bluuebunny/crossref_metadata_2025 huggingface dataset:
Using an Agroecological Approach to Farming Systems Research
Authors: Delate K.
Published: December 2018

Sales of organic products reached $8 billion in the U.S. in 2000, continuing the nearly decade-long trend of 20% annual growth. In Iowa alone, organic production for all crops was 5265 ha (13,000 acres) in 1995 but 60,750 ha (150,000 acres) in 1999. Despite the growth in organic agriculture, our knowledge of organic farming systems remains limited. We have adopted a systems theory approach in our current research program at Iowa State University (ISU) to help address this gap in understanding. Systems theory holds that biological systems, such as agroecosystems, consist of integrated units of people, plants, animals, soil, insects and microorganisms, and each subsystem provides feedback to the other. In order to obtain input on research questions and experimental design, the Leopold Center for Sustainable Agriculture and ISU held six focus groups across Iowa in 1998 before long-term site establishment. Producers and agricultural professionals at the focus groups supported the need for long-term agroecological research (LTAR) sites in four distinct agroecological zones in Iowa. The goal of each LTAR is to examine the short- and long-term physical, biological, and socioeconomic effects of organic and conventional farming systems. By establishing long-term experiments, we are testing the hypothesis that longer crop rotations, typical of organic farms, provide yield stability, improve plant protection, and enhance soil health and economic benefits compared to conventional systems with shorter rotations and greater off-farm inputs. Examples of research results from two LTAR experiments in Iowa include similar pepper (Capsicum annuum) and soybean (Glycine max) yields in the conventional and organic systems. Organic systems used mechanical weed control and locally produced compost in place of synthetic fertilizers. Feedback from the local farm associations that are responsible for farm stewardship and farm finances is inherent in the LTAR process.
Making New York Vegetable Crop and Pest Management Systems Information Available in a Userfriendly Format
Authors: Petzoldt Curtis H. , Reiners Stephen , Hoffmann Michael P.
Published: December 2018

The document Cornell Integrated Crop and Pest Management Guidelines for Commercial Vegetable Production was revised in 1999 to become inclusive and integrative of all aspects of crop and pest management. As an adjunct to the printed publication, additional information was presented in tables at an Internet web site. Links on the web site were made to other sites with more detailed information on specific topics, such as photographs of pests and diagnostic information, soil fertility testing, cover crops, environmental impact of pesticides, pesticide labels, and images, sources, and life cycles of beneficial insects. The revision and web site have proven to be popular with cooperative extension staff and the vegetable industry in New York.
1998 Ornamental Corn Trial in Pennsylvania
Authors: Orzolek M.D. , Lamont W.J. , Otjen L.
Published: December 2018

Twenty-two ornamen tal corn (Zea mays) cultivars were evaluated in the summer of 1998. The cultivars were evaluated for marketable yield, percent cull, stalk characteristics, and ear characteristics. In addition, three ears of each cultivar were photographed to show size and variability in kernel color. The marketable yield of each cultivar was generally related to percent germination, established plant population, and ear size. Highest marketable yields (dozen/acre) were generally harvested from small-eared cultivars [ear size 2.0 to 4.5 inches (5.1 to 11.4 cm)]. Data from this trial suggest that multiple cultivars should be grown in Pennsylvania based on market requirements and extremes in weather patterns throughout the state.
Change over Time in Quality and Cover of Various Turfgrass Species and Cultivars Maintained in Shade
Authors: Gardner D.S. , Taylor J.A.
Published: December 2018

In 1992, a cultivar trial was initiated in Columbus, Ohio to evaluate differences in establishment and long-term performance of cultivars of tall fescue (Festuca arundinacea), creeping red fescue (F. rubra), chewings fescue (F. rubra ssp. fallax), hard fescue (F. brevipila), kentucky bluegrass (Poa pratensis), rough bluegrass (P. trivialis), and perennial ryegrass (Lolium perenne) under low maintenance conditions in a shaded environment. Fertilizer and supplemental irrigation were applied until 1994 to establish the grasses, after which no supplemental irrigation, or pesticides were applied and fertilizer rates were reduced to 48.8 kg·ha-1 (1 lb/1000 ft2) of N per year. Percentage cover and overall quality data were collected in 2000 and compared with data collected in 1994. Initial establishment success does not appear to be a good predictor of long-term success of a cultivar in a shaded environment. There was some variability in cultivar performance under shade within a given turfgrass species. The tall fescue cultivars, as a group, had the highest overall quality and percentage cover under shade, followed by the fine fescues, kentucky bluegrass, rough bluegrass, and perennial ryegrass cultivars.
Restructuring State Major Programs to Address Performance-based Budgeting and Issues Programming
Authors: Gunderson Kathryn , Sargent Steven A. , Cantliffe Daniel J. , Jacob Steven G. , Hochmuth George J.
Published: December 2018

To remain competitive for federal and state funding, state cooperative extension services must proactively incorporate issues programming and performance-based budgeting. State major program (SMP) design teams, which provide linkages between clientele groups and the research base, must conduct needs assessments to adjust to this new atmosphere of accountability. A case study illustrates how one Florida SMP (FL107, vegetable production, harvest, handling and integrated pest management in Florida) restructured its design team to become more flexible and proactive to target a wider range of outcomes. While still in the implementation phase, this model has already resulted in improved communication within the organization, better addressing extension needs at county level while facilitating reporting at the state level.
Factors Affecting Root Rot Control in Mulched Avocado Orchards
Authors: Downer Jim , Faber Ben , Menge John
Published: December 2018

