bluuebunny/crossref_metadata_2025 huggingface dataset:
1-Methylcyclopropene Influences ‘Empire’ and ‘Delicious’ Apple Quality during Long-term Commercial Storage
Authors: DeEll Jennifer R. , Ayres Jennifer T. , Murr Dennis P.
Published: December 2018

This study evaluated the effects of 1-methylcyclopropene (1-MCP) on ‘Empire’ and ‘Delicious’ apples (Malus ×domestica) in commercial controlled atmosphere (CA) storage for 12 months and in commercial cold storage for 6 months. Apples were harvested and delivered by growers to a local commercial storage facility. Four different grower lots were chosen for each of three ‘Empire’ and two ‘Delicious’ storage rooms. Fruit were treated with 1-MCP (≈0.8–1.0 ppm) for 24 hours, while control fruit samples were held in a similar nearby storage room. After treatment, control samples were placed with matching 1-MCP-treated samples into either CA (2.5% O2 + 2.5% CO2 at 2.2 °C or 0 °C for ‘Empire’ and ‘Delicious’, respectively) or air storage at 0 to 1 °C. Initial maturity was relatively uniform among the grower lots, with internal ethylene concentration (IEC) averaging less than 1 ppm for ‘Empire’ and 2 to 3 ppm for ‘Delicious’. IEC was lower in apples treated with 1-MCP after air (3 or 6 months) or CA (6, 9, or 12 months) storage, but this effect was reduced after a 14-day ripening period at 22 °C, and was less dramatic in fruit from CA than from air storage. Apples treated with 1-MCP were also firmer than non-treated fruit upon removal from air or CA storage, and this difference became greater with increased poststorage time at 22 °C. 1-MCP-treated apples stored in air had higher soluble solids concentration (SSC), while there was no significant effect of 1-MCP on SSC in fruit held in CA. Core browning developed in ‘Empire’ held in air for 6 months or in CA for 9 or 12 months, and in ‘Delicious’ after 9 or 12 months in CA. 1-MCP decreased the incidence of core browning in ‘Empire’, but increased the incidence in ‘Delicious’. There was no significant effect of 1-MCP on the incidence of internal browning and storage rots, which developed in both cultivars.
Reduced Foliar Disease and Increased Yield of Pumpkin Regardless of Management Approach or Fungicide Combinations
Authors: Cushman Kent E. , Evans William B. , Ingram David M. , Gerard Patrick D. , Straw R. Allen , Canaday Craig H. , Wyatt Jim E. , Kenty Michael M.
Published: December 2018

Small- and large-scale farmers must often decide when to begin application of fungicides, either before the onset of disease as a preventative treatment or after disease becomes evident in the field. Growers also must decide about products that claim to enhance fungicide efficacy when added to the spray mixture. A study was conducted during the summer of 2002 to investigate control of foliar diseases of vine crops (Cucurbita spp.) with low-input (LI) or high-input (HI) management approaches and six fungicide/spray combinations at four locations in southeastern United States. Fungicide applications began for LI when leaf disease first became evident and for HI about 20 days after seeding. Both approaches continued applications at 7- to 10-day intervals until harvest. Spray treatments consisted of a water-only control or one of six combinations of azoxystrobin/chlorothalonil alone or in combination with potassium bicarbonate, foliar phosphite (0N–12.2P–21.6K), or foliar nitrogen (25N–0P–0K). Azoxystrobin was applied in rotation with chlorothalonil for all treatments except the control. Seeds of ‘Lil’ Goblin’ pumpkin (Cucurbita pepo) were planted July to August and fruit harvested October to November, depending on location. Plants were rated twice for powdery mildew (Sphaerotheca fuliginea and Erysiphe cichoracearum) and downy mildew (Pseudoperonospora cubensis). HI did not significantly increase yield compared with LI. All fungicide treatments significantly increased yield and reduced foliar diseases compared with the water-only control. The simplest of treatments, the azoxystrobin/chlorothalonil rotation without any other chemicals, can be recommended for general use where strobilurin resistance has not been documented.
Loss and Recovery of Research Investment for Applied Sciences: A Salutary Lesson from New Zealand
Authors: Kirkham M.B. , Clothier B.E.
Published: December 2018

In 1992, all governmental resourcing and investment in New Zealand, including that for science, underwent dramatic reform. The global philosophy driving the reform was new public management—a method by which nations could be run more economically by emulating the commercial world. Central to the reform was separation of policy, purchasing (investment), and providers (in the case of research scientists). The reform led to a large reduction in the number of governmental scientists. For example, in 1 year alone, 2001–2002, the Horticultural and Food Research Institute, one of the nine governmental branches of science, lost 51 staff members, 10% of its work force. Over a decade later after the establishment of the reform, in July 2003, the New Zealand government's investment agency announced its budget for the next 6 years. The government-funded science sectors considered to do modern research such as computer technology and biotechnology, and halved funding for land-related sciences. The reduced budget dramatically limited New Zealand's capacity for research in soil and land-use science and ended all research positions in this area (38 jobs). Public outcry through newspaper editorials and from leading businessmen, along with effective leadership from the scientific community, led to the reestablishment of funding in the form of a virtual national center called Sustainable Land Use Research Initiative (SLURI). The elimination of funding for soil and land-use science research in New Zealand was an unexpected and potentially disastrous result of new public management. New Zealand's experience has relevance for the United States, because budgets for agricultural research are being severely reduced or converted to competitive funding. The U.S. President's fiscal year 2006 budget proposed to cut formula funding by 50% and to zero it out in fiscal year 2007. The funds would have been put in competitive grants. In New Zealand, the lack of ability to respond to a scientific problem demonstrated that a balance must be maintained in funding decisions so that scientific capability is retained to solve unforeseen future problems.
Effects of Water Delivery Volume, Rates and Concentrations of Metam Potassium on Purple Nutsedge Emergence in Mulched Beds
Authors: Santos Bielinski M. , Gilreath James P.
Published: December 2018

