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Early spring sweet corn (Zea mays var. rugosa) is usually planted in cold soils at sub-optimal temperatures for seed germination. It is important for growers to understand the relationships among temperature, germination, and vigor of sweet corn in order to plan the earliest planting dates that will not significantly reduce plant stand. The objectives of this research were 1) to determine the minimum temperatures to germinate to 75%, (the minimum germination percent for interstate commerce) for 27 new sweet corn su (sugary), se (sugar enhancer), and sh₂ (shrunken-2) cultivars; 2) to determine vigor differences among the phenotypes; and 3) to select the most promising se, su, and sh₂ cultivars for cold tolerance and vigor for early spring planting. Seeds of each cultivar were placed along a temperature gradient on a thermogradient table, Type 5001 (Seed Processing Holland, Enkhuizen, The Netherlands), and allowed to germinate over a 7-day period. The gradient treatments were [±2 °F (1.1 °C)] 52, 56, 60, 64, 68, 72, 76, 80, 84, and 86 °F (11.1, 13.3, 15.6, 17.8, 20.0, 22.2, 24.4, 26.7, 28.9, and 30.0 °C). Germination data from thermogradient testing were used to determine the minimum temperatures and time required for su, se, and sh₂ cultivars to germinate at ≥75%, defined as minimum acceptable germination percent (MAGP); and the minimum temperature to reach the maximum germination rate (MGR) for a cultivar, defined as the ability to germinate to MAGP at the same rate equally at low and high temperatures. Generally, su phenotypes germinated to MAGP within 4 days, with sh₂ requiring 6 days, but with se requiring 5 days. We found that within each phenotype, however, cultivars reacted uniquely to temperature. The most vigorous and cold tolerant su cultivars were `NK 199' and `Merit' which germinated to MAGP at 52 °F with `NK 199' more vigorous than `Merit'. The su cultivar `Sweet G-90' was vigorous at warm temperatures, but the least cold tolerant and desirable for planting under cold conditions. Within the se cultivars, `Precious Gem', `July Gold', and `Imaculata' germinated to MAGP at 52 °F with `Precious Gem' requiring 6 days and `July Gold' and `Imaculata' requiring 7 days. `Accord' was the least cold tolerant se cultivar, requiring at least 60 °F for MAGP with a slow MGR, even at warm temperatures. None of the sh₂ cultivars reached MAGP within 7 d at 52 °F, as was also observed for certain su and se cultivars.

Extending the production season of melons (Cucumis melo L.) by using very early and late planting dates outside the range that is commercially recommended will increase the likelihood of developing a stronger melon industry in South Carolina. The objective of this study was to determine if early (February) transplanted melons or later (June through July) planting dates are effective in extending the production season of acceptable yields with good internal quality of the melon cultivars: Athena, Eclipse, and Sugar Bowl and Tesoro Dulce (a honeydew melon). Melons were transplanted in Charleston, S.C., in 1998, 1999, and 2000 on 12 and 26 Feb., 12 and 26 Mar., 9 and 23 Apr., 7 and 21 May, 4 and 18 June, and 2 July and required 130, 113, 105, 88, 79, 70, 64, 60, 60, 59, and 56 days from field transplanting to reach mean melon harvest date, respectively. Stands were reduced 67%, 41%, and 22% in the 12 and 26 Feb. and 12 Mar. planting dates, respectively, in contrast to the 26 Mar. planting date but ≤15% in all other planting dates. Planting in February had no earliness advantage because the 12 and 26 Feb. and 12 and 26 Mar. planting dates, all reached mean melon harvest from 19 to 23 June. Comparing the marketable number of melons produced per plot (averaged over cultivar) of the standard planting dates of 12 and 26 Mar. indicated decreases of 21%, 32%, 36%, 36%, 57%, 57%, and 54%, respectively with the planting dates of 9 and 23 Apr., 7 and 21 May, 4 and 18 June, and 2 July. The most productive cultivar of all was `Eclipse', which yielded significantly more melons per plot in all 11 planting dates followed by `Athena' (in 8 of 11 planting dates), `Tesoro Dulce' (7 of 11 planting dates), and `Sugar Bowl' (2 of 11 planting dates). In our study, any planting date with melon quality less than the USDA standard of “good internal quality” or better (Brix ≥9.0) was considered unacceptable because of potential market rejection. Therefore, the earliest recommended planting date with acceptable yield and “good internal quality” was 12 Mar. for all cultivars; the latest planting dates for `Athena', `Eclipse', `Tesoro Dulce', and `Sugar Bowl' were 4 June, 18 June, 7 May, and 9 Apr., respectively. With these recommendations, the harvest season of melons lasted 40 days from 24 June to 3 Aug. for these four cultivars, which extended the production season an additional 2 weeks longer than the harvest date of last recommended 21 May planting date.

