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John T.A. Proctor, Dean Louttit, and John M. Follett

Freshly harvested, immature (green) seeds of north american ginseng (Panax quinquefolius L.) were stratified for 12 months either traditionally in buried wooden boxes outdoors, or in plastic pails in a controlled environment room [3 ± 0.2 °C (37.4 ± 0.11 °F)], 85% ± 5% relative humidity) for about 9 months followed by about 3 months at 20 ± 2 °C (69.8 ± 1.1 °F). Embryo growth in Stage II (mid-May to late August when direct seeded) was more rapid [0.016 versus 0.009 mm·d-1 (0.00062 versus 0.00035 inches/day)] under controlled-temperature conditions. Seedling emergence rate did not vary between treatments. Root dry weight (economic yield) was similar for seedling, 2, 3, and 4-year-old plants whether grown from traditionally or controlled-temperature stratified seed. Controlled-temperature stratification of north american ginseng seed is an acceptable alternative to traditional outdoor, in-ground stratification.

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Robert Wiedenfeld, Eden Hinojosa, and Robert Stubblefield

A study was conducted in subtropical south Texas in 1989 to determine the effects of planting method, polyethylene mulch, and rate of drip irrigation on cantaloupe growth, yield and quality. Irrigation at .25, .50, .75, 1.0, or 1.25 times pan evaporation had little effect on soil moisture or yield, with all water application levels keeping the soil close to field capacity. Transplanting vs. direct seeding enhanced early vine growth and caused earlier yield, although direct seeded plants later caught up and had final cumulative yields slightly higher than the transplants. Black polyethylene mulch also improved earliness and reduced the number of culls compared to bare soil, but at the lowest watering level total yields were reduced by the mulch due to deflection of the rainfall received. The combined practices of transplanting and polyethylene mulch caused approximately a 9 day earliness advantage over the treatment that was direct seeded on bare soil although final yield was unaffected. Soil salinity buildup may cause problems which would affect the position of the drip line and the frequency and amount of water applied.

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Robert Wiedenfeld, Eden Hinojosa, and Robert Stubblefield

A study was conducted in subtropical south Texas in 1989 to determine the effects of planting method, polyethylene mulch, and rate of drip irrigation on cantaloupe growth, yield and quality. Irrigation at .25, .50, .75, 1.0, or 1.25 times pan evaporation had little effect on soil moisture or yield, with all water application levels keeping the soil close to field capacity. Transplanting vs. direct seeding enhanced early vine growth and caused earlier yield, although direct seeded plants later caught up and had final cumulative yields slightly higher than the transplants. Black polyethylene mulch also improved earliness and reduced the number of culls compared to bare soil, but at the lowest watering level total yields were reduced by the mulch due to deflection of the rainfall received. The combined practices of transplanting and polyethylene mulch caused approximately a 9 day earliness advantage over the treatment that was direct seeded on bare soil although final yield was unaffected. Soil salinity buildup may cause problems which would affect the position of the drip line and the frequency and amount of water applied.

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S.B. Sterrett and C.P. Savage Jr.

Commercial production of bunched broccoli on the Eastern Shore of Virginia has been limited because of shortened internodes resulting in thick, tough stalks. A field study was completed to examine the influence of plant type (transplants or direct seeded), plant population (5800 or 8700 plants/ha), and N application (112 kg/N with zero, one, or two sidedress applications of 40 kg·ha–1) on marketable yield, head diameter, and stem diameter of `Packman' broccoli. None of the measured characteristics improved significantly with sidedress N application. Marketable yield and average head weight were significantly correlated (P = 0.01) to the total number of heads harvested (r = 0.70 and r = –0.91, respectively). More heads were harvested for the high population, direct-seeded treatment and fewer for the low-population transplants. Average stem diameter of transplants was slightly greater than that of direct-seeded broccoli being significant (P = 0.05) in the second and third harvests. However, few stems were of commercially acceptable diameter regardless of treatment combination. Additional evaluation of cultural management strategies and cultivar selection is needed to successfully promote commercial production of bunched broccoli in this growing area.

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Theodore M. Webster and A. Stanley Culpepper

Halosulfuron is a proposed alternative to methyl bromide for managing nutsedges (Cyperus spp.) in several vegetable crops, including cucurbits. Field studies were conducted to evaluate the crop sensitivity to halosulfuron in a spring squash (Cucurbita pepo L.)—fall cucumber (Cucumis sativus L.) rotation from 2000 to 2002. Treatments included application of halosulfuron to the soil surface after forming the bed, but before laying mulch (halosulfuron-PRE), halosulfuron applied through drip irrigation (halosulfuron-DRIP) after forming bed and laying mulch, metham applied through drip irrigation after forming bed and laying mulch, a nontreated control with mulch, and nontreated control without mulch. Each treatment was applied to both direct seeded and transplanted zucchini squash. Halosulfuron treatments reduced squash plant diameter relative to metham, however plant diameters in halosulfuron-PRE (transplant and direct seed) and halosulfuron-DRIP (transplant) treatments were not different from the nontreated control. Halosulfuron-PRE delayed squash fruit production relative to the mulched nontreated control. However, application of halosulfuron-PRE and halosulfuron-DRIP did not reduce squash yield at the conclusion of the season, relative to the nontreated control. Cucumbers were transplanted and direct seeded into previous squash plots and received either an application of halosulfuron-DRIP, or were not treated. Differences in cucumber yields were not detected with second crop treatments. Cucumbers appear to have adequate tolerance to halosulfuron, making it a potential replacement for methyl bromide for nutsedge control. Suppression of early season squash growth by halosulfuron may hinder the adoption of halosulfuron as a methyl bromide alternative for squash.

