bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetable Crop Yield and Quality following Differential Soil Management (Compost Versus No Compost Application) in Transitional- and Certified-organic Systems in Ohio
Authors: Kleinhenz Matthew , Wszelaki Annette , Walker Sonia , Ozgen Senay , Francis David
Published: February 2019

Successful organic farming requires synchronizing soil-based processes affecting nutrient supply with crop demand, variable among and within crops. We report here on two studies conducted in transitional- (TO) and certified-organic (CO) systems containing subplots that, annually, were either amended with compost or not amended prior to vegetable crop planting. Dairy-manure compost was added at rates providing the portion of a crop's anticipated nitrogen requirement not provided by a leguminous rotation crop and/or carryover from previous compost application. In the TO study, potato (2003), squash (2004), green bean (2005), and tomato (2006) were planted in main-season plots in open fields and high tunnels, and beet, lettuce, radish, spinach, and swiss chard were planted in high tunnels in early spring and late fall. Long-term CO open-field plots (±compost) were planted to multiple varieties of lettuce, potato, popcorn, and processing tomato in 2004–2006. Drip irrigation was used in all TO plots and CO lettuce and processing tomato plots. Treatment effects on crop physical and biochemical variables, some related to buyer perceptions of crop quality, were emphasized in each study. Yield in TO, compost-amended plots exceeded yield in unamended plots by 1.3 to 4 times, with the greatest increases observed in high-tunnel-grown mesclun lettuce and the smallest response observed in potato. Similar results were found in CO plots, although compost effects differed by crop and variety. The data suggest that: 1) compost application and the use of specific varieties are needed to maximize yield in organic vegetable systems in temperate zones, regardless of age; and 2) production phase management may influence buyer-oriented aspects of crop quality.
A Simple and Rapid Procedure for the Detection of Self-Compatible Individuals in Japanese Apricot (Prunus mume Sieb. et Zucc.) Using the Loop-Mediated Isothermal Amplification (LAMP) Method
Authors: Habu Tsuyoshi , Kishida Fumio , Morikita Miki , Kitajima Akira , Yamada Toshiaki , Tao Ryutaro
Published: February 2019

Japanese apricot (Prunus mume Sieb. et Zucc.) exhibits S-RNase-based gametophytic self-incompatibility as do other Prunus species. Both self-incompatible and self-compatible Japanese apricot cultivars are grown commercially in Japan. These self-compatible cultivars are shown to have a common S-haplotype called Sf that contains Sf-RNase and SFBf (S-haplotype-specific F-box protein). This study describes a simple and rapid detection of SFBf, in Japanese apricot, based on loop-mediated isothermal amplification (LAMP) method. A set of 4 primers, F3, B3, FIP, and BIP primer, were designed from the exon and the putative inserted sequence of SFBf. Optimal reaction time at 63 C was determined to be 90 minutes. It appeared that the LAMP method combined with the ultrasimple DNA extraction efficiently detected SFBf. The advantage of the marker-assisted selection of self-compatibility based on the LAMP method was discussed.
Genetic Variation in Somatic Embryogenesis of Rose
Authors: Burrell A. Millie , Lineberger R. Daniel , Rathore Keerti S. , Byrne David H.
Published: February 2019

Fifteen genetically diverse roses were evaluated for the ability to undergo somatic embryogenesis. Over the two media (MS and B5), two sugars (glucose and sucrose), and two explants (filaments and petiole) used, 20 to 30% of the `Tournament of Roses' callus was embryogenic whereas only crystalline callus was produced in cultures of `Baby Love', `Ingrid Bergman', `Perfume Delight', `Prominent', `Sunflare', and 90-202. Cultures of `Tournament of Roses' consistently produced somatic embryos whereas `Baby Love' produced no embryos. An F1 progeny of `Tournament of Roses' × `Baby Love' was chosen to test whether the ability to undergo embryogenesis in Rosa hybrida L. is heritable. Data collected from tests on F1 progeny between these genotypes suggest that the ability to undergo embryogenesis is indeed heritable in an additive fashion.
Fruit and Nut Genebanks in the U.S. National Plant Germplasm System
Authors: Postman Joseph , Hummer Kim , Stover Ed , Krueger Robert , Forsline Phillip , Grauke L.J. , Zee Francis , Ayala-Silva Tomas , Irish Brian
Published: February 2019

The year 2005 marked the 25th anniversary of the establishment of the U.S. Department of Agriculture (USDA) National Plant Germplasm System (NPGS), repositories devoted to clonally propagated, horticultural fruit and nut crops. During this quarter century, facilities in Hilo, Hawaii; Mayaguez, PR.; Miami, Fla.; and Riverside, Calif. were developed to preserve collections of tropical and subtropical fruit and nut crops; facilities in Brownwood, Texas; Corvallis, Ore.; Davis, Calif. and Geneva, N.Y. preserve the temperate crops. Each of these facilities now has internationally recognized, globally diverse collections of genetic resources for their assigned genera. Germplasm of unique genotypes are maintained as growing plants, evaluated for phenotypic and genotypic traits, documented in a national public germplasm database, and freely distributed as clonal propaggules to researchers and other germplasm users around the world. Seed collections represent wild populations for some crop relatives. These 8 genebanks maintain 30,000 accessions representing 1600 species of fruit and nut crops and their wild relatives. The genebanks distribute more than 15,000 accessions annually to international researchers. Although originally conceived as working collections for crop improvement, NPGS genebanks have also become invaluable in providing the raw materials for basic plant genetic research, reservoirs for rare or endangered species or vulnerable landraces, archives of historic cultivars, and field classrooms for educating the public. These collections preserve botanical treasures as well as the American horticultural heritage for now and for future generations.
Harvest Time and Storage Condition Affect Germination, Moisture, Abscisic Acid, and Indoleacetic Acid in Pecan
Authors: Jover Pedro , Matta Frank B. , Shah Fawad S.
Published: February 2019

