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Abstract

In field tests, the most effective film mulch in deterring insects and reducing insect damage to fruits was aluminum. The insects affected were aphids, brown stink bugs, aphid parasites, and Diabrotica spp. Mosaic virus diseases were reduced among aluminum-mulched squash (Cucurbita pepo L.) and cucumber (Cucumis sativus L.) plants. Plant growth, flowering, and fruiting were delayed in tomatoes (Lycopersicon esculentum Mill.) and southernpeas (Vigna unguiculata (L.) Walp.).

Open Access

In a yellow summer squash (Cucurbita pepo L.) experimental line developed by Seminis Vegetable Seeds, the coat protein gene of an American strain of squash mosaic virus (SqMV-M88), conferred resistance to Arizona, California, New Jersey, and New York strains belonging to the two pathotypes of the virus. An analysis of genetic populations derived from crosses and reciprocal backcrosses of a homozygous SqMV-resistant line A127-1-2 with the susceptible cultivar Butterbar revealed that the high level of resistance mimics the response of a single recessive gene.

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Abstract

Zucchini squash (Cucurbita pepo L. cv. Romanesco) were stored 19 days at 5°C in 21% ± 1% O2 plus 0.0%, 2.5%, 5.0%, or 10.0% CO2 and then stored an additional 4 days at 13° in air. High CO2 levels inhibited the rate of CO2 production and reduced the development of chilling injury symptoms at all three maturities (16, 20, and 22 cm fruit). There was a high negative correlation between CO2 levels and reduction of chilling injury. At the end of the 23-day storage period, 82% of the 22-cm squash held in 10% CO2 appeared salable, but they had a slight off-flavor and were soft; 79% of the fruit held in 5% CO2 were salable, firm, and free of off-flavors; samples from 2.5% CO2 and air were unacceptable because of decay and pitting. The percentage of unsalable fruit increased from 16- to 20-cm squash. Carbon dioxide concentrations around 5% may be useful for storing zucchini squash at about 5°, a temperature that normally causes chilling injury in zucchini.

Open Access

Summer squash (Cucurbita pepo L.) plants were grown in pots with high (290% capacity) or low (45% to 70% of capacity) soil moisture. The plants were exposed or not exposed to sweetpotato whiteflies (Bemisia tabaci Genn.). Only the plants exposed to whiteflies developed leaf silvering. Silvering was more severe in plants subjected to low soil moisture.

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Two experiments were conducted to evaluate processing pumpkin and processing squash tolerance to preemergence herbicides. The experiments were randomized complete block designs with three or four replications. The herbicides were applied after seeding the crop using a CO2-pressurized sprayer delivering 233 L/ha. We evaluated clomazone alone, and in combination with either halosulfuron or sulfentrazone. The first experiment was conducted in Morton, Ill., using `Libby's Select' processing pumpkin (Cucurbita moschata). None of the treatments caused any significant pumpkin phytotoxicity. On 7 July all treatments reduced the number of grass weeds compared to the untreated control. There were no differences in grass control between the herbicide treatments. Broadleaf control was best in sulfentrazone at 0.56 kg/ha or clomazone + halosulfuron at 0.56 + 0.13 kg/ha and worst in the untreated control. Weed control decreased by the 29 July rating; grass and broadleaf weed control was unacceptable in all treatments due to infestation with perennial weeds. Sulfentrazone alone or with clomazone was safe for use on pumpkins in heavier soils. The second experiment, conducted in Champaign, Ill., used `NK530' processing squash (Cucurbita maxima). None of the treatments caused any squash phytotoxicity. The best control on 14 July was with combinations of clomazone and sulfentrazone. On 10 Aug., all herbicide treatments were similar in their control of broadleaf weeds. Sulfentrazone and halosulfuron do not injure processing pumpkin or squash when applied either alone or in combination with clomazone.

