The lead review “Risk assessment of genetically modified crops for nutrition and health” by Magaña-Gómez and Calderon de la Barca,1 ends with a common plea: “more research is needed”. It is valid to put both this plea and the justification for other similar research into perspective. How selective are the reviews that lead to the conclusion that more of such research is needed?What comparators ...

This study is an endeavor to evaluate statistically predicts a weather-crop yield-forecasting model to generate early crop production estimates. The weather-crop yield-forecasting model was applied to estimate prospective production of Aus rice in Jessore and Rajshahi districts of Bangladesh. This model is the relationship between the crop yield and input weather parameters influencing the crop...

drought stress is a major factor limiting crop production. investigation of physiological characteristics related to drought tolerance and crop production may be useful in selecting drought tolerant cultivars as well as in improving crop yield. two drought tolerant (azar2 & back cross roshan) and two drought susceptible (marvdast & shiraz) cultivars were investigated in both greenhouse and fiel...

Orthomosics and digital surface models (DSM) derived from aerial imagery, acquired by consumer-grade cameras, have the potential for crop type mapping. In this study, a novel method was proposed for extracting the crop height from DSM and for evaluating the orthomosics and crop height for the identification of crop types (mainly corn, cotton, and sorghum). The crop height was extracted by subtr...

Returning crop residue improves water conservation and storage, nutrient availability, and crop yields. We have little knowledge, however, of the residual impacts of crop residues on soil and crop production. We hypothesized that residual impacts of crop residues vary with the amount of residues used. A 10-yr study near Lincoln, NE, evaluated the residual effects of an earlier 8-yr study of var...

Conservation agriculture (CA) is promoted as a cropping system that has potential to alleviate poor crop yields in smallholder farming while protecting the environment. It involves maintenance of permanent soil cover, diverse crop rotations and/or interactions; and minimum soil disturbance. CA is associated with crop residue management challenges due to low crop biomass yields and crop-livestoc...

The next advance in field crop productivity will likely need to come from improving crop use efficiency of resources (e.g., light, water, and nitrogen), aspects of which are closely linked with overall crop photosynthetic efficiency. Progress in genetic manipulation of photosynthesis is confounded by uncertainties of consequences at crop level because of difficulties connecting across scales. C...

A with the introduction of many new With the development of automated weather station technologies, whether it be medical, mechanical, networks in the early 1980s, hourly values of temperaor Internet related, are promises; sometimes, too many ture, solar radiation, precipitation, relative humidity, promises are made about the potential capabilities of wind direction, and wind speed become avail...

Soil compaction is recognized as a yield limiting factor in crop production. Compaction problems continue to exist for several reasons, including; 1) the large size (mass) of agricultural vehicles; 2) increased operations on wet soils because of larger farm acreage and multi-axle driven equipment; and, 3) the lack of controlled traffic patterns in fields. Where compaction is identified as a pro...

The response of agriculture to changes in relative prices is an important factor in the success of structural adjustment programs in Africa. In this paper I estimate supply functions for total agricultural output, food crops and export crops in 14 African countries for the years 1975 to 1990. Food and export crops are substitutes in production in the short run. Total agricultural output respond...