bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF PRODUCTION ENVIRONMENT ON SEED VIGOR
Authors: Coons Janice
Published: February 2019

The environment that seeds experience during development, storage, and planting significantly affects seed vigor. Yet, relatively few studies have focused on how environment during seed development affects seed vigor. Our objective was to compare vigor of seeds developed in summer vs. winter. Lettuce (Lactuca sativa L.) seeds from six cultivars were developed in summer and winter at Yuma, Ariz. Seed vigor of these seedlots was compared using field plantings and growth chambers (at 20, 25, 30, and 35C). Seed vigor was greater for seed produced during summer than for that produced during winter, based on greater field emergence, higher germination percentages, and longer roots. These seedlot differences in vigor were greatest at 35C. Another way to estimate seed vigor is by ion leakage from seeds. Fewer ions leaked from seeds produced in summer than from those produced in winter. Thus, lettuce seed is more vigorous when produced in summer than in winter, and ion leakage is a good indicator of that vigor.
SEED PELLETING-HISTORY AND MODERN FUNDAMENTALS
Authors: Hill H.J.
Published: February 2019

The use and improvement of pelleted seed technology has greatly expanded in the last 15 years. Vegetable and flower seeds are pelleted to improve the singulation and planting placement in the field and greenhouse. Improved planting placement increases final-stand establishment, crop uniformity, and decreases seed and production costs. The commercial history of pelleted seed in the U.S. started after WWII with the development of the clay pellet by Filtrol Inc. Seed tablets and seed tape technologies were also developed but faded from the industry with the advent of better pelleted products. Current technology consists of a “splitting” seed pellet that allows for improved oxygenation. Improved technology also allows for pellet weights that can be tailored to meet the planting requirements of different species and planting systems.
VARIABLE URBAN IRRADIANCE AND SHADE ACCLIMATION IN NORWAY MAPLE STREET TREES
Authors: Kjelgren Roger
Published: February 2019

Shade acclimation response of Emerald Queen Norway maple street trees to variable urban irradiance levels was investigated. Specific leaf area, trunk growth, and crown density were measured from trees in 13 sites ranging from urban canyons in the business core to open exposures in residential areas of Seattle, Wash. Percentage of potential seasonal input of global shortwave radiation for each site was modeled based on the azimuth and elevation angles of the surrounding horizon topography. Building height in the business core reduced estimated irradiance to a range of 27% to 90% of that for an unobstructed horizon topography, while those outside the business core had 90% to 95% irradiance. As estimated potential irradiance decreased, growth of these maple street trees exhibited responses characteristic of shade acclimation in a dose-response pattern. Specific leaf area increased and trunk growth and crown density decreased to acclimated levels at -70% of potential irradiance. These acclimation responses did not degrade the function of the trees in their urban-canyon locations. Their foliage was healthy, and reduced crown density was not apparent since there were no full-sun-grown trees for comparison.
SEED ENHANCEMENT AND THE PUBLIC: A PARTNERSHIP PROPOSAL
Authors: Sanders Joseph
Published: February 2019

Agricultural biotechnology, in such areas as seed enhancement, is making significant progress in overcoming a variety of conceptual and practical problems. As a result, the near-term potential is tremendous for improving agricultural productivity and efficiency on marginal lands, for decreasing reliance on synthetic chemicals, and for enhancing environmental acceptability. However, a number of major challenges lie ahead, at least three of which require the development of a strategic plan, if the seed industry is to remain viable. The emergence of resistant viral strains and more aggressive insects, as well as herbicide-resistant weeds, requires access to a greater diversity of genetic resources. Then: too, with governmental oversight, there must be a credible, sound review process that is flexible and assures safety while facilitating technology development, transfer, and use. Third, the public must develop a far better understanding of the applications of biotechnology and the actual risks they may pose. This can be accomplished through a process that recognizes the tremendous potential benefits biotechnology offers, while also eliminating irrational fears, mistrust of recombinant DNA, and ill-founded aversion to genetically engineered products. The purpose of this paper is to address these challenges concerning seed enhancement by proposing and outlining a partnership strategy supportive of school-based community seedbank programs. Also explored in this presentation, because they can ensure the success of such initiatives, are the reciprocal, conceptual changes that society appears to require of the seed enhancement industry and, more generally, agricultural biotechnology. In such respects, the emphasis is on the conservation of plant genetic resources. This includes the germplasm of crop plants, their wild relatives, and other plant species possibly contributing important genetic characteristics and scientific understanding of their oligogenic nature.
Seed Source and Quality Influence Germination in Purple Coneflower [Echinacea purpurea (L.) Moench.]
Authors: Wartidiningsih N. , Geneve R.L.
Published: February 2019

Six seed lots of purple coneflower were purchased from four commercial seed sources and evaluated for germination in either light or darkness in combination with two temperature regimes (constant 27C vs. alternating 30C for 8 hours and 20C for 16 hours). Seed lot differences accounted for the majority of variation, with two seed lots exhibiting high (81% to 91%) germination and the remaining seed lots having 39% to 66% germination. There was no effect of light on germination, regardless of the seed lot. However, alternating temperatures improved germination in one of the low-germination seed lots. Seed size and inflorescence position did not affect seed germination. Seed harvested at physiological maturity (maximum seed dry weight), but before drying had occurred, had a higher germination percentage than seeds harvested after desiccation, and they maintained a higher germination percentage even after 1 year in storage.
Dry Matter Distribution of Three Peach Growth Types
Authors: Giovannini Daniela , Glenn D. Michael , Scorza Ralph , Welker W.V.
Published: February 2019