Over the years, efficacy of metam potassium (MK) on purple nutsedge (Cyperus rotundus) control has been inconsistent, in many cases because of a lack of knowledge about application techniques. Therefore, field studies were conducted to determine the effect of water delivery volumes and flow rates on purple nutsedge control with MK, and the influence of MK rates and concentrations on purple nutsedge control. Three separate studies were established for 1) water application volumes and flow rates, 2) MK application rates and concentrations, and 3) MK concentration levels. For the water application volumes and flow rate trials, a single MK rate of 60 gal/acre was injected with either 1 or 2 acre-inch/acre (27,154 or 54,308 gal/acre) of water. The water flow rates were 0.30, 0.45, and 0.60 gal/100 ft of row per minute within each water volume. An nontreated control was included. In the application rate and concentrations studies, treatments were a nontreated control, 30 gal/acre applied with 0.5 acre-inch/acre of water (≈3000 ppm), 60 gal/acre applied with either 0.5 or 1 acre-inch/acre of water (≈6000 and 3000 ppm), 120 gal/acre applied with either 1 or 2 acre-inch/acre of water (≈6000 and 3000 ppm), and 240 gal/acre applied with 2 acre-inch/acre of water (≈6000 ppm). In the MK concentration trials, 0, 2000, 3000, 4000, 5000, and 6000 ppm were tested. Results indicated that neither water volumes nor flow rates used for MK application had a significant impact on purple nutsedge control at 10 weeks after treatment (WAT). However, there was a significant effect of the combinations of MK rates and water delivery volumes on purple nutsedge densities at 4 and 15 WAT. Similarly, MK concentrations obtained from a single application rate resulted in improved purple nutsedge control up to 10 WAT, reducing densities to less than 5 plants/ft2 with 6000 ppm of MK.
Cold Storage to Control Codling Moth Larvae in Fresh Apples
Authors: Hansen J.D. , Watkins M.A. , Heidt M.L. , Anderson P.A.
Published: December 2018

Codling moth [Cydia pomonella (Lepidoptera: Tortricidae)], found in exported apples (Malus sylvestris), can disrupt international markets. Cold storage at 1.1 °C was examined for possible control of three physiological larval states in ‘Fuji’ apples: diapausing (overwintering), diapause-destined, and nondiapausing. All nondiapausing larvae were dead within 12 weeks, diapaused-destined larvae were controlled by the seventh week, yet more than half of the original populations of diapausing larvae were still alive after 11 weeks. Because the diapaused-destined larvae were younger than the nondiapausing larvae, they may have been more susceptible to cold. Because larvae normally diapause outside the fruit, cold storage would not be applicable for controlling larvae in this state.
Effects of Silver Reflective Mulch, White Inter-row Mulch, and Plant Density on Yields of Pepper in Maine
Authors: Hutton Mark G. , Handley David T.
Published: December 2018

Bell peppers (Capsicum annuum) are an economically important yet difficult to grow crop in northern New England. Yields of bell peppers can be increased through the use of plastic mulches; however, refinements are needed to make bell peppers a more viable crop in regions with short, variable growing seasons. The objectives of this study were to (1) compare the effects of black mulch with white inter-row much, reflective silver mulch, and standard black plastic mulched beds on bell pepper yield and quality and (2) compare the effects of two in-row plant arrangements [single rows at 12-inch within-row spacing (7260 plants/acre) and double rows spaced 18 inches apart with 18-inch in-row spacing (9680 plants/acre)] on pepper yield and quality. Treatments were factorial combinations of three mulch treatments and two within-row planting arrangements. Double rows produced more fruit by number and weight than single rows; however, fruit harvested from the double-row plots tended to be smaller than fruit harvested from the single-row plots. Mulch treatments significantly influenced total marketable yield and yield of cull bell peppers grown in Maine. The plots receiving the inter-row white mulch or reflective silver mulch treatment produced significantly greater yield than standard black plastic mulch treatment. The reflective mulch treatment produced significantly more cull fruit per acre compared with the white inter-row mulch and black plastic.
Off-season Flower Induction of Longan with Potassium Chlorate, Sodium Chlorite, and Sodium Hypochlorite
Authors: Matsumoto Tracie K. , Nagao Mike A. , Mackey Bruce
Published: December 2018

Flower induction of longan (Dimocarpus longan) with potassium chlorate has improved the availability of longan fruit, but potassium chlorate is potentially explosive and often difficult to purchase, transport, and store. Previous reports suggested that hypochlorite enhances natural longan flower induction. This study is the first to demonstrate that chlorite- and hypochlorite- (bleach) induced off-season longan flowering is similar to chlorate-treated trees. Hypochlorite induction of flowering with bleach was likely the result of chlorate in the bleach solution. Chlorate was present in the leachate from potted longan trees treated with bleach and was detected in bleach before soil application. The quantity of chlorate found in bleach induced flowering to the same or greater extent as equivalent quantities of potassium chlorate, suggesting chlorate is an a.i. responsible for longan flowering.
Effects of Yellow and Purple Nutsedge Time of Establishment on Their Distance of Influence on Bell Pepper
Authors: Santos Bielinski M. , Gilreath James P. , Esmel Camille E. , Siham Myriam N.
Published: December 2018

