bluuebunny/crossref_metadata_2025 huggingface dataset:
267 RECLAIMED WATER EFFECTS ON LEAF, SOIL AND SOIL SOLUTION NUTRIENT LEVELS OF GRAPEFRUIT
Authors: Maurer M.A. , Davies F.S. , Graetz D.A.
Published: February 2019

A field study was conducted on mature `Redblush' grapefruit trees (Citrus paradisi Macf.) on sour orange (Citrus aurantium L.) rootstock from 1991 to 1993 near Vero Beach, Fla. on poorly drained (flatwoods) soil to determine the effects of reclaimed water on leaf, soil and shallow well-water nutrients. Treatments consisted of a canal water applied based on soil moisture depletion, and reclaimed water applied at 23.1, 30.7 and 36.6 mm/wk. Reclaimed water treatments received supplemental fertilization in addition to the N present in the water. All treatments received about 130 kg/ha/yr N. Leaf tissue N, P, K, Ca, Mg and Na concentrations were similar for all treatments, but B concentrations were significantly higher for the reclaimed water treatments in 1991 and 1993. Soil P and Na concentrations also increased in the reclaimed water treatments. Water samples taken from shallow depth wells showed that reclaimed water treatments had lower levels of NO, compared to the control possibly due to leaching. Reclaimed water contained only trace or undetectable levels of heavy metals.
271 EXPRESSION OF NADP-MALIC ENZYME RNA LEVELS IN RIPENING PEACH FRUIT
Authors: Callahan Ann M. , Bassett Carole L.
Published: February 2019

NADP-dependent Malic Enzyme (NADP-ME, EC 1.1.1.40) catalyzes the decarboxylation of malate, resulting in the release of CO2. In C3 plants the enzyme does not contribute CO2 directly to photosynthesis. Rather, it is associated with the supplemental synthesis of glycolytic and Krebs Cycle intermediates, although it may also be involved in regulating intracellular pH. NADP-ME activity increases during ripening of several fruits e.g. tomato and apple, usually in association with increased respiration of the developing fruit. We examined expression of NADP-ME during ripening in peach using a cDNA probe derived from F. trinervia (C4 dicot). The probe hybridized to a single RNA species of the predicted size and was low in abundance as expected for a C3 NADP-ME. As fruit matured, the RNA levels increased to a maximum around 133-140 days after bloom (fully ripe). NADP-ME RNA was not detectable from leaves isolated at the same time.
287 IMPROVED PERFORMANCE OF SHRUNKEN-2 SWEET CORN USING TRICHODERM HARZIANUM AS A BIOPROTECTANT
Authors: Björkman Thomas , Price Hugh C. , Harman Gary E. , Ballerstein James , Nielsen Patricia
Published: February 2019

A strain of the biocontrol fungus Trichoderma harzianum was tested for effectiveness in improving the performance of sh2 sweet corn using a variety of delivery methods. In greenhouse trials, Trichoderma seed treatment reduced the proportion of weak plants (unlikely to make a marketable ear) from 40% to 10%. This is evidence that the characteristically uneven stand establishment of supersweet corn should be overcome by using Trichoderma. In field trials, Trichoderma and Gliocladium (a related fungus) were inoculated as a seed treatment without fungicide in spring-tilled plots. Yields of uninoculated controls were 2.2, Gliocladium-treated were 2.6, and Trichoderma -treated were 3.6 T/ac. Delivering the same lines of fungus in the fall to a rye cover crop resulted in high populations the following spring. The cover crop was killed and fungicide-treated seed of `Zenith' sweet corn was planted without tillage. Yield with Trichoderma was 4.0, with Gliocladium was 3.7, and uninoculated was 2.4 T/at. The uninoculated, conventionally-tilled plots also yielded 4 T/at. Thus the beneficial fungi overcame the inhibition caused by no-till. Trichoderma was delivered effectively both as a seed treatment and on a winter cover crop to improve stand uniformity and overall yield.
289 GENOTYPIC DIFFERENCES IN THE INDUCTION OF DISEASE RESISTANCE WITHIN CUCUMIS SATIVUS
Authors: Newell Lavetta , Widders Irvin , Hammerschmidt Raymond
Published: February 2019

