'Maffei 15' baby lima bean seeds were sown every 6 cm in rows 76 cm apart to yield a nominal stand of 215,000 plants/ha at two locations in Delaware over 2 years. Seedlings were thinned within 2 weeks of planting to provide 0%, 16.7%, 33.3%, and 50.0% stand reduction at two in-row spacing patterns to determine subsequent effects on vegetative and reproductive growth. Shoot fresh weight per square meter was decreased only in 2003 by 21% and bean fresh weight per square meter was decreased only in 2004 by 13.8% when plant stand decreased to 50%. This disproportional vegetative and reproductive growth response to stand reduction resulted from a compensatory linear increase in shoot fresh weight, usable pod number, and bean fresh weight of individual plants. Thus, 'Maffei 15' lima bean tolerates a considerable loss of plant stand with little or no effect on yield.
Wallace G. Pill, Thomas A. Evans, Michael W. Olszewski, Robert P. Mulrooney, and Walter E. Kee Jr.
R.P. Bracy, R.L. Parish, and E.B. Moser
Field studies were conducted in Fall 1991 and 1992 to determine if cauliflower (Brassica oleracea L. Botrytis Group) could be precision seeded to a stand without subsequent thinning and what the optimum seed spacing necessary to directly seed cauliflower to a stand. Seed spacings of 10, 20, and 30 cm at one seed per hill and 30 cm at two seeds per hill were evaluated for effect on yield, head weight, plant population, and early harvest percentage. As evaluated in the laboratory, seeder precision (accuracy) was good with regard to seed counts and spacing measurements at the various seed spacings. Seeder precision evaluated in the field varied in distribution patterns among seed spacings and years. Cauliflower was successfully precision seeded to a stand without thinning during 2 years of fall plantings. Cauliflower directly seeded at one seed per hill and a 20-cm spacing produced total and average head weights similar to cauliflower seeded 10 cm apart and thinned to 30 cm—the seeding method currently used by some commercial operators.
Regina P. Bracy, Richard L. Parish, and E.B. Moser
Field studies were conducted in Fall 1991 and 1992 to determine 1) if cauliflower (Brassica oleracea L. Botrytis Group) could be precision-seeded to a stand without subsequent thinning and 2) the optimum seed spacing necessary to directly seed cauliflower to a stand. Seed spacings of 10, 20, and 30 cm at one seed per hill and 30 cm at two seeds per hill were evaluated for effect on yield, head weight, plant population, and early harvest percentage. As evaluated in the laboratory, seeder precision (accuracy) was good in regard to seed counts and spacing measurements at the various seed spacings. In the field, seeder precision varied in distribution patterns among seed spacings and years. Cauliflower directly seeded at one seed per hill and a 20-cm spacing produced yields and head weights similar to cauliflower seeded 10 cm apart and thinned to 30 cm—the seeding method currently used by some commercial operators.
Regina P. Bracy, Richard L. Parish, Paul E. Bergeron, E.B. Moser, and R. J. Constantin
Field studies were conducted in Spring 1989 and 1990 to determine if cabbage (Brassica oleracea L. Capitata Group) could be precision-seeded to a stand without subsequent thinning and to determine the optimum seed spacing necessary to seed cabbage directly to a stand. Seed spacings of 10, 20, and 30 cm at one seed per hill and 30 cm at two seeds per hill were evaluated for effect on yield, head weight, plant population, and harvest percentage. Seeder precision (accuracy) with regard to seed counts and spacing measurements at the various seed spacings, as evaluated in the laboratory, was good. Seeder precision evaluated in the field varied in distribution patterns among seed spacings and years. Cabbage directly seeded at one seed per hill and a 30-cm spacing produced yields and head weights similar to or higher than cabbage seeded 10 cm apart and thinned to 30 cm-the seeding method currently used by some commercial operators.
R. P. Bracy, R. L. Parish, P. E. Bergeron, E. B. Moser, and R. J. Constantin
A study to evaluate the seeding rate necessary for precision seeding cabbage to a stand was initiated during the spring of 1989. A Stanhay precision seeder was used to plant cabbage seed at 10-cm (thinned to 30-cm), 20-cm, 30-cm (1 seed/hill), and 30-cm (2 seed/hill) spacings. Total weight was not significantly affected by seed spacing, but head size decreased with an increase in number of heads. Cabbage spaced 30 cm (1 seed/hill) apart produced the highest yield of marketable heads (1007 gms). Lab measurements were determined by operating the planter over a lubricated board and measuring seed spacing. Lab measurements of spacing indicated actual spacing was closely associated with expected spacing of each treatment. Field measurements of plant spacing were used to associate seed placement between lab and field spacings. Graphical analysis indicated spacing within a treatment was similar in both lab and field treatments. Small differences between data collected in the lab or field were attributed to loss of plants in the field.
James R. Cooksey, Brian A. Kahn, and James E. Motes
Nontreated seed, primed seed, and transplants were compared for effects on stand establishment, plant morphology, and yield of paprika pepper (Capsicum annuum L.). Nontreated seed was satisfactory for stand establishment, although primed seed had the potential to provide greater initial stands. When populations were made equal by thinning, there were few differences in stem and leaf dry weight, fruit yield, or plant morphology attributed to seed treatment. Generally, morphology of plants established by direct seeding was favorable for mechanical harvest. Using transplants did not result in higher marketable fruit yields than direct seeding in 2 of 3 years. When compared to plants established by direct seeding, three trends were consistent across all 3 years for plants established by transplanting: 1) they were more massive, 2) they had larger vertical fruiting planes, and 3) they had more branches. These traits increase the difficulty of mechanical harvest and create the potential for more leaves and stems (trash) in the harvested product. Thus, transplanting is not recommended for stand establishment of paprika pepper intended for mechanical harvest.
