Eggplants (Solanum melongena L.) were grown from transplants in a field study at Bixby, Okla., in 2005. Plants were harvested twice a week for 7 weeks. Data were taken from 3 individual plants per plot × 11 cultivars × 3 replications. The open-pollinated `Black Beauty' was inferior to the hybrids for yield and fruit quality. Patterns of cumulative percent marketable fruit number did not differ for 3 of the 4 cultivars producing the numerically highest (not always statistically highest) marketable fruit weights per plant (`Classic', `Nadia', and `Santana'). `Dusky' was the exception; fruit number peaked relatively early, but it still totaled among the highest for marketable fruit weight per plant. This might be considered an efficient fruiting pattern. Apart from `Dusky', a relatively high cumulative percent marketable fruit number throughout the season tended to be associated with an intermediate to low marketable fruit weight per plant. Two factors usually were responsible for this pattern: relatively low average marketable fruit weight, or high cull production. Despite significant differences in individual marketable fruiting patterns and average fruit weights, one relatively simple curvilinear model gave an excellent estimation of total and marketable eggplant fruit production (respectively) over time. The model was pct = 1/(1+exp(-(a+b*day))), where pct = estimated cumulative percent based on number of fruit, a = intercept, and b = slope.
Brian A. Kahn and Mark E. Payton
Janet C. Cole, Robert O. Brown and Mark E. Payton
Shearing is an important cultural practice for maintaining plant size and appearance during nursery crop production. However, oakleaf hydrangea (Hydrangea quercifolia) is susceptible to dieback after shearing. The objective of this study was to determine whether foliar or substrate surface applications of ancymidol or uniconazole can reduce plant growth of oakleaf hydrangea similar to pinching, which was used to simulate shearing. ‘Alice’ or ‘Pee Wee’ oakleaf hydrangea plants were treated in 2002 or 2006, respectively, with ancymidol or uniconazole as a substrate surface application at 0, 1, 2, or 4 ppm; ancymidol as a foliar application at 0, 25, 50, or 100 ppm; or uniconazole as a foliar application at 0, 12.5, 25, or 50 ppm. Both cultivars received the same plant growth regulator treatments in 2012, and a pinched control was included in the 2012 experiment. Ancymidol and uniconazole had limited and inconsistent effects on growth of ‘Alice’ and ‘Pee Wee’ plants regardless of application method. Uniconazole was more effective at controlling growth of ‘Alice’ in 2002 when the study was conducted from October through December than in 2012 when the study was conducted during a more typical growing season of May through September. Plants treated with either ancymidol or uniconazole by either application method usually grew more during the first 2 weeks after application than those that were pinched. During the remainder of the growing season, little difference in growth between pinched plants and growth regulator-treated plants occurred. At harvest in 2012, pinched ‘Alice’ plants had more leaves but a smaller leaf area per leaf than plants treated with growth regulators resulting in no difference in total leaf area or in leaf, shoot, or root dry weight among the treatments. ‘Pee Wee’ treated with uniconazole using either application method or uniconazole as a foliar application had fewer leaves than pinched plants.
Lynn Brandenberger, William McGlynn, Lynda Wells, Bruce Bostian and Mark Payton
Root yield and quality were evaluated in 15 carrot (Daucus carota) cultivars for use in processing. Marketable yield varied between the fall and spring production seasons for seven of the 15 cultivars with the highest yields recorded in the fall. ‘C 8771’ and ‘Heritage’ had the highest yields in Fall 2003. ‘Bremen’ and ‘Neptune’ were the highest yielding in Spring 2004. Root length was longest in the fall for a majority of cultivars with ‘PS 103397’ being the longest in the fall and ‘Pipeline’ longest in the spring. Forking of roots did not vary significantly for either season. Field color ratings were taken to indicate color differences between the interior core and cortex of the roots. ‘Florida’, ‘Heritage’, ‘Kamaran’, and ‘C 8771’ had consistently less difference between the core and cortex colors. Based on consistent yield and color uniformity, the authors would recommend the use of ‘C 8771’ and ‘Kamaran’ for both spring and fall production seasons in Oklahoma and the use of ‘Heritage’ and ‘Florida’ for fall production.
Cheryl R. Boyer, Janet C. Cole and Mark E. Payton
A survey of commercial nursery growers was conducted to identify cultural practices used in wintercreeper euonymus (Euonymus fortunei) production. Growers that have or have not experienced anthracnose incited by Colletotrichum gloeosporioides on wintercreeper euonymus participated in the survey. Nurseries reported using a variety of practices to produce quality plants for sale. Plant culture appeared similar between nurseries with anthracnose problems on wintercreeper euonymus and those without anthracnose problems.
