bluuebunny/crossref_metadata_2025 huggingface dataset:
VARIABILITY IN CHLOROPHYLL, RUBISCO, AND FOURTH DERIVATIVE SPECTRA AND THEIR RELATIONSHIP TO CO2 ASSIMILATION RATES OF EIGHT FRAGARIA CHILOENSIS GENOTYPES
Authors: Foote Paul W. , Cameron J. Scott , Chen Chuhe , Klauer Stephen F.
Published: February 2019

Gas exchange rates were measured in the field on middle leaflets of Fragaria chiloensis (L.) trifoliates which were then used for Rubisco quantity and activity assays. Side leaflets of the same leaf were utilized for fourth-derivative spectroscopy, chlorophyll extraction, and specific leaf weight data. Differences of CO2 assimilation (A) rates were highly significant between genotypes ranging from 16.2 to 27.6 μmol CO2·s·m. Chlorophyll a and b, and total chlorophyll per unit area were positively correlated to A (r = 0.48**, 0.45**, and 0.49**, respectively). Total chlorophyll per unit dry weight had a correlation coefficient with A of 0.6**.

Fourth-derivative analysis of in vivo leaf attenuance spectra showed a positive correlation between A and Ca693 peak amplitude and a negative correlation of A and Ca677 peak amplitude. Peak amplitude of Ca693 was also correlated with chlorophyll content.

Activity per unit Rubisco was not a significant factor influencing A, but Rubisco quantity on either a leaf area or a dry weight basis was positively linked to A (r = 0.40** and 0.44**, respectively).
THE INFLUENCE OF FOLIAR APPLICATIONS OF BA AND GA3 ON BRYOPHYLLUM PLANTS
Authors: Al-Mana Fahed A. , Idris Tajelsir I.M.
Published: February 2019

Foliar spray of either BA or GA3 alone or in combinations of the two growth regulators were tested for their effects on Bryophyllum plants. Neither BA nor GA3 alone succeeded in stimulating lateral branching or flowering. GA3 totally inhibited bulbils formation. In a panel evaluating the ornamental quality, plants treated with GA3 at 100 ppm ranked top. The combination of BA and GA3 enhanced growth, branching, flowering and bulbils formation. The combinations of BA and GA3 at 50 ppm each, significantly improved the propagative qualities of the bulbils. Chemical names used: N-(phenylmethyl) -H purin-6-amine (BA), Giberllic acid (GA3).
ACTION OF REDUCED OXYGEN AND ELEVATED CARBON DIOXIDE ON ANAEROBIC METABOLISM OF `BARTLETT' PEARS
Authors: Kader A.A. , Ke D. , Mateos M. , Yahia E.
Published: February 2019

Fruits of `Bartlett' pear (Pyrus communis L.) at green (preclimacteric) and yellow (postclimacteric) stages were kept in 0.25% O2 (balance N2), 80% CO2 (balance O2), or 0.25% O2 + 80% CO2 (balance N2) for 1, 2, or 3 days followed by transfer to air at 20C for 3 days to study the effects of these controlled atmosphere (CA) treatments on anaerobic products and enzymes. All the three CA treatments caused greater accumulation of ethanol, acetaldehyde, and ethyl acetate than the air control. The postclimacteric pears were more sensitive to CA treatments as indicated by occurrence of skin browning, enhanced activity of pyruvate decarboxylase, and higher concentrations of the anaerobic volatiles. For the preclimacteric pears, the 0.25% O2 treatment dramatically increased alcohol dehydrogenase (ADH) activity, which was associated with the induction of one ADH isozyme. Exposure of preclimacteric pears to 80% CO2 slightly increased ADH activity while treatment with 0.25% O2 + 80% CO2 resulted in lower AD11 activity than 0.25% O2 alone.
THE RELATIONSHIP BETWEEN LIGHT INTENSITY, LEAF SPECIFIC WEIGHT, LEAF NITROGEN LEVELS, AND FRUIT SIZE AT HARVEST FOR MANZANILLO OLIVE.
Authors: Krueger William H. , Escobar Ricardo Fernandez
Published: February 2019

The relationship between changes in Photosynthetically Active Radiation (PAR), specific leaf weight, nitrogen per leaf area and fruit size at harvest were investigated within the canopy of Manzanillo olive. Increasing PAR in the tree canopy related linearly to increasing: specific leaf weight, nitrogen per leaf area and fruit size at harvest for samples collected adjacent to where the light measurements were made. From these results it appears as though specific leaf weight, and nitrogen per leaf area may be useful indicators for determining if light intensity is a limiting factor on fruit sizing within the canopy of Manzanillo olive. These and additional data will be discussed.
DEFINING ACTION LEVELS FOR LEAFHOPPERS ON THOMPSON SEEDLESS RAISIN VINEYARDS IN THE SAN JOAQUIN VALLEY OF CALIFORNIA
Authors: Peacock William L. , Dokoozlian Nick K. , Shaver Billie J.
Published: February 2019

In the San Joaquin Valley of California, leafhoppers (Erythroneura elegantula and Erythroneura variabilis) can severely damage the foliage of grapevines resulting in economic loss. Most Thompson Seedless raisin vineyards, however, don't require treatment for leafhoppers every year. To help make the correct treatment decision, monitoring guidelines and action levels are important. This study provides information on monitoring techniques and action levels for this leafhopper complex. A sustained population of 20 nymphs per leaf during summer broods results in 20% to 30% visible damage to the canopy by harvest in early September. Populations higher than this may require chemical intervention to prevent an economic loss. The photosynthetic activity was reduced in proportion to visible leaf damage. Methods of estimating damage to the canopy from leafhopper activity are presented.
EVALUATION OF NONIONIC SURFACTANTS FOR CONTROL OF CLUBROOT OF CABBAGE USING BAREROOT AND PLUG TRANSPLANTS OF TWO CULTIVARS
Authors: Tietjen W. , Nitzsche P.J. , Cowgill W.P. , Maletta M.H. , Johnston S.A.
Published: February 2019

