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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
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.
`Packman' hybrid broccoli was grown under three tillage systems at three locations in 1989 and 1990 to study the feasibility of no-till production. Tillage systems consisted of 1) conventional tillage with no winter cover, 2) conventional tillage with wheat winter cover, and 3) no-till transplanted directly into paraquat-killed wheat cover. Locations were at Knoxville, Greeneville and Crossville, TN. Yield, value and marketability of broccoli were significantly reduced in no-till vs conventional tillage. The possibility that small grain cover crops have a deleterious effect on broccoli growth was then investigated. Broccoli was grown in greenhouse pots with solutions of ferulic, syringic, p-coumaric, p-hydroxybenzoic and vanillic acids at 1, 10, 100 and 1000 μM concentrations and compared to controls which received only water. Shoot dry weight and plant height were both reduced with increasing acid concentrations. Soil samples were taken from field plots in 1990 and analyzed for levels of these acids using HPLC. Soils with higher levels of mulch had higher levels of ferulic and p-coumaric acid, but similar levels of the other acids. Allelopathic effects of the cover crop is a potential cause of reduced broccoli yields under no-till conditions.
`Packman' hybrid broccoli was grown under three tillage systems at three locations in 1989 and 1990 to study the feasibility of no-till production. Tillage systems consisted of 1) conventional tillage with no winter cover, 2) conventional tillage with wheat winter cover, and 3) no-till transplanted directly into paraquat killed wheat cover. Locations were at Knoxville, Greeneville and Crossville, TN. Yield, value and marketability of broccoli was significantly reduced in no-till vs conventional tillages. The possibility that small grain cover crops have a deleterious effect on broccoli growth was then investigated. Broccoli was grown in greenhouse pots with solutions of ferulic, syringic, p-coumaric, p-hydroxybenzoic and vanillic acids at 1, 10, 100 and 1000 μM concentrations and compared to controls which received only water. Shoot dry weight and plant height were both reduced with increasing acid concentrations. Soil samples were taken from field plots in 1990 and analyzed for levels of these acids using HPLC. Soils with higher levels of mulch had higher levels of ferulic and p-coumaric acid, but similar levels of the other acids. Allelopathic effects of the cover crop is a potential cause of reduced broccoli yields under no-till conditions.
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.
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.
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.
Production of witloof chicory (Cichorium intybus) roots for chicons or for inulin is typically a northern U. S. or European enterprise. Although chicons (Belgian endive) command a high market price, nearly all are imported from Europe. If appropriate cultivars and optimum summer growing conditions can be identified, Tennessee's mild winters may permit relatively low cost forcing techniques. Studies with these objectives were initiated in 1992 at two locations using six cultivars, two planting dates and two within row plant densities. Root yields varied from 13 to 40 Mg·ha-1 between locations and among cultivars. Incidence of bolting was greater than 50% for the earliest maturing cultivar, `Daliva', but less than 5% for the late maturing cultivar, `Rinof', at the warmer experimental site (Knoxville, elev. 251m). No bolting of any cultivar occurred at the cooler experimental site (Crossville, elev. 549m). Data on yield and quality of forced chicons and nitrate content of edible leaf tissue will be presented.
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.