Obtaining equipment for research in developing countries can be difficult, but it is possible to build some simple equipment with local materials. Onion varietal testing for the export market from Central America has been a major emphasis for the Honduran Agricultural Research Foundation. They have been carrying out evaluations since their inception in 1985, but did not have a good way to consistently grade large quantities of onions. To evaluate the yields, simple low-cost, and easily transportable grading equipment was constructed from materials readily available in the domestic market. Grading equipment must give uniform and repeatable results. Two grading systems were designed to provide that consistency. The first was the use of PVC (polyvinylchloride) tubing to construct 3and 4-inch grading rings. Yellow and sweet onions for export are divided into two classes—jumbo (3-4 inches with 65% 3-1/2 or larger in diameter) and colossal (larger than 4 inches in diameter). Rings were constructed by cutting 1-inch cross-sections of tubing and putting one inside the other until the desired diameter was reached. The rings were functional for small plots, but were not appropriate for large trials. A compact, collapsible grader, easily carried in the back of a small truck or van, was constructed for use on large trials. Local wood and steel bars were used for the section table and sizers. At the same time, growers were looking for a grading system that could be used in areas where there was no electricity. The grader was redesigned for commercial use, but was still portable. The designs for and cost effectiveness of the grading equipment will be discussed.
Wesley L. Kline and Shirley T. Kline
C. Andrew Wyenandt and Wesley L. Kline
Twenty-eight bell pepper cultivars and breeding lines were evaluated for resistance to the crown and stem rot phase of Phytophthora blight (Phytophthora capsici) and for silvering of fruit at two sites in southern New Jersey in 2005. A randomized complete block design with four replications was setup at Rutgers Agricultural Research and Extension Center (RAREC), Bridgeton, New Jersey and at an on-farm site in Vineland, NJ. Number and weight of fruit with silvering varied significantly depending on pepper line, harvest date, and location. Percentage of phytophthora-infected plants ranged from 0% to 26% at RAREC and 0% to 78% at the on-farm site depending on pepper line. In some cases, new breeding lines exhibited levels of Phytophthora-resistance comparable to the resistant cultivar Paladin. Depending on pepper line, percentage of harvested fruit with silvering decreased with later harvest dates. The percentage of fruit with silvering ranged from 0% to 92% during first harvest, 1% to 56% during second harvest and from 5% to 35% during third harvest at RAREC, and from 0% to 22% during second and 0% to 15% during third harvest at the on-farm site depending on pepper line. Less fruit silvering developed in lines with no resistance or tolerance to P. capsici. Reports have suggested that phytophthora-resistance is linked to increased silvering in fruit. Silvering in Paladin was 66%, 56%, and 35% compared to only 0%, 1%, and 5% in Camelot (susceptible cultivar) during each harvest at RAREC and was 22% and 15% in Paladin compared to 0% in Camelot at the on-farm site. Interestingly, silvering was lower when pepper lines were grown on high-ridged bare soil beds with overhead irrigation (on-farm site) compared to same pepper lines grown on black plastic mulch with drip irrigation (RAREC).
Wesley L. Kline, Stephen A. Garrison, and June F. Sudal
Heirloom tomato production is increasing in the Eastern United states as consumer demand increases. Pruning and suckering heirloom tomatoes have not been studied to see if there is any need for this labor-intensive activity. A 2-year study was undertaken to evaluate whether pruning or suckering would affect yield or fruit size for two heirloom cultivars (`Mortgage Lifter' and `Prudens Purple'). The treatments imposed on the cultivars were 1) removing all suckers from the second or third stem down after the flower cluster; 2) removing the bottom two suckers, or 3) removing no suckers. Pruning had no effect on early yield or fruit size (harvests 1–4). Mid-season (harvests 5–7) total and marketable yields were significantly higher for removing two suckers or not suckering over the other two treatments for year 1, but not year 2. The tomato fruit size was only reduced for the non-suckering treatment. There were no statistical differences among the pruning treatments for yield or fruit size for late season harvests (8-10) for both years. Marketable yields were statistically higher for no suckering over the two- and three-stem treatments, but not different from two suckers when all harvests were combined for the season for year 1. No statistical differences were observed in year 2. However, fruit size was reduced when not suckering compared to the other treatments. The cultivar `Prudens Purple' did have higher total and marketable yield than `Mortgage Lifter' for both early and total combined harvests, but not for mid- or late-season harvests in year 1. There were no statistical differences between the two cultivars for year 2.