Mulches can exert positive (disease controlling) or negative (disease enhancing) potential when applied to young avocado (Persea americana) trees. Regulation of root disease in avocado is a complicated process that is affected by host resistance, inoculum density, temperature, soil salinity and soil water potential. There are short-term immediate effects from mulching and subtle long-term effects that regulate disease caused by the root rot pathogen Phytophthora cinnamomi. Short-term effects include increased soil moisture and soil temperature moderation. Long-term effects include increases of: soil mineral nutrients, soil aggregation and drainage; microbial activity; and cellulase enzyme activities. Biological control of Phytophthora in mulched soil is partially regulated by cellulase enzyme activities. This soil enzyme concept of biological control is discussed in regard to the classical Ashburner method of biological control.
Leading Edge of Plant Protection for Almond
Authors: Connell Joseph H.
Published: December 2018

Almond, [Prunus dulcis (synonym Prunus amygdalus)] planted on approximately 595,000 acres (240,797 ha), is California's largest acreage tree crop. California's Central Valley accounts for nearly 100% of the U.S. domestic production of almonds. Integrated pest management (IPM) programs that integrate cultural practices and pest and disease monitoring with selective controls have improved plant protection in almond. Methods of orchard floor management and their effects must also be taken into account. Minimizing dust reduces mites while harvesting earlier and the destruction of overwintering refugia are cultural practices that reduce worm damage. Improved methods for field sampling and monitoring have reduced the need for pesticide applications while improving timing and effectiveness of needed crop protection sprays. Selective controls have further reduced the impact on nontarget species. Augmentative parasite releases have also helped manage navel orangeworm (Ameylois transitella). Effective use of new selective fungicides will require precise application timing and greater knowledge of diseases and resistance management. A better understanding of disease life cycles leading to improved monitoring of the fungal diseases, shothole (Wilsonomyces carpophilus), almond scab (Cladosporium carpophilum), and anthracnose (Colletotrichum acutatum) have reduced fungicide applications. Future challenges include the potential loss of effective pest control products, the need to continually develop improved utilization strategies, and maintaining economic sustainability.
The Influence of Reflective Film and ReTain on Red Skin Coloration and Maturity of `Gala' Apples
Authors: Layne Desmond R. , Jiang Zhengwang , Rushing James W.
Published: December 2018

Replicated trials were conducted in Summers 1998 and 1999 at two commercial orchards (A and B) to determine the influence of a metalized, high density polyethylene reflective film (SonocoRF) and aminoethoxyvinylglycine (ReTain), on fruit red skin coloration and maturity of `Gala' apples (Malus sylvestris var. domestica). There were four experimental treatments: 1) nontreated control; 2) reflective film (RF); 3) ReTain; and 4) RF + ReTain. RF was applied 4 weeks before anticipated start of harvest by laying a 5-ft-wide (150-cm) strip on each side of the tree row in the row middle. ReTain was applied 4 weeks before harvest at the commercial rate in one orchard and at 60% of the commercial rate in a second test. ReTain delayed fruit maturity. Fruit from RF trees had a significantly greater percent surface red color than fruit from trees not treated with RF. Fruit from RF + ReTain were significantly redder and had higher soluble solids concentration (SSC) than fruit from trees treated with ReTain alone. There were no differences in size, fruit firmness or starch content between fruit from RF and RF + Retain. RF appears to be a method to increase red skin coloration in `Gala' apples treated with ReTain without adversely impacting maturity.
Using the SPAD 502 Meter to Assess Chlorophyll and Nitrogen Content of Benjamin Fig and Cottonwood Leaves
Authors: Loh Felix C. W. , Grabosky Jason C. , Bassuk Nina L.
Published: December 2018

A Minolta SPAD-502 leaf chlorophyll meter was used for nondestructive data collection on the chlorophyll and nitrogen (N) status of benjamin fig (Ficus benjamina) and cottonwood (Populus deltoides) to quantitatively evaluate foliage quality. The goal was to provide a specific calibration for interpreting SPAD data within a media study for each species. Triplicate SPAD readings were collected from each of six leaves, sampled from forty plants per species, then processed for foliar analysis. Leaf tissue disks were also collected directly over SPAD testing sites for chlorophyll concentration measurement. Significant linear correlations were found between SPAD data and chlorophyll concentrations (r2 = 0.90 in benjamin fig and r2 = 0.91 for cottonwood). A significant, but lower correlation was found between SPAD data and N concentration. The SPAD-N correlations improved from the fifth month to the ninth month harvest (r2 = 0.32 to 0.53 for benjamin fig and 0.26 to 0.42 for cottonwood). The SPAD-502 could be useful for in landscape plant management, and in time for production situations, but baseline data is needed. Consistent protocol in sample collection and seasonal timing is needed prior to use as a predictor for tissue N levels. Development of species, and perhaps cultivar, specific baseline data and sampling procedures will need development, but could yield a rapid, quantitative, in expensive field diagnostic for foliage quality for making cultural management decisions.
An Updated Hardiness Zone Map for Dallas-Fort Worth, Texas
Authors: Harp Derald A. , McWilliams Edward L. , Arnold Michael A. , Griffiths John F.
Published: December 2018