Systemic resistance to necrotic lesion forming pathogens can be induced in certain plant species by inoculating a young leaf with a limited amount of pathogen or by treating with specific non-pesticidal chemical compounds. A physiological change correlated with the induced resistance response is an increase in the activity of acidic apoplastic peroxidases. When seedlings of 17 inbred lines of fresh market and pickling cucumbers were foliar treated with 20 ppm 2,6-dichloroisonicotinic acid (Ciba Geigy 41396) and subsequently inoculated with either Pseudomonas syringae pv. lachrymans or Colletotrichum lagenarium, significant differences were observed in the number of lesions that developed. CG 41396 treatment also gave rise to 4-fold (Producer and Early Russian), 3-fold (Poinsett and Straight 8) and 2-fold (Delcrow, WI 2757, TMG-1, TG 72) increases in peroxidase activity within inbred lines. Distinct changes in acid peroxidase electrophoretic isozyme banding patterns were observed within certain inbred lines after treatment with CG 41396. These results indicate that genetic variability exists within Cucumis sativus with respect to plant response to physiological disease resistance inducing treatments.
290 COMPARING THE EFFICACY OF CHEMICAL CONTROLS FOR ROOT-KNOT NEMATODE ON WATERMELON
Authors: Brust G.E. , Scott W.D.
Published: February 2019

Nine treatments, arranged in a RCB design with 4 replications on 20m rows/plot, were all soiled applied and incorporated under black polyethylene mulch, prior to planting. The treatments were: methyl bromide (MB) 98 and 67 & chloropicrin at 168 kgha-1, metham sodium at 17 & 34 1ha-1, oxamyl at 1.6 & 3.21 1ha-1, fosthiazate 6.5 & 13 kgha-1, and a control. Four week-old `Crimson Sweet' watermelon (Citrullus lanatus) transplants were established 3 weeks after chemical applications were made. Soil samples were taken in the plastic row-middle, plastic edge, 30 cm off the plastic edge and 15, 30 & 45 cm deep at each sampling location 3 and 6 weeks after transplanting. The presence of Root-knot Nematode, RKN, (Meloidogyne spp.) was established by using `Mountain Pride' tomato as a bioassay. Fruit size and total yield were recorded and the economic return for each control practice calculated. The 1.6 1ha-1 oxamyl plots yielded 6,832 kgha-1 more than the control which corresponds to a return of $183 for the investment of that control. The 3.2 1ha-1 plots had a yield increase of 7,728 kgha-1 and a return of $103, followed by, in order of yield response, 17 1ha-1 Metham plots, 18,592 kgha-1 & $498, 34 1ha-1 Metham plots, 25,872 & $693, MB 67 plots, 35,952 kgha-1 & $752, and MB 98 plots, 37,072 kgha-1 & $851.
291 OVERVIEW OF HERBICIDES AVAILABLE FOR CABBAGE PRODUCTION IN ILLINOIS AND WISCONSIN FOR THIRTY YEARS (1965-1994)
Authors: Hopen Herbert J.
Published: February 2019

Based on recommendations for commercial cabbage producers fourteen herbicides were labeled over the thirty year period of 1965 to 1994. The number of herbicide choices ranged from two in 1965 and 1982 to ten in 1993 and 1994. The ten herbicides labeled for use in Wisconsin in 1994 are clomazone, DCPA, glyphosate, metolachlor, napropamide, sethoxydim, trifluralin, oxyfluorfen, paraquat and pyridate. Thirty two candidate herbicides were evaluated in thirteen of the thirty years but have not been approved for use in cabbage production. State “emergency” and state “third party” labels will be discussed as a means to provide herbicides for specific grower uses. The efficacy of each of the labeled herbicides will be discussed as supported by field, greenhouse and laboratory studies.
294 SINK ACTIVITY AND CARBOHYDRATE ALLOCATION PATTERNS WITHIN DEVELOPING APPLE FRUIT WITH AND WITHOUT FRUIT THINNING
Authors: Archbold Douglas D.
Published: February 2019

Over 4 years, using estimates of fruit dry weight derived from diameter measurements in situ, cultivar variation in apple fruit relative growth rate (RGR) in the period following June drop was evident. These differences diminished as the season progressed however. Using estimates of dry weight per cell, fruit cell absolute growth rate increased over time and RGR showed no clear pattern in contrast to the RGR of whole fruit. There were no cultivar differences in carbohydrate allocation among the soluble, starch, and remaining ethanol-insoluble, non-hydrolyzable pools irrespective of cultivar RGR. The storage carbohydrate pool comprised an increasing fraction of the total dry weight over time with the starch pool comprising 10 to 25% of the storage carbohydrate, varying with season and cultivar. Neither fruit competition within a cluster nor post-June drop thinning altered fruit RGR or carbohydrate allocation patterns when compared to fruit thinned post-bloom.
301 c and n fluxes in brussels sprouts (Brassica oleracea VAR. gemmifera) during bud growth
Authors: Booij Remmie , Meurs Bert
Published: February 2019

