Thomas F. Morris

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High nitrate (NO3-N) concentrations in Iowa rivers have been linked to areas of intensive row crop production, but they have not been experimentally linked to specific management practices used during row crop production. This study demonstrates how the late-spring test for soil NO3-N and the end-of-season test for cornstalk NO3-N can be used to measure N(More)
The rate of follicular development in hens was assessed by measuring the increase in the diameter of follicles during 120 h before ovulation and the mass of follicles during 48 h before ovulation. The rate of follicular maturation was estimated by the ovulatory response of follicles to an injection of GnRH and the ability of follicles to produce(More)
Concentrations of metals in the tissues of the sharks Callorhinchus capensis, Rhinobatos annulatus and Rhinobatos blochii collected in False Bay and Saldanha Bay, South Africa, in 2013 were investigated. Metal concentrations in the tissue of the parasites Gyrocotyle plana infecting the spiral intestine of C. capensis and Proleptus obtusus infecting the(More)
Discussions of N fertilizer needs for corn (Zea mays L.) usually are based on the assumption that economic optimum rates (EORs) of N provide the best benchmark to indicate the rates most likely to maximize profits for producers. We describe methods for calculating some additional benchmarks and illustrate how efforts to improve N management could be(More)
5-geranoxypsoralen (Bergamottin) does not photosensitize bacteria or a bacterial virus. It does, however, photosensitize mammalian cells in tissue culture. Irradiation with either black light (300-400 nm) or fluorescent ceiling lights produced at least four photobiologically active degradation products, the chemical nature of which still remains to be(More)
Trapping results indicate that pepper maggot, Zonosemata electa (Say), flies occupy tree canopies adjacent to fields when not on host plants. Several in- and near-field trap positions were used to find a reliable monitoring system for adult pepper maggots. Traps baited with liquid ammonium hydroxide (Stills-style trap), hung in the canopy of trees on the(More)
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