Our objective was to evaluate the dry-matter partitioning between the roots and shoots of two genetically size-controlled peach [Prunus persica (L.) Batsch] types, dwarf and pillar, compared to a full-sized standard peach type. Compared to the pillar and standard types, the dwarf type had a reduced leaf: root ratio, less allocation of dry matter to woody tissue and more to leaf tissue. Genetically size-controlled peach trees have a smaller root system, but a lower leaf: root ratio and may require modified soil and water management techniques to ensure high productivity.
Comparative Growth and Development of Nerine bowdenii W. Watson: Bulbs in Situ versus Replanted
Authors: Theron Karen I. , Jacobs Gerard
Published: February 2019

Flowering-size Nerine bowdenii bulbs were sampled from a commercial planting at 2-week intervals from 13 Aug. 1991 to 14 June 1992. They were dissected, and the following variables were recorded: 1) number and dry weight of fully sheathing leaf bases or leaves of each growth unit, 2) length and dry weight of foliage leaves, 3) fresh weight of outermost inflorescence, and 4) dry weight of daughter bulbs. Bulb organs that served as sinks and sources changed as the bulb progressed in its growth and developmental cycle. Before the new foliage provided photosynthates, growth depended on reserves deposited and stored in leaf bases during the preceding seasons. Reserves were used for the development of new leaves (foliage and bases), roots, and daughter bulb enlargement. Once the foliage became the photosynthate source, reserves were stored in old and new leaf bases. The inflorescence became the major sink when elongation of the scape initiated. Thereafter, daughter bulbs became the dominant sinks, receiving photosynthates from the senescence foliage and the reserves stored in leaf bases. The decrease in dry weight of the leaf bases was prominent in bulbs that remained in situ.
Postharvest Shelf Life of Sweet Basil (Ocimum basilicum)
Authors: Lange Diana D. , Cameron Arthur C.
Published: February 2019

Shelf life (defined by visual quality) of freshly harvested greenhouse-grown sweet basil was maintained for an average of ≈ 12 days at 15C. Chilling injury symptoms were severe at storage temperatures of 5C and below. Shelf life was found to be only 1 and 3 days at 0 and 5C, respectively. Moderate chilling injury was noted at 7.5 and 10C. Harvesting sweet basil later in the day (i.e., 1800 or 2200 hr) increased shelf life by almost 100% when harvested shoots were held at 10, 15, and 20C, compared to harvesting at 0200 or 0600 hr. However, the time of day of harvest did not alter the development of visual chilling injury symptoms or improve shelf life at 0 or 5C.
Fruit Diameter and Daily Fruit Growth Rate of Three Apple Cultivars on Rootstock–Scion Combinations
Authors: Hussein Ismail A. , Slack Donald C.
Published: February 2019

The effect of three vigor-control apple (Malus domestics Borkh.) rootstock (seedling, MM.106, and M.7a) on fruit diameter of three cultivars ('Red Delicious', `Granny Smith', and `Gala') was studied over two growing seasons (1990-91) in the arid climate of Willcox, Ariz. Daily fruit growth rate (DFGR) and effective fruit growth period (EFGP) data indicate cultivar differences in DFGR as well as EFGP. Cultivars with a high DFGR had a relatively shorter EFGP. Rootstock had no significant effect on EFGP. Cultivar x rootstock interaction on fruit diameter was significant for DFGR, but not for EFGP. `Red Delicious' and `Granny Smith' trees produced larger fruits on MM.106 and M.7a than on seedling rootstock. For `Gala', there was no significant effect of all rootstock on fruit diameter.
Planting-hole Amendments Modify Growth and Fruiting of Apples on Replant Sites
Authors: Neilsen G.H. , Beulah J. , Hogue E.J. , Utkhede R.
Published: February 2019

The effects of various nonfumigant planting-hole treatments on growth and yield of apple (Malus domestics Borkh.) trees were measured during the first 3 years after planting. Eight orchards diagnosed as having a replant problem were monitored. First-year shoot growth, the number of blossoms in the second year (inmost orchards), and first-year trunk cross-sectional area increment (TCAI) in 50% of test orchards were increased by monoammonium phosphate (MAP) fertilizer+ peat, MAP+ mancozeb, or MAP + peat + a bacterial antagonist. By the end of year 3, TCAI generally was not affected by treatments, but treatments resulted in more blossoms by the third season in two of seven orchards that blossomed in the second season. Cumulative yield after 3 years increased significantly in only three orchards, with the best treatment, MAP+ peat, resulting in cost recovery in only one orchard. Inadequate K or Cu nutrition may have reduced growth in some of the orchards, which were characterized by a wide range in yields, independent of planting-hole treatment.
Phosphate Fertilizer Enhances Arsenic Uptake by Apricot Liners Grown in Lead-arsenate-enriched Soil
Authors: Creger T.L. , Peryea F.J.
Published: February 2019

