George B. Frisvold

Reducing the Risks of Herbicide Resistance: Best Management Practices and Recommendations

Herbicides are the foundation of weed control in commercial crop-production systems. However, herbicide-resistant (HR) weed populations are evolving rapidly as a natural response to selection pressure imposed by modern agricultural management activities. Mitigating the evolution of herbicide resistance depends on reducing selection through diversification of weed control techniques, minimizing the spread of resistance genes and genotypes via pollen or propagule dispersal, and eliminating additions of weed seed to the soil seedbank. Effective deployment of such a multifaceted approach will require shifting from the current concept of basing weed management on single-year economic thresholds.

Does supervision matter? Some hypothesis tests using Indian farm-level data

Abstract A model is developed and estimated to test for heterogeneity of family and hired labor in agricultural production and to estimate the impact of employer supervision on the productivity of hired labor. Plot-level data are used from a rice-growing village in semi-arid tropical India. The hypothesis that family and hired labor are homogeneous inputs was rejected. Results indicate that family member supervision is required to increase hired labor productivity. Output loss attributable to operating at reduced supervision intensity was greater than 10% on over 40% of the plots.

Fertilizers to support agricultural development in sub-Saharan Africa: what is needed and why

Abstract Substantial growth in inorganic fertilizer use is a prerequisite for sustained agricultural growth in sub-Saharan Africa. Increased fertilizer use can lead to modest but immediate and important increases in yields, while the profitability of other technologies will be stifled without adequate plant nutrients. Average fertilizer application rates in sub-Saharan Africa need to increase from 10 kg/ha to 50 kg/ha within 10 years to prevent mining of soil nutrients. That implies an 18% annual growth rate. This is substantially higher than trends in the region, but within a reasonable range of historically observed levels from other parts of the world. While over-use of fertilizers can create environmental problems, this is not a widespread problem in sub-Saharan Africa, and should not become one as a result of applying 50 kg/ha of inorganic fertilizers. Rather, near-term environmental concerns in agriculture in sub-Saharan Africa will stem from the lack of intensification. Farmer demand for fertilizers and the physical capacity to make fertilizers available are the two key issues that determine whether a 50-kg/ha goal will be attained. However, demand-side incentives cannot be separated from fertilizer supply possibilities. Several studies document that the simple physical availability of fertilizers to farmers, in the appropriate quantity, packages and at the appropriate time of year, remains a main constraint on increased fertilizer use in sub-Saharan Africa.

Economic Value of Biological Control in Integrated Pest Management of Managed Plant Systems

Biological control is an underlying pillar of integrated pest management, yet little focus has been placed on assigning economic value to this key ecosystem service. Setting biological control on a firm economic foundation would help to broaden its utility and adoption for sustainable crop protection. Here we discuss approaches and methods available for valuation of biological control of arthropod pests by arthropod natural enemies and summarize economic evaluations in classical, augmentative, and conservation biological control. Emphasis is placed on valuation of conservation biological control, which has received little attention. We identify some of the challenges of and opportunities for applying economics to biological control to advance integrated pest management. Interaction among diverse scientists and stakeholders will be required to measure the direct and indirect costs and benefits of biological control that will allow farmers and others to internalize the benefits that incentivize and accelerate adoption for private and public good.

Sources of agricultural productivity growth and stagnation in sub-Saharan Africa

This paper examines sources of agricultural growth in sub-Saharan Africa. Growth in the stock of traditional inputs (land, labor, livestock) remains the dominant source of output growth. Growth in modern input use was of secondary importance, but still accounted for a 0.2-0.4% annual growth rate in three of four sub-regions. Econometric results support earlier studies that suggest that land abundance may be a constraint on land productivity growth. Growth in agricultural exports and historic calorie availability had positive impacts on productivity. These latter results suggest that positive feedback effects exist between export performance and food security on one hand and agricultural productivity on the other.

Transboundary water management Game-theoretic lessons for projects on the US-Mexico border*

Of the twelve million people who live within 100 km of the US-Mexico border, 90 percent are clustered in trans boundary sister cities that share common water sources and pollution problems. New institutions created to address environmental concerns over NAFTA offer the promise of greater financial and technical assistance for water management in border cities. This paper reviews US-Mexico border water issues and institutions. Using insights from game theory, it draws policy lessons for institutions funding border water projects. We examine how the design of assistance programs, technical support, and pre-existing water rights and regulations affect project outcomes. The diversity and geographic dispersion of water conflicts suggests potential for applying the interconnected game approach to US-Mexico water negotiations.

Economic and Welfare Impacts of Climate Change on Developing Countries

The impact of global climate change on developing countries is analyzed using CGE-multimarket models for three archetype economies representing the poor cereal importing nations of Africa, Asia, and Latin America. The objective is to compare the effects of climate change on the macroeconomic performance, sectoral resource allocation, and household welfare across continents. Simulations help identify those underlying structural features of economies which are the primary determinants of differential impacts; these are suggestive of policy instruments to countervail undesirable effects. Results show that all these countries will potentially suffer income and production losses. However, Africa, with its low substitution possibilities between imported and domestic foods, fares worst in terms of income losses and the drop in consumption of low income households. Countervailing policies to mitigate negative effects should focus on integration in the international market and the production of food crops in Africa, and on the production of export crops in Latin America and Asia.

The convention on biological diversity and agriculture: Implications and unresolved debates1

Summary. - The Convention on Biological Diversity addresses two controversies that surround plant genetic resources (PGRs). One debate has been over property rights governing PGRs and the distribution of benefits from their use. The second has been over the adequacy of measures to maintain crop genetic diversity. This paper examines how these two debates are linked and reviews previous multilateral attempts to address them. The Convention signals wider international acceptance of stricter property rights over PGRs and the need for multilateral assistance for PGR conservation. However, current proposals to implement the Convention appear too limited in scope to achieve their stated conservation objectives, while several areas of controversy remain. These include debates over: (i) intellectual property protection for biological inventions; (ii) control over PGRs in international gene banks; (iii) the international biosafety protocol regulating biotechnology; (iv) mechanisms to finance PGR conservation; and (v) the allocation of funds between in situ and ex situ conservation. Q 1998 Elsevier Science Ltd. All rights reserved

Genetic improvements in major US crops: the size and distribution of benefits

The distribution of welfare gains of genetic improvements in major US crops is estimated using a world agricultural trade model. Multi-market welfare estimates were 75% larger than estimates based on the price-exogenous ‘change in revenue’ method frequently used by plant breeders. Annual benefits of these genetic improvements range from US

AIR POLLUTION AND FARM-LEVEL CROP YIELDS: AN EMPIRICAL ANALYSIS OF CORN AND SOYBEANS

400–600 million depending on the supply shift specification. Of this, 44–60% accrues to the US, 24–34% accrues to other developed countries. Developing and transitional economies capture 16–22% of the welfare gain. The global benefits of a one-time permanent increase in US yields are US