`Market Prize' and `Bravo' cabbage (Brassica oleracea Var. capitata L.), transplanted as peat plug and bareroot plants into a field naturally infested with Plasmodiophora brassicae, Woronin, were treated immediately after planting with a liquid or a granular surfactant. APSA 80™, applied in transplant water, significantly reduced percent clubbing and disease severity index (DSI) compared to control treatments. Miller Soil Surfactant Granular™ did not significantly reduce percent clubbing or DSI. There was a significant effect of cultivar on percent clubbing and DSI. There was no significant effect of transplant type on percent clubbing or DSI. This year's study culminates five years of investigation of surfactants for clubroot control. Specific surfactants have proven to be an effective control of clubroot in cabbage. Chemical names used: nonylphenoxypolyethoxyethanol (APSA 80™); alpha-alkanoic-hydro omega-hydroxy poly (oxyethylene) (Miller Soil Surfactant Granular™).
A NEW ROOTSTOCK AND CONTAINER SIZE AFFECT PROPAGATION AND SUBSEQUENT GROWTH OF ROSE BUSHES IN AN ALKALINE SOIL
Authors: Wang Yin-Tung
Published: February 2019

Cuttings of a thornless mutation of Rosa odorata (RO) and R. multiflora (RM) were rooted in Feb., budded with Rosa `Queen Elizabeth' on 21 Apr. 1987, and planted in 2.6- or 5.2-liter containers. Five weeks after budding, over 50% of the buds on the thornless RO had developed into shoots, while only 4% of the buds on the RM were growing. After an additional 10 weeks, 80% and 60% of the buds on the thornless RO and RM, respectively, had development into shoots. Six months after budding, plants in the 5.2-liter pots produced 1 to 2 folds more flowers than those in 2.6-liter pots. Plants from all four production treatments were planted in a field with alkaline soil on 3 Nov. 1987. During the next four years, plants on RM showed severe chlorosis and had 5% and 45% survival for those produced in 2.6- and 5.2-liter pots, respectively. Those on the thornless RO had 85% and 100% survival when produced in 2.6- and 5.2-liter pots, respectively after four years. Leaves of plants on the thornless RO rootstock had higher concentrations of chlorophyll than those on the RM. However, analyses of leaves did not reveal differences in elemental concentrations among treatments.
IMPORTING PLANT GERMPLASM INTO THE UNITED STATES
Authors: Dale Mary E.
Published: February 2019

International plant germplasm resources are an invaluable source of information, and bringing viable plant materials into the United States is a necessity for many researchers.

Quarantine regulations vary based on the plant pests and pathogens occurring in the country of origin to prevent the introduction of injurious plant pests and diseases. These regulations also depend on the type of germplasm (such as live plant, cuttings, or seeds), size and age of specimen, and the media grown in. Plants in soil are prohibited, while those in agar, or bare root may be allowed to enter.

Procedures to follow for bringing plant germplasm of international origin (including CITES species), forms and permits, ports of entry, delays to expect or avoid along with other information on successfully bringing plant germplasm resources into the United States will be discussed.
SIMULATION OF TRANSPIRATION OF CITRUS GOVERNED BY LEAF CONDUCTANCE
Authors: Allen Leon H. , Brakke Mary P. , Jones James W.
Published: February 2019

A water flow model was developed which uses irradiance, leaf-to-air vapor concentration difference, and soil water potential to establish stomatal conductance. Water flow to the roots was computed using a linear approximation of radial flow through the soil toward the axis of the roots across concentric shells. Root length density and soil rooting volume within four separate layers or compartments were included in the model. The simulation was executed in small time step iterations. A small increment of transpiration was translated to a water content deficit at the root and then sequentially through the concentric shells to simulate water uptake and change of soil water potential. The change in soil water potential was used to increment changes in stomatal conductance and transpiration. The output of the model simulated the pattern of diurnal stomatal behavior observed in other types of experiments, as well as the total soil water extraction patterns of young potted citrus trees.
PEACH CULTIVAR DEVELOPMENT BY THE LOUISIANA AGRICULTURAL CENTER BREEDING PROGRAM
Authors: Bourgeois Wayne J. , Johnson Charles E. , Young William A. , Adams Alvin J.
Published: February 2019

The peach breeding program in Louisiana was initiated in the late 1940's to develop adapted cultivars for Louisiana. The objectives of the program have been to develop large fruited disease resistant fresh market cultivars for all areas of Louisiana. The state is divided into three climatic zones in reference to the breeding program (north, south, and coastal). Cultivars have been developed that are adapted specifically for each zone. A few cultivars produce marketable fruit in all three zones. The annual chill units vary from 350 to 1000+ over the three zones. Seventeen cultivars have been released since 1969 and these are used throughout the southeast U.S. in production areas. A primary breeding objective is to develop a sequence of cultivars to service the market from late April through September. Also equally important is development of genetic disease resistance to bacterial spot, Xanthamonas campestris pv pruni.
BREEDING FOR COLD HARDINESS OF MEI HUA (PRUNUS MUME)
Authors: Qixiang Zhang
Published: February 2019

