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  • Author or Editor: D. L. Coffey x
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Abstract

Catfacing on tomato fruit (Lycopersicon esculentum mill. cv. Manapal) was affected more by time of pruning than amount of pruning. Results indicated that a 2 stem, delayed pruning system produced a lower percentage of catfaced fruit than either 1 or 2 stem early pruning system. Catfacing rates in an unpruned system were equal to that of the delayed pruning system, but early marketable yields were depressed with the unpruned plants. Differences noted in vegetative characteristics, treatment response, and the nature of the deformity suggest that growth regulator balance may influence the formation of catfaced fruit

Open Access

Some chicory (Cichorium intybus L.) cultivars, especially early and extra-early cultivars, often bolt and flower the first year of growth, contrary to the expected behavior of biennials. The extra early hybrid cultivar `Daliva' was grown in the field under bare soil and straw mulched conditions to examine possible correlations between growth rates, leaf and root sizes and bolting. Plants, sown on 19 June, were harvested weekly from 4 July to 1 Oct.; a total of 14 harvests. Root variables of length and diameter were best described by linear equations but root dry weight was decidedly quadratic in response. Leaf number, area and dry weight and crown diameter data were fitted to the Richards function to describe their sigmoidal phases of growth. In most cases, when using the Richards function, the two treatments (mulch vs. no-mulch) required different parameters to fit a line to the observed points with r 2 values >0.95. A statistical comparison between treatment parameters (as obtained from SAS PROC NLIN and SigmaPlot) will be discussed.

Free access

Cabbage, tomatoes and broccoli were grown sequentially at three levels of N fertilization with or without black polyethylene mulch in 1988 and 1989. Urea-NH4NO3 at 136, 270 or 404 kg·ha-1 was applied preplant or in triweekly increments via drip irrigation. Economic returns were estimated from wholesale prices and production expenses. Crops receiving the medium and high N levels produced higher yields than those receiving the low N level. Nitrate concentrations in the soil corresponded to the levels applied and declined over the season. Yields of the first crop of the sequence (cabbage) were higher from preplant than from irrigation applied N. Yields of the second crop (tomatoes) were not affected by method of N application. Mulched plots produced higher yields than nonmulched plots. Soil nitrate concentrations were higher from mulched than from nonmulched plots but the rates of decline over the seasons were no different between mulched and nonmulched plots. Estimated net returns among all treatments varied from 20 to 30 and -9 to 5 thousand dollars per hectare in 1988 and 1989, respectively. Tomatoes contributed greatest to the estimated returns. Weather conditions and wholesale prices fluctuated widely between years.

Free access

Abstract

Six accessions of edible amaranths (Amaranthus spp. L.) of varied geographic and genotypic origin were grown in a soil enriched with 0, 50, or 100 kg·ha–1N. Leaves were harvested at 25, 35, 45, 55, and 65 days after germination (DAG) and analyzed for crude protein (CP), neutral detergent fiber (NDF), and NO3 N. In grain-bearing accessions, leaf CP content increased with N application but declined linearly over harvest dates. In vegetable types, leaf CP levels tended to fluctuate over time. In both types, NDF content declined with N application, whereas response to harvest date varied. Leaf NO3 increased two-fold in plants from fertilized plots compared to plants from unfertilized plots, but declined rapidly with time. Leaf content of NO3 did not exceed 239 mmol·kg–1 dry weight with any N fertilization treatment. Edible amaranth appeared to be adapted to soils and climate of the southeastern United States. A. tricolor was most susceptible to disease among the accessions evaluated.

Open Access

Studies were initiated in 1989 to characterize phonological events with corresponding growth and development phenomena of `Eagle' and `Provider' snap beans (Phaseolus vulgaris L.) Ten plantings at approximately 15 day intervals were made at Knoxville, TN from April 17 through July 27. Days to reach growth stages V0 thru R7 were recorded for each cultivar for each planting date. Air temperature, total radiant energy, wind speed and relative humidity were recorded hourly throughout the 171 day test period. Growing degree days (GDD) computed by 8 methods and growing degree hours (GDH) computed by 2 methods were regressed against plant developmental stages. GDD and GDH, along with pod size and pod fiber content, will be discussed as possible indices for predicting harvest maturity. With the methods used to calculate heat summation in this study, GDD and GDH from planting to pod maturity ranged from approximately 550 to 975 and 9,700 to 20,000, respectively.

Free access

Tomatoes and sweet corn grew and produced equally well under no-tillage and conventional tillage methods in 1989. Simulated rainfall was applied through an overhead irrigation system four times during the growing period with 2.8 cm of water applied during each event. Total solids in collected runoff water were higher with conventional tillage than with no-tillage. Residue levels of atrazine, metolachlor, mancozeb, esfenvalerate, metribuzin, and metalaxyl and concentrations of N, P, and K in runoff water were determined and varied with runoff event, pesticide, nutrient, crop, and tillage method.

Free access