Showing papers by "International Potato Center published in 1994"

Pesticide Use and Farm Worker Health in Ecuadorian Potato Production

Abstract: Potatoes are a dietary staple in Ecuador as they have been for thousands of years. In 1992, about 50,000 hectares of potatoes were grown in Ecuador, mostly by small farmers. Almost all potato farmers in Ecuador rely on chemical fertilizers and pesticides to increase yields. Potato farmers are perceived as overusing pesticides, both in quantity and quality, with mixtures of chemicals, known locally as cocktails, being the favored form of application. As in many other countries, there is growing popular concern about the environmental and health impacts of agricultural chemical use. Residue testing on fresh vegetables in Ecuador found levels above those recommended by the FAO-WHO food safety guide, Codex Alimentarius. Human poisoning data were slowly accumulated during the 1980s after pesticide poisoning became a notifiable illness under the public health surveillance system. Focused surveys found widespread ignorance of the symptoms of pesticide poisoning and little use of personal protective equipment among farmers and farmworkers. With the widespread use of backpack sprayers (versus tractor or aerial application in developed countries), these groups are most likely to be at risk of excessive exposure. The research results presented here are from a case study to assess impacts of pesticide use in potato production. This case study follows methodological guidelines laid out by Antle and Capalbo to quantify the interaction between production technology, environmental quality, and human health. Two adjacent watersheds totaling about 150 kilometers in Montufar Canton in Carchi Province in a cool moist highland zone in northern Ecuador served as the case

The effect of using a Horsfall‐Barratt scale on precision and accuracy of visual estimation of potato late blight severity in the field

Abstract: Assessments of potato late blight severity by eleven people using directly estimated percentage severity (EPS) of potato late blight caused by Phytophthora infestans were compared with the assessments of another group of ten people using a Horsfall-Barratt scale with wider intervals in the mid range of severity (25-75% infection). This scale is frequently used at the International Potato Center (CIP) to select for resistant germplasm. EPS readings had greater variability among assessors at mid range of severity than at extremes, as predicted by Horsfall and Barratt (1945). Transformation of EPS to CIP scale units or logits corrected uneven variances. Direct utilization of the CIP scale in the field, however, did not correct uneven variances. This may have been due in part to subconscious linearization of scale intervals, which are based on logarithms. Direct comparisons made by converting EPS to CIP scale levels demonstrated that precision and accuracy were greater among assessors using EPS.

Child anthropometry and mortality in Malawi: testing for effect modification by age and length of follow-up and confounding by socioeconomic factors.

Abstract: The author has previously shown in a review of 28 studies that anthropometric measurements of preschool-aged children are consistently related to the risk of subsequent mortality in community-based studies from Asia and Africa. A number of questions however remain about the relationship. This study was therefore conducted to address two of the questions using data from a similar study in rural northern Malawi. First in relation to screening are the anthropometry-mortality relationships affected by childs age and the interval between measurement and death and second in relation to policy is the anthropometry-mortality relationship due to confounding by socioeconomic factors especially when considering mild to moderate malnutrition? The authors find that mortality prediction is significantly affected by childs age and length of follow-up but the strength and direction of the effect modification varies across the four commonly used anthropometric indicators of weight-for-age height-for-age weight-for-height and arm circumference-for-age. There are no statistically significant differences in prediction across the four indicators when applied to children aged 6-23 months and employing a one-year follow-up period. As for confounding the study found the anthropometry-mortality relationship to not be due to socioeconomic factors when all grades of malnutrition are considered.

Diploid potato germplasm derived from wild and land race genetic resources

Abstract: Diploid cultivated species, haploids derived from tetraploid cultivars, and their wildSolanum relatives were used to generate various diploid potato genetic stocks. These stocks have significant value in potato breeding because: 1) genetic diversity in the potato population can be kept variable with the diploid germplasm which confers genetic variation from wild and cultivated species; 2) crossability of this diploid germplasm is facilitated by the function of 2n gametes; and 3) high levels of pest resistances originating from the process of introgression of the wild and cultivated genetic resources can be used to improve the tetraploid cultivated potato genepool.

A case for setting common objectives for natural resource management

Abstract: The payoffs from developing a more accurate objective for NRM are likely to increase as scientists enhance their ability to improve the accuracy of natural resource models and simulations. Better definitions of objectives will also help policymakers and researchers work more effectively in widely different ecologies and with different natural resource user groups.

Bulk pollen extraction procedures and the potency of the extracted pollen

Abstract: Three methods of bulk extraction of potato pollen were compared for their efficiency and for the potency of extracted pollen in affecting berry set, seeds/berry and 100 seed weight. Extracting pollen from pre-dried anthers using a sieve of nylon netting with 1 mm perforations was the most economical with respect to time, labour and cost of equipment and that would be applicable for commercial production of hybrid TPS.