Wesley L. Kline, Stephen A. Garrison, and June F. Sudal
The cultivar `Mortgage Lifter' was planted in a 2-year trial to evaluate staking systems. All plots were established with black plastic and drip in a randomized complete block design with three or four replications. In year 1, treatments consisted of straw mulch and plants grown on 4 and 8 ft tomato stakes without straw mulch. In year 2, treatments were added to include topping plants at 4 and 6 ft, when plants grew to the top of the stake and down to touch the plastic or not topping. All were grown on 4-ft stakes. Additionally, plants were grown on 8-ft stakes, but topped at 5, 6, 7, and 8 ft. The first year there were no statistical marketable yield differences between plants grown on 4 or 8-ft stakes, but the yields were significantly higher than the straw mulch treatment after the seventh harvest. The straw mulch treatment did have significantly more cull fruit, lower percentage marketable fruit and a smaller marketable fruit size for all harvests compared to the staking treatments. In year two, there were no statistical differences for marketable yield among the treatments until the late harvests (9–12). For the late harvest, all treatments grown on 8-ft stakes had higher marketable yields than all other treatments. When all harvests were combined, the 6- and 7-ft treatments had higher marketable yields with the exception of the 5- and 8-ft treatments and the 6-ft treatment on 4-ft stakes. Cull fruit yields were only significant among treatments for the mid season harvest (5–8) with the straw mulch treatment having more cull fruit than all other treatments. There were no statistical differences for percentage marketable fruit for any harvest.
Christian A. Wyenandt, Wesley L. Kline, Daniel L. Ward, and Nancy L. Brill
From 2006 to 2008, four different production systems and five bell pepper cultivars (Capsicum annuum) with either no resistance (Alliance and Camelot), tolerance (Revolution), or resistance (Paladin and Aristotle) to the crown rot phase of phytophthora blight (Phytophthora capsici) were evaluated for the development of skin separation or “silvering” in fruit at a research facility and four commercial vegetable farms in southern New Jersey. Cultivar, production system, and year, each had a significant effect on the total percentage of fruit with skin separation and marketable yield. The percentage of bell pepper fruit with skin separation was higher in both phytophthora-resistant cultivars compared with the phytophthora-susceptible cultivars across all four production systems. Marketable yield was highest when bell peppers were grown in double rows on raised beds with black plastic mulch and drip irrigation compared with bell peppers grown on single rows on raised beds with black plastic mulch and drip irrigation and bell peppers grown on single rows on raised, bare ground beds with buried drip irrigation. Marketable yields were lowest when bell peppers were grown in single rows on high, ridged beds with overhead irrigation. Results of this study suggest that the development of skin separation or “silvering” in fruit is more closely associated with genotype than type of production system.
Wesley L. Kline, Christian A. Wyenandt, Daniel L. Ward, June F. Sudal, and Nancy L. Maxwell
In this study, the effects of six nitrogen fertility programs and two bell pepper (Capsicum annuum) cultivars were evaluated for marketable yield and incidence of skin separation in fruit. In 2006 and 2007, bell pepper cultivar Aristotle, which is tolerant to the crown rot phase of phytophthora blight (Phytophthora capsici), and a susceptible cultivar, Camelot, were established in a split-plot design with cultivar as the whole-plot factor and fertilizer regime as the subplot factor. Each year, fertility treatments included 1) 180 lb/acre of soluble nitrogen (N) plus phosphorus (P) and potassium (K) as 20N–8.7P–16.6K, 2) 300 lb/acre of soluble N (4N–0P–6.6K), 3) 180 lb/acre of soluble N (30N–0P–0K), 4) 135 lb/acre of soluble N (30N–0P–0K), 5) 180 lb/acre of granular N (43N–0P–0K), and 6) 135 lb/acre of granular N (43N–0P–0K). Soluble fertilizer treatments 1–4 were applied weekly through drip irrigation during the production season. Granular fertility treatments 5 and 6 were applied after bed making but before laying black plastic mulch each year. Additionally, all plots received 180 lb/acre each of P and K (0N–2.6P–4.9K) plus 2 lb/acre of boron distributed season-long in weekly fertilizer applications. In 2006 and 2007, cultivar had no effect on marketable yield or percent marketable fruit. In 2007, the percentage of harvested fruit with skin separation was significantly higher in fertility programs 1 and 2 compared with program 5. In 2006 and 2007, there were no significant interactions between cultivar and fertility program for marketable yield per plot, fruit with skin separation, percent marketable fruit, or marketable yield per acre. In both years, harvest date has a significant effect on marketable yield per plot, fruit with skin separation, percent marketable fruit, and marketable yield per acre. The percentage of harvested fruit with skin separation was higher in phytophthora-tolerant ‘Aristotle’ compared with phytophthora-susceptible ‘Camelot’ in 2006 and 2007. Results of this study suggest that the development of skin separation in bell pepper fruit is more influenced by genotype than N fertility program.