The harvest season for Brussels sprouts runs mainly from September to March. During this period the daylength is relatively short and the light intensity is low. Bud growth occurs, when photosynthesis is low. The question is, whether actual photosynthetic rate or rcdistrubution of earlier fixed photosynthates is the main source for bud growth. The aim of the present experiment was first to determine the gain of C and N and the distribution of these plant constituents within the plant, and second the role of the apical bud. Partitioning of dry matter over the plant parts and the allocation along the stem were determined. Contents of C, N, NO3 and soluble sugars in the dry matter were ascertained, and the total amounts of these components could be determined. From this analysis fluxes were calculated and the role of redistribution was investigated. Redistribution of soluble sugars and N from leaves before shedding contributed substantially to bud growth. The apical bud did not affect total dry matter production, but if removed, more dry matter became available for bud growth in the top region of the plant, resulting in a higher total bud yield.
305 PRESSURE OF SAP EXUDATE OF TOMATO PLANTS IN VARIED ROOT ENVIRONMENTS
Authors: Yao Fude , Corey Kenneth
Published: February 2019

Sap pressure of cut tomato stems was monitored using a real time data acquisition system to assess changes in the root zone environment. Hydroponically-grown tomato plants were cut and a gas-free connection made to a temperature-compensated pressure transducer. When plants were bathed in nutrient solution under isothermal conditions, pressure increased to a maximum within 10 to 75 min; maxima varied in the range of 20 kPa to 150 kPa. A fatigue phenomenon occurred with all plants, exhibited by decreases in pressure maxima over time. When root zone aeration was stopped or a nitrogen atmosphere was used, pressure dropped following a lag of about 30 min. This decrease in pressure was partially reversible when aeration was resupplied. Near instantaneous changes in sap pressure occurred when the root zone was manipulated by imposing a temperature gradient or by increasing the osmolarity of the solution. The technique reported may be useful for continuous monitoring of changes in the root zone environment and in assessing plant health.
307 CYTOKININ-RESPONSIVE GENES IN Phaseolus vulgaris.
Authors: McDaniel Kerrie , Lightfoot David
Published: February 2019

Physiological differences between cttokinins are well documented. An explanation for these differences is that cytokinins differentially regulate genes. Gene response has been analyzed in cell culture and organized tissue of Phaseolus vulgaris L. cv. Great Northern. Two novel cDNAs, L-221 and L-22, have been identified that are cytokinin responsive. In leaf tissue L-221 was repressed by zeatin, benzyladenine and thidiazuron at 50 μM. In suspension cell culture mRNA abundance of L-221 remained constant regardless of cytokinin treatment. By contrast, the abundance of L-22 mRNA was increased differentially by treatment with each of the 3 cytokinins in leaf tissue. Suspension cells analyzed for expression of L-22 after cytokinin treatment also showed differential gene expression. S-1 Nuclease Protection Assays revealed that gene expression is a transient phenomenon dependent upon the time of cytokinin application and cytokinin concentration. Callus bioassays showed that dihydrozeatin and O-glucosylzeatin gave greater responses than the co-application of zeatin and dihydrozeatin or zeatin and O-glucosylzeatin. The conjugate and the reduction derivative also gave greater responses than zeatin alone. Effects of dihydrozeatin and O-glucosylzeatin on gene expression will be reported.
315 TISSUE PROLIFERATION ON MARK ROOTSTOCK SHANKS: EFFECT ON TREE GROWTH, AND CORRELATION WITH SITE FACTORS
Authors: Stover E.W. , Walsh C.S.
Published: February 2019

A factorial planting of three scion varieties (`Gala', `Fuji', and `Braeburn') on each of four rootstocks (Mark, M.26, M.7a, and MM.1 11) was established at two locations in MD in 1990. In 1993, trees were scored for trunk circumference (TC), extension growth, leaf color, burrknots (BK) and gall-like swellings (GLS) both above and below ground, and presence of pests on the shanks. Mark was the only rootstock with GLS; 75% of the trees examined had these tissue proliferations, Mark grafted with `Fuji' had 2-3X higher %TC composed of GLS below ground than was observed with other scion varieties. Across rootstocks, %TC composed of BK below ground was significantly affected by location. ln each rootstock, regressions between growth parameters and % of TC with BK or GLS were almost all negative and many bad significant correlations. ln Mark, % of TC with GLS below ground (but not above) was significantly correlated with reduced TC at 25 cm. The occurrence of GLS was much greater below ground than above. Orchard surveys of trees on Mark were also conducted at several commercial sites in MD and NY. The percentage of trees showing GLS ranged from 0 to 90%. There was a significant reduction in TC at 25 cm correlated with increasing levels of GLS. The percentage of trees with GLS and mean % of TC with GLS significantly correlated with percentage of trees having visible woolly apple aphids or their distinctive galls.
317 PERFORMANCE OF FOUR APPLE CULTIVARS GRAFTED ON FOUR ROOTSTOCKS
Authors: Granger Raymond L. , Khanizadeh Shahrokh , Groleau Yvon
Published: February 2019