Field trials were conducted to determine the effect of yellow nutsedge (Cyperus esculentus) and purple nutsedge (C. rotundus) time of establishment on their distance of influence on bell pepper (Capsicum annuum). A single seedling of each weed species was transplanted 1, 2, 3, 4, and 5 weeks after transplanting (WAT) bell pepper. Each weed was separately established in the center of plots within double rows of bell peppers. Crop height and yield were determined from bell pepper plants located at 6, 13.4, 24.7, and 36.5 inches away from each weed. Bell pepper height was unaffected by weed species, time of establishment, or the interaction between these factors. Marketable yield data indicate that yellow nutsedge was more aggressive than purple nutsedge interfering with bell pepper. When yellow nutsedge was established at 1 WAT, bell pepper yield reduction was between 57% and 32% for plants at 6 and 13.4 inches away from the weed respectively, which represents a density of ≈0.14 plant/ft2. One purple nutsedge plant growing since 1 WAT at 6 inches along the row from two bell pepper plants (0.43 plant/ft2) produced a yield reduction of 31%. These results indicate that low nutsedge densities, which are commonly believed to be unimportant, can cause significant bell pepper yield reductions.
Comparing Fumigant Retention of Polyethylene Mulches for Nutsedge Control in Florida Spodosols
Authors: Santos Bielinski M. , Gilreath James P. , Siham Myriam N.
Published: December 2018

Although methyl bromide (MBr) has been phased out in developed countries, limited amounts will still be available in the United States for the next few years through critical-use exemptions. Therefore, production practices reducing MBr use are desirable from the grower and environmental standpoints. Fumigation efficacy depends on the duration of fumigants in the soil and mulch permeability; thus, field trials were conducted to compare MBr retention of low- and high-density polyethylene (LDPE and HDPE respectively) mulches with seven metallized mulches and virtually impermeable films (VIF) from different manufacturers, and to assess the effect of MBr retention on nutsedge (Cyperus rotundus and C. esculentus) control with these mulches. The compared mulches were 1) white VIF; 2) black VIF; 3) white-on-black VIF; 4) cowound VIF, which has a clear nylon layer that covers the bed and is superimposed with a layer of black HDPE mulch; 5) metallized; 6) metallized heat trap with a black stripe on the bed center; 7) metallized with a black stripe on the bed center; 8) black LDPE mulch; and 9) black HDPE mulch. All treatments received 175 lb/acre of MBr + chloropicrin (Pic; 67:33 v/v). A nonfumigated control plot covered with LDPE mulch, and a treatment covered with HDPE mulch and fumigated with 350 lb/acre of MBr + Pic were also established. Nutsedge emergence through mulches increased rapidly beginning 18 days after treatment (DAT). Nutsedge populations at 28 DAT in the nonfumigated control covered with LDPE mulch had the greatest emergence (88.8 plants/ft2), followed by LDPE and HDPE mulches with 175 lb/acre of MBr + Pic (67.0 plants/ft2), HDPE mulch with 350 lb/acre of MBr + Pic (25.0 plants/ft2), and VIF and metallized mulches with 175 lb/acre of MBr + Pic (<2 plants/ft2). There were no significant differences in fumigant retention between the metallized mulches and VIF. These mulches retained 3.7 and 1.8 times more MBr than HDPE and LDPE mulches fumigated with 175 and 350 lb/acre of MBr + Pic, respectively.
Comparing Chemical and Biological Control Strategies for Twospotted Spider Mites in Mixed Production of Ivy Geranium and Impatiens
Authors: Holt Kiffnie M. , Opit George , Nechols James R. , Margolies David C. , Williams Kimberly A.
Published: December 2018

Biological and chemical control strategies for the twospotted spider mite (TSM; Tetranychus urticae) were evaluated in a greenhouse experiment replicated over time in mixed production of ivy geranium (Pelgargonium peltatum ‘Amethyst 96’) and two impatiens cultivars (Impatiens wallerana ‘Impulse Orange’ and ‘Cajun Carmine’). Chemical control using the miticide bifenazate was compared with two release strategies for biological control using the predatory mite, Phytoseiulus persimilis. Specific treatments included 1) a single application of bifenazate at 0.3 g·L−1 formulation (22.6% a.i.); 2) a single release of predatory mites at a 1:4 predator to pest ratio based on sampled pest density; 3) a weekly release of predatory mites at numbers based on the area covered by the crop; and 4) an untreated control. TSM populations were monitored for 4 weeks. After another 4 weeks, when plants were ready for market, plant quality ratings were recorded. The number of TSM per leaf dropped for all treatments on all genotypes but increased in the untreated plants. On ivy geranium, the fact that there were significantly more TSM on untreated plants was not reflected in average plant quality, but it did reduce the proportion of containers rated as salable at full price compared with both chemical and biological control. On impatiens, both treatment and cultivar had significant effects on the mean plant quality rating and on the proportion of containers rated as salable at full price. The use of a sampling plan to determine the appropriate number of predators to release was as effective as the currently recommended management treatments for TSM in bedding plants.
Physical and Chemical Characteristics of a Commercial Potting Substrate Amended with Vermicompost Produced from Two Different Manure Sources
Authors: Bachman Gary R. , Metzger James D.
Published: December 2018

