No description available.

The objective of this research was the selection of the most efficient arbuscular mycorrhizal (AM) fungus on pepper (Capsicum frutescens L. cv. North star) and sweet corn (Zea mays L. cv. Bicolor) growing under controlled and field conditions. The inoculum treatments consisted of 9 different AM inocula and an autoclaved mix of roots and sand used as a control. Plants were inoculated and planted in a pasteurized growth medium (greenhouse) and non-fumigated soil in 4 different field locations for each crop. Glomus intraradices (GinA) and both the same strain (GinA) and a mix of Sclerocysitis rubiformis and G. fasciculatum (Sru$+$) developed the highest AM colonization in sweet corn and pepper, respectively, under controlled conditions. However, no significant increases in growth were found compared with non-mycorrhizal plants. Only a mix of G. microagreggatum, G. mosseae and G. fasciculatum (Gmi+) produced a greater shoot dry mass compared with the control treatment in sweet corn under controlled conditions. None of the mycorrhizal strains used in the field experiments increased the growth of sweet corn or pepper compared with non-inoculated plants under field conditions.

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No description available.

The objectives of this study were to evaluate the effects of earlier corn (Zea mays L.) harvest, on corn yield, intercrop growth, and soil N levels, and to evaluate the effects of red clover (Trifolium pratense L.) compared to ryegrass (Lolium multiflorum Lam.) as intercrops on corn yield and soil N levels. / After two years, earlier corn harvest did not result in greater intercrop growth or higher soil N levels compared with later corn harvest and there was no significant soil N contribution by legume intercrops in either harvest period. Thus, no soil N benefit was found from using intercrops in earlier harvest for silage compared to later harvest for grain corn, nor from using red clover compared to ryegrass as an intercrop. / In the early harvested silage system, a quadratic corn yield response to added N suggested that near-maximum corn dry matter yields were obtained at the rate of 140 kg N ha$ sp{-1}$. Maximum total dry matter yields were not obtained in the late harvest grain system in any site-year. Legume and non-legume intercrop species had similar effects on corn yield.

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No description available.

No description available.

The potential of granular zeolites as a heating medium for drying corn was evaluated in a batch type experimental dryer. At temperatures from 150-250$ sp circ$C and residence times of 3-8 minutes, synthetic zeolites (4A and 13X) removed 9-18 percentage points from the initial moisture of corn. These values were about double those of sand, the most commonly used particulate medium. / Using an adiabatic dryer, the kinetics of moisture sorption in corn-zeolite mixtures was investigated. The heating medium in this part of the study was a natural zeolite (chabazite) and the corn was yellow dent type. Diffusivity values for corn were 1.012 $ times$ 10$ sp{-5}$ $-$ 3.127 $ times$ 10$ sp{-5}$ cm$ sp2$/s with zeolite at temperatures of 140-220$ sp circ$C. These values are much smaller than those for zeolite. Therefore, it is believed that the diffusion of moisture in corn itself is the main resistance to the transfer of moisture. The heat transfer coefficient between corn and zeolite was found to be in the range of 50-312 W/m$ sp2 cdot$K. Luikov's model for simultaneous heat and mass transfer was applied to corn-zeolite mixtures and the equations were solved by the Numerical Method of Lines (NMOL). These numerical solutions agreed closely with the experimental data. / The processed corn was subjected to in vivo and chemical analyses. Results of feeding experiments using laboratory rats did not indicate that the nutritive quality of the processed corn was adversely affected. Similarly, the acid detergent fibre analysis did not show a significant reduction in the availability of corn protein.

Transcription in mammalian and yeast mitochondria proceeds from a few well defined promoters, with processing of polycistronic transcripts producing the mature RNAs. The levels of different sequences in the steady-state RNA populations depend on differential promoter strengths, transcription attenuation and/or selective termination, and differential RNA stabilities. To gain insights into the processes governing transcription and RNA levels in plant mitochondria, a system using isolated maize mitochondria, which synthesize bona fide mitochondrial RNAs, was developed and partially characterized with respect to exogenous requirements and sensitivity to inhibitors of DNA-dependent RNA synthesis. / Although initiation and processing probably occur at reduced levels in isolated maize mitochondria, endogenous DNA templates are extensively transcribed at the same relative rates as in vivo. Isolated maize mitochondria were used to demonstrate that differential rates of both synthesis and turnover help determine the steady-state abundances of various mitochondrial RNA sequences and that mitochondria from certain lines possess an autonomously-replicating, RNA-based genetic system.