The combination of concrete and asphalt surfaces, large buildings, lack of surface water, and anthropogenic heat inputs result in urban temperatures warmer than surrounding rural areas. This effect is often most pronounced with winter minimum temperatures and may cause changes in local plant hardiness zones. Local minimum temperatures were obtained for the years 1974-96 from the National Climatic Data Center and the Office of the State Climatologist of Texas for all recording stations within the Dallas-Fort Worth, Texas metropolitan area. Data were averaged and analyzed in two groups: 1974-86 and 1987-96. Contour maps were created using Surfer software. The 1974-86 local map had only one major difference from the 1990 USDA Plant Hardiness Zone map, which was the inclusion of 8a temperatures in more western portions of the metroplex. The inclusion of the years 1987-96 resulted in the westward expansion of 8a and a new 8b zone near downtown Dallas. These changes mimic the expansion of suburban development and increased urbanization over the last decade. We propose an updated plant hardiness zone map for this metropolitan area, which should more accurately reflect changes that have occurred since publication of the USDA Plant Hardiness Zone map.
Bitterness and Composition of Lettuce Varieties Grown in the Southeastern United States
Authors: Simonne Amy , Simonne Eric , Eitenmiller Ronald , Coker Christine Harris
Published: December 2018

Lettuce (Lactuca sativa) production historically has been limited in the southeastern United States because of the risk of early bolting and unacceptable bitterness. Small-scale vegetable growers may be able to include lettuce in their production through selection of bolt tolerant and nonbitter varieties. The objectives of this research were to evaluate earliness, bitterness, vitamin E, ascorbic acid, folate, β-carotene, and lutein content in 17 lettuce varieties. Significant difference were found among varieties for days to harvest (DTH) (47 DTH for `Epic' to 37 DTH for `Big Curly'). Observed DTH in this study was consistently 7 to 10 days less than commercial descriptions of the lettuce varieties, due to the use of transplants. Only `Slobolt' and `Greengo' bolted before reaching marketable size. Panelists found that the bitterness was acceptable for most varieties, but not for `Nancy,' `Big Curly,' and `Slobolt'. Significant differences among varieties were also found in vitamin E, ascorbic acid, folate, β-carotene, and lutein. `Redprize' and `Nevada' were the best varieties overall, while `Salinas 88 Supreme,' `Epic,' `Legacy,' `Big Curly,' `Slobolt,' and `Greengo' were unacceptable.
Herbicide Losses in Runoff of Containerized Plant Production Nurseries
Authors: Riley Melissa B.
Published: December 2018

Herbicide use in containerized plant production nurseries is a vital tool for weed management and the production of plants desired by the consumer. Clemson University researchers have conducted studies aimed at determining the amount of herbicide runoff during normal nursery operation, if herbicides accumulate in containment ponds at nurseries, and how herbicide runoff could be reduced. A 2-year study at commercial nurseries found that herbicide concentrations were higher in containment ponds soon after herbicide application, when compared with months with less herbicide application; and herbicides did not accumulate over the 2-year period. Herbicide runoff was greatest immediately after application and up to 15% of the herbicide applied was lost in the first irrigation event after application when using more water soluble herbicides. Bed material and herbicide formulation were also important in determining the amount of herbicide lost. Total losses were highest from plastic- and fabric-covered beds when using granular formulations and highest from gravel beds when spray formulations were used. The combination of using cyclic irrigation and grass waterways resulted in a reduction of about 25% of isoxaben loss when compared with clay and gravel waterways with continuous irrigation. The effects of reduced herbicide treatments compared to standard spray schedules were evaluated on herbicide transport, weed development, and plant growth and health. Results indicated that plant marketability was not affected, and total herbicide runoff was significantly reduced. Based on these studies, several recommendations can be made to commercial container plant production nurseries, which should reduce herbicide runoff and thereby reduce the environmental concerns associated with nurseries.
Production Steps to Reduce Seed Contamination by Pathogens of Cucurbits
Authors: Lovic Branko R. , Hopkins Donald L.
Published: December 2018

Selecting production areas for low disease pressure, implementation of preventive spray programs, and continuous monitoring for disease symptoms are important steps to keep seed production fields free of potentially seedborne diseases, such as bacterial fruit blotch of cucurbits (Cucurbitaceae), caused by Acidovorax avenae ssp. citrulli. However, seeds of cucurbit crops and other fleshy vegetables typically remain remarkably free of pathogenic bacteria and fungi while in intact fruit. The most significant risk for seed contamination comes at harvest when the inoculum present in the field or in the seed harvesting area may contaminate the seeds. Properly executed fermentation and seed drying processes significantly reduce seed contamination. Application of a no-rinse disinfectant formulation to freshly harvested seed just before drying may be the single most efficacious procedure to reduce the seed contamination risk. However, the disinfection step should not be expected to be effective unless applied as part of a fully controlled seed harvest process.
Efficacy of Plant Growth Regulators on the Growth of Vigorous Osteospermum Cultivars
Authors: Gibson James L. , Whipker Brian E.
Published: December 2018

