures of consumer preferences for health.     

鲜切果蔬保鲜技术研究进展

鲜切果蔬因其丰富的营养,新鲜、方便的特性广受消费者欢迎,然而鲜切果蔬在加工、贮藏、销售等过程中,由于机械损伤、自身生理作用、微生物的侵染等因素易导致其变质衰老的进程加快,影响产品的货架期。本文从物理、化学、生物及果蔬贮藏新技术等方面论述了鲜切果蔬的保鲜技术,以期为今后鲜切果蔬的加工与生产提供理论依据与参考。     

The Adoption of Genetically Modified Cotton and Poverty Reduction in Pakistan

This article employs a propensity score‐matching approach to examine the direct effects of adoption of Bacillus thuringiensis (Bt) cotton on yields, pesticide demand, household income and poverty, using cross‐sectional data from a survey of farmers in the Punjab province of Pakistan. Generally, the findings reveal that adoption of the new technology exerts a positive and significant impact on cotton yields, household income and poverty reduction, and a negative effect on the use of pesticides. The positive and significant impact of the technology on yields and household income is consistent with the potential role of new agricultural technology in directly reducing rural poverty through increased farm household income.