Phosphate fertilizer additions to soils containing lead arsenate (LA) pesticide residues can increase As volubility. Apricot (Prunus armeniaca L.) rootstock liners were grown in nondraining pots containing Burch loam soil that received a factorial treatment combination: 1) LA enrichment [no added LA (-LA), and LA added at 138 mg Pb/kg and 50 mg As/kg (+LA)]; 2) fertilizer type [monoammonium phosphate (MAP) and its sulfur analog ammonium hydrogen sulfate (AHS)]; and 3) fertilizer anion rate (0-26.1 mol/m3 soil). Measured response variables were soil salinity and pH, plant biomass, and plant As and Pb concentrations. Both MAP and AHS increased soil electrical conductivity (EC) and decreased soil pH, with AHS usually being more salinizing and acidifying than MAP was at equivalent rates. Adding LA reduced shoot and root mass and increased As and Pb concentration in shoots and roots. Shoot and root mass were inversely related to soil EC in the -LA soil but not in the +LA soil. Adding MAP increased shoot and root As concentration in the +LA soil, but adding AHS had no effect. Fertilizer type and rate did not influence shoot As concentration or root Pb concentration in the -LA soil or shoot Pb concentration in either the +LA or -LA soil. Adding AHS to the +LA soil increased root Pb concentration. These results are consistent with a P-enhanced solid-phase As release mechanism, which consequently increases plant uptake of soil As. Phosphate amendment had no effect on soil Pb phytoavailability.
Weed Control in Container-grown Herbaceous Perennials
Authors: Derr Jeffrey F.
Published: February 2019

Tolerance of transplanted black-eyed Susan (Rudbeckia hirta var. pulcherrima Farw.), lanceleaf coreopsis (Coreopsis lanceolata L.), shasta daisy (Chrysanthemum × superbum Bergmans ex. J. Ingram), purple coneflower [Echinacea purpurea (L.) Moench.], and blanket flower (Gaillardia aristata Pursh) to preemergence herbicides was evaluated in container trials. Herbicides were applied at the maximum use rate and twice the maximum use rate. Dithiopyr, pendimethalin, and prodiamine provided excellent control of spotted. spurge (Euphorbia maculata L.) and yellow woodsorrel (Oxalis stricta L.) with little injury to the five herbaceous perennials. DCPA, oxadiazon, and metolachlor were tolerated by all treated species, but these chemicals provided lower control of one or both weed species. Oryzalin, isoxaben + trifluralin, and napropamide caused unacceptable injury and shoot fresh-weight reductions in some of the perennials at one or both application rates. Chemical names used: dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA); S,S-dimethyl 2-(difluoromethyl) -4-(2 -methylpropyl)-6-trifluoromethyl-3,5-pyridinedicarbothioate(dithiopyr);N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide(isoxaben); 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide(metolachlor);N,N-diethyl-2-(l-naphtha1enenyloxy) propanamide(napropamide);4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin);3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethy1)-l,3,4-oxadiazol-2-(3H)-one (oxadiazon); N-(1-ethylpropyl) -3,4-dimethyl-2,6-dinitrobenzamine (pendimethalin); N,N-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine); 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzamine (trifluralin).
Plant Spatial Arrangement Affects Growth, Yield, and Pod Distribution of Cayenne Peppers
Authors: Decoteau Dennis R. , Graham Heather A. Hatt
Published: February 2019

The effect of planting population density (as a function of in-row plant spacing and number of rows per bed) on the growth, yield, and pod distribution of cayenne pepper (Capsicum annuum var. annuum L. cv. Carolina Cayenne) was investigated in a 2-year study. In 1988, 15 -, 30-, 45-, and 60-cm in-row spacings in a single row were evaluated, and in 198915 -,30-, and 60-cm in-row spacings in single and double rows were evaluated. Plant population densities at these respective spacings ranged from≈ 11,100 to 44,400 and 11,100 to 88,900 plants/ha. In 1988, pepper plants grown at the highest density (15-cm in-row spacing, 44,400 plant/ha) produced less fruit per plant but more fruit per hectare than those grown in lower densities. In 1989, yields with either a 15-cm in-row spacing in a single row or a 30-cm in-row spacing in double rows (both with 44,400 plants/ha) were higher than in the others. In general, less fruit were located in the lower part of the plant canopy when planted in higher plant population densities.
Reversal of Heat-induced Resetting in Eustoma grandiflorum with Low Temperatures
Authors: Ohkawa Kiyoshi , Yoshizumi T. , Korenaga M. , Kanematsu K.
Published: February 2019

The effects of seedling age and temperature regimes and durations on the reversal of Eustoma grandiflorum (Raf.) Shin. heat-induced rosette formation were clarified. When E. grandiflorum seedlings were grown in a natural-light phytotron (600-800 μmol·m-2·s-1) for 4 weeks at 33/28C (12-h day/12-h night) from germination to the four true-leaf stage, the optimum temperature and duration required to break rosette formation was 15C for 4 weeks with continuous illumination (35 μmol·m-2·s-1). However, when seedlings were grown for 12 weeks at 33/28C from germination to the eight true-leaf stage. shoot elongation required 6 weeks at 10C.
Comparison of Paclobutrazol Drench and Spike Applications for Height Control of Potted Floriculture Crops
Authors: Barrett James E. , Bartuska Carolyn A. , Nell Terril A.
Published: February 2019

Experiments with' White Christmas' and `Carolyn Wharton' caladiums (Caladium × hortulanum Birdsey), croton (Codiaeum variegatum), brassaia (Brassaia actinophylla Endl.), `Annette Hegg Dark Red' poinsettia (Euphorbia pulcherrima Wind.), and `Super Elfin Red' and `Show Stopper' impatiens [Impatiens wallerana (L.) Hook.f.] determined effectiveness of paclobutrazol in solid spike form as compared to media drench applications for height control. Paclobutrazol drenches and spikes were effective for all crops tested, with a similar concentration response for all, except that drenches had greater efficacy than spikes on caladium. A reduced effect was observed when spikes were placed on the medium surface of `Super Elfin Red' impatiens, while placement in the middle of the pot or around the side was equally effective. These results indicate that the spike formulation of paclobutrazol has potential to provide adequate size control for floriculture crops with the possible exception of rapidly developing crops, such as caladiums. Chemical name used: (2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-1,2,4-triazol-1-yl-) penten-3-ol (paclobutrazol).
Influence of Management Practices on Rhizoctonia Large Patch Disease in Zoysiagrass
Authors: Green D.E. , Fry J.D. , Pair J.C. , Tisserat N.A.
Published: February 2019