Vigorous osteospermum (Osteospermum ecklonis) cultivars Congo and Wildside received foliar sprays of daminozide or daminozide + chlormequat (Expt. 1). Both cultivars responded similarly to the plant growth regulator (PGR) treatments. Only a limited amount of plant height control occurred using 5,000 mg·L-1 (ppm) daminozide + 1,500 mg·L-1 chlormequat or 5,000 mg·L-1 daminozide + 3,000 mg·L-1 chlormequat. Flowering was delayed, phytotoxicity was observed, while peduncle length increased, suggesting that higher concentrations of daminozide or chlormequat may or not be effective at any concentration and may result in increased phytotoxicity. In Expt. 2, `Lusaka' received foliar sprays or substrate drenches of paclobutrazol or uniconazole. Foliar sprays ≤80 mg·L-1 paclobutrazol or ≤24 mg·L-1 uniconazole were ineffective in controlling plant growth. Substrate drenches of paclobutrazol (a.i.) at 8 to 16 mg/pot (28,350 mg = 1.0 oz) produced compact plants, but at a cost of $0.23 and $0.46/pot, respectively, would not be economically feasible for wholesale producers to use. Uniconazole drenches were effective in producing compact `Lusaka' osteospermum plants. Uniconazole drench concentrations of 0.125 to 0.25 mg/pot were recommended for retail growers, while wholesale growers that desire more compact plants should apply a 0.25 to 0.5 mg/pot drench. Applying uniconazole would cost $0.06 for a 0.25 mg drench or $0.12 for a 0.5 mg drench.
Survival of Blackeyed Susan from Different Regional Seed Sources under Low and High Input Systems
Authors: Marois James J. , Norcini Jeffrey G.
Published: December 2018

Survival of black-eyed susan (Rudbeckia hirta) from three regional seed sources was evaluated after inoculation with the pathogenic fungus Fusarium oxysporum in the greenhouse, and after they were planted in fumigated or nonfumigated and irrigated or nonirrigated field plots. The three seed sources were northern Florida (NFL), central Florida (CFL), or Texas (TEX). Plants from the three seed sources were inoculated individually under greenhouse conditions with four isolates of F. oxysporum originally isolated from the roots of diseased black-eyed susan grown in ecotype trials near Monticello, Fla. About 20% of the inoculated plants developed symptoms similar to those observed in the field, but no consistent ecotype or isolate effects were observed. In the field trial, planting beds were fumigated with methyl-bromide and chloropicrin and irrigated with drip irrigation (high input), not fumigated and irrigated, fumigated and not irrigated, or not fumigated and not irrigated (low input). During the first month of the trial, treatment and seed source had a significant effect on survival due to the low initial survival of NFL in the nonfumigated-nonirrigated plots. After the first month, only seed source had asignificant effect on survival, with TEX decreasing rapidly and the NFL population decreasing to a lesser degree. The decline of TEX could not be directly attributed to pests or climatic effects.
A System to Measure Evapotranspiration of In-ground Container Plants of Mexican Elder
Authors: St. Hilaire Rolston , Feser Cathleen F. , Sammis Theodore W. , St. Hilaire Anderson S.
Published: December 2018

Accurate measurement of evapotranspiration (ET) is difficult and expensive for large, in-ground container (pot-in-pot) plants. We engineered and used a simple and inexpensive system to determine evapotranspiration of in-ground container trees. The system was shop-assembled and used a block and tackle system attached to a collapsible tripod. A unique container harness system attached to the block and tackle system was used to lift containers that were sunken in the ground. Containers were weighed with a battery-operated balance that was accurate to 1 g (0.04 oz) at its maximum load capacity of 60 kg (132.3 lb). One person operated the system, and the weight of the system exclusive of the balance was 17.5 kg (38.50 lb). Gravimetric water use data obtained with the system werecombined with meteorological data to compute crop coefficients (Kc) of mexican elder (Sambucus mexicana). The system detected small changes in daily water use of mexican elder trees grown in 76-L (20-gal) in-ground containers. Crop coefficients ranged from 0.17 to 0.71. The acquisition of evapotranspiration data from relatively large, containerized landscape plants may be facilitated because the system is simple, inexpensive, and accurate.
Postharvest Handling of Heliconia, Red Ginger, and Bird-of-Paradise
Authors: Jaroenkit Teeranuch , Paull Robert E.
Published: December 2018

Heliconia (Heliconia spp.), red ginger (Alpinia purpurata), and bird-of-paradise (Strelitzia reginae) inflorescences have similar stem structures and postharvest handling regimes. Inflorescences, especially heliconia, should be harvested in the morning while still turgid, and at the most suitable stage of development which varies with the species, its proposed use, and market requirements. Treatments that extend postharvest vase life, either or both enhance water uptake or prevent water loss and provide an exogenous energy source. Use of the most suitable temperature for shipping and storage prolongs vase life. Heliconia should be shipped and stored at >10 °C (50.0 °F), red ginger >12 °C (53.6 °F), and bird-of-paradise at >8 °C (46.4 °F). Sucrose (10% w/v), citric acid [150 mg·L-1 (ppm)] and 8-hydroxyquinoline citrate (250 mg·L-1) are major chemicals used in pulsing and holding solution for bird-of-paradise. Holding solutions for red ginger are similar except 2% (w/v) sucrose is recommended. The response of heliconia inflorescences to different pulsing and holding solutions has been shown to be negligible. A 200-mg·L-1 benzyladenine spray extends the vase life of red ginger and heliconia. Hot water treatment of red ginger at 49 °C (120.2 °F) and 50 °C (122.0 °F) for 12 to 15 min extends postharvest vase life, kills most of the pests that infest red ginger, and reduces the geotropic response. The major postharvest problems are saprophytic mold on bird-of-paradise, negative geotropic response of red ginger, and insect infestation of all three flowers. There is no reported method to control the postharvest nectar and slime production on bird-of-paradise that provides a substrate for saprophytic mold growth. Dipping inflorescences in benomyl or thiobendazole (TBZ) at 200 mg·L-1 does help control postharvest mold growth in bird-of-paradise and heliconia. Compared to most temperate flowers, there is a need for greater understanding of morphological and physiological factors that limit the vase life of heliconia, red ginger and bird-of-paradise flowers.
Influence of Fertilizer Placement on Plant Quality, Root Distribution, and Weed Growth in Container-grown Tropical Ornamental Plants
Authors: Broschat Timothy K. , Moore Kimberly K.
Published: December 2018