Moisture percentage, free abscisic acid, and total indoleacetic acid (IAA) content were determined at shuck-split in `Hughes' and `Owens' pecan kernels (nuts harvested from the tree), immediately after harvest from the ground, and after subsequent storage periods of 45, 90, and 135 d at 3 °C or 10 °C. In `Hughes', seed germination increased when nuts were harvested from the tree compared with germination of nuts harvested from the ground or nonstratified and stratified nuts. Germination of nuts harvested from the ground did not differ from germination of nuts stored at 3 °C in moist media for 45, 90, or 135 d. Significant positive correlation between germination of `Hughes' and `Owens' and moisture percentage was observed. There was no relationship between abscisic acid levels and germination in either cultivar. However, there was a significant correlation between germination of `Hughes' and IAA. Germination of `Owens' did not correlate with IAA levels.
Timing Cyclanilide and Cytokinin Applications in the Nursery to Obtain Desired Lateral Branch Height in Apple and Sweet Cherry Trees
Authors: Elfving Don C. , Visser Dwayne B.
Published: February 2019

The height above the bud union at which induced feathers develop on fruit trees in the nursery is an important determinant of tree quality for an intended market. The bioregulators cyclanilide (CYC; Bayer Environmental Science, Research Triangle Park, NC) and a proprietary formulation of 6-benzyladenine and gibberellins A4 and A7 (Promalin [PR]; Valent BioSciences, Walnut Creek, CA) affected the final height above the union of the lowest induced sylleptic shoot (feather) differently in apple and sweet cherry trees in the nursery. In apple, both products resulted in the lowest induced feather developing at approximately 4 to 20 cm below the height of the central leader shoot tip at the time of bioregulator application. In sweet cherry, the lowest induced feather typically originated starting approximately 2 to 20 cm above the central leader shoot tip height at the time of bioregulator application. Nursery tree height can serve as a suitable criterion for timing bioregulator applications to obtain feathers starting within a specific range of height above the bud union as long as species-specific feathering response characteristics are taken into account. Chemical names used: 1-(2,4-dichlorophenylaminocarbonyl)-cyclopropane carboxylic acid (Cyclanilide), N-(phenylmethyl)-1H-purine-6-amine + gibberellins A4A7 (Promalin), polyoxyethylenepolypropoxypropanol, dihydroxypropane, 2-butoxyethanol (Regulaid).
Impact of AVG Preharvest Spray and Soil Injection on Yield and Quality of Melon
Authors: Leskovar Daniel I. , Goreta Smiljana , Franco Jose A.
Published: February 2019

The aim of this study was to determine whether aminoethoxyvinylglycine (AVG), an inhibitor of ethylene synthesis, would affect earliness, increase yield, and improve overall at harvest and postharvest quality of melon (Cucumis melo L. group Cantalupensis, `Sol Real'). Field experiments were conducted during two seasons with AVG (124 g·ha–1 a.i.) applied as spray or soil injected into the root zone with a single or double application between 7 d and 21 d before harvest. The AVG soil injection method increased earliness compared with AVG spray in one season. Total marketable yield increased with AVG injection but not with the AVG spray method compared with the control. Regardless of method of application, AVG did not affect fruit firmness, rind thickness, netting, or soluble solids content when measured at harvest. However, AVG spray decreased fruit size and seed cavity in one season. Similarly, AVG spray did not affect fruit quality after storage, whereas AVG soil injection increased fruit firmness. Overall, melon yield and fruit quality responses to preharvest AVG applications were superior for the soil injection than the spray method.
Blossom Thinners Reduce Crop Load and Increase Fruit Size and Quality of Peaches
Authors: Coneva Elina D. , Cline John A.
Published: February 2019

The purpose of this research was to determine the effectiveness of three blossom-thinning compounds on crop density and fruit quality of two peach cultivars. Treatments consisted of 15 ml·L–1 and 30 ml·L–1 ammonium thiosulphate, 30 ml·L–1 and 40 ml·L–1 decyl alcohol, and 40 ml·L–1 lime sulfur. Treatments were applied to `Redhaven' and `Harrow Diamond' peach trees at two phenological stages: 80%, and 100% full bloom in 2002 and 2003. In both years, treatments reduced the crop density in both cultivars, and in 2003 the amount of hand thinning required to adjust the crop load was significantly reduced. Fruit size from several blossom-thinned treatments was comparable with that observed from hand-thinned trees. However, treatments caused significant leaf phytotoxicity to `Harrow Diamond' trees in 2003, likely a result of hand spray gun applications. These data indicate that chemical sprays at bloom can be used successfully to reduce fruit set, but are very environmentally, dose, and cultivar dependent.
Conjoint Analysis Reveals Consumers Prefer Long, Thin Asparagus Spears
Authors: Behe Bridget K.
Published: February 2019