Interest in using alternative materials for potting substrate is increasing in response to availability and rising costs of peat and other conventional materials. Vermicompost (VC) is one such material. It is important to understand physical and chemical changes in potting substrate when amended with VC produced from different waste sources, pig (PVC) and beef cattle (BVC) manure in this study. Distribution of particles greater than 2 mm decreased, particles 0.5 to 1 mm increased, and particles less than 0.5 mm remained unchanged as PVC and BVC amendment increased. Dry bulk density and water-holding capacity increased with increasing PVC and BVC amendment. Porosity and air volume were inversely related to VC amendment, decreasing with increasing VC amendment. Saturated substrate extract sampling revealed nitrate nitrogen, phosphorus, calcium, magnesium, zinc, copper, iron content as well as electrical conductivity increased with increasing PVC and BVC amendment.
Merging the Roles of Learning, Research, and Outreach in a Nursery Irrigation Exercise
Authors: Picchioni Geno A. , Singh Jagtar , Mexal John G. , Goss Ryan M.
Published: December 2018

The authors used a simple procedure to teach how to generate evapotranspiration (ET) data for both 1- and 5-gal pots of the xeric shrub apache plume (Fallugia paradoxa) and the mesic vine japanese honeysuckle (Lonicera japonica ‘Halliana’). In-class instruction and assigned reading prepared students for collecting data over a 22-day period (12 Apr. to 3 May), processing data on an electronic spreadsheet, accessing the Internet to acquire reference plant ET data, calculating a crop coefficient (Kc), preparing graphs, organizing a digital presentation, and presenting the findings to commercial nursery participants and instructors. When averaged across days and pot sizes, ET of japanese honeysuckle was 1.22 cm·d−1, whereas ET of apache plume was only 0.80 cm·d−1. This finding supported the students' hypothesis that a nursery block of potted mesic vines would use more water than a nursery block of potted xeric shrubs per unit of ground area. Commercial nursery participants adopted the ET monitoring technique after viewing the student presentation, indicating effective transfer of information by the students. The simple, inexpensive, 3-week exercise furthered the students' horticulture knowledge and comprehension while allowing for a collaborative effort with the local nursery industry.
Nitrogen Sources for Organic Vegetable Crops
Authors: Gaskell Mark , Smith Richard
Published: December 2018

Fertilization is the most expensive cultural practice for the increasing numbers of organic vegetable growers in the United States. Nitrogen (N) is the most important and costly nutrient to manage, and cost-effective N management practices are needed for efficient organic vegetable production. There is a wide array of organic N sources available, but they vary in cost, N content, and N availability. Compost and cover crops are commonly used sources of N for vegetables because they are relatively inexpensive and offer additional nutrients or soil improvement qualities in addition to N. Studies have shown that compost quality factors that affect N mineralization vary by source and among different batches from the same source. Compost carbon to N ratio should be equal to or less than 20:1 to assure net short-term mineralization. Cover crops also vary in N content and mineralization rate after incorporation. Leguminous cover crops decompose and release N more rapidly than grass or cereal cover crops at the preheading stage typically incorporated. Even the most efficient N-supplying composts, cover crops, or other organic N sources do not release appreciable N to a subsequent crop beyond 6 to 8 weeks from incorporation, and this burst of early N may not synchronize with N requirements for many vegetable crops. Other potential organic fertilizer N sources have been evaluated for vegetables, and they vary in N cost and N mineralization rate. Materials evaluated include seabird guano, liquid fish, feather meal, corn meal (Zea mays), blood meal, and liquid soybean meal (Glycine max) among others. Of those evaluated, feather meal, seabird guano, and liquid fish stand out as more economical organic sources of available N. Organic sources generally lack uniformity and are bulky, unstable, and inconsistent as a group, and this contributes to additional hidden management costs for organic growers. Liquid organic N sources for use in microirrigation systems may have additional disadvantages caused by loss of valuable nutrient N that is removed by filters.
Managing Potassium for Organic Crop Production
Authors: Mikkelsen Robert L.
Published: December 2018

An adequate potassium (K) supply is essential for both organic and conventional crop production. Potassium is involved in many plant physiological reactions, including osmoregulation, protein synthesis, enzyme activation, and photosynthate translocation. The K balance on many farms is negative, where more K is removed in harvested crops than is returned to the soil. Although various organic certification agencies have different regulations governing allowable sources of K, the behavior of soil K is largely governed by its solubility. The slow release of K from soil minerals is generally insufficient to meet the peak nutrient demand of high-yielding crops, but they can contribute to the long-term improvement of soil fertility. There are many excellent K sources allowed for organic crop production, including soluble minerals such as langbeinite, sylvinite, and potassium sulfate. Potassium sources such as wood ash, greensand, and seaweed can also supply K but require special management because of their low nutrient content, their effect on soil pH, low solubility, or bulky nature. The concentration of K in manures and composts is highly variable, but it is generally quite soluble and available for plant uptake. Some rock minerals may supply a portion of the K requirement of plants, but many are too insoluble to be of practical significance.
Relationships between Leaflet Nitrogen: Potassium Ratio and Yield of Pecan
Authors: Wells M. Leonard , Wood Bruce W.
Published: December 2018