Mowing heights from 1.2 to 5.1 cm, five N sources with two application rates (74 and 148 kg N/ha per year), and seven preemergence herbicides were evaluated in field studies in Manhattan and Wichita, Kan., for their effect on large patch disease, caused by Rhizoctonia solani Kuhn AG 2-2, in zoysiagrass (Zoysia spp.). Turf mowed at 1.2 and 2.5 cm was more severely blighted than turf mowed at 4.5 or 5.1 cm. At all mowing heights, turf recovered by August or September. Disease severity was not influenced by N source, N rate, or preemergence herbicides.
Histological Studies on the Black Discoloration of Peach Fruit Skin Exposed to Iron
Authors: Arakawa Osamu , Ogawa Joe M.
Published: February 2019

The skin of `Elegant Lady' peach [Prunus persica (L.) Batsch.] fruit turned black when exposed to 100 ppm ferrous sulfate solution. This color change appeared on the red and the yellow portions of the fruit. Microscopy of the skin showed blue-black pigment distribution in epidermal and hypodermal tissues. Some epidermal and hypodermal cells discolored immediately when exposed to ferrous solutions, but many cells turned black later. Some cells with anthocyanin pigments did not discolor. Chromic acid showed that tannic substances were distributed in the epidermal and hypodermal cells, and they likely are the main factor in black discoloration of peach fruit exposed to solutions containing Fe.
EARLY PERFORMANCE OF FOUR APPLE CULTIVARS GRAFTED ON THE MICROPROPAGATED OTTAWA THREE ROOTSTOCK AND TRAINED IN TWO SYSTEMS
Authors: Granger Raymond L. , Khanizadeh Shahrokh , Groleau Yvon
Published: February 2019

In experimental plots established in 1989, `Spencer', `Empire', `MacSpur', and `Lobo' trees grafted on the in vitro-propagated Ottawa 3 (0.3) rootstock were trained in the triple axis and in the slender spindle systems. They were planted at 5 (between rows) × 2.04 m and laid out in a split plot array with four replicates. There were five trees per subplot unit. All trees were trickle-irrigated every year. Fruit thinning was chemically done for the first time in 1993. Trees from this experiment came into bearing in 1991, and their total cumulative yield was significantly superior in the case of trees of the Spindlebush system. Since no interactions were found, we cannot conclude that any given combination is better than the others. `Lobo', which has averaged nearly 21 tonnes/ha per tree, was best in terms of total cumulative yield and also in terms of yield efficiency. `MacSpur' and `Empire' were the second best ones in yield efficiency, and `Spencer' was significantly lower. Fruit size was very good for all combinations in 1993. At their fifth-leaf stage in 1993, the yield of `Empire' trees from this experiment was higher by an average of more than 1 kg per tree than that of comparable trees of conventionally propagated O.3 trees planted in adjacent test plots. The tree vigor of the micropopagated O.3 trees was better than that of the conventionally propagated ones as revealed by the trees' trunk and canopy development. However, a few trees exhibited slight burr-knot growth on their trunk. This has never been observed on the conventionally propagated O.3 rootstock.
RELATIONSHIPS BETWEEN PREFERENCE TYPES OF EMPLOYEES AND RESPECTIVE JOB CLASSIFICATIONS IN PUBLIC HORTICULTURE
Authors: Goin Angela L.
Published: February 2019

The purpose of this research was to measure relationships between preference types of employees and their respective job classifications in public horticulture. Preference type is the way people prefer to look at the external world, perceive information, make decisions, and live a lifestyle. Improved employee interpersonal relations and productivity, and decreased stress and conflict may result from understanding preference types. The Myers Briggs Type Indicator was used to determine preference types at Longwood Gardens, and at Morris, Scott, and Tyler arboreta. According to this research, a correlation exists between preference types and job classifications. In addition, when job classification preferences were compared to each other, they showed areas of potential conflict and miscommunication. In conclusion, my data generally agree with the general preference type theory.
ESTABLISHMENT OF THYME (THYMUS VULGARIS L.) BY DIRECT SOWING OR TRANSPLANTING AT TWO DENSITIES
Authors: LaFlamme Lucette , Michaud Marie-Hélène , Tremblay Nicholas
Published: February 2019

Cultivation of thyme for medicinal purposes should result in high dry-matter yield and sufficient active principals concentrations. In this experiment two methods of crop establishment were compared: direct sowing (final plant density: 100,000 plants/ha) and planting at two densities: D-1 (100,000 plants/ha) and D-2 (166,000 plants/ha). The use of transplants promoted growth and resulted in yields three times higher than direct sowing (3340 vs. 1002 kg dry matter/ha). There were significant differences in biomass between the two densities evaluated. Plants under D-1 weighed 33 g dry matter/plant vs. 22 g dry matter/plant for D-2. Hence, dry-matter yield per hectare was not affected by planting density. Active principals concentrations were not affected by treatments. So far, it is recommended that cultivation of thyme under Quebec's conditions be based on transplanting at moderate (100,000 plants/ha) density.
DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH
Authors: Lavoie Eric A. , de Halleux Damien , Gosselin André , Dufour Jean-Claude
Published: February 2019