In two experiments, chinese hibiscus (Hibiscus rosa-sinensis), bamboo palm (Chamaedorea seifrizii), areca palm (Dypsis lutescens), fishtail palm (Caryota mitis), macarthur palm (Ptychosperma macarthurii), shooting star (Pseuderanthemum laxiflorum), downy jasmine (Jasminum multiflorum), plumbago (Plumbago auriculata), alexandra palm (Archontophoenix alexandrae), and foxtail palm (Wodyetia bifurcata) were transplanted into 6.2-L (2-gal) containers. They were fertilized with Osmocote Plus 15N-3.9P-10K (12-to14-month formulation) (Expt. 1) or Nutricote Total 18N-2.6P-6.7K (type 360) (Expt. 2) applied by either top dressing, substrate incorporation, or layering the fertilizer just below the transplanted root ball. Shoot dry weight, plant color, root dry weights in the upper and lower halves of the root ball, and weed shoot dry weight were determined when each species reached marketable size. Optimal fertilizer placement method varied among the species tested. With the exception of areca palm, none of the species tested grew best with incorporated fertilizer. Root dry weights in the lower half of the root ball for chinese hibiscus, bamboo palm, and downy jasmine were greatest when the fertilizer was layered and root dry weights in the upper half of the root ball were greatest for top-dressed chinese hibiscus. Weed growth was lower in pots receiving layered fertilizer for four of the six palm species tested.
Genotypic Variation in Chilling Sensitivity of Mature-green Bananas and Plantains
Authors: Morrelli Keri L. , Hess-Pierce Betty M. , Kader Adel A.
Published: December 2018

The variation in chilling sensitivity of mature-green specialty bananas (Musa paradisiaca var. sapientum) and plantains (Musa paradisiaca var. paradisiaca) was examined using four cultivars of bananas and one plantain cultivar stored under various time and temperature combinations. Cold storage for 1 day at 5.0, 7.2, or 10.0 °C (41, 45, or 50 °F) resulted in acceptable fruit quality for up to 8 days at 20.0 °C (68 °F) for `Petite' and `Red Macabu' bananas and `Dominico Harton' plantains. `Grand Nain' and `Yangambi' bananas were considered unmarketable due to moderate to severe graying after 8 days at 20.0 °C when fruit were previously stored for 1 day at 5.0 or 7.2 °C. Storage for 3 days at 10.0 °C was acceptable for all cultivars tested, however 5 days at 10.0 °C resulted in moderate to severe browning and graying of the `Grand Nain' fruit. The traditional Cavendish-type, `Grand Nain', as well as `Petite' and `Yangambi', required temperatures greater than 10.0 °C for a 7-day storage duration while `Red Macabu' bananas could be safely stored for 7 days at 10.0 °C. Plantains could be stored at 7.2 °C for 7 days without visible chilling injury symptoms. The storage of specialty bananas and plantains at or above their minimum safe temperatures resulted in improved uniformity of ripening and overall quality of the fruit due to a decrease in chilling injury symptoms.
Impact of a Brief Postharvest Hot Water Drench Treatment on Decay, Fruit Appearance, and Microbe Populations of California Lemons and Oranges
Authors: Smilanick Joseph L. , Sorenson David , Mansour Monir , Aieyabei Jonah , Plaza Pilar
Published: December 2018

A brief (15 or 30 seconds) high-volume, low-pressure, hot-water drench at 68, 120, 130, 140, or 145 °F (20.0, 48.9, 54.4, 60.0, or 62.8 °C) was applied over rotating brushes to `Eureka' lemons (Citrus limon) and `Valencia' oranges (Citrus sinensis). The impact of this treatment on populations of surface microbes, injury to the fruit, the incidence of green mold (Penicillium digitatum)or sour rot (Geotrichum citri-aurantii), when inoculated into wounds one day prior to treatment, and temperatures required to kill the spores of these fungi and P. italicum suspended in hot water were determined. Fruit microbial populations were determined immediately after treatment. Decay and injuries were assessed after storage for 3 weeks at 55 °F (12.8 °C). The efficacy of the hot water treatments was compared to immersion of fruit in 3% wt/vol sodium carbonate at 95 °F (35.0 °C) for 30 seconds, a common commercial practice in California. Initial yeast and mold populations, initially log10 6.0 per fruit, were reduced to log10 3.3 on lemons and log10 4.2 on oranges by a 15-second treatment at 145 °F. Green mold control improved with increasing temperature and treatment duration. Green mold incidence was reduced from 97.9% and 98.0% on untreated lemons and oranges, respectively, to 14.5% and 9.4% by 30 seconds treatment with 145 °F water. However, immersion of lemons or oranges in 3% wt/vol sodium carbonate was superior and reduced green mold to 8.0% and 8.9%, respectively. Sour rot incidence on lemons averaged 84.3% after all water treatments, and was not significantly reduced, although arthrospores of G. citriaurantii died at lower water temperatures than spores of P. digitatum and P. italicum in in vitro tests. Sodium carbonate treatment for 30 seconds at 95 °F reduced sour rot to 36.7%. None of the treatments caused visible injuries to the fruit.
Survival, Growth and Establishment of Grafted Pawpaws in Upstate New York
Authors: Merwin Ian A. , Byard Rachel , Pomper Kirk W.
Published: December 2018

