Widespread planting of transgenic insecticidal (TI) crops for pest control has raised concerns about potential harm to nontarget arthropods. Because the first generation of TI crops produce single Bacillus thuringiensis (Bt) toxins causing little or no harm to most nontarget arthropods, they are not likely to cause such negative effects. However, varieties of transgenic crops with multiple Bt t...

Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativ...

Rodents cause serious losses to crops in many different parts of the world. The house mouse (Mus domesticus, Schwarz and Schwarz 1943) is a serious pest to agriculture in Australia. The impacts of house mouse damage to crops in Australia were examined. Plagues of mice (>1,000 mice/ha) cause enormous economic and social stress to rural communities in Australia. The mouse plague in 1993/94 caused...

Aflatoxins are potent poisons that contaminate crops in warm regions worldwide and reduce health and economic welfare in several portions of Africa. Crops are contaminated in two phases: First, Aspergillus species infect crops during development; and second, after maturation contamination builds during exposure to warm humid conditions. Identification of the exact fungi causing contamination ca...

Contamination of crops with aflatoxin, a naturally occurring toxin produced by Aspergillus flavus and A. parasiticus, frequently reduces the value and marketability of crops. The selection of resistant germplasm has great potential to reduce this problem, but highly quantitative nature of the trait makes this a difficult endeavor. However, to derive commercial benefit from these resistance mark...

Does economic development depend on geographic endowments like temperate instead of tropical location, the ecological conditions shaping diseases, or an environment good for grains or certain cash crops? Or do these endowments of tropics, germs, and crops affect economic development only through institutions or policies? We test the endowment, institution, and policy views against each other us...

Regional crops distribution is an import subject for developing modern agriculture now. Based on existing distribution of 7 grain and oil crops in Sichuan province, this paper chose 5 economic evaluation indexes to discuss the regional distribution of grain and oil corps in Sichuan with the method of grey situation decision. According to the row decision and column decision, this paper shows th...

iii CHAPTER

BACKGROUND AND AIMS French wheat grains may be of little value on world markets because they have low and highly variable grain protein concentrations (GPC). This nitrogen-yield to yield ratio depends on crop nitrogen (N) fertilization as well as on crop capacity to use N, which is known to vary with climate and disease severity. Here an examination is made of the respective roles that N remobi...