This study examines the relationship between foliar nitrogen:potassium (N:K) ratio and in-shell yield of pecan [Carya illinoinensis (Wangenh.) K.Koch]. Regression analysis of linear and curvilinear relationships between leaflet N:K ratio and in-shell yield identified associations relevant to orchard nutrition management. Analysis revealed that ON (heavy crop) year N:K ratio correlates with ON year yield (r2 = –0.69), OFF (light crop) year yield (r2 = +0.34), 2-year average yield (r2 = −0.52), and difference between ON and OFF year yields (r2 = –0.69) below the optimum yield level (less than 1800 kg·ha−1) for southeastern U.S. pecan orchards. Pecan yield therefore appears to be associated with N:K ratio. This study suggests that a decline in pecan yield is associated with high N:K ratios in the ON year, thus meriting further investigation into the relationships of N and K to yield. It is suggested that pecan orchards be managed such that foliage contains a N concentration of 2.5% to 2.9% and a K concentration of 1.3% to 1.5% while maintaining the N:K ratio at ≈2:1 for maximization of pecan yields in the southeastern United States over the long term.
Pre-emergence Liverwort Control in Nursery Containers
Authors: Newby Adam , Altland James E. , Gilliam Charles H. , Wehtje Glenn
Published: December 2018

Experiments were conducted in Auburn, AL, and Aurora, OR, to evaluate herbicides for pre-emergence liverwort (Marchantia polymorpha) control. Granular pre-emergence herbicide efficacy varied by location and product. Summarizing across all experiments, flumioxazin and oxadiazon provided the most effective control in Alabama, whereas flumioxazin and oxyfluorfen + oryzalin provided the most effective control in Oregon. Sprayed quinoclamine provided pre-emergence liverwort control, but efficacy and duration of control were reduced compared with granular herbicides.
Storage Effects on Dormancy and Germination of Native Tickseed Species
Authors: Norcini Jeffrey G. , Aldrich James H.
Published: December 2018

Fresh seeds of prevariety germplasms of goldenmane tickseed (Coreopsis basalis), florida tickseed (Coreopsis floridana), lanceleaf tickseed (Coreopsis lanceolata), and leavenworth's tickseed (Coreopsis leavenworthii) were harvested from cultivated plants and stored under dry conditions for 1 to 24 weeks at 15 or 32 °C to alleviate dormancy, that is, to promote after-ripening. The relative humidity (RH) was 33% for all species except lanceleaf tickseed (23% RH). Seeds were subsequently stored for 24 weeks in a commercial storage facility at 23% RH/17 to 19 °C to determine whether after-ripened seeds could be stored without loss in quality (viability, germination velocity). The only substantial after-ripening occurred with seeds of lanceleaf tickseed, although most after-ripening of lanceleaf tickseed seeds occurred during the 24 weeks of dry storage in the commercial storage facility regardless of storage conditions for the previous 24 weeks. After the 24 weeks in commercial storage, germination of lanceleaf tickseed seeds was 48% to 80%, but germination was only 2% to 15% after 24 weeks of dry storage at 15 or 32 °C, respectively. Freshly harvested seeds of the other three species were much more nondormant than seeds of lanceleaf tickseed, but after-ripening effects were still evident because there were increases in germination or germination velocity (an indicator of after-ripening). Maintenance of seed quality was species-dependent. Seed quality of the two upland species, goldenmane tickseed and lanceleaf tickseed, was maintained during the initial 24 weeks of dry storage plus the subsequent 24 weeks in the commercial storage facility. In contrast, viability of seeds of the two wetland species, florida tickseed and leavenworth's tickseed, declined to varying degrees either during the initial 24 weeks of after-ripening or during storage in the commercial facility. The greatest decline in quality occurred for florida tickseed seeds that were stored for 24 weeks at 32 °C and then for 24 weeks in the commercial storage facility.
Prohexadione–calcium Inhibits Shoot Growth but Reduces the Efficacy of Gibberellin A4 + A7 in Suppressing ‘Stayman’ Apple Cracking
Authors: Miller Stephen S.
Published: December 2018

The ‘Stayman’ apple (Malus ×domestica) is a high-quality apple with good fresh-fruit and processing characteristics. Trees are of moderate to high vigor where it is grown in large numbers in the mid-Atlantic region of the United States. However, ‘Stayman’ is prone to skin cracking, which in some seasons can result in losses that exceed 60% to 80% of the crop. A series of experiments was conducted between 1997 and 2001 to examine the effect of prohexadione–calcium (PCa) and a mixture of gibberellins A4 plus A7 (GA4+7) on shoot growth and cracking in ‘Stayman 201’ apple. PCa consistently reduced terminal shoot growth when applied in two or three sprays between petal fall (PF) and PF + 6 weeks [May and June (postbloom)]. PCa applied postbloom combined with three or four preharvest (July and August) PCa applications reduced the growth of water sprouts. The level of ‘Stayman’ fruit cracking varied with year, but in three of five experiments conducted from 1997 through 2001, five biweekly GA4+7 sprays applied alone preharvest reduced the percentage of cracked fruit at harvest. With only a few exceptions, spraying with PCa increased fruit cracking. When GA4+7 was applied to trees previously treated postbloom with PCa, the percentage of cracked fruit was often reduced, but not always, and generally not to the same level as that in non-PCa-treated trees. Fruit cracking was increased compared with the untreated control when a spray adjuvant was included with the postbloom PCa spray. PCa or GA4+7 had no effect on yield or fruit weight at harvest. The results of this study suggest caution in the use of PCa to suppress shoot growth in bearing ‘Stayman’ apple trees because of the potential for increased fruit cracking, which may be only partially reversed by the application of GA4+7.
Visitor Responses to an Ethnic Garden Display in a Botanical Garden
Authors: Steinhauer Melissa , Brennan M.A. , McConnell Dennis , Reinhardt-Adams Carrie , Sandrock David
Published: December 2018