In 1988 a randomized complete block design with five blocks was used to evaluate the performance of four cultivars (`Empire', `Cortland', `Summerland McIntosh' and `Lobo') grafted on four rootstocks {Budagovsky(Bud.)9, Malling(M.)7,Ottawa(O.)3 and Malling Merton(M.M.)111}. The sixteen cultivar-rootstocks combinations were planted randomly at 2.5m apart in the row. The distance between the rows was 5m. The trees have been trickle irrigated every year and came into bearing in 1990. On the basis of cumulative yield efficiency the combination `Lobo'/O.3 was significantly superior to all others. The second best performer was `Empire'/O.3 followed by `Lobo'/Bud9. `Empire'MM.111, `Summerland McIntosh'/M.M.111, `Cortland'/M.M.111, `Summerland McIntosh'/M.7 and `Empire'/M.7 had the least cumulative yield efficiency. Generally the cultivar `Lobo' was superior to others and O.3 was the best rootstock followed by Bud.9, M.7 and M.M.111.
318 FIELD PERFORMANCE OF 28 PRUNUS ROOTSTOCKS AND INTERSTEMS IN SOUTH CAROLINA
Authors: Reighard Gregory L.
Published: February 2019

A `Redglobe' peach orchard budded to 22 rootstock cultivars was planted in 198X on a Lakeland sand near Columbia, SC. Six of the 22 cultivars were also used as interstems on Nemaguard. The rootstocks tested were Lovell, Halford, Nemaguard, Bailey, Tennessee Natural, Tzim Pee Tao, Rutgers Redleaf, Higama, Rubira, Montclar, GF 305, Juseito, Myran, Ishtara, S.2729. St. Julian A, Citation, Marianna 2624, GF 557, GF 677, (S×R 185)6 and `Redglobe' own-rooted. Trees on Marianna 2624 grew poorly and eventually died from incompatibility. Plum hybrid rootstocks St. Julian A. Ishtara and Myran were susceptible to Pseudomonas syringae. Some peach X almond (S×R 185)6 trees died from unknown causes. Tzim Pee Tao was the only rootstock to delay bloom significantly later (1.5 days) than Lovell. All Nemaguard interstem combinations and Tzim Pee Tao had significantly more-rootstock suckers. Nemaguard, Myran and Higama trees were 25 to 43% larger in TCSA than Lovell. Ishtara trees were only 61% of Lovell in TCSA. St. Julian A and Citation trees were small, weak and unproductive. The highest yielding rootstocks were Nemaguard (Myran interstem), GF 305, Nemaguard (Ishtara interstem), Montclar and Rubira which averaged 69, 65, 64, 62 and 60 kg/tree, respectively in years 4 through 6.
321 GIBBERELLIN METABOLISM AND FLOWERING IN APPLE
Authors: Ban Jun , Dennis Frank G.
Published: February 2019

Some apple cultivars are biennial. Experiments with the facultatively parthenocarpic apple cultivar `Spencer Seedless' indicated that seeds are responsible for inhibiting flowering (Chan and Cain, Proc. ASHS 91:63-68, 1967). Because gibberellin inhibits flowering in apple, seed GAs may be responsible for biennial bearing, or seeds may affect metabolism of GAs in bourse shoots. To obtain additional information, 14C - G A12 was injected into seeds or bourse shoots of `Spencer Seedless' and the metabolites were extracted after 24 or 48 hr. Metabolites moved from seeds to bourse shoots and vice versa in 1992, only the most polar compound(s) being transported. However, transport was not observed in 1993. Five metabolites of 14C - G A12 were found in apices following injection, 5 to 7 in seeds. Two metabolites occurred in fruit flesh following seed treatment. The presence of seeds appeared to have no qualitative effect on metabolism in the bourse shoot, although the metabolites have not yet been identified.
327 LEAF WATER POTENTIAL, RELATIVE WATER CONTENT AND GAS EXCHANGE OF STRAWBERRY LEAVES IN RESPONSE TO WATE.R STRESS
Authors: Chen Chuhe , Cameron J. Scott , VanDerZanden Ann Marie
Published: February 2019