A pawpaw regional variety trial (PRVT) was established at Cornell University, Ithaca, N.Y. in Apr. 1999 consisting of 28 commercially available pawpaw (Asimina triloba) varieties or advanced selections from the PawPaw Foundation (PPF; Frankfort, Ky.). Eight replicate trees of each selection, grafted onto seedling rootstocks, were planted in a randomized block design. The first two winters at the test planting site were unusually mild for the Finger Lakes region, with the lowest recorded temperatures above -16 °C (3.2 °F). Despite these mild winters, there was extensive winter mortality of some pawpaw varieties. Survival rates were >75% for 11 varieties, and were <40% for five other varieties. Poor establishment of grafted clonal pawpaws and insufficient pollination or fertilization of established pawpaws were important limitations of successful commercialization of this new fruit crop under conditions typical of upstate New York. Open mesh black plastic trunk guards provided adequate shade and protection for newly planted pawpaws, whereas translucent plastic tree-tubes caused heat stress and scorching of the young trees.
High-density Apple Orchard Performance on an Orchard Replant Site: An 11-year Summary
Authors: Unrath C.R.
Published: December 2018

High-density apple (Malus domestica) orchard management techniques and productivity were evaluated on an old orchard replant site in North Carolina. Trees were planted at 5 × 10 ft (1.5 × 3.0 m), giving a tree density of 871 trees/acre (2152 trees/ha). Well-branched `Smoothee Golden Delicious' trees on `Mark' rootstock were planted in 1990. Orchard-management factors which increased cumulative yield were supplemental irrigation (+21%), slender spindle training (+19%), preplant tree-hole fumigation (+11%), and fumigation + postplant mefenoxam (Ridomil) collar drench (+17%). Collectively, these factors increased cumulative yield by 55%. Supplemental irrigation was the only treatment to significantly impact fruit quality, increasing average fruit size by 20% over the 11-year study.
Sowing Dates and Priming Influence African Marigold Field Emergence
Authors: Conway Kenneth E. , Dole John M. , Bosma Theresa L. , Maness Niels O.
Published: December 2018

Field seedling emergence of four african marigold (Tagetes erecta) breeding lines, A-975, E-1236, I-822, and `Orange Lady', was examined using three or four spring sowing dates and either osmotic or solid matrix priming. Delayed sowing decreased emergence time. Sowing from middle to late April [average soil temperatures 77.0 to 84.2 °F (25 to 29 °C)] resulted in the highest total emergence percentages. Greater fl ower quantities [4.9 to 5.1 million/acre (12.11 to 12.60 million/ha)] and estimated yield [7.5 to 10.8 tons/acre (16.81 to 24.20 t·ha-1)] indicate mid to late April is the optimum time period for direct sowing unprimed seed in the southern Great Plains. Differences between lines were evident in emergence parameters and fl ower harvest data for each year examined, but results were inconsistent from year to year. However, A-975 and E-1236 produced harvestable fl owers most quickly, about 15 d before I-822, which could result in an additional harvest during a season. Osmotic priming of E-1236 and I-822 seed shortened emergence time, increased emergence uniformity, and increased total emergence percentage at early sowing dates as compared to both solid matrix primed and unprimed seed.
Evaluation of Medium-applied Insect Growth Regulators Against Fungus Gnats and Western Flower Thrips Populations on African Violets
Authors: Ludwig Scott W. , Hoover Kelli , Berghage Robert
Published: December 2018

In a previous study, three insect growth regulators, diflubenzuron, pyriproxyfen, and fenoxycarb, were shown to reduce the emergence of western flower thrips (Frankliniella occidentalis) from potting medium under experimental conditions. Our objective was to evaluate the impact of potting medium applications of fenoxycarb, diflubenzuron, and pyriproxyfen on western flower thrips and fungus gnats (Bradysia spp.) populations in conventionally grown african violets (Saintpaulia ionantha). In two trials conducted at a university greenhouse and one trial at a commercial flower grower's greenhouse, no reductions were observed in western flower thrips populations. In one university trial, all three insect growth regulators resulted in lower fungus gnat populations. In addition to medium treatment, results from the commercial greenhouse indicated that a pesticide application to the soil under the benches may also be needed to provide management of fungus gnats.
Value-added Vegetable Cultivars: An Assessment of Farmers' Perceptions
Authors: Velasquez Cesar , Eastman Catherine , Masiunas John
Published: December 2018

