Using polyethylene mulches has increased earliness, yields, and fruit quality in muskmelon, resulting in their extensive use for melon production with numerous commercial products. However, two problems are associated with polyethylene use: removal and disposal following production. Organic mulches are potential alternatives but, in this study, resulted in significantly lower soil temperatures than all other treatments and generally had lower yields. Soil temperature, yield, fruit size and percent soluble solids were increased by polyethylene mulches compared to bare soil. Crop response differences between polyethylene mulches were not significant for most characteristics measured. There were significant differences in durability and ease of removal of polyethylene mulches. Based our results, durability and ease of removal are the main characteristics on which to base selection. Proper mulch selection can reduce removal costs and enable commercial producers to leave a mulch in place for the production of a second crop.
Lynn Brandenberger and Bob Wiedenfeld
Brian A. Kahn and Lynn P. Brandenberger
Field studies were conducted in Oklahoma from 2010 to 2012 to develop protocols for fall sweet corn (Zea mays) production. Variables examined included a transgenic cultivar that expresses the CryIA(b) toxin from the bacterium Bacillus thuringiensis (Bt) and its nontransgenic near-isoline, seeding rates and planting dates, and various insecticide regimens. We found that, in eastern Oklahoma, a suitable planting window would correspond roughly to the last 2 weeks in July. Within this favorable period and given timely irrigation, it was possible to sow corn to an acceptable stand. A seeding rate ≈1½ times the desired final stand of one plant/ft appeared to be satisfactory. Use of a cultivar (GSS-0966) with genetic resistance to lepidopteran pests was a critical factor for successful production of fall sweet corn. Efforts to produce a crop with a nontransgenic cultivar using insecticides with relatively low mammalian toxicity were unsuccessful. Our experiments support previous recommendations for applying supplemental insecticides to transgenic Bt sweet corn to potentially increase production of “premium” ears by reducing the percentage of ears with severe insect damage (damage >1½ inches from the cob tip). We demonstrated that a spray schedule that rotated two insecticides with intermediate mammalian toxicity (carbaryl and permethrin) was as effective in reducing severe insect damage to ears of ‘GSS-0966’ as a similar schedule that rotated two highly toxic insecticides (esfenvalerate and methomyl).
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.
Lynn P. Brandenberger*, Lynda K. Wells, and Bruce B. Bostian
The objectives of this trial were to collect yield and quality data on a fall planted carrot trial. Fifteen different carrot varieties were included in the trial. Plots were 20 feet by 2.5 feet and consisted of two rows of carrots with 15-inch row centers. Plots were replicated 4 times in a RBD. Carrots were direct seeded on 8 Aug. 2003 at 20 seeds per foot. Plots were fertilized with 90 lbs/acre of nitrogen and received overhead water as needed. Yield and quality data were recorded on 5 Dec. 2003. Data included exterior root color, interior root color, percentage of split and forked roots, overall yield, average root length and weight. Exterior root color did not vary significantly for any of the cultivars in the trial, but interior root color varied significantly for several cultivars. `First Class', `Bolero', and `C 7105' had the most distinct differences between the pith and out ring colors as indicated by the interior root color ratings and `Ingot' had the lowest. Interior root color ratings for these four cultivars were 3.8, 3.6, 3.1, and 1.4, respectively. Crispness did not vary for either the initial or second ratings that were recorded. Of potential defects only the percentage of forked roots varied significantly and of these four cultivars had less than 10% forked roots. `Florida', `Kamaran', `Pipeline', and `C 7105' had 5%, 7%, 9%, and 9% forked roots, respectively. `Samantha' had 31% forked roots, the highest percentage recorded in the trial. No differences were recorded for root weight, diameter or length. The three highest yielding cultivars in the trial were `Ingot', `Heritage', and `Neptune' that had overall yields of 24.9, 20.6, and 20.6 tons/acre. `Bremen' recorded the lowest yield in the trial with 13.7 tons/acre.
Lynn Brandenberger, Lynda K. Wells, and Michel M. Haigh
Nine (2001) and eight (2002) spinach (Spinacia oleracea) cultivars, including hybrid and open pollinated types, were tested for yield and quality characteristics during two spring production seasons in Oklahoma. Cultivars were evaluated for emergence, vigor, color, bolting resistance, and yield. Cultivars did not vary significantly for yield, which ranged from 11.9 to 14.9 tons/acre. `Baker', `Bolero', `Catalina', `Olympia', and `Padre' had significantly higher levels of bolting resistance than other cultivars in the trials. 'Catalina', `Olympia', and `Padre' also exhibited the darkest green color of those cultivars with bolting resistance. Based upon bolting resistance, `Catalina', `Olympia', `Padre', `Baker', and `Bolero' are five cultivars that can be recommended for use in spring planted spinach in Oklahoma and the southern plains.
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.
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.