Michigan fresh asparagus marketers were interested in profiling asparagus consumers in the Northeast and Midwest with regard to preferences, purchases, preparation, and consumption. A computer-assisted survey was conducted with a total of 1126 respondents representative of the population on average in 12 selected states in the Northeast and Midwest. Even though the U.S. Department of Agriculture recommends adults consume three servings of vegetables daily, on average over the 2 weeks before taking the survey, 62% did not. Only 39% of the persons in the sample ate fresh asparagus in the 4 weeks preceding the survey. Twenty-five percent ate it steamed on the stovetop. The conjoint analysis accounted for 63% of the variance in asparagus preference with attribute relative importance decreasing from price (42.0%), to brand (29.9%), to spear diameter (23.5%), to spear segment (4.6%). Light users consumed fresh asparagus at least once in the 4 weeks before the survey, during the peak fresh asparagus season. The potential to increase consumption in this large group (28% of the sample but 71% of asparagus consumers) is tremendous. They placed high relative importance on price per pound and will likely be the more price-sensitive group. If their consumption can be increased by one more asparagus consumption event per month, it could increase asparagus demand by 14%. Results show there is good market potential for a prepackaged fresh asparagus product in the Northeast and Midwest.
Master Gardener Perception of Genetically Modified Ornamental Plants Provides Strategies for Promoting Research Products Through Outreach and Marketing
Authors: Klingeman William , Babbit Beth , Hall Charles
Published: February 2019

Although genetically modified (GM) ornamental cut flowers are now available commercially, we have no knowledge of consumer perception about GM ornamental plants for landscape use and must make inferences from models drawn for GM foods. If we misjudge the customer, and consumers object to GM ornamental plant products for moral reasons, governmental or scientific mistrust, or limited understanding about GM technology, the market for GM ornamental plant commodities will fail. A survey of Master Gardener volunteers was conducted in 2004 to address this gap. Although Master Gardener perceptions likely differ from those of general U.S. consumers, responses are expected provide insight about beliefs applicable to the gardening public. Results from 607 Tennessee respondents revealed that concerns about GM ornamental plants parallel those expressed in the United States about GM foods. On average, Master Gardeners anticipate slight benefits to both the environment and human health should GM ornamental plants be introduced into the landscape. Male respondents chose perennials to provide the most environmental benefits, whereas females indicated grasses and turf. Genetically modified ornamental plants are also expected to be about the same or less invasive in the landscape than non-GM plants. Of respondents who anticipated more potential for GM ornamental plant invasiveness, women were more likely than men to predict plant escape. Men and women differed in relative acceptance of genes added from different organisms as a method of achieving genetic transformations in plants. This result suggests that outreach and marketing to promote new GM plant products should emphasize attributes of benefit rather than processes used to accomplish the goal. Regardless, although ≈73% of TN Master Gardener respondents reported interest in buying GM ornamental plants if sold commercially, participants advocated a requirement that GM plant products be clearly labeled at point-of-sale.
RNA Extraction Method from Fruit Tissue High in Water and Sugar
Authors: Davis Angela R. , Levi Amnon , Kim Sungil , King Stephen R. , Hernandez Alvaro
Published: February 2019

RNA isolation from ripe fruit can be complicated by high concentrations of sugar and water. These sugars interfere with RNA extraction often resulting in low RNA quality and quantities, and high water concentrations dilute the RNA, making isolation difficult. We report a simple but novel method by which the majority of the excess sugar and water in mature fruit of tomato (Lycopersicon esculentum Mill.), watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai], and muskmelon (Cucumis melo L.) can be easily removed from tissue before RNA extraction. This method produced quality RNA in a shorter time than the currently accepted method for fruit tissue RNA isolation and does not require liquid nitrogen or a freeze dryer.
Cover Crop Rotations Alter Soil Microbiology and Reduce Replant Disorders in Strawberry
Authors: Seigies Ann Toren , Pritts Marvin
Published: February 2019

In July 2001, a study was established in a field with a 30-year history of perennial strawberry production to examine effects on replant disorder of 12 different species of preplant cover crops, soil fumigation (methyl bromide plus chloropicrin), and fallow management. In May 2002, strawberries (`Jewel') were planted into pots containing soils with the incorporated cover crops, grown for 1 year, and then fruited. Strawberry yields in 2003 were highest in pots containing indiangrass (Sorghastrum avenaceum) and brown mustard (Brassica juncea) -incorporated soils, resulting in 32% and 28%, respectively, higher yield than plants in pots containing untreated, bare fallow soil. Yield was lowest in fumigated soil or soil incorporated with sunnhemp (Crotolaria juncea), having 19% and 10% less yield than the fallow treatment, respectively. In Aug. 1999, a complementary study was established in a field with a 7-year history of continuous perennial strawberry production to examine the effects of single species and multiple species rotations on replant disorder, bacterial populations, and fungal pathogens over 2 fruiting years. Cover crop treatments included various monocultures and sequences of perennial alfalfa (Medicago sativa), brown mustard, kale (B. oleracea `Winterbor'), sweet corn (Zea mays `Saccharata'), rye (Secale cereale), hairy vetch (Vicia villosa), marigold (Tagetes patula `Nema-gone'), oats (Avena sativa `Newdak'), and sudangrass (Sorghum bicolor × S. sudanese). These rotations were compared with the effects of fumigation using methyl bromide with chloropicrin (99:1), continuous strawberry, and bare fallow. Symptoms of replant disorder developed in the continuous strawberry plots within a few months of planting. Plants in the fumigation treatment produced greater fruit yield than all other treatments in 2003, 139% more than plants from the continuous strawberry treatment. Strawberry plants grown in the kale/sweet corn/rye treatment had consistently high yield, and both the hairy vetch/marigold/rye and the oats/sudangrass/rye treatments led to marked improvement over the continuous strawberry treatment. Plants from the brown mustard treatment also were more vigorous and productive than plants from the continuous strawberry treatment during 2002 despite having relatively low foliar biomass and a relatively high level of fungal infection on strawberry plant roots. In the field, symptoms of replant disorder were best overcome by fumigation with methyl bromide or multiple species rotations, particularly that of kale followed by sweet corn and rye. Although Rhizoctonia levels were associated with poor root health, general fungal and bacterial root infection rates were not consistently associated with the presence of visible symptoms of replant disorder nor with strawberry plant growth and productivity.
Sequential Controlled Atmosphere Storage for `McIntosh' Apples
Authors: Lévesque P. Guy , DeEll Jennifer R. , Murr Dennis P.
Published: February 2019