On the basis of investigating pollination habits of 45 cultivars of Mei Hua, interspecific hybridization between Mei Hua and apricot (Prunus armeniaca). David's peach (P. davidiana) as well as siberian apricot (P. sibirica) were made from 1982 to 1991. With total number of pollination flower 17,050, 168 hybrid seed and 75 hybrid seedlings were obtained. Embryo culture in vitro was used for undeveloped young hybrid embryos. Test of freezing resistance both in artificial freezing and in overwintering for the hybrid seedlings showed that there were 5 hybrids with double and nice flower to be very hardy to low temperature. They were able to tolerate as low as -35C for 30 days in open ground, and now they were planted in northwest China's Gansu province and northeast China's Liaonin province without cold injury.
FLOWERING HABIT AND YIELD OF CALABAZA GENOTYPES
Authors: Maynard D. N. , Elmstrom G. W. , Wessel-Beaver L. , McCollum T. G.
Published: February 2019

The flowering habit and yield potential of seven calabaza [Cucurbita moschata (Duchesne), Poir.] genotypes were studied in the fall 1991 season. Earliest flowering and mature fruit were produced on bush plants developed from `Burpee Butterbush'. Time of flowering and distance from the crown was intermediate in time in the Florida developed varieties `La Primera' and `La Segunda' and latest in the Puerto Rican developed entries `Borinquen', Linea C Pinta, and Soler. Highest yields were produced by `La Primera' and `La Segunda', whereas, lowest yields were produced by the bush lines because of very small fruit size. Fruit size of `Borinquen' and Linea C Pinta was mostly in the desirable range of 2.3 to 4.5 kg. Most `La Primera' and `La Segunda' fruit were round, `Borinquen', Linea C Pinta, and Soler fruit were flat, and the bush lines produced variable shaped fruit. Further backcrossing to round types is required to overcome the problem of small fruit size and variable fruit shape in the bush lines.
PHYLOGENETIC ASSESSMENT IN THE GENUS ALLIUM USING RESTRICTION FRAGMENT LENGTH POLYMORPHISMS
Authors: Bradeen James M. , Havey Michael J.
Published: February 2019

The genus Allium contains about 500 species, several of which have been cultivated for millennia. Despite its long history of cultivation and its worldwide economic importance, little is known phylogenetically about Allium. Identification of the likely progenitor of A. cepa (the bulb onion) will focus future collection efforts on wild germplasm that may be useful in the genetic improvement of the bulb onion. Several classification schemes based on morphological characteristics have been proposed for A. cepa and its presumed closest relatives. None of these schemes has been definitive. Nuclear restriction fragment length polymorphisms (RFLPs) were identified among Allium species in sections Cepa and Phyllodolon. These were used to unbiasedly estimate phylogenetic relationships.
Phosphorus Fertility in the Strawberry Nursery
Authors: Albregts Earl E. , Chandler C. K.
Published: February 2019

The phosphorus content is usually high in soils on which strawberry production occurs in west central Florida because of moderate P levels in the virgin soil and yearly applications of P by the growers. A P rate study was conducted to test the calibration of P for strawberry nursery production, and a randomized complete block design with four replicates was used. Rates of 0, 11, 22, and 33 kg/ha P were applied to a Seffner sand which had an initial soil P level of 86 mg/kg using the Mehlich II soil extractant. Soil tests routinely show P soil concentrations up to 250 mg/kg or greater with 86 mg/kg rated in the high range. In this study the P applied to the beds was cultivated into the soil and six plants of two strawberry clones (Fl 87-210 and Fl 85-4925) were set in each plot on 28 May 1991. All nutrients except P were applied as needed during the season. Leaf P content of daughter plants on 20 Aug 1991 varied from 0.23 to 0.25% among P treatments and were not different because of P rates. All marketable size daughter plants were harvested on 8 Oct 1991. The number, total wt, and average wt of daughter plants were not different because of applied P rates.
OSMOTIC POTENTIAL IS RELATED TO SINK STRENGTH IN VEGETATIVE AND FLORAL BUDS OF APPLE AND PEACH
Authors: Yang W.G. , Glenn D.M.
Published: February 2019

The osmotic potential and development of apple and peach floral and vegetative buds and tissue were determined pre- and post-bloom. Apple and peach floral and vegetative buds were removed pre-bloom and the osmotic potential and bud development measured pre- and post-bloom. The osmotic potential of vegetative and floral buds was related to the phenology of bud development. Developing buds had a lower (more negative) osmotic potential than dormant buds. Removal of peach floral buds lowered osmotic potential and increased vegetative bud development and early leaf growth rate. Removal of peach vegetative buds, however, reduced fruit bud development, fruit growth, and embryo survival. Osmotic potential was an index of sink activity during the pre- and post-bloom stages of development.
CALCIUM FERTILIZATION INFLUENCE ON POTATO YIELD, TUBER MINERAL CONCENTRATION, AND QUALITY
Authors: Clough George H.
Published: February 2019

In a 3-year study on a fine sandy loam soil, potato (Solanum tuberosum) cvs. `Atlantic' (1989), `Frontier' (1990, 1991) and `Russet Burbank' (1989-1991) response to rate and time of Ca fertilization was evaluated. Calcium was applied preplant at 0, 90, 180, and 270 kg·ha-1 as CaSO4 and side-dress at lay-by at 0, 67 and 134 kg·ha-1 as Ca(NO3)2, with treatments combined in a complete factorial. Preplant Ca fertilization increased soil Ca each year. Calcium fertilization had little effect on yield or grade distribution. Tuber P, K and S concentrations increased with increasing preplant and sidedress fertilization rates in 1989. Concentrations of S and Ca in Russet Burbank and Frontier increased linearly with preplant CaSO4 application rate in 1990 and 1991. Little or no internal brown spot (IBS) occurred in Atlantic or Russet Burbank, but in Frontier IBS was reduced both years by pre-plant and/or side-dress Ca application. The incidence of IBS did not change after storage for 4 months for any cultivar. In 1990, Russet Burbank fry color improved as pre-plant Ca fertilization rate increased.
EFFECTS OF AMENDING SOIL WITH PROCESSED MUNICIPAL WASTE ON GROWTH AND YIELD OF TOMATO
Authors: Bryan H. H. , Schaffer B. , Ozores M.
Published: February 2019