Robert F. Bevacqua and Dawn M. VanLeeuwen
Chile pepper (Capsicum annuum L.) yields are highly variable and are strongly influenced by disease and weather. The goal of two field experiments was to evaluate crop management factors, especially planting date, that could contribute to improved and more consistent crop production. Current practice in New Mexico is to direct seed the crop from 13 to 27 Mar. In the first experiment, chile pepper was direct seeded on three planting dates, 13, 20, and 27 Mar. 2000, without or with a fungicide treatment of pentachloronitrobenzene and mefenoxam for the control of damping off. The results indicate planting date had no effect on stand establishment or yield. Fungicide treatment, significantly reduced stand, but had no effect on yield. In the second experiment, chile pepper was direct seeded on six planting dates, 13, 20, 27 Mar. and 3, 10, 17, Apr. 2001, with or without an application of phosphorus fertilizer, P at 29.4 kg·ha-1, banded beneath the seed row. During the growing season, this experimental planting suffered, as did commercial plantings in New Mexico, from high mortality and stunting due to beet curly top virus, a disease transmitted by the beet leafhopper. The results indicate planting date had a significant effect on crop performance. The best stand establishment and highest yield were associated with the earliest planting date, 13 Mar. This date also resulted in the least viral disease damage. Phosphorus fertilizer had no effect on stand establishment or yield. Chemical names used: pentachloronitrobenzene (PCNB); (R)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid methyl ester (mefenoxam).
David S. de Villiers and Robert W. Langhans
Protein is an important and essential dietary component. Common bean, a major source of vegetable protein in the Americas, was chosen for study in controlled environments with a view to its potential for use in space colonies. Eighteen 0.58-m2 stands of the cranberry type of bean, `Etna', were grown in the greenhouse at plant densities of 7, 15, and 28 plants/m2 in a recirculating ebb-and-flow system. Duration of photoperiod and thermoperiod was 16 h. Day/night temperatures settings were 25/20 °C. Daily light integral was matched across greenhouse sections by means of supplemental lighting; it averaged 17 mol/m2 per day. Crop cycle was 70 days from seed to harvest. At harvest, plants were dismembered so that dry weights of leaf, branch, stem, pod, and bean yields could be separately measured by node of origin. Internode lengths were recorded, and all loose trash recovered. The relationship between yield and plant density followed the form expected. Yield of edible biomass at 7 plants/m2 (284 g/m2) was 88% of that at 28 plants/m2 (324 g/m2), a significant difference. At 15 plants/m2 it was 97%. The trend suggests that further gains (but only very small) in yield can be expected with increased density in this cultivar. Productivity and quantum yield at 28 plants/m2 were 4.69 g/m2 per day and 0.27 g/mol, respectively. The coefficient of variation for plants grown at 28 plants/m2 was three times that of plants grown at 7 plants/m2 (0.88 vs. 0.26). Yield component analysis, harvest index, and plant morphology at the different planting densities are discussed.
Anwar A. Khan, James D. Maguire, George S. Abawi, and Satriyas Ilyas
1 Professor, Dept. of Horticultural Sciences. 2 Visiting Fellow, Dept. of Horticultural Sciences. Present address: Dept. of Agronomy and Soils, Washington State Univ., Pullman, WA 99164. 3 Professor, Dept. of Plant Pathology. 4 Graduate Student
Salvador Vitanza, Celeste Welty, Mark Bennett, Sally Miller, and Richard Derksen
The impact of pesticide application technology and crop stand density on bell pepper production was evaluated in a series of field trials, during 2004 and 2005, at the North Central Agricultural Research Station, Fremont, Ohio. In 2004, one trial tested three sprayers, at a speed of 8 and 4 mph, using insecticides at half the recommended rate and one treatment at full rate. Sprayers evaluated included an air-assisted electrostatic sprayer, a Cagle sprayer equipped with AI-11005 or AI-110025 nozzles, and an air-blast sprayer with XR-1003-VS or XR-110015-VS nozzles. In 2005, one experiment tested the interaction of two application technologies, three planting distances within row, and single vs. twin rows. Another experiment compared the Cagle sprayer (with TJ60-11003 or AI-110025 nozzles) and the airblast sprayer (with XR-110015-VS nozzles), at a speed of 4 mph, and insecticides at half the recommended rate. In 2004, the Cagle sprayer with air-induction nozzle, half rate, at 8 mph obtained the highest fruit yield. There was not significant improvement in European corn borer control by applying insecticides at full rate with the Cagle sprayer and all treatments achieved significantly better bacterial soft rot control than the untreated control. In 2005, the trials were terminated early due to crop destruction by Phytophthora capsici. Red fruit weighed less at high than at medium or low plant stand densities. Clean yield of red fruit was significantly greater in single rows than in twin rows. Marketable yield of green fruit was greater using the TJ60-11003 than using the AI-110025 nozzles.