Kristian E. Holmstrom, Marilyn G. Hughes, Wesley L. Kline, Sarah D. Walker, and Joseph Ingerson-Mahar
In 1998, Rutgers Cooperative Extension (RCE) and the Grant F. Walton Center for Remote Sensing and Spatial Analysis (CRSSA) at Rutgers University began a joint program to use global positioning system (GPS) and geographic information systems (GIS) technologies to map the spatial distribution of corn earworm (Helicoverpa zea Boddie (Lepidoptera:Noctuidae)) and European corn borer (Ostrinia nubilalis Hübner (Lepidoptera:Pyralidae)). In 1999 the Rutgers Cooperative Extension Vegetable Integrated Pest Management (IPM) Program operated a network of 81 blacklight insect survey traps in New Jersey. These 15 W blacklight traps were used to monitor adult populations of vegetable crop pests including corn earworm and European corn borer. All blacklight trap sites were mapped using a hand held GPS unit. Average daily corn borer population data were imported into a GIS software package, and then linked to corresponding mapped locations throughout New Jersey. State wide spatial distributions of adult corn earworm and European corn borer population data were imported into a GIS software package, and then linked to corresponding mapped locations throughout New Jersey. State wide spatial distributions of adult corn earworm and European corn borer populations were produced weekly, and distributed via extension newsletters and web sites to augment the current RCE IPM outreach program.
Charles S. Krasnow, Andrew A. Wyenandt, Wesley L. Kline, J. Boyd Carey, and Mary K. Hausbeck
Phytophthora crown and root rot, incited by Phytophthora capsici, is an important and limiting disease in bell pepper (Capsicum annuum) production in many vegetable-producing areas of the United States. Soilborne oospores initiate disease when conditions are favorable, and polycyclic production of sporangia and zoospores occurs on infected plant tissue during the production season. Raised-bed plant culture, resistant cultivars, and oomycete-specific fungicides are commonly used to manage P. capsici. The objective of this study was to evaluate four bell pepper cultivars and four experimental breeding entries (collectively termed entries) for resistance to P. capsici in Michigan (MI) and New Jersey (NJ) and to determine the effect of a fungicide program on plant health and yield. The pepper cultivars included Camelot X3R (susceptible), Aristotle (intermediately resistant), and Paladin and Archimedes (resistant) for comparison. Disease symptoms included plant wilting and sunken necrotic stem lesions. In NJ, blighting of stems and foliage was also observed. In MI, >90% of the susceptible ‘Camelot X3R’ plants in the untreated plot wilted and died in both years of the study. All other entries had <10% plant wilting and death in 2014. In 2015, ‘Archimedes’ and ‘Paladin’ had <10% wilt and plant death; ‘Aristotle’, AP4835, 13SE12671, and AP4841 had 10% to 30% symptomatic plants. The fungicide program reduced disease to <10% for all entries except ‘Camelot X3R’ in 2014 and ‘Aristotle’ and ‘Camelot X3R’ in 2015. In NJ, ‘Paladin’, ‘Aristotle’, and ‘Camelot X3R’ (2014) and ‘Archimedes’, ‘Aristotle’, and ‘Camelot X3R’ (2015) had >30% plant wilting and death in the untreated plot. In the fungicide-treated plot, AP4841, AP4835, and AP4839 (2014), and AP4839 (2015) had <10% of plants with disease symptoms; ‘Camelot X3R’ and ‘Aristotle’ had >40% plant wilting and death in both years. In MI, marketable yield for ‘Paladin’ in fungicide-treated and untreated plots was significantly higher than the other entries in both years (P < 0.05). AP4839 was the highest yielding entry in NJ in the untreated plot, and AP4839 and ‘Archimedes’ were highest yielding in the fungicide-treated plot in 2014 and 2015, respectively. Fruit size for 13SE12671 was the largest among entries in both locations. There was no entry × fungicide program interaction in MI.
Jorge M. Fonseca, Hyun-Jin Kim, Wesley L. Kline, Christian A. Wyenandt, Murshidul Hoque, Husein Ajwa, and Ned French
The effect of preharvest application of a newly developed second-generation harpin product (2G-Harpin) on shelf life of fresh-cut lettuce (Lactuca sativa) was investigated. The lettuce plants were grown in three locations in the United States: Watsonville, CA, Cedarville, NJ, and Yuma, AZ, and treated 5 days before harvest at 140, 280, and 420 g·ha−1 (30, 60, and 90 mg·L−1). Lettuce processed and bagged were stored at 1 to 3 °C and evaluated for quality for 20 days. Lettuce from California treated with 2G-Harpin at 280 to 420 g·ha−1 consistently showed better visual quality and lower microbial population than the control. Overall results in New Jersey showed no major differences among treatments. In Arizona, microbial population was lower and visual quality was higher in lettuce treated at 280 and 420 g·ha−1 during part of the storage period. In further experimentation, we examined the phenolic content of lettuce harvested 1 and 7 days after treatment with 2G-Harpin. The results showed that phenolic content was higher in all treated lettuce than in the control lettuce after 24 h. Six days later, the levels fell back to the initial stage. Antioxidants capacity increased by 40% in head leaves when plants were treated with 280 and 420 g·ha−1 2G-Harpin, but no change was observed in outer leaves. Overall, it was revealed that a field application of 2G-Harpin can improve quality of fresh-cut lettuce under environmental conditions that need to be determined. Our results with phenolic content and antioxidant activity suggested that improvement in quality is probably the result of alteration of metabolites' composition and demonstrated that increased phenolics do not correlate with lower quality of fresh-cut products.