The effects of amending soil with processed municipal waste (PMW), and the interaction of PMW with trenching, irrigation rates, and fertilizer rates on growth, and yield of tomato plants were tested. In a series of experiments, two rates of each of the following PMWs were incorporated into calcareous limestone soil: 1) Agrisoil (processed trash), 2) Daorganite (processed sewage sludge), 3) Eweson compost (processed trash and sludge), and 4) no PMW (control). In some experiments, secondary applications of PMW were applied to the beds at either a high rate, a low rate or not applied (control). There was no effect of secondary PMW applications on growth or yield. Generally, plants grown on trenched plots had greater growth and yield than plants on non-trenched plots. Plants grown in Daorganite had greater growth and yield than plants grown in the other PMWs. Plants in Daorganite tended to have higher photosynthelic and transpiration rates than plants in the other treatments. For all treatments, plants grown at one-half the standard fertilizer rate had less growth than plants receiving higher fertilizer rates. There was no interaction between irrigation rate and PMW for photosynthesis, growth, or yield. Plants grown in Daorganite had the greatest growth and tended to have greater yields, regardless of the fertilizer or irrigation rate. Processed trash composts (Agrisoil and Eweson) did not increase growth and yield, which may have been due to suboptimal application rates of these materials. Further studies are underway incorporating higher rates of these materials into the soil.
COMMERCIAL TRANSPLANT PRODUCTION PRACTICES AND RECENT RESEARCH IN JAPAN
Authors: Kozai Toyoki , Ito Tadashi
Published: February 2019

Commercial transplant production in Japan has been increasing rapidly since 1985. Transplant production began with plug seedlings for bedding plants, followed by carnation and Chrysanthemum plug transplants vegetatively-propagated using cuttings. Next, production more recently includes plug seedlings of lettuce and cabbage, and micropropagated tubers of potato plants and grafted transplants of tomato, eggplant, cucumber, and watermelon plants. The reasons for the rapid increase in commercial production of transplants will be reviewed. The current “cutting edge” practices include hardening before shipping or planting. The pros and cons of current transplant production systems in Japan will be discussed. Recent research advances in production of micropropagated, grafted and seedling transplants are reviewed with special reference to environmental control for hardening or acclimatization. Research on robotic or automated systems for micropropagation, grafting, and transplanting currently developed in Japan are described.
WHAT'S NEEDED IN THE GREENHOUSE TO HELP AUTOMATE TRANSPLANTING
Authors: Shaw Lawrance N.
Published: February 2019

The use of containerized transplants will increase in the future because of greater survival rates and improved yields. Many transplant operations are already mechanized. Fully automatic field transplanting is highly feasible in the future for several vegetable crops and may become a common practice with most commercial crops. Technology is developing that uses the greenhouse growing trays as magazines to be loaded into the transplanting machines. Automatic field transplanters will then set plants into the soil at rates of 3 to 4 per second. To accomplish this, the following are required: highest quality uniform seedlings; greater seedling tolerance to handling stresses; no dead or missing plants in transplant trays; standardized cell containers; and precise cell arrangement to allow whole rows of plants to be mass removed simultaneously to reach the highest transplanter machine capacity. Plant production and greenhouse growing systems need to be modified to facilitate automatic field transplanting.
THE EFFECT OF POLYAMINES ON THE SENESCENCE OF CARNATION PETALS.
Authors: Son Ki-Cheol , Chae Y.
Published: February 2019

The interaction between polyamines and ethylene is still not clear for floral tissues. The aim of the present paper is to examine the senescence on the isolated petals of carnation (Dianthus caryophyllus cv. Desio) but not the whole flower in an attempt to clarify the exact role of polyamines. Petals were treated with putrescine (Put; 0.0, 1.0, 10mM), spermidine (Spd; 0.0, 1.0, 10mM), spermine (Spn; 0.0, 1.0, 10mM), Put+Spd (1.0mM), Put+Spn (1.0mM). The fresh weight of petals in all 10mM treatment was decreased less than those in the other treatments at all times but there were no significant differences. The differences in ethylene production were significant. In petals maintained in 10mM of polyamines, ethylene production was completely inhibited until 13 days and senescence was considerably retarded. However, ethylene productions in 1.0mM polyamines treatments were delayed 2-3 days with reduced amounts. These results suggest that high concentrations of polyamines retard senescence and completely inhibit ethylene production. ACC content, activities of ACC synthase and SAM decarboxylase were analyzed. Finally, the role of SAM in ethylene and polyamines biosynthesis will be discussed.
MONOTERPENOID SYNTHESIS IN CALLUS INDUCED FROM STEM SEGMENTS
Authors: Tawfik Azza A. , Read Paul E. , Cuppett Susan L.
Published: February 2019

Callus of Rosmarinus officinalis L. 'Lockwood de forest' was induced from stem segments (3 mm long) using different concentrations of thidiazuron (TDZ). The original stem segments used as explants were found to have a higher level of linalool than was found for leaf segments. Linalool is one of the monoterpenes identified in rosemary plants and it has a pleasant aroma. TDZ has a significant effect on callus formation and callus texture. The callus formed was light green to yellow and/or had some meristimatic dark green cells. TDZ had a significant linear effect on the callus fresh weight. The meristimatic green cells formed on all calli except those proliferated on the lowest concentration of TDZ (0.5 mg/l). No callus was induced from stem segments cultured on TDZ-free medium. The fresh calli from other treatments were soaked in hexane as a solvent for monoterpene analysis using GC/MS. No monoterpenes could be detected in the callus induced on the medium containing the lowest concentration of TDZ. Comparing to the stem segments taken from the parent plants only 4 of 10 monoterpenes identified were found in the callus: α-pinene, β-pinene, 1,8-cineole, and camphor.
EFFECT OF GROWING SEASON TEMPERATURES ON THE FATTY ACID PROFILE AND OF PECAN KERNELS
Authors: Bahri Sami , Sistrunk Laurence , Brown Robert , Storey J. Benton
Published: February 2019