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Zucchini and straightneck yellow squash are important crops for vegetable farmers. Variety choices change from year to year, based on breeding programs that try to find disease tolerance or resistance by developing new lines. A study was conducted at the Rutgers Agricultural Research and Extension Center in Bridgeton, N.J., to determine yield and quality of 14 zucchini, 6 yellow squash, and 5 specialty squash varieties. Squash were seeded on 17 May 2004, at 30 inches between holes into black plastic mulch on high raised beds. Rows were spaced 60 inches apart. Drip irrigation was used for supplying water and fertigation. Prefar4E at a rate of 5 qt/acre applied on the soil surface just before laying plastic was used for preemergent weed control. Five days after planting, Sandea75WF at a rate of 1 oz/acre and Gramoxone Max 3SC at a rate of 1.5 pt/acre were applied with a backpack sprayer between the rows for added weed control. Admire was applied in the seed hole at a rate of 24 oz/acre after planting using a backpack sprayer for control of aphids and cucumber beetle. Harvests began on 22 June 2004, and were continued 3 times weekly for 5 weeks for a total of 15 harvests. Zucchini varieties `Revenue', `Cashflow', `Justice III', `Spineless Beauty', `Senator', `HMX-2724', and `EXT 04629728' had statistically higher yields than did `Radiant', `Wildcat', `Payroll', `HMX-2723', `Lynx', `Tigress', and `Independence II'. Varieties are listed in values from highest yielding to lowest yielding, respectively. All yellow squash varieties had statistically similar yield values. These included `General Patton', `Cougar', `Sunray', `XPT1832', `Goldbar', `Sunbar'. Specialty varieties evaluated included `Zephyr', `Starship', `Magda', `Flying Saucer', and `Costata Romanesco'

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Abstract

Data from a cross between ‘Table King’, B +/B +, bearing green fruits, and ‘Precocious Small Sugar’, B/B, bearing yellow fruits, revealed the existence of 2 independent modifier genes, designated Ep-1 and Ep-2, each of which can extend the boundaries of precocious fruit pigmentation conditioned by gene B. The effect of these modifiers of B is cumulative, but the dosage of B plays an important role in controlling the extent of precocious pigmentation. Some commercial hybrids are B/+ and these tend to produce bicolor fruits, an undesirable feature in squash. The present findings suggest that B/+ hybrids can produce yellow fruits exclusively, provided they carry 2 or more Ep genes.

Open Access
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Greenhouse and field experiments were conducted to determine the influence of transplant age on growth and yield of `Dixie' and `Senator' summer squash (Cucurbita pepo L.). Dry weight and leaf area measurements indicated that 28- to 35-day-old greenhouse-grown transplants grew more slowly after transplanting than plants that were 10, 14, or 21 days old. Older transplants flowered earlier; however, earlier flowering did not result in higher early yields. Transplants of varying ages did not differ greatly in yield and yield components in the field, although all transplants had higher early yields than the directly seeded controls. Results from these experiments suggest that 21 days may be a reasonable target age for transplanting summer squash. If transplanting were delayed by adverse planting conditions, 21-day-old transplants would likely have at least a 10-day window of flexibility before yields would be reduced notably by additional aging.

Free access

Three transgenic yellow crookneck squash (Cucurbita pepo var. melopepo) and five transgenic cantaloupe (Cucumis melo, Reticulatus group) lines were field-tested in 1993 and 1994, respectively, for resistance to Zucchini Yellow Mosaic Virus and Watermelon Mosaic Virus II. During both years, non-transgenic plants were inoculated with virus before transplanting to provide a high virus threat to the transgenic plants. Before and after transplanting, serological (ELISA) testing was used to obtain baseline information on transformed plants and to confirm field virus infection. In both years, plant disease development was rated weekly; yield was assessed during 1993. Disease progression, yield, and end-of-season ELISA indicated a significant reduction in frequency of disease incidence in the transgenic lines. Total squash yields did not differ between the transformed and unchanged lines, but the transgenic lines yielded more marketable fruit than the non-transgenic line.

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Irrigation scheduling programs were developed for cabbage and zucchini squash that produced high yield and water-use efficiency with a minimum number of irrigations. The irrigation programs are based on a soil water balance model developed by the USDA. The procedure involved selecting irrigation programs developed for similar crops and using them as standards for cabbage and zucchini for three growing seasons. The treatments involved irrigation levels higher and lower than the standard. After the third year, the best treatment for each year was selected. Coefficients for the standard model then were adjusted by trial and error to produce a program that called for the same number of irrigations and the same amount of water as the best-performing treatment when using the same weather data. These revised programs for cabbage and zucchini squash are available on computer disks and may be used on any IBM compatible PC provided wind, temperature, solar radiation, humidity, and precipitation data are available,

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