Sequential decreases or increases in the levels of O2 in controlled atmosphere (CA) were investigated as techniques to improve fruit quality of `McIntosh' apples (Malus ×sylvestris [L.] Mill. var. domestica [Borkh.] Mansf.), a cultivar that tends to soften rapidly in storage. Precooled fruit that were harvested at optimum maturity for long-term storage were placed immediately in different programmed CA regimes. In the first year, CA programs consisted of 1) `standard' CA (SCA; 2.5–3.0% O2 + 2.5% CO2 for the first 30 d, 4.5% CO2 thereafter) at 3 °C for 180 d; 2) low CO2 SCA (2.5–3.0% O2 + 2.5% CO2) at 3 °C for 60 d, transferred to low O2 (LO; 1.5% O2 + 1.5% CO2) at 0 or 3 °C for 60 d, and then to ultralow O2 (ULO; 0.7% O2 + 1.0% CO2) at 0 or 3 °C for 60 d; and 3) ULO at 3 °C for 60 d, transferred to LO at 0 or 3 °C for 60 d, and then to SCA or low CO2 SCA at 0 or 3 °C for 60 d. In the second year, the regimes sequentially decreasing in O2 were compared with continuous ULO and SCA. After removal from storage, apples were held in ambient air at 20 °C for a 1-week ripening period. Fruit firmness was evaluated after 1 and 7 d at 20 °C, whereas the incidence of physiological disorders was assessed only after 7 d. Lowering the temperature while decreasing O2 was the best CA program with significant increased firmness retention during storage and after the 1-week ripening period. Reduced incidence of low O2 injury in decreasing O2 programs and absence of core browning at the lower temperature were also observed.
Evaluating Chemical Indices of Growing Media for Nursery Production of Quercus rubra Seedlings
Authors: Salifu K. Francis , Nicodemus Michael A. , Jacobs Douglass F. , Davis Anthony S.
Published: February 2019

We evaluated suitability of chemical indices of three media formulations or substrates (A, B, and C) consisting of composted pine bark, coconut coir pith, sphagnum peatmoss, processed bark ash, and perlite in varied proportions for growing northern red oak (Quercus rubra L.) seedlings. These substrates were ranked according to their ability to promote seedling growth. The low-yielding substrate (A) was devoid of pine bark and perlite and the medium-yielding substrate (B) contained no peatmoss or processed bark ash. The high-yielding substrate (C) contained all components. Additionally, we tested plant response to high nitrogen (N) fertilization on each substrate. Media EC, pH, and total dissolved solids measured at transplanting explained 68%, 43%, and 66%, respectively, of the variation in plant dry weight and 39%, 54%, and 46%, respectively, of the variation in shoot height. Vector diagnosis effectively ranked nutritional limitations on seedling growth as N > P > K. High N fertilization highlighted element deficiency in seedlings grown on substrate A, but resulted in element toxicity and antagonistic interactions in plants established on substrates B and C, respectively.
`Italico' and `Mediterraneo': Two Seiridium cardinale Canker-Resistant Cypress Cultivars of Cupressus sempervirens
Authors: Danti R. , Panconesi A. , Di Lonardo V. , Rocca G. Della , Raddi P.
Published: February 2019

Common cypress (Cupressus sempervirens L.) is an integral feature of the landscape of many Mediterranean regions (particularly in Tuscany). Furthermore, common cypress has multiple uses as ornament, timber, windbreaks, recovery of deteriorated soils, protection of slopes and the production of essential oils. During the last three decades, Seiridum cardinale canker of cypress has caused severe losses in woods, windbreaks and ornamental plantings in the Mediterranean area, significantly limiting the use and cultivation of this tree.

In this paper we describe `Italico' and `Mediterraneo', two C. sempervirens varieties which were patented in 2004 for their resistance to cypress canker. Both varieties are particularly suitable for ornamental purposes because of their fastigiated columnar habit and the low production of male flowers and cones. `Italico' and `Mediterraneo' represent the recent result of the breeding programme on cypress, in progress since the 1970s. This program aims at: 1) obtaining a high number of canker-resistant cypress clones and multi-clonal varieties to be used for ornamental plantings and windbreaks and 2) finding mother trees for the production of improved seed for reforestation purposes.
`Clé des Champs' Strawberry
Authors: Khanizadeh Shahrokh , Deschênes Martine , Levasseur Audrey , Carisse Odile , Cao Rong , Yang Raymond , DeEll Jennifer , Sullivan J. Alan , Privé Jean-Pierre
Published: February 2019

`Clé des Champs' is a new June-bearing strawberry cultivar (Fragaria ×ananassa Duch.) bred for Eastern Central Canada and climates similar to Quebec conditions. `Clé des Champs' was released for pick-your-own and shipping because it has very attractive light red, glossy (Fig. 1), and firm fruit, which have an excellent shelf life compared with `Kent'.
Using GIS-Based Tools and Distribution Modeling to Determine Sweetpotato Germplasm Exploration and Documentation Priorities in Sub-Saharan Africa
Authors: Villordon Arthur , Njuguna Wambui , Gichuki Simon , Ndolo Philip , Kulembeka Heneriko , Jeremiah Simon C. , LaBonte Don , Yada Bernard , Tukamuhabwa Phinehas , Mwanga Robert O. M.
Published: February 2019