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Stephen M. Olson, George J. Hochmuth, and Robert C. Hochmuth

Studies were conducted at the NFREC, Quincy, and AREC, Live Oak, Fla., to compare watermelon {Citrullus lanatus [(Thumb.) Matsum & Nakai]} plant establishment by transplanting and direct-seeding. Cultivars used were `Charleston Gray' in 1984, 1985, 1986, and 1989; `Jubilee' in 1988 and 1989; and `Crimson Sweet' in 1987 to 1990. Early yields were greater with transplants for all three cultivars in all years. With `Charleston Gray', total yields with transplants were higher in 1985 and 1989, but not in 1984 or 1986. The average fruit weights with transplants were also greater in 1985 and 1989 than in 1984 or 1986. With `Jubilee', total yield with transplants was higher in 1989, but not in 1988. Average fruit weight with transplants was greater in 1989 than in 1988. With `Crimson Sweet', total yields were higher with transplants in 1989 and 1990, but not in 1987 or 1988, but fruits were larger with transplanting compared to direct-seeding only in 1990. In all experiments, yields with transplants were never less than those with direct-seeded plants.

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John T. A. Proctor

American ginseng is propagated by seed. In commercial practice ginseng seed is harvested in August or September, placed in a stratification box for about 12 months, and then direct seeded into raised beds. Germination takes place the following spring, some 18 to 22 months after seed harvest. Little is known about the dormancy-controlling mechanisms of ginseng seed. The objective of this study was to investigate seed development and temperature in the stratification box until it was removed 12 months later and seeded in the field. During stratification 3 embryo growth stages were identified. In Stage I of 250 days (September to mid-May) embryo length increased from about 0.5 to 1.0 mm, in Stage II of 100 days (mid-May to late August) length increased to 2.0 mm and in Stage III (late August to late November) length increased to 5.3 mm. Exocarp split width could also be placed in 3 stages. Changes in embryo length correlated with values for embryo: endosperm length ratio. The stratification box temperatures at all depths never exceeded -2°C even when the air temperatures dropped to -13°C and, therefore, were not damaging to the seeds.

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Michael W. Smith, Becky S. Cheary, and Becky L. Carroll

Parameters were defined to germinate pecan [Carya illinoinensis (Wangenh.) C. Koch] seeds in aerated water followed by container planting. Germination was not affected by the ratio of seeds to water in the germination containers. Highest germination rates with the greatest uniformity in germination were obtained with a water bath temperature of 32 °C. Stratification up to 188 days increased the rate of germination, but the largest response was between no stratification and 56 days (6.5 days vs. 2.3 days to reach 50% germination, respectively). Seeds that were germinated in a water bath, then planted in containers, achieved 50% emergence in 4.7 days compared to 12.4 days for direct-planted seed. Emergence was more uniform when seeds were germinated in water before planting compared with seeds that were directly planted in containers (7.0 days vs. 9.5 days between 10% and 90% emergence, respectively). Also, by germinating the seeds before planting, nonviable seeds were eliminated, resulting in 100% emergence compared to 76% emergence when planted directly.

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A.G. Taylor

173 WORKSHOP 29 Seed Storage

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Charles L. Webber III and James W. Shrefler

Corn gluten meal (CGM) has been identified as a potential organic preemergence and preplant-incorporated herbicide. It is an environmentally friendly material that has demonstrated ability to decrease seedling development and plant survival by inhibiting root and shoot development. Unfortunately, CGM can also decrease the development and plant survival of direct-seeded vegetable crops. As a result, the use of CGM is not recommended in conjunction with direct-seeded vegetables. The development of equipment to apply CGM in banded configurations has created an opportunity to investigate whether banded CGM applications will provide significant crop safety for direct-seeded vegetables. The objective of this research was to determine the impact of banded CGM applications on squash plant survival and yields. A factorial field study was conducted during the summer of 2004 on 81-cm-wide raised beds at Lane, Okla., with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and non-incorporated), and three application rates (250, 500, and 750 g·m–2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on 18 Aug. The banded application created a 7.6-cm-wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 2.5 to 5.0 cm of the soil surface with a rolling cultivator or left undisturbed on the soil surface. `Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was not a significant difference between powdered and granulated CGM formulations or incorporating and non-incorporating the CGM for either squash plant survival or yields. CGM application rates made a significant difference for both squash survival and yields, when averaged across all other factors. As the CGM application rate increased, the plant survival and yields decreased. When averaged across all other factors, the banded application resulted in significantly greater crop safety (59% plant survival) and yields (228 cartons/ha) than the solid applications (25% plant survival and 118 cartons/ha). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in a banded application configuration. Additional research should further investigate the interaction of CGM application rates and the width of the CGM-free zone on crop safety for various vegetables.