Leaf water potential (LWP). relative water content (RWC), gas exchange rates and 4th-derivative spectra were measured in water-stressed and normally Irrigated plank of Totem' strawberry (Fragaria × ananassa) grown in a growth chamber. CO2 assimilation rate (A) dropped sharply when LWP decreased from -0.5 to -1.2 MPa and almost ceased as LWP fell below -1.5 MPa. There was a significant but more gradual decline of A as RWC decreased form 90% to 55%. An exponential relationship with A was observed across a wide range of LWP and RWC (Rz= 0.64, 0.86, respectively). LWP was more closely related with transpiration and leaf and stomatal conductances than with A and water use efficiency. RWC was highly correlated with all gas exchange parameters.

Under moderate water stress, younger leaves maintain higher RWC and A than older leaves. There was no relationship between LWP and leaf age.

RWC and A were both negatively correlated with peak amplitudes of Ca 684 and Ca 697 and positively correlated with Ca 693 in their 4th-derivative spectra of chlorophyll. LWP had a negative correlation with Cb 640.
328 EVALUATION OF gti METHOD TO ASSESS HEAT AND DESICCATION INJURY AMONG FRAGARIA SPECIES
Authors: McDonald Suzanne S. , Archbold Douglas D. , Lailiang Cheng
Published: February 2019

The expression gti, or tissue ionic conductance, was proposed to describe the efflux of ions from leaf disks (Whitlow et al., 1992, Plant Physiology, 98:198-205). The objective of this study was to determine the effectiveness of the gti method to screen germplasm for heat and desiccation tolerance using representative selections of 5 Fragaria species. Leaf disks were exposed to 4 levels of heat, 25, 35, 45, and 55 C, and 4 levels of desiccation. 60, 70, 80 and 100% relative water content (RWC). F. virginiana glauca was consistently ranked as the leakiest in all treatments including controls, with gti values 70 to 100% higher than in the other species. Temperatures of 25 to 45 C did not influence gti over time. A temperature of 55 C was lethal to the tissue and, thus, the ion flux was initially very high but soon diminished. At 70% RWC F. virginiana glaucu tissue was the leakiest, and F. virginiana and F. vesca tissues were somewhat leakier than those of F. × ananassa and F. chiloensis. Differences among species diminished with time in bathing solutions.
333 RAPD MARKER FREQUENCY CHANGES IN TWO RED BEET POPULATIONS UNDERGOING RECURRENT SELECTION
Authors: Eagen K.A. , Goldman I.L.
Published: February 2019

Red beet contains betalain pigments recently adopted for use as natural food colorings. In an effort to develop beet populations with higher levels of betalain pigment, recurrent half-sib family selection for high pigment and both high and low solids was practiced in two populations for 7 cycles. PCR-based RAPD marker frequencies were assessed on genomic DNA samples isolated from 47 randomly-chosen individual plants from cycles 1, 3, and 6 in both populations. Number of PCR products per RAPD primer varied, with some yielding up to 5 scorable products. Chi-square and regression analyses were performed to determine presence/absence of linear trends in marker frequencies associated with selection. Significant linear trends in RAPD market frequencies were detected for certain primers both between populations and among cycles. These data demonstrate changes in RAPD marker frequencies with selection and suggest linkage of RAPD markers to genes controlling pigment and solids in red beet.
336 PHYLOGENETIC RELATIONSHIPS OF CELERY AND ITS WILD RELATIVES BASED ON RESTRICTION FRAGMENT LENGTH POLYMORPHISMS
Authors: Huestis Gordon M. , Quiros Carlos F.
Published: February 2019

Phylogenetic relationships of seven Apium species, including three horticultural types of A. graveolens, were assayed for RFLPs using cDNA, chloroplast DNA, and rDNA probes. Most of the probes had been previously mapped in celery. The three horticultural types of A. graveolens were found to be less polymorphic than the wild species and in phylogenetic analysis they clustered together. The wild species formed a cluster on the dendrogram corresponding to their origin in the southern hemisphere. A. nodiflorum, a wild species from Ethiopia formed a branch on the phylogenetic tree apart from all other species. This, along with morphological considerations, suggests that A. nodiflorum should be reclassified outside the genus Apium.
339 ACC-DERIVED ETHYLENE PRODUCTION, A RAPID TEST FOR SEED VIGOR
Authors: Khan Anwar A.
Published: February 2019