Detailed information on the geographic distribution of a crop is important in planning efficient germplasm conservation strategies but is often not available, particularly for minor crops. Using germplasm collection data from Kenya, Tanzania, and Uganda, we used distribution modeling to predict the distribution of sweetpotato [Ipomoea batatas L. (Lam.)] in sub-Saharan Africa. We used a consensus modeling approach using the following algorithms: genetic algorithm for rule set prediction (GARP), maximum entropy, BIOCLIM, and DOMAIN. The predicted distribution encompasses known sweetpotato production areas as well as additional areas suited for this crop species. New geographic areas where at least three models predicted presence were in Angola, Cameroon, Central African Republic, The Congo, Democratic Republic of Congo, Gabon, Ghana, Angola, Ethiopia, Mozambique, Rwanda, and the Central African Republic. This information can be used to fill gaps in current sweetpotato germplasm collections as well as to further enhance the current presence-only based distribution model. Our approach demonstrates the usefulness of considering several models in developing distribution maps.
Efficacy of Bacterial or Fungal Soil Amendments on Vegetables Following Peanut
Authors: Russo Vincent M.
Published: February 2019

Amendment of soil with microorganisms during the growth cycle of one crop may affect development of succeeding crops. Species of Rhizobium bacteria or abuscular-mycorrhizal fungi were added alone to, or in combination with, potting soil in pots in a greenhouse. Controls were no amendments. Seed of peanut (Arachis hypogaea L.) were planted and two levels of a combination NPK fertilizer, the recommended and one-fourth the recommended rate, were applied. After harvest of peanut and remoistening of soil, seed of the bell pepper (Capsicum annuum L.) or navy bean (Phaseolus vulgaris L.) were sown into the same planting medium in pots without additional inoculation with microbes. Dry weights of above-ground vegetative and edible portions of crops were determined. Inoculum type only affected peanut top and total dry weights. The recommended fertilizer level did not affect peanut yield but did cause improvement in bell pepper and navy bean yield over that of the deficient fertilizer rate. In field experiments, peanut was planted into soil receiving Rhizobium spp. bacteria, or arbuscular-mycorrhizal fungi alone or in combination. Controls consisted of no amendment. Only the recommended fertilizer rate was used. In the next 2 years, bell pepper or navy bean were established in plots without use of additional microbial amendment. Yields and nutrient contents of crops were determined. Type of inoculum did not affect yield or nutrient content in any crop. Bell pepper marketable yield was unaffected by year, and navy bean seed yield was higher in 2004 than in 2005. In both years, navy bean yields were below U.S. averages. Concentrations of most nutrients in edible portions of bell pepper and navy bean were lower in 2004 than in 2005. Results of the field trials were generally similar to those of greenhouse studies. Use of inocula did not provide substantial benefits to yield or nutrient content of peanut or vegetable crops that followed.
Effects of Soaking Cucumber and Tomato Seeds in Paclobutrazol Solutions on Fruit Weight, Fruit Size, and Paclobutrazol Level in Fruits
Authors: Magnitskiy Stanislav V. , Pasian Claudio C. , Bennett Mark A. , Metzger James D.
Published: February 2019

Determination of plant growth regulator accumulation in fruits and vegetables for human consumption is an important safety issue even when it is applied to seeds. Paclobutrazol accumulated preferentially in the seedcoats when soaking cucumber (Cucumis sativus L., cv. Poinsett 76SR) seeds in 1000 or 4000 mg·L–1 paclobutrazol. Cucumber plants grown from seeds soaked in 1000 mg·L–1 paclobutrazol had lower average fruit weights than the control plants. Individual fruit length in cucumber was reduced by 40% when seeds were soaked in 1000 mg·L–1 paclobutrazol solutions for 180 minutes. Soaking tomato (Solanum lycopersicum L., cv. Sun 6108) seeds in 0 to 1000 mg·L–1 paclobutrazol did not reduce average fruit weight or diameter per treatment. Paclobutrazol residue was not detected in cucumber and tomato fruits harvested from plants grown from seeds soaked in 1000 mg·L–1 paclobutrazol for 180 minutes. Soaking seeds in paclobutrazol solutions represents a promising method of applying plant growth regulators to tomato and cucumber without accumulation of paclobutrazol residue in fruits.
Genetic Variation in Carotenoid Concentrations among Diploid and Amphidiploid Rapid-cycling Brassica Species
Authors: Kopsell Dean A. , McElroy J. Scott , Sams Carl E. , Kopsell David E.
Published: February 2019