Fresh-market vegetable production in the midwestern U.S. has been declining due to diminished returns received by farmers, competition from vegetables produced in other regions, older farmers retiring and not being replaced, and urban sprawl. To reverse this trend, midwestern-U.S. vegetable farmers must find ways to enhance the value of their production. One way might be the production of vegetable cultivars that have enhanced attributes desired by consumers. Our objective was to assess how Illinois farmers' current perceptions may affect acceptance and production of vegetable cultivars with enhanced health benefits. About 20% of Illinois fresh-market vegetable growers were surveyed. We found that the current media attention on genetically modified organisms (GMOs) infl uenced grower response. Farmers who were concerned about GMOs were 5 times more likely to reject growing new vegetable cultivars with enhanced health benefits even those developed with conventional breeding methods. However, farmers who were not concerned or who were undecided in their opinions concerning GMOs were 11 times more likely to adopt new cultivars. Education and research programs must be developed to supply information about vegetable cultivars with enhanced health benefits and to address farmers' concerns about GMOs.
Predicting Nitrogen Availability in Irrigated Potato Systems
Authors: Snapp S.S. , Fortuna A.M.
Published: December 2018

Growers lack practical decision aides that accurately predict nitrogen (N) credits for organic sources to adjust fertilizer rates. The simulation model, DSSAT, was used to predict N supply in relationship to N demand in irrigated potatoes (Solanum tuberosum). Tuber yield and soil inorganic N levels were substantially higher in the simulations than in field experiment observations, indicating the need for model improvement. DSSAT was successful at predicting relative mineralization rates and potato N uptake for different organic and inorganic N source combinations. Interestingly, both simulation and field experiment observations indicated that combining a high quality organic manure at 5000 lb/acre (5604.2 kg·ha-1), total applied N 250 lb/acre (280.2 kg·ha-1), and a fertilizer source of N 160 lb/acre (179.3 kg·ha-1) markedly increased yields and lowered leaching potential. Simulated tuber yield for the combined treatment was 660 cwt/acre (74.0 t·ha-1) with 48 lb/acre (53.8 kg·ha-1) inorganic-N in the profile at harvest, whereas the highest simulated N fertilizer response was to 235 lb/acre (263.4 kg.·ha-1), which produced 610 cwt/acre (68.4 t·ha-1) with 77 lb/acre (86.3 kg·ha-1) inorganic-N in the profile at harvest. The synchrony of N release and uptake for combined manure and fertilizer treatments may explain the efficient N uptake observed. Common soil types and weather scenarios in Michigan were simulated and indigenous soil N mineralization was predicted to be 6 lb/acre (6.7 kg·ha-1) inorganic-N in the topsoil at planting, similar to observed levels. The increasing aeration associated with a sandy versus a sandy loam soil only slightly increased the predicted rate of mineralization from organic inputs. Simulated soil inorganic N levels with different organic inputs was modestly increased in a warm spring [4.5 °F (2.50 °C) over normal temperatures] compared to a cool spring (-4.5 °F less than normal temperatures). For Michigan irrigated potato systems, DSSAT simulations indicate that the most important factor determining inorganic N supply will be the quality and quantity of organic inputs, not environmental conditions.
Nitrate Leaching Potential under Variable and Uniform Nitrogen Fertilizer Management in Irrigated Potato Systems
Authors: Whitley K.M , Davenport J.R
Published: December 2018

Potato (Solanum tuberosum) production in Washington State's Central Columbia Plateau faces nitrogen (N) management challenges due to the combination of coarse textured soils (sandy loam to loam) and hilly topography in this region as well as the high N requirement of potato. Potato growth and development can vary with the N availability across the field. In this 2-year study, two adjacent potato fields were selected each year (1999 and 2000). Each field was soil sampled on a 200 × 200 ft (61.0 m) grid to establish existing soil N content. One field was preplant fertilized with variable N rate while the other was conventionally preplant fertilized, applying a uniform rate across the field based on the field average. During the growing season, each field was monitored for nitrate leaching potential using ion exchange membrane technology. Soil and plant nutrient status were also monitored by collecting in-season petiole and soil samples at two key phenological stages, tuber initiation and tuber bulking. Overall this research showed that variable rate preplant N fertilizer management reduced N leaching potential during the early part of the growing season, but did not persist the entire season. Since preplant N accounted for only 40% of the total seasonal N applied, it is possible that further gains could be made with variable rate in-season N application or with variable rate water application.
Computer Controlled Portable Frost Simulator for Field Studies of Frost Effects on Wild Blueberries
Authors: Havard Peter , Eaton Leonard J. , Hicklenton Peter R.
Published: December 2018

Two commercial freezers were modified to provide an inexpensive chamber system to investigate frost effects on wild, lowbush blueberries (Vaccinium angustifolium) under field conditions. A computer control system was developed with software written in Visual Basic 6.0 for MSWindows, which precisely controlled temperature in the plant canopy when the chambers were placed over blueberry plants in the field. Frost events (with temperatures ranging from -2 to -15 °C (28.4 to 5.0 °F)) were simulated by user input to control the cooling and warming rates, and minimum temperatures. The system records temperature set points, and current temperature in the plant canopy, or elsewhere in the plant environment, and provides a graphical display of key parameters. Trials have verified the reproducability of temperature profiles and the chambers have been used to provide preliminary information on the effects of frost at bloom on fruit set and development.
Shadecovers Affect Degradation of Carbaryl on Field-grown Pakchoi
Authors: Marutani Mari , Endirveersingham Veronica
Published: December 2018

