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  • Author or Editor: Stuart A. Weiss x
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Snow pea (Pisum sativum var. saccharatum) and sugar snap pea (P. sativum var. macrocarpon) are high-value crops typically grown in temperate regions. Temperature is the main limiting factor to growing edible-pod peas in warmer U.S. states and territories. The objective was to evaluate edible-pod peas performance in tropical climates and to make cultivar recommendations to farmers in the U.S. Virgin Islands based on fruit yield. Trials were performed in two consecutive years (2014 and 2015), testing six cultivars of edible-pod peas: three snow pea (Little Sweetie, Mammoth Melting, and Oregon Giant) and three sugar snap pea (Super Sugar Snap, Cascadia, and Sugar Sprint) in a complete randomized block with four replications. ‘Little Sweetie’ produced the highest total fruit yield for the season (15,442 kg·ha−1) and ‘Mammoth Melting’ (4249 kg·ha−1) and ‘Sugar Sprint’ (3349 kg·ha−1) produced the lowest total fruit yield in Year 1. The same trend happened in Year 2, where ‘Little Sweetie’ (14,322 kg·ha−1) and ‘Super Sugar Snap’ (12,511 kg·ha−1) were higher yielding and ‘Mammoth Melting’ (4582 kg·ha−1) and ‘Sugar Sprint’ (1929 kg·ha−1) were the lowest yielding cultivars. ‘Mammoth Melting’ showed a marketable yield below 80% of total yield in Years 1 and 2. ‘Mammoth Melting’ and ‘Super Sugar Snap’ produced the tallest plants in Year 1, while ‘Mammoth Melting’ was significantly taller than the others in Year 2. As expected, sugar snap pea presented fruit soluble solids concentration (SSC) 2.7% to 6.5% higher than snow pea. The snow pea cultivars had longer mean fruit length (81 to 86 mm) than sugar snap pea (60 to 68 mm). The opposite trend occurred with fruit thickness; sugar snap pea averaged 28.5% thicker than snow pea. The shoot dry weight of ‘Sugar Sprint’ was on average 78.5% smaller than ‘Mammoth Melting’ and ‘Oregon Giant’, resulting in poor performance due to small plant size. ‘Mammoth Melting’ and ‘Super Sugar Snap’ had the lowest chlorophyll content compared with the other cultivars. Results of this experiment indicate that edible-pod peas have potential as a specialty, short-season, high-value crop when grown in the cool–dry winter months of the U.S. Virgin Islands. Of the cultivars tested, Little Sweetie was the highest yielding cultivar evaluated within the environmental and geographical conditions of this study for two consecutive years.

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Drip irrigation presents higher distribution efficiency than sprinkler irrigation. Proper system design and the use of pressure-compensating emitters have important roles in irrigation uniformity and efficiency, which directly affect plant growth. This study evaluated the performance of four pressure-compensating and noncompensating emitters and the effects of these irrigation equipment on the yield of three okra [Abelmoschus esculentus] varieties cultivated in the U.S. Virgin Islands. Trials were performed in two seasons (Spring and Fall 2016), and tested four types of irrigation equipment (flow control drip tape, thin wall drip line, thin wall drip tape, and heavy wall drip line) and three varieties of okra (‘Clemson Spineless 80’, ‘Clemson Spineless’, and ‘Chant’), arranged on a complete randomized block design with three replications. Irrigation was performed based on reference evapotranspiration and measured daily using an automated weather station. Soil moisture, electrical conductivity (EC), and soil temperature were monitored using capacitance sensors. The ability of the irrigation equipment to increase pressure was evaluated in the laboratory, in experimental modules using clean water, and while simulating three different slopes (leveled, uphill, and downhill). In the field trial, yield and leaf physiological parameters were influenced by season (P < 0.05) and the percentage of the marketable yield was influenced by variety (P < 0.05); however, fruit morphological parameters and soluble solids content were variety-dependent (P < 0.01). The pressure-compensating emitters maintained water flow within the range indicated by the manufacturers when used within the recommended pressure range. Distribution uniformity decreased over time for all equipment except the heavy wall drip line in Fall 2016. Irrigation equipment did not impact okra morphological attributes and yield, indicating that the same productivity can be successfully maintained while improving irrigation efficiency. Equipment should be selected based on price and irrigation efficiency to reduce the amount of water used.

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