Vegetable crops can be significant sources of nutritionally important dietary carotenoids, and Brassica are sources that also exhibit antioxidant and anticarcinogenic activity. The family Brassicaceae contains a diverse group of plant species commercially important in many parts of the world. The six economically important Brassica species are closely related genetically. Three diploid species (B. nigra, B. rapa, B. oleracea) are the natural progenitors of the amphidiploid species (B. juncea, B. napus, B. carinata). The objective of this study was to characterize the accumulation of important dietary carotenoid pigments among the genetically related Brassica species. High-performance liquid chromatographic quantification revealed significant differences in carotenoid and chlorophyll pigment concentrations among the Brassica species. Brassica rapa accumulated the highest concentrations of antheraxanthin [0.79 mg/100 g fresh weight (FW)], lutein (8.89 mg/100 g FW), and zeaxanthin (0.75 mg/100 g FW). The highest concentrations of β-carotene (4.41 mg/100 g FW) and total chlorophyll (125.9 mg/100 g FW) were found in B. juncea. Brassica nigra accumulated the highest concentrations of 5,6-epoxylutein (0.41 mg/100 g FW) and violaxanthin (2.28 mg/100 g FW), whereas B. oleracea accumulated the highest concentrations of neoxanthin (2.10 mg/100 g FW). For many of the pigments analyzed, the amphidiploids B. carinata and B. napus accumulated significantly less carotenoid concentrations than the diploid species and B. juneca. Brassica convey unique health attributes when consumed in the diet. Identification of genetic relationships among the Brassica species would be beneficial information for improvement programs designed to increase carotenoid values.
Clarifying Taxonomy and Nomenclature of Fothergilla (Hamamelidaceae) Cultivars and Hybrids
Authors: Ranney Thomas G. , Lynch Nathan P. , Fantz Paul R. , Cappiello Paul
Published: February 2019

Fothergilla L. spp. are valuable nursery and garden plants. However, clear differentiation among F. gardenii Murray, F. major Lodd., and potential hybrids can be difficult based solely on morphological characteristics. The objectives of this work were to verify and describe the existence of interspecific hybrids and to clarify the proper nomenclature for cultivars of Fothergilla that are commonly grown in the nursery industry. A comparison of morphological characteristics was made among diverse clones representing both species and potential hybrids. A combination of chromosome counts and DNA contents was used to clearly differentiate among F. gardenii (2n = 4x = 48), F. major (2n = 6x = 72), and hybrids (2n = 5x = 60). It was determined that the majority of cultivars represented in commerce were hybrids. Fothergilla ×intermedia Ranney and Fantz (hybrid fothergilla) is proposed as the name for these hybrids and is validated with a Latin diagnosis. Although certain morphological characteristics can be used to differentiate between F. gardenii and F. major, the hybrids tend to be intermediate and are particularly difficult to separate from F. major on the basis of appearance. The correct classification and nomenclature for 17 different taxa are presented.
Breeding for Early Bearing in Olive
Authors: León Lorenzo , de la Rosa Raúl , Barranco Diego , Rallo Luis
Published: February 2019

The initial results of a comparative field trial of the first 15 selections of the olive (Olea europaea L.) breeding program of Cordoba, Spain, are presented. These selections came from crosses among ‘Arbequina’, ‘Frantoio’, and ‘Picual’ that were also included in the trial as controls. The trial was planted in July 2001 in a randomized block design with 16 replications and was systematically evaluated for earliness of bearing, vigor, crop, and yield efficiency from 2001 to 2005. Significant differences among selections were found for all characters measured. A greater proportion of early-bearing genotypes than in previous cultivar collections were found, whereas mean accumulated yield was similar to former evaluations. Therefore, the shorter unproductive period obtained in this work seems to indicate that the selection of seedlings for a short juvenile period has provided a shorter unproductive period of the subsequent new cultivars. No correlation between vigor at the seedling stage and vigor in the corresponding adult vegetative propagated selection was found. If the data presented here are confirmed further, some early-bearing cultivars could be suggested as new olive cultivars, the first obtained by cross-breeding in Spain. Additionally, some of them also show a low vigor and could be adapted to high-density hedgerow orchards.
Evaluation of Rootstock Resistance to Fusarium Wilt and Gummy Stem Blight and Effect on Yield and Quality of a Grafted ‘Inodorus’ Melon
Authors: Crinò Paola , Lo Bianco Chiara , Rouphael Youssef , Colla Giuseppe , Saccardo Francesco , Paratore Antonino
Published: February 2019

Grafting represents an effective tool for controlling the race 1,2 of Fusarium oxysporum f. sp. melonis (FOM) and Didymella bryoniae in melon (Cucumis melo L.). Although not considered a soilborne pathogen, D. bryoniae survives on plant remains in the soil. The lack of effective resistant commercial hybrids and the gradual reduced use of soil fumigation with methyl bromide increase the risk of damages by both these pathogens. We determined the effectiveness of eight commercial rootstocks, ‘RS 841’, ‘P 360’, ‘ES 99-13’, ‘Elsi’ (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne), and ‘Belimo’, ‘Energia’, ‘Griffin’, ‘ES liscio’ (Cucumis melo genotypes), for their resistance to FOM and D. bryoniae. During 2003 and 2004 growing seasons, the inodorus F1 hybrid Incas was grafted onto each of these commercial rootstocks and then evaluated, under greenhouse conditions, in terms of productivity and fruit quality. Cucurbita rootstocks (‘RS 841’, ‘P 360’, ‘ES 99-13’, ‘Elsi’) were highly resistant both to the race 1,2 of FOM (100% survival) and to D. bryoniae (almost absent crown lesions and low leaf disease index); this reaction clearly differed from that of both the C. melo rootstocks (‘Belimo’, ‘Energia’, ‘Griffin’, ‘ES liscio’) and the control Incas. In both years, the highest yield was recorded in the graft combination Incas/‘RS 841’ with 5.6 and 8.1 kg·m−2 during 2003 and 2004, respectively. The Cucurbita rootstock ‘RS 841’ produced yields higher than C. melo rootstocks (‘Belimo’, ‘Energia’, ‘Griffin’, ‘ES liscio’) and the control Incas. Fruit dry matter, titratable acidity, total soluble solid contents, fruit firmness, and Hunter color [L* (brightness), a* (redness), and b* (yellowness) parameters] of grafted melons were similar to those of the plants grown on their own roots.
Salinity Tolerance of Lupinus havardii and Lupinus texensis
Authors: Niu Genhua , Rodriguez Denise S. , Aguiniga Lizzie , Mackay Wayne
Published: February 2019