1-aminocyclopropane-1-carboxylic acid (ACC) was used to measure seed vigor of lettuce, cabbage, tomato, snap bean and sweet corn seeds. Accelerated aging at 40C and 93% RH over saturated solution of KH2PO4 and natural aging under ambient storage conditions (5-7C, 28 to 60% RH) were used to obtain seeds of differing vigor levels. Depending on the type of seeds, the amount of ACC needed for maximal ethylene production (saturating dose) ranged from 0.25 to 2mM. Seeds produced much larger amounts of ethylene in the presence than in absence of ACC, the ACC-derived ethylene was detected prior to germination, and ACC had no adverse effect on germination. ACC-derived ethylene production paralleled vigor loss as determined by percentage germination, mean germination time (for lettuce only) and seedling growth (for snap bean only). Second degree polynomial and logarithmic equations generated for the relationship of ACC-derived ethylene production to germination or growth parameters following seed aging, provided good to excellent fit. As a vigor test, the ACC-ethylene procedure has several advantages over the non-ACC ethylene procedure: it greatly improves the sensitivity of the test by enhancing ethylene production, it permits detection of small differences in vigor levels and it allows detection of ethylene prior to germination within a few hours of soaking.
341 EFFECTS OF HYDROPRIMING AND OSMOTIC PRIMING ON MUSKMELON SEED PERFORMANCE
Authors: Yeoung Young Rog , Wilson Dale O.
Published: February 2019

Pregermination techniques of osmotic priming and hydropriming have been used to enhance seed performance on planting Osmotic priming and hydropriming method were compared on the basis of germination performance O2, N2 and air were supplied to 500 ml vessels containing seeds with distilled water or -1.31 MPa PEG solution for 10 days On removing seeds from vessels, seeds were dried back to original water content. There were no differences in total germination between osmotic priming and hydropriming treatments t50 was reduced dramatically from 112 to 32 hours, using hydropriming with air and N2supply for 1 day, compared to 70 hours of osmotic priming. Solute leakage from O2supply of both methods was higher than air or N treatment, Indicating the loss of membrane integrity Hydropriming with O2induced radicle emergence and loss of desiccation tolerance around 28 hours after treatment LEA protein levels were not changed in both treatments except for hydropriming with O2. The timing of desiccation tolerance loss was correlated with that of degradation of LEA protein. O2supply caused the adverse effects on seed performance from both methods 1 day after treatment
343 INCREASING CELL SIZE AND MEDIA PACKING ENHANCES THE GROWTH OF LETTUCE SEED LINGS. TRANSPLANT QUALITY, AND FIELD PRODUCTION
Authors: Nicola Silvana , Cantliffe Daniel J.
Published: February 2019

Cell size and media density can modify plant quality of greenhouse grown transplants through variation in light competition among plants, water and nutrient retention and root growth volumes required to fill the cells Thus, `South Bay' lettuce (Lactuga sativa L.) seedlings were grown in the greenhouse during different seasons to investigate the effect of different cell size and media packing density on transplant quality and yield for lettuce grown on sand and muck soils at different latitudes. Four Speedling flat cell sizes (882, 392, 242, 124 cells/flat) and two media packing densities (unpacked and packed - 1.5 times in weight) were tested in all the trials. Few seedling data parameters had an interaction between cell size and media density at transplanting. The larger cell size (242, 124 cells/flat) and greater media density led to increase leaf area, leaf length, shoot and total dry weight, RGR and LWR Conversely, RWR and the root:shoot ratio had the opposite trend, reaching the greater values with smaller cell size and less media density. High root growth can improve the pulling of the plants from the tray at transplanting and quicker establishment in the field. The treatments did not affect yield of plants grown on organic soil. When plants were grown on sandy soil head weights were greater from plants grown in 392, 242, or 124 cells/flat compared to 882 cells/flat.
347 ETHYLENE-INDUCED GENE EXPRESSION DURING FLOWER PETAL ABSCISSION OF ZONAL GERANIUM
Authors: Clark David G. , Evensen Kathleen B.
Published: February 2019

Ethylene-regulated gene expression is being studied in several plant systems, but the exact mechanism of ethylene action during plant development and senescence is poorly understood. When geranium (Pelargonium Xhortorum) flowers are exposed to 1 μ1/L of ethylene gas for 1 hour, petals begin to abscise within 60-90 minutes from the start of treatment, The rapidity of the response implies that it must be very direct. We now demonstrate that ethylene acts at the level of message accumulation. We have constructed a cDNA library from mRNA isolated from ethylene-treated geranium gynoecia. Ethylene-induced clones have been isolated by differential screening of this library with cDNA probes synthesized from ethylene-treated and untreated geranium gynoecia mRNA. Identification and characterization of these clones will be discussed.
350 VASE-LIFE DETERMINATION OF SIX SPECIALTY CUT FLOWER SPECIES
Authors: Redman Paul B. , Dole John M.
Published: February 2019