Warren Roberts, Penny Perkins-Veazie, Jonathan Edelson, Jim Shrefler, and Lynn Brandenberger
Forty-one watermelon cultivars were compared for yield and fruit size. Fields were prepared with raised beds 1 m wide covered with black plastic and equipped with drip irrigation. Plots were 2.7 m wide × 15.2 m long, with 10 plants being spaced 2.7 m apart in the row, and the remaining 6.1 m of each plot being used as a buffer zone. There were 4 replications of each plot, arranged as a randomized complete block. Seeds were placed in pre-moistened Jiffy-9 pellets in a greenhouse on 16 June 2003. Germinated seedlings were transplanted to the field on June 30. There were 27 triploid cultivars grown, with an average yield of 34.3 t·ha–1, and 14 diploid cultivars grown, also with an average of 34.3 t·ha–1. The three highest yielding diploids were `Gold Strike' with 51.7 t·ha–1, `Jamboree' with 44.8 t·ha–1, and `Dulce'with 43.0 t·ha–1. The three highest yielding triploids were `Sweet Slice' with 49.1 t·ha–1, `Sweet Delight' with 46.6 t·ha–1, and `Samba' with 45.0 t·ha–1. Small, personal sized melons are gaining popularity in the markets, and several small sized cultivars were included in this study. The cultivars with the smallest fruit, and their average fruit sizes, were `HA 5133', 2.6 kg; `HA 6007', 2.7 kg; `HA 5109', 2.8 kg; `Minipol', 3.0 kg; `WD-02-05', 3.4 kg; `HA 6008', 3.4 kg; `HSR 2920', 3.5 kg; `HA 6009], 3.7 kg; `HA 5116', 3.7 kg; and `WT-03-05', 4.2 kg.
Hardeep Singh, Bruce Dunn, Niels Maness, Lynn Brandenberger, Lynda Carrier, and Bizhen Hu
Tomato (Solanum lycopersicum L.) is one of the most extensively cultivated horticultural crops in the world. Factors such as yield, size, taste, and lycopene content are important criteria that may impact the selection of tomato cultivars for different production systems. The aim of the current study was to evaluate different slicer and cherry tomato cultivars for production under greenhouse and open field conditions. Three cultivars of slicer (BHN 964, Trust, and Geronimo) and cherry (BHN 268, Favorita, and Sakura) tomatoes were tested using randomized complete block design in 2019 and 2020. Results showed that the performance of tested cultivars differed under greenhouse verses open field conditions. Among cherry tomato cultivars in 2020, BHN 268 and Sakura produced significantly greater yield under open field conditions, while under greenhouse conditions yield of BHN 268 was the lowest. Similarly, cherry tomato fruit size from ‘BHN 268’ and ‘Sakura’ was also significantly greater than ‘Favorita’ under field conditions, whereas under greenhouse conditions, the fruit size of ‘Sakura’ was significantly greater than both ‘BHN 268’ and ‘Favorita’. Among slicer tomato cultivars, BHN 964 produced significantly greater yield and had a greater average fruit size than the other two cultivars under greenhouse conditions in 2020 while, Geronimo produced significantly similar or larger yield and had a similar average fruit size compared with BHN 964 under open field conditions. Tomatoes produced under open field conditions were rated significantly greater for taste compared with those produced under greenhouse conditions. Lycopene content in both slicer and cherry tomato cultivars was influenced by the interaction of production type, cultivars, and harvest time. Therefore, it can be concluded that BHN 964 and Geronimo were the highest in lycopene among slicer tomato cultivars for greenhouse and open field production, respectively. Among cherry tomato cultivars, BHN 268 was the highest in lycopene for open field production and Sakura for greenhouse production. Additionally, open field–produced tomatoes taste better than greenhouse-produced tomatoes, but lycopene content may be constrained for mid- and late-season fruits due to high temperature conditions under open field conditions.
Carlos A. Lazcano, Frank J. Dainello, Leonard M. Pike, Marvin E. Miller, Lynn Brandenberger, and Larry R. Baker
Carrot (Daucus carota Mill. cv. Caropak) was studied under four population densities, and three numbers of seed lines per bed, and was harvested under three root size harvest parameters. Four phases (cutting, grading, peeling, and marketable yield) in the cut-and-peel baby carrot process were evaluated. Root length was most desirable when plots were harvested when 25% to 35% of the roots measured > 2 cm in diameter. Roots were longest (14.7 cm) in the treatments containing six seed lines per bed. The harvest criteria of 25% to 35% root diameter >2 cm also produced the highest fresh mass (48.1 t·ha-1), and the highest cut and graded mass (37.7 and 32.3 t·ha-1, respectively). A population density of 321 plants/m2 produced the highest fresh and cut mass. Percent cut waste (21.6% crowns and tips) was not affected by root size at harvest, but percent graded waste was lowest (14.2%) when plants were harvested at the greatest root size. Four seed lines per bed produced the highest graded (18.4%), and total waste (61.2%), but not cut waste. The lowest total waste, estimated at 59.7% and the highest projeced marketable yield (19.4 t·ha-1) occurred when roots were harvested using the 25% to 35% root diameter >2-cm parameter. Total waste and marketable yield were obtained using a fixed waste value of 40% in the peeling phase (peeling, polishing, and grading before packing). This percentage could vary depending on the equipment specifications and quality control of a given processing facility. Root size at harvest proved to be the main factor affecting projected marketable yield of cut-and-peel baby carrots at the population densities used in this study.