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.
TIME-RESOLVED IMAGING SPECTROSCOPY OF PLANT ADAPTATIONS TO CHANGES IN THE LIGHT ENVIRONMENT AND APPLICABILITY TO SCREENING MUTANTS
Authors: Dubé Sylvain L. , Allen John F.
Published: February 2019

Photosynthesis, a major determinant in growth and survival of plants, is very sensitive to the energy balance of the processes triggered by the physico-chemical environment. It is, therefore, an excellent indicator of the plants' physiological state. Fundamental events in photosynthesis can be studied non-invasively and non-destructively by examining there-emission of absorbed light energy as chlorophyll a fluorescence. In this study we present digitized consecutive images of fluorescence of intact leaves of Arabidopsis sp. The relative intensity and kinetics of fluorescence of several AOI (areas of interests) of each image have been analyzed and compared. We demonstrate the feasibility of this technique for studying the physiology of light adaptations (state-transitions) of several organisms simultaneously and its applicability in indentifying mutants. Implications of this technique to the horticulture industry will be discussed.
A FRAMEWORK FOR COMPUTERIZED FARM DECISION-SUPPORT SYSTEMS
Authors: Gauthier Laurent , Néel Thierry
Published: February 2019

A software system (SAGE) was built for on-farm decision support. The objective was to provide a framework for constructing and deploying knowledge-based decision support in the areas of integrated pest management, fertilization, and field operations. The framework is open by design and includes a generic model of an agro-ecosystem as well as various mechanisms allowing for the continued growth in scope and function of the software. The SAGE system is designed to provide a number of building blocks and predefined decision-support strategies that can be adapted to specific needs and situations. It operates on a personal computer and is based on the use of an objectoriented technology for software construction and operation. A prototype of the system has been built and is being used to build commodity-specific decision-support modules.
POTENTIAL OF PROTEINASE INHIBITORS FOR THE PRODUCTION OF TRANSGENIC PLANTS TOLERANT TO INSECT PESTS. II. POTENTIAL LIMITATIONS
Authors: Overney Serge , Michaud Dominique , Nguyen-Quoc Binh , Yelle Serge
Published: February 2019

In recent years, several studies have demonstrated the potential of proteinase inhibitors (PIs) for controlling insect pests. Used as a component of an integrated pest management program, such an approach must, however, be considered with care, given the potential risks of interference on other control approaches. In particular, the effect of PIs on digestive proteinases of beneficial insects must be determined. As an example, this study analyzed the effect of oryzacystatins (OCs), two cysteine PIs isolated from rice, on digestive proteinases of Perillus bioculatus, a predator of the Colorado potato beetle (CPB; Leptinotarsa decemlineata Say), a major pest. Electrophoretic analyses showed the existence of several cysteine proteinase forms in the digestive tract of P. bioculatus. For each developmental stage, OCs dramatically inhibited proteolytic activity, showing an affinity between these inhibitors and the digestive proteinases of the predator. Despite their potential for controlling CPB, the two rice cystatins thus represent possible growth-suppressing compounds for the beneficial insect P. bioculatus. Work is currently under way to assess the compatibility of the two control approaches.
EFFECTS OF CONTINUOUS LIGHTING ON ENZYME ACTIVITIES OF LEAF CARBON METABOLISM OF TOMATO AND PEPPER PLANTS
Authors: Demers Dominique-André , Yelle Serge , Gosselin André
Published: February 2019

Exposure of tomato and pepper plants to long photoperiods (20 hours or more for tomato; 24 hours for pepper) results in leaf chlorosis (tomato), leaf deformities (pepper), and decreased growth and productivity (both species). Some researchers have suggested that excessive starch accumulation in the leaves could be the cause of the negative effects. We observed that tomato and pepper plants do accumulate more starch in their leaves when grown under a long photoperiod (24 hours) compared to a shorter one (16 hours). However, our results indicated that these accumulations were not caused by a limited sink strength but by an alteration of the carbon metabolism at the leaf level. In our last experiment, we studied the activity of enzymes [sucrose phosphate synthase (SPS), sucrose synthase (SS), invertase] of leaf carbon metabolism in tomato and pepper plants grown under different photoperiods (natural, natural + supplemental light of 100 μmol·m-2·s-1 during 16 and 24 hours). We observed a 10% to 15% decrease in leaf SPS activity in tomato (not in pepper) plants grown under a 24-hour photoperiod. In both species, invertase and SS activities were not affected by photoperiod treatments. In tomato plants grown under a 24-hour photoperiod, the decrease in SPS activity corresponded to the appearance of leaf chlorosis (6 to 7 weeks after the beginning of treatments). Therefore, it appears that leaf carbon metabolism could be involved in the development of negative effects of long photoperiod in tomato plants, but not in pepper plants. The fact that photoperiod had no apparent effect on leaf carbon metabolism of pepper may explain why this species can tolerate longer photoperiods than tomato plants.
SOMATIC EMBRYOGENESIS OF MUSSAENDA `QUEEN SIRIKIT'
Authors: Cramer Christopher S. , Bridgen Mark P.
Published: February 2019

