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Open access

G. H. Sullivan and G. E. Wilcox

Abstract

Analysis of costs of tomatoes for processing indicated savings from direct seeding as compared to transplanting. Total production costs for direct seeding averaged $17.34 per acre, or 11% less than for transplanting operations, excluding potential returns from increased useable yields under direct seeding.

Open access

G. E. Wilcox and G. H. Sullivan

Abstract

Cost budgeting methods were used to determine harvesting costs and net returns under hand, combination, and mechanized harvest operations. Mechanized harvest methods generated the highest net return potentials for growers. Gross receipts per unit area, required to break even, were significantly lower under mechanized harvest operations. Net returns per unit of area for hand harvest and combination harvest were similar.

Open access

G. E. Wilcox and P. E. Johnson

Abstract

An integrated tomato seedling system was developed by assembling components to regulate plant population, apply starter fertilizer, and promote seedling emergence. Plant population was regulated by the release of 4-7 seeds per clump at the desired spacing in the row. Starter fertilizer was sprayed on the seed as a 2-3-0, N-P-K (2-7-0 oxide form) solution at 500 ml per 30 m (1 pint per 100 ft) of row. An anticrustant was applied into the seed furrow and firmed by a press wheel with a concave surface. The system was adapted to several commercial seeders and enabled the establishment of dependable stands on soils with crusting tendencies.

Open access

Jose R. Magalhaes and G. E. Wilcox

Abstract

Tomato plants ‘Campbell 1327’ grown in peat with NH4 nutrition had no visible symptoms of NH4 toxicity, while severe symptoms of NH4 toxicity were displayed in solution or sand culture. Growth of plants was much better with NO3-N than NH4-N in sand, vermiculite, or solution culture; but in peat, growth of NH4-treated plants equalled or exceeded that of NO3-treated plants in sand, vermiculite, and peat. The total dry weight of NH4-treated plants grown in peat was 2, 2.5, and 3.4 times higher than plants grown in vermiculite, sand, and solution culture, respectively. Content of uncomplexed ASHS.109.3.406 in NH4-treated plants grown in peat was reduced markedly compared with other media. NH4-treated plants grown in sand, vermiculite, and solution culture, displaying NH4 toxicity symptoms, had a total amino acid:free NH4 + molar ratio < 2, compared to 6-8 with NO3. For NH4-treated plants grown in peat the ratio was similar to that of NO3-treated plants. Asparagine and glutamine in NH4-treated plants grown in peat were 3.5 and 11.3 times higher than with NO3-N, indicating a high efficiency in detoxification of NH4 through incorporation into these amino acids. The medium on which a plant is grown can have a marked influence on the plant response to N form.

Open access

S. C. Mason and G. E. Wilcox

Abstract

Recently matured whole leaves of tomato Lycopersicon esculentum Mill cvs. Centennial and Knox) gave the most reliable indication of total N, while NO3-N in older mature leaf petioles better reflected N availability and absorption. The NO3-N content of petioles was more indicative of N status of the plant than total N analysis of whole leaves. The NO3-N and total N contents of leaf parts generally decreased with increasing maturity. Soil solution NO3-N concentration increased exponentially with increasing N application rates. The first 45 kg N/ha increments increased soil solution NO3-N concentration only 10 ppm whereas the fourth 45 kg N/ha increment increased NO3-N concentration 40 ppm. Ninety kg N/ha application produced a concentration of 48 ppm NO3-N that resulted in a nearly maximum petiole concentration of 14,500 ppm NO3-N, indicating that this NO3-N concentration provided sufficient available N for the immediate reserve requirements for plant growth.

Open access

H. C. Dostal and G. E. Wilcox

Abstract

Total yield and percentage of ripe tomato fruit were significantly increased following single foliar applications of 0.84 lb. per acre (2-chloroethyl)phosphonic acid (ethephon). Maximum responses were noted at 14 days after treatment. Three tomato cultivars seeded on 3 dates responded similarly. Seventeen days after ethephon application at the 15 percent ripe fruit stage, useable ripe fruit yield was increased to more than 90 percent of the total fruit yield, compared to 59 percent useable ripe fruit for the control. The application of ethephon advanced harvest by 12 to 14 days, with an increase in useable ripe fruit yield of 5 to 10 tons per acre over the optimum potential of the normal ripening rate for single-harvest culture.

Open access

G. H. Sullivan, R. Y. Uyeshiro, and G. E. Wilcox

Abstract

Traditional methods of bulk handling mechanically harvested tomatoes in pallet bins were compared with handling in bulk trailer units. Substantially greater cost reduction resulted from the bulk trailer system; costs per ton to handle and transport mechanically harvested tomatoes in pallet bins averaged $4.59 compared to $1.86 under the bulk trailer system. Additional savings were realized from utilization of the equipment in the bulk trailer system with more than 1 mechanical harvesting unit.

Open access

J. E. Hoff and G. E. Wilcox

Abstract

Tomato fruit accumulated nitrate when the controlled environmental conditions combined high temperature, high N fertilization level, and low light intensity. Nitrate accumulation in the fruit was preceded by a condition of low nitrate reductase activity and nitrate accumulation in the leaves. The processed product with high concentration of nitrate caused extensive detinning of internal can surfaces after 6 months’ storage at room temperature.

Open access

G. E. Wilcox, C. A. Mitchell, and J. E. Hoff

Abstract

A shift from NO3 to NH4-N nutrition for tomato (Lycopersicon esculentum Mill.) plants resulted in a significant decrease in xylem exudation rate within 15 minutes. Ammonium treatment also decreased Ca and Mg concentration in exudate in the 1.5 to 2.5 hour interval after the shift, whereas free NH4 and amides increased in the same period. Potassium ion concentration did not change in the time interval from 15 minutes to 7 days following the change of N form. Reduced exudate concentration or reduced exudation rate resulted in large decreases in the total amount of K, Ca, and Mg delivered in the presence of NH4 relative to that of NO3, and offers a possible explanation for the observed deficiencies of these cations in shoot tissues of plants under conditions of NH4 toxicity.

Open access

J. E. Hoff, G. E. Wilcox, and C. M. Jones

Abstract

The N form had a pronounced effect on the levels of free amino acids. When compared to NO3, NH4 brought about a several fold increase in free amino acids (dry basis) in the roots, while smaller increases were observed in mature, fully expanded leaves, in young growing leaves, and in tomato fruit. Plants fed a combination of the 2 N forms had intermediate levels. The pattern of response to NH4 indicated that aspartic and glutamic acids as well as their amides were predominantly snythesized in the roots when the N source was NH4. The site of synthesis shifted to the leaves when the N source was NO3. The amino acids arginine, serine, alanine, and γ-aminobutyric acid were predominantly synthesized in the leaves irrespective of N form. Topical application of Ca on fruit grown with NH4 resulted in amino acid levels in the fruit similar to those of NO3 fruit. Ammonium toxicity was found to be accompanied by large increases in the levels of GABA and serine in the leaves. It is suggested that ammonium toxicity is a manifestation of intracellular Ca deficiency.