Program developers and administrators in settings such as botanical gardens are increasingly in need of information on the needs and interests of various groups. A need also exists for information on how to broaden interests in garden displays (exhibits including both plants and signs centered on a theme or topic) and increase the diversity of visitors. This article reports on research that explored visitor perceptions of an ethnic garden display highlighting African-American contributions to horticulture. The research also examined overall attitudes toward a botanic garden in Florida where the display was constructed. The results suggested that race did not affect visitors’ overall attitudes toward a botanic garden. Younger visitors, those who visit gardens more, and weekend visitors had a more positive attitude toward botanic gardens. Race was, however, related to visitor attitude toward the ethnic display. African-Americans liked the African-American horticulture display more than any other ethnic group. Sociodemographic characteristics, frequency of botanic garden visits, and time of year for visits all shaped visitor attitudes and opinions.
Postharvest Decline Symptoms after Simulated Shipping and During Shelf Life of 21 Cultivars of Vegetative Annuals
Authors: Starman Terri W. , Beach Shannon E. , Eixmann Kristen L.
Published: December 2018

Twenty-one cultivars from nine species of vegetative annuals were grown under optimum greenhouse production practices until maturity. At harvest, they were subjected to 0, 1, or 2 days of simulated shipping. After shipping, plants were rated for quality, and flower abscission was counted postship and weekly for 3 weeks in a simulated retail environment. There were few decreases in flower number and quality directly postship, but decline symptoms became evident as time lapsed in the postharvest environment. Flower abscission resulting from increased shipping duration occurred on ‘Sun Chimes Coral’ diascia (Diascia ×hybrida) and ‘Aromatica White’ nemesia (Nemesia ×hybrida). During the postharvest evaluation, ‘Dreamtime Copper’ bracteantha (Bracteantha bracteata), ‘Superbells Trailing Blue’ calibrachoa (Calibrachoa hybrid), ‘Aromatica White’ nemesia, and ‘Candy Floss Blue’ sutera (Sutera cordata) were the only cultivars to abscise all flowers (<0.4 flowers) by the end of the first week. Five cultivars still had flowers at termination of the experiment. Of these five, four were bracteantha cultivars including ‘Florabella White’, ‘Florabella Gold’, ‘Dreamtime Cream’, and ‘Sundaze Golden Yellow’, and ‘Cascadias Pink’ petunia. After 2 weeks postharvest, 12 of the 21 cultivars that were shipped 1 or 2 days did not have a high enough quality rating (<3.0 points) to be considered marketable. Each species in this study had one or two postharvest decline symptoms common to all cultivars of that species. However, cultivars within species also varied in their postharvest decline symptoms and longevity. More optimum environmental conditions, better care, and faster turnover in the retail market are needed to improve shelf life of vegetative annuals sold in containers.
Postharvest Calcium Chloride Application and Moisture Barrier Influence on Peach Fruit Quality
Authors: Lysiak G. , Florkowski W.J. , Prussia S.E.
Published: December 2018

Peaches (Prunus persica) were evaluated for storability after dipping in a 2% calcium chloride (CaCl2) solution at 20 °C for 30 min and storing them at 4 °C for 2 weeks in boxes uncovered or covered with polyethylene bags. Generally, there were significant improvements in storability resulting from the CaCl2 and the polyethylene barrier. The CaCl2 treatment improved firmness, largely maintained the soluble solids content, and increased the ratio of soluble solids-to-titratable acid ratio. Polyethylene bags minimized weight loss, and two out of three times, bagged fruit had lower acids after storage than did the control.
Kaolin Particle Film Product Applications Before Harvest Begins May Not Improve Marketable Yields of Fresh Tomatoes
Authors: Kahn Brian A. , Damicone John P.
Published: December 2018

Drip-irrigated, stake-and-weave supported tomato (Lycopersicon esculentum) plots were established in 2005 and 2006. All plots (except controls) were treated with a kaolin particle film product (Surround WP) mixed at 0.5 lb/gal of water and applied with a pressurized hand sprayer. Sprays began after transplanting and were repeated as needed to maintain a particle film on the foliage. Sprays were discontinued either at anthesis, at first green fruit 5 cm in diameter, or at first colored fruit harvest. Multiple hand harvests were made as fruit matured. In 2005, all kaolin treatments reduced marketable fruit number and weight, whereas in 2006 there were no significant effects. Cull fruit weight and average weight per marketable fruit were unaffected by treatments during either year. Results indicate that when applied before harvest begins, Surround may not improve marketable yields of fresh tomatoes.
Survey of Cultural Practices Used in Production of Wintercreeper Euonymus
Authors: Boyer Cheryl R. , Cole Janet C. , Payton Mark E.
Published: December 2018