The postharvest attributes of six specialty cut flower species were studied. First year results indicate that Achillea filipendulina `Coronation Gold' had a vase-life of 10.7 days in deionized water (DI) and can be stored one week at 1.7°C and shipped for one day. Buddeleia davidii (Butterfly Bush) had a vase life of 3.8 days in DI water and tolerated two weeks of cold storage and two days of shipping. Celosia plumosa `Forest Fire' (Plume Celosia) had a vase-life of 5.9 days in DI water and tolerated 2 days of shipping. Cercis canadensis (Redbud) had a vase-life of 9 days in DI water and tolerated one day of shipping. Echinacea purpurea `Bright Star' (Purple Coneflower) had a vase-life of 4.6 days in DI water and tolerated 2 weeks of storage and five days of shipping. Helianthus maximilianii (Maximillian Sunflower) had a vase-life of 6.3 days in DI water and tolerated one week of storage. In addition, silver thiosulfate and 8-hydroxyquinoline citrate increased vase-life of Buddeleia davidii, Celosia plumosa, Echinacea purpurea, and Helianthus maximilianii.
351 POSTPRODUCTION EVALUATIONS ON FORCED ASTILBE
Authors: Pemberton G.H. , Nell Terril A. , Leonard Ria T. , De Hertogh A.A. , Gallitano Lena , Barrett James E.
Published: February 2019

Forced `Bumalda' and `Etna' Astilbe were evaluated for postproduction quality and longevity. Plants were sleeved, boxed and held at 9±2C for 3 days to simulate shipping at the following stages of floral development: tight bud (TB), 1-3 florets open, 25% florets open, 50% florets open, and 75% florets open. They were then placed at 21C and 14 μmol·m-2·s-1 (12h daylength) until flower senescence. Percent of inflorescences flowering increased from 34% at TB stage to 94% when shipped with 25 % of the florets open. `Etna' longevity increased from 3 days at TB stage to 12 days at 25% open stage. Optimum quality and longevity occurred when ≥ 25% of the florets were opened at shipping.

In a second experiment, `Bumalda' and `Etna' Astilbe were held at 18, 21 and 24C at irradiance levels of 7 or 14 μmol·m-2·s-1 when 25% of the florets were open. At 18C, longevity increased under 14 μmol·m-2·s-1 from 14 to 17 days. At 24C, longevity was only 10 days for both irradiance levels.
354 REDUCING ROOTING-OUT PROBLEMS IN POT-IN-POT PRODUCTION SYSTEMS
Authors: Ruter John M.
Published: February 2019

A study was conducted with Lagerstroemia indica x fauriei `Acom a' to evaluate methods for reducing rooting-out problems in a PIP production system. The products tested were Biobarrier™, a geotextile fabric impregnated with trifluralin; Root Control'” fabric bag material; and Spin Out™, a commercial formulation of copper hydroxide (7.1%) in latex paint. Biobarrier™ reduced plant height, shoot dry weight, percent root dry weight outside of the planted container and total biomass compared to the non-treated control. For the control, 7.1% of the total root dry weight was found between the holder pot and planted container compared to 0.2% for the Biobarrier™ treatment. When the holder pot and planted container or the planted container and Root Control™ fabric were both treated with Spin Out™, plant height and shoot dry weight were reduced. Spin Out™ reduced root circling on the sidewalls of the planted containers but not on the bottom of the containers. All treatments except the control reduced rooting-out to a degree that allowed for the manual harvesting of the planted container from the holder pot after seven months in the field.
359 RESEARCH PROGRESS OF IR-4 ORNAMENTAL PROGRAM
Authors: Frank J. Ray , Kunkel Daniel L.
Published: February 2019

Since the IR-4 Project for Ornamental Uses was initiated in 1977, over 13,500 research trials have been conducted. This effort has lead to over 3100 label-registrations for fungicides, herbicides, insecticides, nematicides and growth regulators.

