nowadays, remote sensing comes under the title of management method for precision farming. for provision of the land cover and therefore land use map use must be made of satellite images. for an assessment of the type of agricultural crops it is required to have satellite images of high resolution. from specifications of the satellite images one is to produce maps with varied scales. in this re...

Rough set theory provides a systematic way for rule extraction, attribute reduction and knowledge classification in information systems. Some measurements are important in rough sets. For example, information entropy, knowledge dependency are useful in attribute reduction algorithms. This paper proposes the concepts of the lower and upper covering numbers to establish measurements in covering-b...

C hemical control methods against illicit drug crops in producer countries have long been a fixture of the 20-year U.S. war on drugs. In 1998, President Bill Clinton unveiled *an unprecedented $16 billion antidrug initiative that induded a generous allotment for applying herbicides to crops in drug-producing nations. The U.S. initiative follows protocols outlined in the 1988 United Nations (UN)...

One of the effective steps in use of water resources is accurate estimation of plants water requirement. Lack of accurate estimation of this amount leads to water loss and failure to achieve optimum yield, reduced potential of production, soil resources degradation by too much irrigation or lack of enough leaching and salinization of soils by irrigation less than necessary level, which would ul...

Chromosome organization and evolution in the Brassicaceae family was studied using comparative linkage mapping. A total of 160 mapped Arabidopsis thaliana DNA fragments identified 284 homologous loci covering 751 cM in Brassica nigra. The data support that modern diploid Brassica species are descended from a hexaploid ancestor, and that the A. thaliana genome is similar in structure and complex...

Vegetable production constitutes an important sub-sector of the agricultural economy of KwaZulu-Natal. Most vegetables are cultivated in mixed-cropping types of farming systems. The technical efficiency of vegetable based cropping systems was estimated in order to identify the potential increase in production without incurring additional costs. The factors affecting technical efficiency and con...

Long-term exposures to high ozone concentrations have harmful effect on the crops and reduce the yield. The exposures are measured in terms of AOT40 (Accumulated exposure Over Threshold of 40 ppb). The threshold of 40 ppb has been accepted after several years of experimental research in open top chambers throughout Europe. As a result of these experiments a critical level of 3000 ppb.hours has ...

Brassica napus is an economically important crop across different continents including temperate and subtropical regions in Europe, Canada, South Asia, China and Australia. Its widespread cultivation also brings setbacks as it plays host to fungal, oomycete and chytrid pathogens that can lead to serious yield loss. For sustainable crop production, identification of resistance (R) genes in B. na...

Over the last fifty years there has been a continual reduction in horticultural and agricultural biodiversity of nutritionally important plants, including those of the Solanaceae family. To add to this, the broad range of traditional crops, previously grown on a sustainable scale in some parts of the world, has been replaced by a narrow range of major crops grown as large-scale monocultures. In...