`Cheyenne', `Mohawk', `Pawnee', and `Osage' grown in different locations in the United States were analyzed for fatty acid composition. The effect of heat units accumulated 12 weeks prior to shuck split were studied. Growing area affected the fatty acid profile for all cultivars. `Cheyenne' and `Mohawk' showed a positive correlation between heat units and oleic/linoleic acid ratios (r = 0.905 and r = 0.720 respectively), a positive correlation between heat units and oleic acid content (r = 0.863 and r = 0.773 respectively), and a negative correlation between heat units and linoleic acid content (r = -0.871 and r = -0.792 respectively). However, no correlation was obtained between heat units and the fatty acid profiles for `Osage' and `Pawnee'.
COMPARISON OF PRUNING TECHNIQUES TO INVIGORATE LOW-VIGOR ALMOND TREES
Authors: Micke Warren , Freeman Mark , Beede Bob , Hendricks Lonnie , Yeager Jim
Published: February 2019

Some precocious almond varieties often produce little vegetative growth once they reach full maturity. A pruning trial was established using 11 year old `Harvey' trees that were healthy but making little or no new growth. The four treatments were: 1) severe heading or dehorning trees to six foot in height (first year only), 2) heading one third of the tree for three years, 3) making 20 small heading cuts all over the tree each year, and 4) normal thinning cuts (or control). All heading treatments caused more shoot growth than did the conventional thinning cuts (or control). The dehorning treatment (#1) responded with the most vigorous growth but much lower yields during the next two years compared to the control (#4). Yields were comparable between the two treatments during years three to five however. The heading treatments #2 and #3 had comparable yields with the control by the second year. They also showed more shoot growth. Tree yields from treatment #2 tended to lag below treatment #3 and the control, even though they were statistically the same. This trend may indicate that three years of moderately severe pruning is too much. Treatment #3 may be the best technique for invigorating healthy low vigor trees while minimizing yield losses, but will be the most expensive.
FERTIGATION EFFECTS ON APPLE TREE GROWTH, CROPPING, AND DRY WEIGHT PARTITIONING
Authors: Robinson T. L. , Stiles W. C , Lakso A. N.
Published: February 2019

In two field studies with `Redchief Delicious'/MM.106, 'Empire'/M.9/MM.106 and 'Mutsu'/M.9/MM. 106 trees on fertile silt loam soils, trickle irrigation increased vegetative growth during the first three years and resulted in a 16%-20% increase in cumulative yield over the first five years. When fertilizer was injected into the irrigation water weekly from mid-April until the end of June, tree growth was further increased and cumulative yield was improved an additional 11%-15% for a total of 27%-35% greater yield than the non-irrigated trees. In these studies, ground fertilization did not improve growth or yield unless trickle irrigation was also applied. However, ground fertilization was not as effective as fertigation.

Irrigation and fertigation increased the dry weight of roots by 23% and that of shoots by 36% in the first year resulting in a 10% reduction in the root/shoot ratio. Total tree dry weight was increased by 30% if trees were planted early (April 14) but only 14% if trees were planted late (June 10).

Early planting resulted in 17% greater cumulative yield than trees planted late. Initial tree caliper also had a significant effect on early growth and yield with large caliper trees yielding 12% more than the small caliper trees. The interaction of planting date, tree caliper and fertigation resulted in a 50%-70% increase in yield during the first five years.
ALTERNATIVE ORCHARD GROUNDCOVER MANAGEMENT SYSTEMS AFFECT APPLE QUALITY AND MATURITY INDICES
Authors: Merwin L A. , Blanpied G.D.
Published: February 2019

Alternative groundcover management systems (GMS) beneath establishing 'Jonagold' apple trees have been evaluated since 1986 in an orchard field test Tree-row GMS being studied include post-emergence herbicide (glyphosate) “killed sods”, pre-emergence herbicides (norflurazon and diuron). a crownvetch “living mulch”, hay-straw mulch, monthly cultivation, and a closely mowed sodgrass. Trees in herbicide and straw-mulch plots produced the most fruit in 1990, but in 1991 there were no GMS-related differences in crop load. Fruit were larger in herbicide and straw-mulch plots in 1990 and 1991, and red color development was better in sod and crownvetch GMS. Starch-to-sugar conversion was advanced in apples from sodgrass and straw mulched plots. The ethylene climacteric was delayed in fruit from crownvetch and straw-mulch GMS, and peaked rapidly as mean starch indices approached 4.0 in all GMS treatments. Differences in soil moisture and nutrient availability under alternative GMS may have influenced fruit quality and maturity.
COMPARISON OF DORMANT APPLICATIONS OF PETROLEUM AND SOYBEAN OIL ON APPLE BUD DEVELOPMENT.
Authors: Deyton D.E. , Sams C.E. , Cummins J.C.
Published: February 2019

Treatments of 0, 10, 20, 30, or 40% (v/v) refined (salad) or crude soybean oil or 0, 5, 10, 15, or 20% petroleum (dormant) oil at 0, 5, 10, 15, or 20% were sprayed until drip on `Smoothee' apple trees on 27 February 1991. The internal carbon dioxide concentration was elevated and the oxygen content reduced within one day in buds-twigs treated with oil and remained influenced for up to 12 days. All oil treatments delayed fruit bud development. The lowest tested concentration of soybean oil (either crude or refined) resulted in the greatest delay in bud development and the greatest delay in bloom (approximately 4 days). Crude soybean oil treatment resulted in less damage to flower buds than petroleum oil.
INCORPORATION OF THE GUS GENE INTO ORCHIDS VIA EMBRYO ELECTROPHORESIS
Authors: Griesbach R.J.
Published: February 2019