Disinfected midrib sections of Mussaenda `Queen Sirikit' ≈3 to 4 mm in size were cultured on a basal medium of Murashige and Skoog salts and vitamins, 87.7 mm sucrose, and 5 g Sigma agar/liter supplemented with several concentrations of indole-3-acetic acid (IAA) (0, 5.0, 10.0, 20.0 μm) and 6-benzylaminopurine (BAP) (0, 0.5, 1.0, 2.5, 5.0, 10.0, 25.0, 50.0 μm). Cultures were subculture onto the same treatment after 5 weeks and observed weekly for 15 weeks for the presence of somatic embryos. As somatic embryos were produced, they were subculture onto basal medium supplemented with 0.5, 1.0, 2.5, or 25.0 μm BAP. Callus was first observed at 2 weeks in cultures grown on basal medium supplemented with 5.0–20.0 μm IAA and 0–50.0 μm BAP. Somatic embryos were observed at 8 weeks on basal medium supplemented with 5.0–10.0 μm IAA and 2.5–5.0 μm BAP. Callus cultured on 0–10 μm IAA and 5.0–10.0 μm BAP produced the greatest number of somatic embryos by 15 weeks. Somatic embryos subculture to basal medium supplemented with 25.0 μm BAP proliferated shoots, while eliminating BAP from the medium resulted in root and callus production. Shoots and entire plants were removed from in vitro conditions and successful] y acclimated to greenhouse conditions. Somatic embryo-derived plants flowered sporadically 25 to 35 weeks after removal from in vitro conditions. Variations in sepal number and leaf number per node were observed at 1% to 5%.
CLASSIFICATION OF SWEET PEA CULTIVARS BY MEANS OF DISCRIMINANT ANALYSIS
Authors: Tremblay Nicolas
Published: February 2019

Processing plants requires that cultivars be categorized as either small, medium, or large peas to meet the different markets. A reliable nutrient diagnosis system based on sweet pea leaf analysis should be robust to the type of cultivar. The objective of this study was to determine whether the type of cultivar should be taken into account in producing the nutrient diagnosis. Proportions of peas in categories 1 (small) to 5 (large) were determined for 18 cultivars produced under commercial conditions over 3 years. Cluster analysis was conducted with the constraint of revealing three groups, as homogeneous as possible with regard to their proportions in the different categories. Three cultivars were identified as belonging to the small, nine to the medium, and six to the large group. The archetype of each group was characterized. The function discriminated among the cultivars perfectly along the canonical axes. However, no classification was possible when the nutrient composition variables (N, P, K, Ca, Mg, B, Fe, Mn, Zn) were used for discriminating cultivars' types. Hence, sweet pea cultivars of different types do not differ substantially in leaf composition.
ANTIFUNGAL CONSTITUENTS OF CHENOPODIUM PROCERUM (CHENOPODIACEAE) HOCHST EX MOQ
Authors: Bergeron Chantal , Marston Andrew , Hakizamungu Etienne , Hostettmann Kurt
Published: February 2019

Dried ground aerial parts were extracted successively with dichloromethane and methanol at room temperature. Antifungal activity was determined by a TLC bioassay using Cladosporium cucumerinum. Four compounds were isolated from a dichloromethane extract by different chromatographic techniques (silicagel CC, Sephadex LH-20 gel filtration, and low-pressure LC on Diol): the isoflavones irilin A and irilin B, the flavonone dihydrowogonin, and sesquiterpene pygmol. The latter three were antifungal. The minimal amount that inhibited the fungal growth of C. cucumerinum was 5 μ for these compounds. Four flavonol glycosides were obtained from the non-fungicidal extract by Sephadex LH-20 gel filtration and centrifugal partition chromatography. The structures of the compounds were elucidated by spectroscopic methods (UV, 1H NMR, 13CNMR, MS).
Paclobutrazol Reduces Insecticide Phytotoxicity on Salvia
Authors: Latimer Joyce G. , Oetting Ronald D.
Published: February 2019

Four-week-old salvia (Salvia splendens F. Sellow `Red Pillar') seedlings were treated with 0 or 50 ppm paclobutrazol, followed 5 h later by 0, 1, 2, or 4 times (0×, 1×, 2×, or 4×, respectively) the recommended label rate of bendiocarb (0.6 g a.i./liter), a carbamate insecticide. Seven days after treatment (DAT), phytotoxicity ratings increased with bendiocarb rate on all plants, but 50 ppm paclobutrazol reduced damage at 1× and 4× bendiocarb. Paclobutrazol also improved plant recovery from phytotoxicity damage at 21 DAT. Bendiocarb decreased the height of plants not treated with paclobutrazol at 7, 14, and 21 DAT. Plants treated with 40 ppm paclobutrazol had lower maximum phytotoxicity damage at 14 DAT, and even better recovery at 21 DAT than plants treated with 20 or 60 ppm paclobutrazol. Plants treated with paclobutrazol 4 days before applying bendiocarb had lower maximum phytotoxicity ratings relative to controls than plants treated 8 days before, the same day as, or 4 days after bendiocarb application. Chemical names used: β- [(4-chlorophenyl)methyl]- α -(1,1-dimethylethyl)-1 H- 1,2,4-triazole-1-ethanol (paclobutrazol); 2,2-dimethyl,1,3-benzodioxol-4-yl-methylcarbamate (bendiocarb).
Seasonal Variation in Low-temperature Tolerance of Vaccinium angustifolium Ait.
Authors: Cappiello Paul E. , Dunham Scott W.
Published: February 2019