Use of recycled water to irrigate urban landscapes and nursery plants may be inevitable as fresh water supplies diminish and populations continue to grow in the arid and semiarid southwestern United States. Lupinus havardii Wats. (Big Bend bluebonnet) has potential as a cut flower and Lupinus texensis Hook. (Texas bluebonnet) as a bedding plant, but little information is available on salt tolerance of these species. A greenhouse study was conducted to characterize the growth in response to various salinity levels. Plants were grown in 10-L containers and drip-irrigated with synthesized saline solutions at electrical conductivity levels of 1.6, 3.7, 5.7, 7.6, or 9.4 dS·m−1. Although shoot growth of L. texensis was reduced as salinity levels increased, it was visually acceptable (without any visual injury) when irrigated with salinity levels of less than 7.6 dS·m−1. All plants survived at 7.6 dS·m−1, whereas only 15% did at 9.4 dS·m−1. In contrast, L. havardii had leaf injury at 5.7 dS·m−1. No plants survived at 9.4 dS·m−1, and only 7% plants survived at 7.6 dS·m−1. In addition, growth of L. havardii was significantly reduced and plants were shorter at elevated salinity levels. Cut raceme yield of L. havardii decreased at salinity levels greater than 3.7 dS·m−1. However, no difference in cut raceme yield was observed between the control and 3.7 dS·m−1, although shoot growth was reduced. Overall, L. texensis was more salt-tolerant than L. havardii.
Relative Salinity Tolerance of Intermountain Western United States Native Herbaceous Perennials
Authors: Zollinger Nickolee , Koenig Richard , Cerny-Koenig Teresa , Kjelgren Roger
Published: February 2019

The authors investigated salinity tolerance of four intermountain western United States native (Penstemon palmeri, Mirabilis multiflora, Geranium viscosissimum, and Eriogonum jamesii) and four common (Echinacea purpurea, Lavandula angustifolia, Leucanthemum ×superbum ‘Alaska’, and ×Penstemon mexicali ‘Red Rocks’) ornamental herbaceous perennials. Each was irrigated with a solution containing 2 CaCl2 : 1 NaCl (m ratio) at salinity levels of 0 (control), 1000, 3000, and 5000 mg·L−1 during two 8-week experiments. They measured weekly visual quality and gas exchange and final shoot and root dry weights. Mirabilis multiflora, L. ×superbum, and L. angustifolia maintained high visual quality and 100% survival across salinity levels. However, dry weights for L. ×superbum decreased at salt levels ≥ 3000 mg·L−1 in both experiments and for L. angustifolia in one experiment. Mortality rates of 12% to 100% were observed for the remaining five species irrigated with 3000 and 5000-mg·L−1 solutions. Visual quality of P. palmeri, G. viscosissimum, and E. purpurea varied with time of year the experiment was conducted, with low visual quality associated with high temperatures and light intensities, whereas dry matter and gas exchange responses to salinity were similar between the two experiments. Penstemon ×mexicali and E. jamesii exhibited high mortality, low visual quality, and low gas exchange in the case of E. jamesii at high salinity treatments regardless of when experiments were conducted. Based on visual quality responses, M. multiflora, L. ×superbum, and L. angustifolia are relatively more salt tolerant, and P. ×mexicali and E. jamesii are relatively more intolerant, than the three other species. Penstemon palmeri, G. viscosissimum, and E. purpurea exhibited intermediate tolerance to salinity with acceptable quality during periods of cool temperatures and lower light intensities.
Response of a Gibberellin-deficient Potato Mutant to Induction and Growth Regulators as a Working Model for Tuber Initiation
Authors: Wang Bing , Langille Alan R.
Published: February 2019

To explore further the role endogenous gibberellins play in the formation of the potato tuber, a gibberellin-deficient dwarf of Solanum tuberosum subsp. andigena (PI 281036) and its normal sibling were used in this study. Because gibberellins are known to be elevated and to affect tuber formation negatively when potato plants are grown under long day conditions, test plants were first grown in a growth chamber under conditions that did not favor tuberization (noninducing conditions). The stem apices of dwarfs received weekly applications of a 100-ppm gibberellic acid (GA3) solution to achieve growth similar to that of normal plants. When the requisite height was achieved, five dwarfs and five normal sibs were treated to foliar runoff with a 100-ppm GA3 solution, and a like number of these plants received a control spray of distilled water. These plants were then placed in a growth chamber adjusted to inducing conditions for tuber initiation. An additional five dwarfs and five normal sibs were sprayed with 600 ppm paclobutrazol (PB), a gibberellin inhibitor, and a similar number of plants received a distilled water control spray. This group of plants was returned to the noninducing chamber. After 1 week, plants were removed from their respective growth chambers and divided into two-node apical, medial, and basal leaf-bud cuttings. Basal buds of the cuttings were buried in moist potting mix in a mist chamber with a 16-hour photoperiod. Rhizome and tuberization responses were evaluated after 3 weeks. The experiment was repeated and results combined for statistical treatment. Orthogonal contrasts revealed that apical cuttings from normal donor plants produced rhizomes only under noninducing conditions or when treated with GA3. No rhizomes formed on apical cuttings from normal plants growing under inducing conditions (favoring tuberization) or noninduced plants receiving PB (a gibberellin inhibitor). For apical dwarf tissues, there were no effects of treatments on rhizome production, except for the PB treatment, which resulted in shorter rhizomes. Tuberization was observed in apical tissues of induced and noninduced dwarfs, which lack the ability to synthesize gibberellin, but only in induced cuttings of normal sibs. Noninduced dwarf cuttings tuberized as well as those from normal plants receiving the antigibberellin treatment. Tuber weights from induced apical cuttings of dwarfs and normal sibs were not significantly different. These results support the significant role played by gibberellins in tuber formation.
Gibberellic Acid, Rootstocks, and Post-freeze Fruit Quality of ‘Rohde Red’ Valencia Oranges
Authors: Davies Frederick S. , Zalman Glenn
Published: February 2019