Feverfew has aspirin-like properties and has been utilized for the treatment of pain, particularly migraine headache. Parthenolide is the sesquiterpene lactone believed to be responsible for the medicinal properties. The potential for utilizing existing tobacco production and handling systems for the production and postharvest handling of feverfew was investigated. In year one, 8 commercial tobacco growers each planted about one-half acre of feverfew (Tanacetum parthenium L. Schulz-Bip.). The yield of dry herb varied among farmers from about 122 to 772 (55 to 350 kg) pounds per half-acre. The parthenolide content of the dried herb from most producers was within the range desired by industry, but four factors precluded its salability: a) presence of foreign matter, primarily weeds; b) excessive ash content due to contamination from sandy soils; c) mold resulting from processing with excessive moisture content, and; d) insect infestation (tobacco beetles Lasioderma serricorne) during storage. All of these limitations resulted from the failure to implement good agricultural aractices (GAPs) and good manufacturing practices (GMPs) during production and handling of the product. A second planting of the feverfew was carried out with strict attention to GAPs and GMPs. In this trial, all of the dried feverfew met the requirements for sale. Here we report on the management of production and handling systems for feverfew that can enable growers to produce high quality herbs that meet the high standards for medicinal use.

Seeds of pale coneflower (Echinacea pallida), purple coneflower (Echinacea purpurea), feverfew (Tanacetum parthenium), and valerian (Valeriana officinalis), classified as “old” (1-year-old seed) or “fresh” (seed crop produced in the current year), were germinated at 62, 65, 69, 72, 75, 78, 82, 85, 89, and 92 °F, (16.7, 18.3, 20.6, 22.2, 23.9, 25.6, 27.8, 29.4, 31.6, and 33.3 °C). The optimum germination temperature, defined in this study as the temperature range within which the percent germination is greatest in the shortest period of time, was determined. Old and fresh pale coneflower seed germinated optimally after 5 days at 69 °F. Old purple coneflower seed required 5 d at 78 to 82 °F, but fresh seed germinated optimally after 3 days at 75 °F. Old feverfew germinated optimally after 5 days at 65 °F, but fresh seed germinated to its optimum after 5 days at 69 °F. Old and fresh valerian seed germinated to its optimum after 3 days at 75 °F.

The experiment screened two spring and two fall planting dates in six regions within North Carolina, South Carolina, and Georgia. The objective was to extend the production over the southeastern United States rather than at a single location. Spring harvests lasted from mid-April to early July. Summer-to-winter harvests lasted from mid-August to late January. Collards were not harvested in any of the locations from late January to mid-April or from early July to mid-August. More extensive planting dates may further increase the longevity of production.

Four bell pepper (Capsicum annuum L.) cultivars were evaluated for yield (total weight of marketable fruit) performance over 41 environments as combinations of 3 years, three planting dates, and seven locations across North Carolina, South Carolina, and Georgia. Cultural practices, including trickle irrigation and double rows planted on black-plastic-covered beds, were uniform across all environments, except for fertilization, which was adjusted at each location based on soil tests. Comparing production over 3 years between the mountain location and the Coastal Plain location in North Carolina, yields were lower on the Coastal Plain. Spring plantings provided higher yields than summer plantings at both locations. Yield increases were obtained from hybrid cultivars over that of the open-pollinated (OP) standard [`Keystone Resistant Giant #3' (KRG#3)] in the summer planting in the mountains compared to the Tidewater Coastal Plain. Across the three-state region, hybrid cultivar yields were higher than those of the OP cultivar for the second spring planting date in 1986 and 1987. Although the hybrid yields were higher than that of the OP standard, the hybrid `Skipper' yielded less than the other hybrids (`Gator Belle' and `Hybelle'). `Gator Belle' generally out-yielded `Hybelle' at all locations, except in Fletcher, N.C. This difference may be related to the relative sensitivity of these two cultivars to temperature extremes, rather than soil or geographic factors, because there was a tendency for `Hybelle' yields to exceed `Gator Belle' in the earliest planting date. Based on the reliability index, the chance of outperforming KRG#3 (the standard) was 85% for `Hybelle', 80% for `Gator Belle', but only 67% for `Skipper'.

Abstract

‘Champion’, ‘Georgia’, ‘Heavicrop’, and ‘Vates’ collards (Brassica oleracea L. var acephala) were planted in Fletcher and Lewiston, N.C.; Charleston, Clemson, and Florence, S.C.; and Attapulgus and Plains, Ga. to determine the most reliable method to predict harvest maturity based on temperature. Although cultivar differences existed within some of the planting dates, when pooled over all planting dates, cultivars yielded similarly within locations. Eight methods of calculating heat units from planting to harvest were applied to daily maximum and minimum air temperatures supplied from local weather bureaus for the spring and fall growing seasons from 1985 through 1987 in the three-state area. Coefficients of variation were used to determine which method was most reliable in predicting day of first harvest. The method with the lowest cv was to sum, over days for planting to harvest, the difference between the daily maximum and a base temperature of 13.4C; however, if the maximum was >23.9C, the base temperature was subtracted from an adjusted maximum equal to 23.9C minus the difference between the maximum and 23.9C. This method produced a cv of 9.1% compared to 11.4% for the standard method of summing the mean temperature minus the base of 4.4C over the entire growing season, or compared to 13.4% for counting days to harvest from planting.