The apical meristems of Calanthe orchid embryos were exposed to 1 mg/ml pBI-121 DNA in an electric field. pBI-121 contains the GUS marker gene glucoronidase under the control of the 35 S cauliflower mosaic virus promoter. A pipette containing 0.3% agarose and acetate buffer containing the DNA was placed on one end of the embryo; while the opposite end was in contact with a pipette containing only buffer and agarose. Uptake of the DNA into the meristem was monitored by 4′6-diamidino-2-phenylindole (DAPI) fluorescence. Optimal uptake occurred after 10 min of electrophoresis at 10 volts and 0.5 milliamps. Under these conditions, 55% of the embryos survived the treatment and 57% of those which survived were transformed as measured by GUS-positive staining. Leaves from 6 month old plants which developed from the transformed embryos expressed specific patterns of GUS staining.
SUPERIOR REGENERATION AND AGROBACTERIUM INFECTABILITY OF BROCCOLI AND CAULIFLOWER TISSUES AND THE IDENTIFICATION OF A PROCEDURE FOR THE GENERATION OF TRANSGENIC PLANTS.
Authors: Wagoner Wendy J. , Kellogg Jill A. , Bestwick Richard K. , Stamp James A
Published: February 2019

Broccoli and cauliflower are among the most regeneratively intractable genotypes found in the brassicaceae. To develop a method for transfer of the gene encoding S-adenosylmethionine hydrolase (SAMase) into inbred broccoli and cauliflower germplasm, we investigated the morphogenic competence and Agrobacterium susceptibility of a wide range of tissues of varied source. Appropriately controlled expression of the SAMase gene should, theoretically, reduce the plant's capacity for ethylene biosynthesis and extend the post harvest shelf life of the flower head.

Through examination of the in vitro response of a wide range of tissues we identified procedures which support caulogenesis from 100% of explants, each producing more than 30 shoots which readily convert to plantlets. Studies with several wild type and disarmed Agrobacterium strains, and utilization of the binary vector system and appropriate marker and reporter genes, led to the identification of methods for high frequency T-DNA transfer to explant tissues and the flow frequency of transgenic plants containing SAMase gene.
FOREIGN GENE EXPRESSION IN TRANSGENIC CRANBERRY PLANTS
Authors: Serres Rod , Russell David , Mahr Dan , McCown Brent
Published: February 2019

Genetically transformed Vaccinium macrocarpon `Stevens' and `Pilgrim' plants have been obtained using electric discharge particle acceleration. Three foreign genes, kan encoding a selectable marker, gus a reporter gene, and B.t.k. conferring lepidopteran resistance, were incorporated into the genome. Expression of kan was assayed by culturing shoots in vitro on media with several concentrations of kanamycin. Expression among transformed clones (transclones) varied from high resistance (normal growth at 300 mg/L kan) to no resistance. Histochemical analyses for gus expression revealed variability among transclones. Some transclones exhibited no gus expression, others had consistent area-specific expression while others displayed random expression. In preliminary feeding trials with blackheaded fireworm larvae, B.t.k. expression was found to be ineffective at controlling insect development. We have recovered plants transformed with a different promoter driving the B.t.k. gene in an effort to enhance expression.
PERFORMANCE OF GREEN AND BLANCHED ASPARAGUS CULTIVARS IN NEBRASKA
Authors: Hodges Laurie , Uhlinger Roger , Brovelli Ernesto , Cuppett Susan , Parkhurst Anne
Published: February 2019

Fourteen asparagus cultivars were established in 1988 in eastern Nebraska on a heavy silty clay soil to determine suitability for Nebraska production. Total & marketable yields differed among cultivars with highest total & marketable yields obtained with “UC157-F1”, “Jersey General”, “Jersey Knight”, 44P×22-8, 51×22-8 & Md10×22-8. Production of the cultivars “Jersey Gem”, “Jersey Giant”, & “Jersey General” was additionally compared as green & blanched (white) production under white-on-black plastic blanching frames. Lowest ratio of culls to marketable spears & highest marketable weight was obtained with “Jersey General” for both blanched & green spears. Although total weight was greater for green asparagus, use of blanching frames reduced the number of culls for each cultivar and increased the weight of marketable spears to exceed that of green asparagus.
ETHANOL INHIBITS RIPENING OF MELON FRUIT
Authors: Saltveit Mikal E. , Ritenour Mark , Mangrich Mary E. , Beaulieu John C.
Published: February 2019

Exogenous application of ethanol (EtOH) vapor to whole tomato fruit or excised pericarp discs inhibits ripening without affecting subsequent quality. Inhibitory EtOH levels are induced in whole tomatoes by a 72 h exposure to anaerobic atmospheres at 20C. In contrast to tomatoes, exposure to EtOH vapor (0 to 6 ml EtOH/kg FW, for 3 to 6 h at 20C) did not retard ripening (e.g., changes in external color, flesh firmness, and soluble solids) of avocado, banana, cucumber, melon, peach, or plum fruit. When the blocked replicates for nectarines were sorted by the firmness of the control fruit, higher levels of EtOH vapor appeared to delay softening of the firmer fruit. From 0 to 4 ml EtOH/kg FW was injected as 95% EtOH into the seed cavity of melon fruit through a surface sterilized area near the equator of the fruit with a plastic syringe fitted with a 7.5 cm long hypodermic needle. Injection of 1 to 4 ml EtOH/kg FW inhibited the softening of `Honey Dew' and muskmelons. Slight tissue necrosis near the site of injection was noted in a few fruit. Unlike the ripening inhibition of tomatoes which is relatively insensitive to the stage of maturity, the inhibition of melon ripening by EtOH appeared to be significantly affected by the maturity of the fruit.
INCREASED PEROXIDATIVE DAMAGE AND DECREASED PROTEIN SYNTHESIS ARE FEATURES OF AGING POTATO SEED-TUBERS.
Authors: Kumar G.N.M , Knowles N.R.
Published: February 2019

