小麦储藏期霉菌活动监测技术进展

小麦是我国最主要的粮食品种,且相对于其他大宗粮食品种,小麦在储藏期间更易滋长霉菌。储藏期霉菌活动是小麦产后变质减损的主要原因之一,危害巨大。小麦储藏期霉菌活动监测对于小麦储藏安全、小麦及其制品食品安全具有重要价值。本文对小麦储藏期霉菌活动监测技术的进展进行了综述。     

留样盲测方法用于原粮质量控制的研究

本文检测了稻谷、玉米和小麦留样的水分及脂肪酸值,阐明了检测期间内留样水分及脂肪酸值的变化规律,探讨了采用留样盲测方法对原粮水分和脂肪酸值检测项目进行质量控制的有效性及适用性。研究结果表明：在温度20℃～25℃、相对湿度60％-80％的保管条件下,稻谷、玉米和小麦水分项目的留样盲测数值在60天的跟踪期均较稳定,适宜用该方法进行质量监控;而对于脂肪酸值检测项目,稻谷和玉米留样再测的有效期则分别缩短至50天和35天。     

Intra- and international commodity market integration in the Atlantic economy, 1800-1913

In this paper, the course of intra- and international market integration in the nineteenth century Atlantic economy is investigated. The most fundamental contribution of the paper is in consistently sketching the course of commodity market integration over the long run. Additionally, this study suggests that the nineteenth century has been somewhat misread in terms of the development of markets as the evidence, especially on price convergence, points to dramatic improvements in intra- and international market integration in the years prior to the mid-century. A collective task for economic historians, then, is to link these developments with the revolutionary commercial and technological developments of the post-1850 period.     

Wheat demand in Japanese flour milling industry: a production theory approach

A production approach based on the translog cost function is used to analyze import demand for wheat differentiated by class and country of origin in the Japanese wheat flour milling industry. Results indicate that US wheat faces strong competition in the Japanese wheat market, but its multiple classes and end‐use characteristics enable the US to preserve the largest market share in Japan.     

英国“20:20小麦”研究项目调查

2012年6月13日,英国洛桑研究所和英国生物技术与生物科学研究理事会联合发起了雄心勃勃的"20:20小麦"研究项目,计划在未来20年内,即到2032年,使英国的潜在粮食产量从目前的大约8 t/hm~2增至20 t/hm~2。实施"20:20小麦"项目可使小麦潜在产量最大化;可确定小麦根系吸水和养分的情况,以提高小麦光合作用的效率;可对作物进行改良。洛桑研究所是英国最大的农业研究中心,有得天独厚的试验条件和世界领先的研究技术,并注重国际合作和开放创新。期望通过对"20:20小麦"研究项目的介绍,为我国农业科研提供参考和借鉴。     

The dilemma of cheap food and self-sufficiency: The case of wheat in Iran

Self-sufficiency in wheat has been one of the major goals of Iranian agricultural policies since the Revolution of 1979. Even so, the country failed to achieve this goal by the early 2000s, despite a satisfactory growth in wheat production. This paper addresses this failure and the political difficulties in introducing reforms that would reduce the need for import. First, the production and consumption of wheat are examined. The conclusion is that the cheap-bread policy has mainly been responsible for the imbalances between domestic supply and demand, and the continued reliance on wheat imports. Moreover, the paper argues that the subsidy program is an expensive safety net for the needy and shows that the Iranian government has intended to reform the program since the early 1990s. However, subsidy reforms are politically sensitive, especially in developing countries where subsidies are considered very important, both for supporting the poor and for political stability. An analysis of the Iranian attempts at subsidy reform suggests that they have not yet succeeded, mainly due to such political considerations.     

National and international market integration in the 19th century: Evidence from comovement

This paper analyzes relative wheat price fluctuations to investigate market integration among 72 European and US cities. Applying a Dynamic Factor Model, which has seldom been used in market integration analysis, prices are decomposed into international, national and local components. Thus, national and international market integration are identified by a statistical restriction, and results for each single market are obtained. The first result is that globalization has accelerated faster in the first than in the second half of the 19th century, putting the post-1850 transport revolution into perspective. The USA integrated only later into the European market, discounting the role of the “grain invasion” for trade history. I also show that the European nations that turned protectionist after 1880 reduced the impact of foreign shocks, while free traders fully integrated into the international economy.     

Do wheat futures returns exhibit long‐range dependence?

The efficient market hypothesis, where asset prices follow a random walk and incorporate all relevant information, is often invoked in financial economics. There is some evidence however to suggest that some asset prices do not follow random walks but display long‐range dependence. Such systematic behavior of past returns is of interest to traders. This article examines long‐range dependence in wheat futures prices using rescaled range analysis and the Hurst exponent. Since this estimate is biased when long‐range dependence is absent and its distribution is unknown, a Monte Carlo simulation approach is proposed. Results show that wheat futures prices show no evidence of long‐range dependence and there are no profitable trading rules.     

Input and output technical efficiencies of wheat production in Kerman, Iran

The Iranian government encourages farmers to produce wheat (a common agricultural enterprise) by increasing farm productivity and efficiency. In this paper, using a Cobb–Douglas frontier production function, a simple relationship between a farm‐level output‐based technical efficiency measure (the Timmer index) and an input‐based measure (the Kopp index) is first developed. Then, using 1995 data from 164 farms in Kerman province, Iran, the average Timmer and Kopp indexes were estimated at 0.93 and 0.91, respectively, and were found to be similarly affected by farm size (positively up to about 9 ha) and by input ratios, though with rather small explanatory power. Thus, there seems some but limited scope to increase the profitability of Iranian wheat production either by increasing the product, given input levels, or by decreasing inputs for the current level of wheat production. However, since wheat producers may be able to adapt their production process more easily and quickly by implementing new techniques, i.e. by more efficient combination of inputs, than by adopting new technology, correction of input over‐use can be regarded as a policy with speedy if limited effect in this case.