Seven Vaccinium angustifolium clones were tested for low-temperature tolerance over two dormant seasons. Flower primordia in the pseudoapical bud were damaged at higher temperatures than were stem tissue and primordia of the fourth floral bud. The flower primordia located at the stem tip also reacclimated earlier and seemed to show a stronger response to abrupt spring warming than did other tissues tested. Given the lowest survival temperatures determined and the ambient temperatures recorded, we recommend that the physiological and economic aspects of cryoprotectants and flower-delaying treatments be studied further.
Interactions Between Vegetative and Floral Buds in Apple and Peach
Authors: Yang W.Q. , Glenn D.M.
Published: February 2019

The osmotic potential and development of apple (Malus domestica Borkh.) and peach [Prunus persica (L.) Batsch] floral and vegetative buds and tissue were determined pre- and postbloom. Apple and peach floral and vegetative buds were removed prebloom and the osmotic potential and bud development were measured pre- and postbloom. The osmotic potential of vegetative and floral buds was related to the phenology of bud development. Developing buds had a more negative osmotic potential than dormant buds. Leaf buds on deflorated shoots had a more negative osmotic potential than leaf buds on shoots with floral buds. However, flower buds on defoliated shoots had a less negative osmotic potential than flower buds on shoots with leaf buds.
Eliminating Zygotic Seedlings in `Turpentine' Mango Rootstock Populations by Visual Roguing
Authors: Schnell R.J. , Knight R.J. , Harkins D.M. , Zill Gary
Published: February 2019

The ability to eliminate zygotic seedlings from the polyembryonic mango (Mangifera indica L.) rootstock `Turpentine' by visual roguing was investigated. Four selected populations, A) randomly selected plants, B) plants selected as off-types, C) seedlings that were of `Turpentine' phenotype, and D) seeds where a single seedling emerged, were examined using electrophoretic analysis and five enzyme systems. Significant differences (χ2 = 39.63, P< 0.001) were found among the four categories, with 28% of the random, 66% of the off-type, 10% of the true-to-type, and 54% of the monoembryonic seedlings being zygotic. These data indicate that visual selection for trueness-to-type and roguing for off-types is useful in reducing the frequency of zygotic seedlings among `Turpentine' rootstock plants.
Interspecific and Intraspecific Pollination Effects in Rabbiteye and Southern Highbush Blueberry
Authors: Gupton Creighton L. , Spiers James M.
Published: February 2019

To determine the effects of pollen source on blueberry production, we made a partial diallel set of crosses involving seven rabbiteye (Vaccinium ashei Reade) and seven southern highbush (SH; V. corymbosum L.) parents. Pollination of rabbiteye blueberry flowers with SH pollen reduced fruit set, seeds per berry, and berry weight and increased fruit development period (FDP) compared to pollination with rabbiteye pollen. Pollination of SH flowers with rabbiteye pollen resulted in about the same fruit set and FDP but fewer seeds per berry and slightly lower berry weight compared to intraspecific pollination. Self-pollination significantly decreased the number of seeds per berry and berry weight and increased FDP in SH. Pollination of rabbiteye and SH flowers with mixed pollen produced the same results as intraspecific pollination. Using `Tifblue' and `Baldwin' (rabbiteye) as the pollen parent significantly increased FDP in rabbiteye blueberry. Using `Georgiagem' and `Cape Fear' as pollen parents produced the longest FDP, and using `O'Neal' and `Gulfcoast' produced the shortest FDP in SH blueberry. The heaviest berries were produced by using `Blue Ridge', `O'Neal', and `Gulfcoast' (SH) as pollen parents on SH females. These results suggest that xenia possibly could be used to increase yield and reduce FDP in blueberry.
004 WINTER COVER CROPS FOR WEED CONTROL IN SUSTAINABLE VEGETABLE PRODUCTION
Authors: Mwaja Vasey N. , Masiunas John B.
Published: February 2019

A three-year study determined the effect of winter cover crops on weeds and vegetable crops in a vegetable production system. Winter rye and hairy vetch were interseeded in the fall of 1990, 1991 and 1992 at 112 and 34-kg ha-1, respectively. The cover crops were killed by ether applying glyphosate at 1.1 kg a.i ha-1 [reduced tillage(RT)] or mowing and disking the cover crop (Disked). The conventional tillage (CT) was bare ground with a preplant incorporated application of 0.84 kg a.i ha-1 of trifluralin. During the three years, the greatest snap bean yields were in the CT; total yields of cabbage and tomato varied between the years; and were not affected by management systems. Weed control was similar in the RT and CT treatments during the three years. Disked cover crop treatments tended to have greater weed numbers than either RT or CT treatments.
005 EVALUATING VELVETBEAN AS PART OF THE CROP ROTATION IN SUSTAINABLE VEGETABLE PRODUCTION
Authors: Brunson Kathryn E. , Phatak Sharad C. , Gay J. Danny , Summer Donald R.
Published: February 2019

Velvetbean (Mucuna deeringiana L.) was used in crop rotation to determine the influence on southern root-knot nematode (Meloidogyne incognita) in sustainable vegetable production. Replicated trials were conducted at four locations. Two cover crop treatments, crimson clover and subterranean clover, were used in the sustainable plots and rye was the plow-down cover crop for the conventional plots. Selected as the vegetable crops were tomato, pepper, and eggplant. Following the final harvest, velvetbean was planted into the sustainable plots and disked under after 90 days. Results from soil samples before and after velvetbean, indicated the sustainable plots had substantially reduced nematode densities, while most conventional plots showed increases. A correlation between location, treatment, root-gall indexes and nematode density occurred in all crops for 1992. In 1993 there was only a correlation between root-gall index and nematode density in pepper. However, root-gall indexes were significant for location and treatment in all crops.
006 SOIL NITROGEN MOVEMENT AND SOIL STRENGTH IN VARIOUS VEGETABLE CROPPING SYSTEMS
Authors: Gilsanz Juan Carlos , Sanders D. C. , Hoyt G. D.
Published: February 2019