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.
Assessing a Garden-based Curriculum for Elementary Youth in Iowa: Parental Perceptions of Change
Authors: Hilgers Kimberly R. , Haynes Cynthia , Olson Joanne
Published: December 2018

The interest and use of gardens as educational tools for youth has increased in recent decades. The positive connection found between children and horticulture has prompted the development of garden-based curricula for use in schools. Iowa State University Extension developed the Growing in the Garden (GITG) curriculum for use in kindergarten through third-grade classrooms. This study examined what impact the GITG curriculum had on the awareness and interest of first graders in the areas of science, nutrition, and environmental awareness. Impact was assessed by a parental survey asking for perceptions of their child's interest and awareness after experiencing three lessons from the GITG curriculum. The sample population consisted of 78 parents of first-grade students from four classrooms in Iowa. The response rate was 60.2%. Results indicate that a significant number of parents completing the survey noted an increased awareness and interest of their children in the areas of science and the environment. Factors such as socioeconomic status, ethnicity, and gender did not influence the outcomes.
Evaluation of the Effect of Different Modified Atmosphere Packaging Box Liners on the Quality and Shelf Life of ‘Friar’ Plums
Authors: Cantín Celia M. , Crisosto Carlos H. , Day Kevin R.
Published: December 2018

The influence of modified atmosphere packaging (MAP) on quality attributes and shelf life performance of ‘Friar’ plums (Prunus salicina) was studied. Plums were stored at 0 °C and 85% relative humidity for a 60-day period in five different box liners (LifeSpan L316, FF-602, FF-504, 2.0% vented area perforated, and Hefty liner) and untreated (control). Flesh firmness, soluble solids concentration, titratable acidity, and pH were unaffected by the box liners. Fruit skin color changes were repressed on plums packed in box liners that modified gas levels and weight loss was reduced by the use of any of the box liners. Plums packed without box liners (bulk-packed) had ≈6% weight loss. High carbon dioxide (CO2) and low oxygen (O2) levels were measured in boxes with MAP box liners (LifeSpan L316, FF-602, and FF-504). Percentage of healthy fruit was unaffected by any of the treatments during the ripening period (shelf life) after 45 days of cold storage. However, after 60 days of cold storage, fruit from the MAP box liners with higher CO2 and lower O2 levels had a higher incidence of chilling injury (CI) symptoms, evident as flesh translucency, gel breakdown, and “off flavor” than fruit from the other treatments. Overall, results indicate that the use of MAP box liners is recommended to improve market life of ‘Friar’ plums up to 45 days cold storage. However, the use of box liners without gas control capability may lead to CI symptoms in fruit cold-stored for longer periods.
Southern Redcedar and Southern Magnolia Wood Chip Mulches for Weed Suppression in Containerized Woody Ornamentals
Authors: Ferguson James , Rathinasabapathi Bala , Warren Clinton
Published: December 2018

Wood chip mulches from southern redcedar (Juniperus silicicola) and southern magnolia (Magnolia grandiflora) were evaluated for their effectiveness in weed control in nursery containers. In greenhouse tests, southern redcedar and southern magnolia wood chip mulches significantly inhibited the germination of redroot pigweed (Amaranthus retroflexus) and large crabgrass (Digitaria sanguinalis). In a field trial, nursery containers with ‘Carolina Beauty’ crape myrtle plants (Lagerstroemia indica) were sown with large crabgrass and redroot pigweed seeds, mulched with southern redcedar or southern magnolia wood chips, and compared with plants without mulch and plants treated with a mixture of isoxaben and trifluralin (Snapshot). Wood chips from both southern redcedar and southern magnolia were as effective as a mixture of isoxaben and trifluralin in suppressing weed growth in nursery containers. The wood chip mulches had no inhibitory effect on the growth of crape myrtle plants. In a similar, longer-term field trial using containerized dogwood (Cornus florida) plants sown with large crabgrass and redroot pigweed, the southern redcedar wood chip mulch was most effective in weed suppression when used in combination with a low dose of the chemical herbicide.
Effects of Electrical Conductivity of Hydroponic Nutrient Solution on Leaf Gas Exchange of Five Greenhouse Tomato Cultivars
Authors: Wu Min , Kubota Chieri
Published: December 2018

