Impact of global warming on Chinese wheat productivity:

"Climate change continues to have major impact on crop productivity all over the world. While many researchers have evaluated the possible impact of global warming on crop yields using mainly indirect crop simulation models, there are relatively few direct assessments on the impact of observed climate change on past crop yield and growth. We use a 1979-2000 Chinese crop-specific panel dataset to investigate the climate impact on Chinese wheat yield growth. We find that a 1 percent increase in wheat growing season temperature reduces wheat yields by about 0.3 percent. This negative impact is less severe than those reported in other regions. Rising temperature over the past two decades accounts for a 2.4 percent decline in wheat yields in China while the majority of the wheat yield growth, 75 percent, comes from increased use of physical inputs. We emphasize the necessity of including such major influencing factors as physical inputs into the crop yield-climate function in order to have an accurate estimation of climate impact on crop yields." Authors' AbstractGlobal warming, Climate, Wheat production,

The Impact of the Kansas Wheat Breeding Program on Wheat Yields, 1911–2006

This paper quantifies advances of the Kansas Agricultural Experiment Station (KAES) wheat breeding program for two time periods: (1) 1911 to 2006 and (2) 1977 to 2006. Using multiple regression, increases in yields of wheat varieties grown in Kansas are quantified, holding growing conditions and other improvements in productivity constant. Differences in KAES variety yields and those released by other public and private breeders are quantified. During the ‘‘new age’’ of wheat breeding (1977–2006), wheat breeding alone is found to have increased yields by 6.182 bushels per acre, or an average increase of 0.206 bushels per year.wheat yield, public wheat breeding, multiplicative heteroscedasticity, economic impact of technological change, Agribusiness, Farm Management, O13, Q16,

Modeling agricultural production risk and the adaptation to climate change

A model that integrates biophysical simulations in an economic model is used to analyze the impact of climate change on crop production. The biophysical model simulates future plant-management-climate relationships and the economic model simulates farmers' adaptation actions to climate change using a nonlinear programming approach. Beyond the development of average yields, special attention is devoted to the impact of climate change on crop yield variability. This study analyzes corn and winter wheat production on the Swiss Plateau with respect to climate change scenarios that cover the period of 2030-2050. In our model, adaptation options such as changes in seeding dates, changes in production intensity and the adoption of irrigation farming are considered. Different scenarios of climate change, output prices and farmers' risk aversion are applied in order to show the sensitivity of adaptation strategies and crop yields, respectively, on these factors. Our results show that adaptation actions, yields and yield variation highly depend on both climate change and output prices. The sensitivity of adaptation options and yields, respectively, to prices and risk aversion for winter wheat is much lower than for corn because of different growing periods. In general, our results show that both corn and winter wheat yields increase in the next decades. In contrast to other studies, we find the coefficient of variation of corn and winter wheat yields to decrease. We therefore conclude that simple adaptation measures are sufficient to take advantage of climate change in Swiss crop farming.climate change, robust estimation, yield variation, corn, winter wheat, market liberalization, Environmental Economics and Policy, Production Economics, Risk and Uncertainty,

ECONOMICS OF WHEAT-FALLOW CROPPING SYSTEMS IN WESTERN NORTH DAKOTA

Income and risk aspects of wheat-fallow cropping systems are analyzed in western North Dakota. A wheat yield trend estimation model based on county yields (1950-77) is developed using independent variables of year, annual precipitation, acres of nonfallowed wheat and a dummy variable for fallow and nonfallow practices. The year-to-year change in wheat yields on fallowed and nonfallowed land indicates that summer fallow is becoming less desirable economically. Based on 1980 costs and yields, summer fallow maximizes returns to land at low yields, low wheat prices, and high nitrogen prices. Income variability is reduced under summer fallow.Crop Production/Industries,

Factors Influencing Wheat Yield and Variability: Evidence from Manitoba, Canada

Production functions to explain regional wheat yields have not been studied extensively in the Canadian prairies. The objective of this study is to employ a Just-Pope production function to examine the relationship between fertilizer inputs, soil quality, biodiversity indicators, cultivars qualifying for Plant Breeders’ Rights (PBR), and climatic conditions on the mean and variance of spring wheat yields. Using regional-level wheat data from Manitoba, Canada, model results show nitrogen fertilizer, temporal diversity, and PBR wheat cultivars are associated with increased yield variance. Mean wheat yield is reduced by the proportion of land in wheat, the interaction of growing temperature and precipitation, and spatial diversity. By contrast, higher soil quality and PBR wheat cultivars increase mean yield. The wheat yield increases attributed to PBR range from 37.2 (1.4%) to 54.5 kg/ha (2.0%). Plant Breeders’ Rights may have enhanced royalties from increased certified seed sales, but the benefits in terms of higher wheat yield or lower yield variability are limited. Future research is required to understand the interactive effects of fertilization practices, genetic diversity, and environmental conditions on regional wheat yield stability.climate, fertilizer, Manitoba, Plant Breeders’ Rights, production risk, wheat, yield, Agribusiness, Crop Production/Industries, Farm Management, Land Economics/Use, Productivity Analysis, Risk and Uncertainty, O18, Q16,