Rye plus crimson clover cover crops were followed by spring potato and fall snap bean or sorghum or fallow. The soil samples at 15 cm increments to 90 cm were evaluated for nitrate levels after each crop and cover crop. After the cover crops, soil nitrate levels were reduced relative to the fallow area. After the potato, crop soil nitrate levels increased above initial spring levels due a uniform fertilization due to the amount of N applied and short cycle of the crop. Snap beans and sorghum had increased plant stands and reduced soil impedance after fall cover crops. HOW nitrate levels varied with soil depth and time will be discussed.
007 NO-TILL CABBAGE PRODUCTION USING RYE COVER CROPS
Authors: Roberts Warren , Cartwright Bob
Published: February 2019

Cabbage (Brassica oleracea L. Capitata) was grown for five years with treatments comparing no till and conventional production systems. Each year, raised beds were formed in the fall and selected plots were seeded with rye (Secale cereale). The rye was allowed to grow during the winter, and the following spring it was either mowed, killed with herbicide, or allowed to grow indefinitely. Different seeding rates of rye and different fertilizer rates were used. Some plots were mowed and the residue removed from the plots, while certain plots had no rye planted but received the rye residue that was removed from other plots. Rye was also gathered and pulverized, and the liquid extract removed from this suspension was sprayed onto plots. Cabbage was planted into each plot in the spring. The yield of cabbage grown in various rye-covered plots was compared to the yield from bare soil plots and from plots covered with black plastic mulch. In general, the plots covered with the various rye treatments had less yield than did the bare soil plots. Plots covered with black plastic mulch often had a greater yield than did the other plots.
008 COVER CROP MANAGEMENT FOR PROCESSING TOMATO PRODUCTION
Authors: Creamer Nancy G. , Bennett Mark. A.
Published: February 2019

A mixture of rye, hairy vetch, barley, and crimson clover was seeded on raised beds at two locations in Ohio in August, 1992. The following May, the mixture was killed with an undercutter and left on the surface as a mulch. Processing tomatoes (OH 8245) were planted into the killed cover crop mulch immediately following undercutting. Four systems of production were evaluated including: conventional (without cover crop mulch), integrated (with reduced chemical input), organic, and no additional input. At the Columbus site, above ground biomass (AGB) was 9,465 kg ha-1 with 207 kg ha-1 N in to AGB. In Fremont, the AGB was 14,087 kg ha-1 with 382 kg ha-1 N in the AGB. Annual weeds were suppressed by the killed cover crop mulch, and no additional weed control for the annual weeds was necessary. Weed suppression by the mulch was equivalent to weed suppression by the herbicides used in the conventional system. Other data that will be reported include soil moistures and temperatures; impact on insects end diseases; and, tomato growth, development, and yield.
010 BREEDING BLUEBERRIES WITH ALTERED FLOWER ARCHITECTURE
Authors: Lyrene Paul M.
Published: February 2019

Genetic variation was surveyed within and among 5 Vaccinium species and several hybrid taxa for 6 aspects of flower size and shape. Sufficient variation was found to allow radical changes in flower architecture through breeding. The goal is a flower that pours pollen directly from the anthers onto the stigma without the assistance of pollinating insects. The flowers of V. elliottii had very short styles (mean in mm 5.3 compared to 10.2 for rabbiteye cultivars and 8.5 for highbush cultivars), and certain short-style recombinants from highbush cultivar × V. elliottii crosses came close to the desired positioning of stigmas relative to anthers. The distance (in mm) from the anther pore to the stigma averaged: V. ashei 2.7; V. corymbosum 2.4; V. darrowi 2.3; and V. elliottii 1.0. Compared to highbush cultivars, rabbiteye cultivars tended to have long corollas and narrow corolla apertures, two features believed to be related to poor honeybee pollination. These features were much more favorable in V. ashei × V. constablaei hybrids, with values averaging close to those for highbush cultivars.
014 MORPHOLOGICAL AND MOLECULAR VARIATION IN WILD OCTOPLOID NORTH AMERICAN STRAWBERRY (FRAGARIA)
Authors: Harrison Richard E. , Luby lames J. , Furnier Glenn R.
Published: February 2019

Runners from 318 plants representing 37 populations across the northern tier of US states, from Washington to New York, were collected and planted in two replications in a common greenhouse environment to assess morphological variation among octoploid strawberries (Fragaria chiloensis, F. virginiana spp. glauca and F. v. spp. virginiana). DNA was also extracted from these plants to determine molecular variation using RAPD's (Random Amplified Polymorphic DNA). Preliminary data suggest that the following morphological characters are useful traits in assessing diversity: flowering and runnering date; sex; petiole and peduncle hairs; petiole and peduncle color; leaf color, size, shape and density; and powdery mildew resistance. Preliminary RAPD data has revealed many useful molecular markers capable of detecting variability from the intrapopulation to interspecific level. Analysis of these data will determine relative genetic distances among the populations and provide a more complete understanding of the diversity available to the strawberry breeder in the octoploid taxa native to North America.