Five cultivars (Blitz, Mariachi, Quest, Rapsodie, and Trust) of tomato (Solanum lycopersicum) were grown hydroponically in a greenhouse to determine photosynthetic and transpirational responses to three electrical conductivities (EC) [2.3 (control), 4.8, and 8.4 dS·m−1] of inflow nutrient solution. Leaf photosynthetic light response curves were measured during the early vegetative growth stage for cv Mariachi and Rapsodie and during the reproductive growth stage for all five cultivars. Leaf transpiration rate and leaf conductance were measured for all five cultivars in both stages. During the vegetative growth stage, high EC treatment of 8.4/14.3 dS·m−1 inflow/efflux solution reduced leaf conductance and transpiration rate by 28% and 29%, respectively, compared with low EC treatment (2.3/5.9 dS·m−1), regardless of cultivar. Effects of EC treatments on leaf photosynthetic light response curves were cultivar specific. For ‘Mariachi’, moderate EC (4.8/8.7 dS·m−1) and high EC treatments in the vegetative growth stage reduced the maximum photosynthetic rate by 49% compared with the low EC treatment. However, for ‘Rapsodie’, the moderate EC treatment increased the maximum photosynthetic rate during the vegetative stage by 8% and 47% compared with low and high EC treatments, respectively. During reproductive growth stage, EC treatment did not significantly affect the transpiration rate, but high EC treatment reduced the leaf conductance by 15%, regardless of cultivar. Parameters of leaf photosynthetic response curves were affected by cultivar and EC treatment. Compared with the low EC treatment, the moderate EC treatment did not significantly affect the maximum photosynthetic rate of any cultivar except ‘Rapsodie’, which showed the greatest maximum photosynthetic rate in the moderate EC treatment. The results showed that the plant physiological response under elevated EC was cultivar and growth-stage specific, and increasing the inflow EC to the moderate level of around 4.8 dS·m−1 during the reproductive growth stage would not negatively impact photosynthesis, transpiration, and leaf conductance of tomato plants, for all cultivars tested in the present experiment.
Effects of Fertilizer Type on Quality and Nutrient Content of Established Landscape Plants in Florida
Authors: Broschat T.K. , Sandrock D.R. , Elliott M.L. , Gilman E.F.
Published: December 2018

In a series of three experiments, st. augustinegrass (Stenotaphrum secundatum ‘Floratam’), areca palm (Dypsis lutescens), canna (Canna × generalis ‘Richard Wallace’), pentas (Pentas lanceolata), allamanda (Allamanda cathartica ‘Hendersoni’), and nandina (Nandina domestica) were grown on highly leached sand soils in two locations in Florida. They were fertilized with typical turfgrass fertilizers having high nitrogen (N)-to-potassium (K) ratios and no magnesium (Mg), or several types of landscape palm fertilizers having low N:K ratios and 100% of their N, K, and Mg in controlled release form. St. augustinegrass, pentas, nandina, and allamanda visual quality were similar for all fertilizer types tested. However, cannas and areca palms had higher visual qualities when fertilized with an 8N–0.9P–10.0K–4Mg palm fertilizer than with higher N:K ratio turf fertilizers. High N:K turf fertilizers resulted in K deficiency severity equivalent to that of unfertilized controls and Mg deficiency that was more severe than unfertilized areca palms.
Macrophytography of Cultivated Liriopogons and Genera Delineation
Authors: Fantz Paul R.
Published: December 2018

Liriopogons (Liriope Lour. spp. and Ophiopogon Ker-Gawl. spp.) are versatile landscape plants with a complexity of taxonomic problems, including the question of whether they are segregate genera or only one genus. Macrophytography (descriptive terminology of morphology) of the liriopogons is described with commentary on patterns of variation and reliable characters for segregation. Liriopogons were found to include two valid genera, delineated and described, and two imposters marketed as liriopogons. Liriope species bear spreading to upright rotate flowers with zygomorphic stamens, of which the filaments are sigmoid, the anthers oblong and poricidal dehiscent, and the style is incurved-falcate. Ophiopogon species bear nodding campanulate flowers with actinomorphic stamens, of which the filaments are subsessile and straight, the anthers sagittate and longitudinally dehiscent, and the style is straight. The imposters are nonvalid liriopogons, and include species of sedges and grasses misidentified as liriopogons. Included are a key to delineation of taxa and a table of taxonomic terminology used in this study for describing liriopogon taxa.
Pumpkin Fruit Size and Quality Improve with Leaf Mulch
Authors: Wyenandt Christian A. , Heckman Joseph R. , Maxwell Nancy L.
Published: December 2018

A key to profitability in many “u-pick” pumpkin (Cucurbita pepo) farm operations is producing attractive, marketable fruit while maintaining suitable field conditions for consumer entry during periods of inclement autumn weather. The use of municipal leaves collected from urban areas may help improve fruit quality and field conditions in u-pick pumpkin operations. In 2005 and 2006, an experiment (randomized complete block design) was conducted to compare four different production systems on pumpkin yield and fruit quality. Treatments consisted of no leaf mulch (bare soil) plus herbicide with 25 lb/acre nitrogen (N) sidedressed (treatment 1), leaf mulch without herbicide with 25 lb/acre N sidedressed (treatment 2), no leaf mulch (bare soil) with herbicide with 75 lb/acre N sidedressed (treatment 3), and leaf mulch without herbicide with 75 lb/acre N sidedressed (treatment 4) during the production season. In 2005, there were no differences in the total number and weight of harvested fruit and weight of orange fruit between production systems. Although the presence of leaf mulch reduced the total number and percentage of orange fruit harvested, there were no significant differences in average weight of orange fruit between production systems. Average weight of orange fruit was significantly higher and similar at both sidedress N rates in both leaf mulch production systems compared with bare soil. In 2006, there were no differences in total number of fruit, number of orange fruit, and percentage of orange fruit at harvest between production systems. Total weight, weight of orange fruit, and average fruit weight of pumpkin fruit was significantly higher and similar at both sidedress N rates in both leaf mulch production systems compared with bare soil. Sidedress N should be applied in accordance to plant growth and environmental factors to overcome any expected N deficiency from N immobilization because of the presence of the leaf mulch and other environmental factors. Applying municipal leaves to the soil surface exhibited a marked advantage over bare soil in producing clean fruit. In both years, the percentage of clean fruit at harvest was higher in both leaf mulch production systems compared with bare soil.