The physiological mechanisms leading to a decline in sprout-vigor, root growth potential and apical dominance during long-term aging of potato seed tubers are currently under investigation. Malondialdehyde (MDA) and ethane, products of peroxidative degradation of PUFA increase in seed-tuber tissues with advancing age (from 2 to 32 months of storage). MDA is known to react with free amino acids to produce lipofuscin-like fluorescent compounds (FC), which build-up in aging/senescent tissues of plants and animals. With advancing seed-tuber age, an increase in free amino acids, MDA and FC concentrations was evident. Moreover, high levels of MDA have been shown to reduce protein synthesis in both plant and animal cells. We therefore examined the extent to which seed-tuber age affects protein synthesizing capacity of tuber tissues during sprouting. Tissue disks from 6- and 18-mo-old seed-tubers at various stages of sprouting, were compared for their protein synthesizing ability by monitoring the incorporation of radiolabelled amino acids into TCA precipitable products. The rate of incorporation (dpm mg protein-1 min-1) was 1.8 to 5.4-fold higher in tissue from 6-mo-old, as compared to that from 18-mo-old seed tubers, at similar stages of sprout development. Loss in protein synthesizing ability (possibly due to direct peroxidative damage) may be an important factor contributing to loss of sprout-vigor from aged potato seed-tubers.
DETERMINATION OF THE POLLEN PARENT AND ITS EFFECT ON LYCHEE FRUIT CHARACTERISTICS BY ISOZYMIC ANALYSIS.
Authors: Degani Chemda , El-Batsri Ruth , Stern Raphael A. , Gazit Shmuel
Published: February 2019

Fruits produced in two commercial lychee (litchi chinensis Sonn.) orchards consisting of adjacent blocks of `Floridian' and `Mauritius' were analyzed for pollen parentage by phosphoglucose isomerase (PGI) isozyme system. 'Mauritius' and `Floridian' were found to possess distinguishable homozygous isozyme phenotypes in PGI, thus allowing the unequivocal identification of their progenies as originating from self- or cross-pollination. The rates of hybrids produced in the two orchards were 69% and 87% for `Floridian' and 17% and 65% for `Mauritius'. In both cvs a significant correlation was found between pollen parent and the weights of fruits and seeds. Fruits originating from cross-pollination were heavier and contained heavier seeds than selfed fruits. The most pronounced effect of the pollen parent on seed weight was found in `Floridian, which appears to exhibit inbreeding depression.
THE EFFECT OF CROP LOAD ON FRUIT DRY WEIGHT AND DRY WEIGHT CONTENT, SPECIFIC LEAF WEIGHT, AND LEAF CARBON EXCHANGE.
Authors: Schechter Ido , Proctor J.T.A. , Elfving D.C.
Published: February 2019

Mature apple trees (Malus domestica Borkh.) were studied in the 1989 and 1990 seasons to explore the effect of differential crop load on fruit dry weight (DW), DW content, specific leaf weight, and leaf carbon exchange, using girdled and non-girdled limbs. Fruit DW and DW content decreased with heavier fruit loads, however, fruit on girdled limbs had higher fruit DW and DW content. Specific leaf weight did not differ in leaves on non-girdled limbs along the crop load gradient, but increased dramatically in leaves on girdled limbs with crop load lighter than one fruit per cm2 cross-sectional area. These leaves also had a low photosynthetic rate, high stomatal resistance, and high internal CO2 concentration. The results suggest a physiological limit for photoassimilate usage by the tree. Exceeding this limit by reducing sink strength resulted in excessive carbohydrate accumulation in leaves, causing physical damage to the photosystem.
ROOTSTOCK EFFECTS ON THE EARLY GROWTH AND PRODUCTIVITY OF `MONTMORENCY' SOUR CHERRY.
Authors: Anderson J.L. , Walker D.R. , Lindstrom T.
Published: February 2019

A `Montmorency' sour cherry planting was established on 20 clonal rootstocks in April, 1987, as part of the NC-140 cherry rootstock trial. After 5 seasons scion/rootstock combinations showed a 2.5-fold range in trunk circumference. During the fifth season there was a 6-day range in bloom date, a 4-fold range in growth rate, a 7.5-fold range in yield and a 3-fold range in yield efficiency as influenced by rootstock. Trees on GM 9 were the smallest, had the lowest yields, smallest fruit and were among the lowest in yield efficiency. Mahaleb has been the standard cherry rootstock in Utah. Rootstocks whose trees were comparable or exceeded those on mahaleb in both yield and yield efficiency during the fifth season included 148-1, 196-13 and M×M 2. Differences were also observed in root sucker tendency.
NITROGEN STATUS INFLUENCES BARK STORAGE PROTEIN GENE EXPRESSION IN POPLAR
Authors: Bañados M. Pilar , Coleman Gary D. , Chen Tony H. H.
Published: February 2019