The authors’ objectives were to determine whether gibberellic acid (GA3) initially increases juice content of ‘Rohde Red’ valencia oranges and prevents or delays decreases in juice content after a freeze, and to determine whether there is an interaction between GA3, rootstock, and juice content. The experiment consisted of a 2 (+, –GA3) × 3 (rootstock) factorial using a completely randomized design with 10 replications per treatment. Gibberellic acid was applied to mature ‘Rohde Red’ valencia [Citrus sinensis (L.) Osb.] orange trees on three rootstocks—Citrus volkameriana Ten. & Pasq.(Volk), Swingle citumelo [C. paradisi Macf. ×Poncirus trifoliata (L.) Raf.], and Carrizo citrange [C. sinensis ×P. trifoliata]—at color break in Fall 2002, 2003, and 2004. Juice content, soluble solids content (SSC), titratable acidity (TA), ratio of SSC to TA, and kilogram solids per box were determined at about 2-week intervals after several freezes. In 2002–03 and 2004–05, juice content in the fall was greater and the rate of decrease in juice content lower for GA3-treated fruit than nontreated fruit for about 8 weeks after a freeze. In contrast, in 2003–04, juice content and rate of decrease in juice content were not different between treatments. Juice content was lower for fruit from ‘Rohde Red’ trees on Volk compared with those on Carrizo and Swingle, and more important, the rate of decrease in juice content after a freeze was greatest for trees on Volk in all three seasons. Soluble solids content, TA, SSC-to-TA ratio, and kilogram solids generally were not effected by GA3 treatment. Therefore, GA3 application at color break in the fall generally increased juice content and slowed the rate of decrease in juice content after a freeze compared with nontreated fruit. In addition, juice content differed significantly with rootstock, but there was no GA3 × rootstock interaction.
Psychological Benefits of Indoor Plants in Workplaces: Putting Experimental Results into Context
Authors: Bringslimark Tina , Hartig Terry , Patil Grete Grindal
Published: February 2019

Laboratory experiments and quasi-experimental field studies have documented beneficial effects of indoor plants on outcomes such as psychophysiological stress, task performance, and symptoms of ill health. Such studies have taken an interest in the value of indoor plants in work settings, but they typically have not considered how the effects of plants might compare with effects of other workplace characteristics. The present study makes an initial attempt to situate the potential benefits of indoor plants in a broader workplace context. With cross-sectional survey data from 385 Norwegian office workers, we used hierarchical regression analyses to estimate the associations that plants and several often-studied workplace factors have with perceived stress, sick leave, and productivity. Other variables included in our models were gender, age, physical workplace factors (e.g., noise, temperature, lighting, air quality), and psychosocial workplace factors (demands, control, social support). After controlling for these variables, the number of indoor plants proximal to a worker's desk had small but statistically reliable associations with sick leave and productivity. Although small, such associations can have substantial practical significance given aggregation over the large number of office workers over time.
Quality of Pink Lady Apples in Relation to Maturity at Harvest, Prestorage Treatments, and Controlled Atmosphere during Storage
Authors: de Castro Elena , Biasi William V. , Mitcham Elizabeth J.
Published: February 2019

Apple [Malus ×sylvestris (L.) Mill. var. domestica (Borkh.) Mansf. ‘Cripps Pink’] fruit were harvested yearly, at two or three maturity stages, from the same California orchard in 2002 through 2005. Fruit firmness, soluble solids, titratable acidity, background color, and percent blush were correlated with the starch pattern index at harvest. Fruit from each harvest were stored at 0.5 ºC in air or in a controlled atmosphere (CA) with 1.5 or 2 KPa O2 in combination with 1, 3, and 5 KPa CO2. Subsets of fruit were treated with 1 μL·L−1 1-methylcyclopropane for 24 hours at 0 ºC or 2200 μL·L−1 diphenylamine (DPA) for 5 minutes. Ethylene production was measured for 30 days after harvest. Ethylene concentration in the storage atmosphere was also monitored during storage. Fruit quality was evaluated after storage plus 5 days of ripening at 20 ºC. Fruit in a CA with 1 or 3 KPa CO2 maintained firmness and green background color, and produced less ethylene during ripening at 20 ºC than fruit stored in a CA with 5 KPa CO2; however, quality of all CA-stored fruit was better than air-stored fruit. Flesh browning developed only in CA storage, appearing by 2 months and not increasing in incidence with further storage periods. 1-Methylcyclopropane conserved fruit quality in air as well as CA during 4 months of storage, and DPA-treated fruit were firmer after CA storage, but similar after air storage, compared with untreated fruit. Diphenylamine did not control a stem-end scald disorder, which increased with time in storage and affected more than 80% of the fruit after 6 months of air storage.