Lynn Brandenberger, Todd Cavins, Mark Payton, Lynda Wells and Tina Johnson
Greenhouse spinach production is an alternative to fruiting vegetables produced in the greenhouse because it allows for multiple short-duration production cycles and a much faster economic return. Ten spinach (Spinacia oleracea) cultivars were evaluated for yield and quality using greenhouse float bed production techniques in Fall 2005 and Spring 2006. Time required for production was 52 days in Fall 2005 and 37 days in Spring 2006. Highest yields in Fall 2005 were 2093, 1996, 1956, 1920, and 1884 g·m−2 for ‘Olympia’, ‘Samish’, ‘Padre’, ‘Bolero’, and ‘F91-415’, respectively. ‘F91-415’ and ‘Bolero’ were the highest yielding cultivars in Spring 2006 with yields of 1649 and 1560 g·m−2, respectively. Bolting ratings were recorded in both tests and only ‘Samish’ had any bolting in Spring 2006 and none in Fall 2005. Quality ratings for leaf color and foliage mass were recorded in Spring 2006 with ‘Samish’, ‘Padre’, and ‘Cypress’ having the highest quality ratings. Color factors, including lightness, hue, and vividness, varied in Fall 2005 but not in Spring 2006. Based on yield and quality factors, the authors recommend further commercial trials of ‘Olympia’, ‘Samish’, ‘Padre’, and ‘F91-415’ for fall greenhouse production and ‘F91-415’ and ‘Padre’ for spring production.
Clydette M. Alsup, Brian A. Kahn and Mark E. Payton
Hairy vetch (Vicia villosa Roth) cover crops were grown in a rotation with sweet corn (Zea mays var. rugosa Bonaf.) and muskmelon (Cucumis melo L. Reticulatus group) to evaluate the legume's ability to remove excess P from soils when poultry litter was used as a fertilizer. Fertilizer treatments were: 1) litter to meet each crop's recommended preplant N requirements (1×); 2) litter at twice the recommended rate (2×); and 3) urea at the 1× rate as the control. Following the vegetable crops, hairy vetch was planted on half of each replication, while the other half was fallowed. The vetch was removed from the field in a simulated haying operation in the spring. Soil samples were taken at 0-15 cm and 15-30 cm depths at the onset of the study and after each crop to monitor plant nutrient concentrations. The vetch sometimes raised soil test N concentrations at the 0-15 cm depth. Soil test P concentrations at the 0-15 cm sampling depth in the vetch system were consistently lower numerically, but not statistically, relative to comparable plots in the fallow system. Soil test P at the 0-15 cm depth was usually increased by litter at the 2× rate relative to the urea control, regardless of cropping system. Yields of both vegetable crops were similar among all cover crop and fertilizer treatments.
Clydette M. Alsup, Brian A. Kahn and Mark E. Payton
Cowpea [Vigna unguiculata (L.) Walp.] cover crops were grown in a rotation with broccoli (Brassica oleracea L. var. italica Plenck.), spinach (Spinacia oleracea L.), and turnip greens [Brassica rapa L. var. (DC.) Metzg. utilis] to evaluate the legume's ability to remove excess P from soils when poultry litter was used as a fertilizer. Fertilizer treatments were: 1) litter to meet each crop's recommended preplant N requirements (1×); 2) litter at twice the recommended rate (2×); and 3) urea at the 1× rate as the control. Following the vegetable crops, cowpeas were planted on half of each replication, while the other half was fallowed. The cowpeas were harvested at the green-shell seed stage and then underwent a simulated haying operation to remove remaining shoot material from the field. Soil samples were taken at 0-15 cm and 15-30 cm depths at the onset of the study and after each crop to monitor plant nutrient concentrations. The cowpeas lowered soil test N concentrations at both soil sampling depths, but had no consistent effect on soil test P concentrations. Soil test P at the 0-15 cm depth was not increased by litter at the 1× rate but was increased by litter at the 2× rate relative to the urea control, regardless of cropping system. Poultry litter was effective as a fertilizer for all three vegetable crops, but the 1× rate appeared inadequate for maximum production of broccoli and turnip greens.