Sources of Productivity Growth in Wheat: A Review of Recent Performance and Medium- to Long-Term Prospects

Sources of yield growth in wheat are investigated based on a stylized framework of technical change. Evidence suggests that the relative contribution of input intensification to yield growth has diminished in recent years and is likely to continue to decline in the future. One potential source of yield growth in wheat during the medium to long term is improved efficiency of input use, rather than input intensification, through sustainable wheat production practices rather than pure input increases. Other large gains could be made with continuous adoption of newer and better modern varieties based on advances in wheat breeding. Wide crossing and biotechnology could improve the stability of wheat yields in the intermediate term; their long-term impact on yield under optimal conditions is less certain. World wheat demand is likely to grow more slowly over the next 30 years than it did in the past 30 years. At the same time, a wider variety of technological options will need to be tapped over the next three decades to achieve the necessary gains in wheat yields. Research costs per unit of increased wheat production are likely to be somewhat higher. Nonetheless, continued investment in wheat research is necessary to achieve production levels consistent with constant or slowly declining real world wheat prices.Crop Production/Industries,

Adjustment of wheat production to market reform in Egypt

In response to slow growth in the agricultural sector and as part of a general shift towards a more market-oriented economy, the Government of Egypt started liberalizing the agricultural sector in 1987. Controls over wheat production and marketing were eliminated and wheat producer prices were brought closer to international levels. As a result, there has been remarkable increases in wheat crop area and yields, causing wheat production to triple from 1986 to 1998. This study analyzes the results of a survey of 800 Egyptian wheat farmers in order to address three issues that are of interest to agricultural reform policy in Egypt. First, what are the patterns in wheat production and marketing that have emerged following the economic reforms? Second, why is the government unable to purchase more than a small portion of national wheat production? Third, how does wheat supply and input demand respond to wheat and input prices? The survey indicates that Egyptian wheat production is based on small-scale farms, yet these farms are highly commercialized and the use of inputs such as labor, fertilizer and irrigation, is intensive. The government has problems reaching its wheat procurement target because most of the wheat produced is consumed in the rural areas and farmers prefer to sell to traders because of better prices and location. Econometric analysis of the survey data suggests that wheat farmers respond significantly to crop and input prices. The estimated own-price supply elasticity is 0.3, implying that the use of price policy alone to pursue wheat self-sufficiency would be costly and ill-advised.Small farmers. ,Wheat Yields Egypt. ,Econometrics. ,Agricultural policy Egypt. ,

Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening

peer-reviewedThis study involved an evaluation of the changes in grain yield, nutritive value, ensilability and harvesting losses of intensively managed winter cereals harvested during the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv. Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002) were assessed. Twenty plots per crop were arranged in a randomised complete block design, with five times of harvest (four for barley in 2002) and four replicate blocks per harvest. Dry matter (DM) yields changed relatively little between harvest dates, but fresh yields declined (P < 0.001) over time due to the moisture loss associated with ripening. Time-course changes in indices of nutritive value, such as concentrations of crude protein, starch and ash, and organic matter digestibility, were relatively small and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble carbohydrate concentrations and buffering capacity, indicated that satisfactory fermentations were likely if such crops were ensiled; buffering capacity, generally declining with advancing maturity. Harvesting losses were not clearly related to growth stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale) DM yields and quality were relatively constant as ripening progressed from DM concentrations of around 550 to >800 g/kg.One of the authors (P.S.) was in receipt of a Teagasc Walsh Fellowship

Proportion of common wheat kernels in commercial samples of durum wheat by chemical methods

Durum wheat (Triticum durum Desf.) is used for production of semolina which is the required raw material for the elaboration of good quality pasta products. Common wheat (T. aestivum L,)t generally used in breadmaking, yields milling products (flour or fariña) that are not suitable for that purpose. Shortage and localization of durum wheat production, as well as its higher cost, have compelled the utilization of common wheat for the production of macaroni. When different blends of hérd or soft wheat (fariña or flour) with durum wheat are used, the quality of macaroni is reduced. Por this reason, the estimation of common wheat in pasta products is an important problem from the point of view of quality and market control, Chemical methods for detection and estimation of common wheat in pasta products have been developed in this laboratory during the past six years. The related problem of estimating the proportion of common wheat kernels in commercial samples of durum wheat has been traditionally solved either by niorphológica1 examination or by cytogenetical methods. The former are too unreliable and the latter too cumbersome, In this paper, we have reviewed the above mentioned chemical methods and investigated their application to the analysis of single kernels and the estimation of the proportion of common wheat kernels in commercial samples of durum wheat in order to avoid the cytogenetical methods or to confirm the morphological examination