The effect of shade covers on degradation of insecticide, carbaryl on field-grown pakchoi (Brassica rapa subsp. chinensis) was examined by a commercial enzyme-linked immunosorbent assay (ELISA) kit. Carbaryl at a.i. 10.6 g·L-1 (1.42 oz/gal) was applied to the plants grown under five different shade treatments including control without any coverings. The experiment was arranged in a randomized complete block design with three replications. Pesticide residue on leaf tissues was examined on dates of 1, 3, 5, and 7 days after pesticide application. On all sampling dates, pesticide residue was greater with treatments with higher shade percentage. Both linear and quadratic relationship of shade (independent variable) and the concentration of remained carbaryl (dependent variable) were significant (P < 0.05). The half-life of carbaryl on pakchoi leaves ranged from 2 days for control to 9 days for the heaviest shade (75%) treatment with rain protection.
Potato Leafhopper Economic Injury Levels on Earlystage Snap and Dry Kidney Beans
Authors: Kuhar Thomas P. , Hoffmann Michael P. , Stivers-Young Lydia J. , Sterrett Susan B. , Marini Michele
Published: December 2018

Field cage experiments were conducted in Ithaca, N.Y. in 2001 to determine the yield effect of potato leafhopper (Empoasca fabae) infestations on early-stage beans (Phaseolus vulgaris). Yields of `Hystyle' snap beans and `Montcalm' dry kidney beans were significantly reduced when infested by potato leafhopper at the cotyledon, two-leaf, and four-leaf stages. For snap beans, no differences in yield response from potato leafhopper were observed among the three plant growth stages. For dry beans, there was a difference in yield response between cotyledon and four-leaf-stage plants. Dynamic economic injury levels for potato leafhopper on early-stage beans are suggested.
Innovations in Extension from Malawi
Authors: Snapp S.S.
Published: December 2018

Extension services around the globe face increasingly limited financial support, yet rural populations require services, training and access to information. In sub-Saharan African countries the demands are particularly severe. Farmer to extension staff ratios are generally over 2000 to 1 and resource constraints are severe, which greatly restricts outreach efforts. Examples are presented of recent innovations from the southern Africa country of Malawi. These include collaboration across private and public institutions. Some extension agents have shifted from a transferring technology mode to a catalytic role where agents help link up diverse stakeholders, from farmers and researchers to potential buyers and input suppliers. Extension has helped farmers respond to new market opportunities, including a food colorant, the paprika pepper (Capsicum annuum), and a multi-use grain and vegetable, pigeon pea (Cajanus cajan). Product quality is critical for these markets and industry organizations have invested in training that involves government extension staff, private crop advisors and farmers. A collaborative team approach across industry, nongovernmental organizations and government services has facilitated farmer access to inputs, new cultivars and training in improved crop management and post-harvest techniques. Many challenges remain, such as outreach to farmers located far from infrastructure and those with limited formal education or no experience with entrepreneurship. Extension must continue to reinvent itself to reach all farmers.
Controlled Delayed Cooling Extends Peach Market Life
Authors: Crisosto Carlos H. , Garner David , Andris Harry L. , Day Kevin R.
Published: December 2018

A commercial controlled delayed cooling or preconditioning treatment was developed to extend peach (Prunus persica) market life of the most popular California peach cultivars. A 24 to 48 h cooling delay at 68 °F (20.0 °C) was the most effective treatment for extending market life of internal breakdown susceptible peaches without causing fruit deterioration. This treatment increased minimum market life by up to 2 weeks in the cultivars tested. Weight loss and softening occurred during the controlled delayed cooling treatments, but did not reduce fruit quality. Detailed monitoring of these fruit quality changes during the delayed cooling period and proper use of fungicides is highly recommended for success in this new fruit delivery system. Rapid cooling after preconditioning is important to stop further fruit deterioration such as flesh softening, senescence, decay and weight loss. Controlled delayed cooling can also be used to pre-ripen susceptible and nonsusceptible peaches to deliver a ready-to-buy product to the consumer.
Air Blowers Are Less Effective Pollinators of Greenhouse Tomatoes than Electric Vibrators but Cost Less to Operate
Authors: Hanna H.Y.
Published: December 2018

A study was conducted to determine if air blowers would be less time consuming, more economical, and as effective as hand-held electric vibrators to pollinate two greenhouse tomato (Lycopersicon esculentum) cultivars. Vibrator-pollinated plants of each cultivar produced greater marketable yield than did blower-pollinated plants. Within cultivars, marketable yield was greater and yields of culls were lower with vibrator-pollinated plants. Fruit weight and diameter and the number of seeds per fruit were greater in vibrator-pollinated plants. Marketable yield of `Trust' was greater and cull yield was lower than that of `Caruso' in 1996. However, marketable yield of `Caruso' was greater than that of `Trust' and cull yield was about the same in 1997. Interactions between pollinating tools and cultivar were not significant except for fruit weight in 1997. The time needed to pollinate 640 plants for 13 weeks was 7.13 and 11.75 person-hours using the air blower and the electric vibrator, respectively. Labor cost for pollination was $49.92 for the air blower and $82.25 for the vibrator. Yield loss using the air blower for pollination was not offset by the savings in operating costs.