In poplar (Populus deltoides) a 32kDa bark storage protein (BSP) accumulates during the fall, and is a major form of stored nitrogen during overwintering. This protein is induced by short-day (SD) photoperiod and may play an important role in nitrogen cycling in the plant. To determine the effect of plant nitrogen status upon BSP gene expression, poplar plants were grown in controlled environmental chambers under either SD or long-day (LD) photoperiods and watered with either 5, 10, 50, and 100 mM NH4NO3 for four weeks. [15N]-NH4NO3 was applied during the first and third weeks. SDS-PAGE and western blot analysis were used to detect the relative amounts of BSP. RNA gel blot analysis was used to determine the changes in BSP gene expression. BSP accumulation was enhanced by increasing levels of nitrogen under both photoperiods, however, SD photoperiod appears to moderate the response. These results indicate that BSP gene expression is dependant upon the nutritional status of the plant. [15N] analysis will also be presented.
COMPARATIVE HEAT TOLERANCE AMONG FIVE SPECIES OF BIRCH
Authors: Ranney Thomas G.
Published: February 2019

Leaf gas exchange and chlorophyll fluorescence measurements were used as indices for evaluating heat tolerance among five species of birch: paper (Betula papyrifera), European (B. pendula), Japanese (B. platyphylla var. japonica `Whitespire'), Himalayan (B. jacquemontii), and river (B. nigra). Measurements were conducted on individual leaves at temperatures ranging from 25C to 40C. Carbon exchange rates (CER) were depressed for all species at 40C. However, there was considerable variation in both absolute and relative (percent of maximum) CER among species at 40C; river birch maintained the highest absolute and relative CER while CER of paper birch was reduced the most. Although stomatal conductance of paper birch decreased at higher temperatures, internal leaf CO2 increased indicating that reduced stomatal conductance was not responsible for decreased CER. Stomatal conductance of river birch increased at higher temperatures which provided for enhanced uptake of CO2 and greater evaporative cooling. Variable chlorophyll fluorescence decreased similarly for both species with increasing temperatures. Measurements of dark respiration rates over the range of 25C to 40C suggested that the primary factor influencing variation in CER at higher temperatures was due to variation in respiration rates at higher temperatures.
VEGETATION MANIPULATION WITH SELECTIVE HERBICIDES IN VINEYARDS
Authors: Elmore C.E. , Donaldson D.R. , Roncoroni J.A.
Published: February 2019

Cover crops are planted between vineyard rows to control erosion, maintain organic material and influence pest management. Planted cover crops are preferable to resident vegetation (weeds) because they can be selected for beneficial characteristic. Sethoxydim and fluazifop-butyl alone and in combination with 2,4-D were applied in December 1988 and 1989 to release Festuca megalura (Zorro fescue). Untreated plots were mowed to maintain vegetation. Frequency, percent cover and biomass of the vegetation was evaluated to determine species shift. The vegetation was composed mainly of: 1. Festuca megalura, Poa annua with other grasses in minor amounts; and 2. Stellaria media, Centaurea solstitialis, Erodium botrys and Erodium cicutarium

Following sethoxydim or fluazifop-butyl treatments, annual grasses other than Festuca megalura and Poa annua were reduced but Centaurea sp. increased over the length of the experiment. Treatments containing 2,4-D Centaurea and Erodium spp. declined in both frequency and percent cover. The desirable cover crop species (Festuca megalura) increased in all treated plots. No species shift was observed in the mowed treatments. Two applications of selective post-emergence herbicides maintained shift of species over the 5 years of the study.
TREATMENT OF ADVANCED ROOT ROT IN DRACAENA FIELD STOCK.
Authors: Riede S.A. , Nishijima W. , Iwata R.Y.
Published: February 2019

Two fungicides and lime were evaluated for their effect on Dracaena fragrans Ker. cv. Massangeana plants which were severely affected by root rot. A completely randomized design with 5 treatments and 4 replicates was utilized. These treatments were: control, lime at 3362 kg/ha, 4 applications of metalaxyl at 10.4 kg/ha, 6 applications of benomyl at 12.92 kg/ha and a metalaxyl/benomyl combination treatment. Field plots were 13 m2, and plants were spaced 0.5 m from center. Data was taken from 15 plants per plot at 0, 10 and 20 weeks.

There were significant differences in plant height and the quality of new growth between the treatments containing metalaxyl and those without metalaxyl. There was no significant difference between the metalaxyl and the metalaxyl/benomyl treatments.
EFFECTS OF A HYDROGEL, WETTING AGENT, AND METALAXYL ON PHYTOPHTHORA WILT IN CONTAINER-GROWN RHODODENDRON
Authors: Smith-Fiola Deborah C. , Gould Anne B.
Published: February 2019

Phytophthora wilt, caused by the root-infecting fungus Phytophthora cinnamomi, is a serious disease of rhododendron. The symptoms of this disease include wilt, dieback, and death of nursery cuttings as well as large plants. The effects of two soil additives, Supersorb (a hygrogel) and Aquagro (a wetting agent), with and without Metalaxyl (Subdue 2E), were assessed on decreasing the incidence of Phytophthora wilt in container grown `Nova Zembla' rhododendron. Rooted cuttings grown in amended or non-amended mix were inoculated with P. cinnamomi. Metalaxyl treatments were applied once at the full label rate of 4 fl oz/100 gal at planting, or twice (at planting and 8 wks later) at 1 or 2 fl oz/100 gal. Trials were conducted from June to September in the greenhouse (1990) and outdoors (1991). Plant growth and disease incidence were evaluated weekly. In both trials, the Supersorb and Aquagro treatments did not affect disease incidence, although they did significantly affect plant growth. All metalaxyl treatments reduced disease incidence significantly when compared to controls.
CROP TOLERANCE TO WEEDS
Authors: Callaway M. Brett
Published: February 2019

Plant breeders have successfully increased crop tolerance to many pests and physiological stresses. However, very little work has examined the potential for increasing levels of tolerance to weeds, despite weed control costs of several billion dollars annually. Evidence will be summarized from the literature supporting the contention that genotypic differences in tolerance to neighboring plants exist. Approaches to screening for tolerance, choice of selection environment, and genotype identification will be discussed.