Hardeep Singh, Bruce Dunn, Mark Payton and Lynn Brandenberger
Nutrient-film technique (NFT) trials were conducted to quantify the effect of two different water-soluble hydroponic fertilizers (5N–4.8P–21.6K and 5N–5.2P–21.6K) on different cultivars of lettuce (Lactuca sativa), basil (Ocimum basilicum), and swiss chard (Beta vulgaris). Results indicated swiss chard yield was affected only by cultivars, with Fordhook Giant producing the greatest fresh weight across fertilizer treatments. For lettuce production, interaction between fertilizers and cultivars was significant. ‘Mirlo’ and ‘Rubysky’ had greater growth compared with other cultivars in both fertilizers, whereas Dragoon performed well using 5N–4.8P–21.6K, but not 5N–5.2P–21.6K. For basil, dry weight production showed a significant interaction between fertilizers and cultivars. ‘Largeleaf’ produced greater dry weight with 5N–4.8P–21.6K, whereas ‘Lemon’ produced greater dry weight with 5N–5.2P–21.6K. For nutrient concentration of leaves, the concentrations were within the recommended range for lettuce when fertilized with 5N–5.2P–21.6K. Nutrient concentrations varied by nutrient from the recommended range for basil, but there was no significant difference between fertilizers. For swiss chard, the nutrient concentrations were in the recommended range and there was no difference between fertilizers. Therefore, growers may need to use more than one type of fertilizer for different lettuce and basil cultivars for optimum production, whereas swiss chard cultivars can be selected based on yield regardless of fertilizer.
Courtney D. DeKalb, Brian A. Kahn, Bruce L. Dunn, Mark E. Payton and Allen V. Barker
Four experiments were conducted under greenhouse conditions in Oklahoma. Pelleted ‘Genovese’ basil (Ocimum basilicum) seeds were sown in polystyrene flats with six different blends of a peat-lite mix (PL0) and yard waste compost [YWC (this batch designated C0)] in 2012 for the first two experiments. The proportions by volume of PL0:C0 included 100%:0%, 80%:20%, 60%:40%, 40%:60%, 20%:80%, and 0%:100%. Seedling establishment was unaffected consistently, but there was a distinct decline in seedling height and dry weight between 100% PL0 and 80% PL0:20% C0, followed by smaller decreases as the percentage of compost increased in the blends. A third experiment was conducted in 2013 with a different batch of peat-lite (PL1) after the compost had aged 17 months (now designated C1). Treatments were 100% PL1, 80% PL1:20% C1, and 80% PL1:20% C1 mixed with sulfur (S) at 1, 2, or 3 lb/yard3 of blend to acidify the media. The 100% PL1 treatment delayed seedling emergence and suppressed height and dry weight relative to seedlings grown in 80% PL1:20% C1 blends. The PL1 subsequently was found to have been produced in 2010, and the wetting agent had apparently degraded. The aged 2012 compost (C1) was not inhibitory to basil seedling growth when blended at 20% with the PL1, and in fact restored utility to the PL1. The carbon:nitrogen ratio of the original 2012 compost (C0) was 10.8:1, suggesting stability. It appeared that the main reason the C0 compost was inhibitory was that mineralization was slow or immobilization occurred, causing a lack of plant-available nitrogen, especially nitrate. Treatments with S lowered pH of the media, but there were no differences in basil seedling growth between the unamended 80% PL1:20% C1 blend and blends with added S. A fourth experiment compared three peat-lite media: PL1; a batch of the same medium as PL1 that was produced in 2013 (PL2); and a different medium also produced in 2013 (PL3). Peat-lite media were either used unblended, or blended with 20% C1 or 20% C2 (a fresh batch of YWC obtained from the same facility that had produced the original C0). The unamended PL1 was again inhibitory to basil seedling establishment and development. The two “fresh” peat-lite media (PL2 and PL3) were not inhibitory and were similar to each other in performance. A blend of 80% PL2 or 80% PL3 with 20% compost produced similar (C2) or somewhat better (C1) results than were obtained with the unamended peat. We conclude that a blend of 80% peat-lite medium and 20% YWC can be used to produce basil transplants. However, producers must consider the quality of the peat-lite medium and the compost based on the age and composition of the components.
Brian A. Kahn, John P. Damicone, Kenneth E. Jackson, James E. Motes and Mark E. Payton
Nematodes (Meloidogyne sp.) are a potential problem when paprika peppers (Capsicum annuum L.) are grown in fields historically planted to peanuts (Arachis hypogaea L.). Nine nematicide treatments were evaluated over 3 years in field experiments on paprika pepper. Materials tested included the chitin nematicide ClandoSan and six chemicals: fosthiazate, carbofuran, aldicarb, oxamyl, fenamiphos, and dichloropropene. Stands at harvest were increased relative to the control by ClandoSan in 2 of 3 years. Other horticultural effects (plant dry mass and fruit yield) were minimal for all nine nematicide treatments. No one nematicide treatment consistently reduced nematode counts at harvest relative to the control. Nematode counts at harvest were greater in plots treated with ClandoSan than in plots treated with any other material in 2 of 3 years. Nematicide treatments were not cost effective under the conditions of these studies.