This cooperative program is conducted by Federal and State workers in conjunction with growers of nursery, floral crop and landscape plant materials.
360 ORIGIN, INHERITANCE, AND EFFECTS OF A DWARFING GENE FROM THE CITRUS ROOTSTOCK PONCIRUS TRIFOLIATA `FLYING DRAGQN'
Authors: Roose Mikeal L. , Cheng Frank Suozhan , Federici Claire T.
Published: February 2019

The `Flying Dragon' cultivar of Poncirus trifoliata L. Raf. is a strongly dwarfing rootstock for Citrus cultivars, reducing canopy volume of 9 year-old `Valencia' orange trees to 1/3 that of trees on standard rootstocks Open-pollinated seed of `Flying Dragon' was screened with isozyme markers to distinguish zygotic from nucellar (apomictic) seedlings. All zygotics had genotypes consistent with an origin by self-pollination. Zygotic seedlings were budded with `Valencia' orange scion and planted in the field. Of 46 progeny evaluated as rootstocks, 35 produced small trees similar to those on nucellar `Flying Dragon' and 11 produced large trees. This ratio is consistent with the 3:1 segregation expected for a single dominant gene. The dwarfing gene was closely linked, or pleiotropic with a gene causing curved thorns and stems. Several RAPD markers close to the dwarfing gene were identified with bulked segregant analysis. `Flying Dragon' apparently originated as a mutation because it had au identical genotype to non-dwarfing strains of trifoliate orange at all 38 isozyme and RFLP markers tested
366 ROSA RESOURCES IN CHINA
Authors: Ma Yan , Chen Junyu
Published: February 2019

From 1986 through 1993 wild rose species were investigated throughout China to catalog and to characterize the rose germplasm resources in mainland China. Many of the 94 rose species and 144 rose varieties in China have not been extensively utilized. The basic features of Chinese rose species are as follows. (1) There are many valuable and rare Rosa species in China. These species are sources of many unique and outstanding characters such as intense fragrance, white and yellow flower color, recurrent flowering and resistance to stress. More than 80% of the rose species in China are native to only China. (2) Although most Rosa species are still in the wild state, a few species cultivated from very early time have many forms available. (3) The number of rose species gradually increases from Northeast to Southwest China. The distribution centers of Rosa species in China are Sichuan and Yunnan Provinces. Chinese rose species can be introduced and used directly in gardens, or in breeding programs to develop new roses.
369 THE INFLUENCE OF PRE-AND POSTHARVEST TREATMENTS ON WASHINGTON NAVEL ORANGE
Authors: Wassel Abdel Hameed M. , Hameed Moawad Abdel
Published: February 2019

Different treatments were carried out inluding that achieved in the modern packing houses which are established for preparing citrus fruits for export. Decay of Washington navel oranges was reduced due to spraying benlate at 500 and 750 ppm as a preharvest treatment. Fruits coated with thin film of wax containing benlate were less susceptible to decay than any other treatment including that carried out in the packing houses. On the other hand no adverse effect could be noticed for this treatment on the chemical properties of the fruils. Thereby, the disinfectant process which is followed by rinsing could be eliminated, conseqently, raising the productive capacity of these packing houses.
373 MITOCHONDRIAL RESPIRATlON OF `HASS' AVOCADOS IN RESPONSE TO ELEVATED CO, CONCENTRATIONS
Authors: Lange Diana Dostal , Kader Adel A.
Published: February 2019

Carbon dioxide-enriched atmospheres can be effective in the retardation of ripening and in the reduction of decay of horticultural commodities. However, concentrations in excess of the tolerance level may cause physiological damage. The goal of our research is to elucidate the specific regulatory mechanisms of CO2 actions. Cytochrome oxidase (CytOx) in vitro activity in preclimacteric avocado fruit stored in air or 40% CO2 + 12.6% O2 was evaluated at 20C. Activities were determined during treatment and also after a transfer to air. Fruit treated with 40% CO2 + 12.6% O2 had elevated CytOx in vitro activity when compared to air-stored fruit. Immunoblot analysis was performed to determine if the increase in CytOx activity could be due to an increase in enzyme concentration. The decline in respiration rate of CO,-treated fruit was most likely due to the decrease in intracellular pH and its effect on the activities of important respiratory enzymes, including CytOx. The regulatory mechanisms of other mitochondrial respiratory enzymes in `Hass' avocados exposed to elevated CO2 atmospheres are also under investigation.
374 PRACTICUM INSTRUCTION AND STUDENT LEARNING
Authors: Fails Barbara
Published: February 2019

Experiential learning is an integral component of successful career preparation for the horticulture industry. The limited-enrollment practicum course through Sparty's Flowers has been taught for 7 years, and accounts largely for the overall success of the retail floriculture program. Structure is built into the course by assigning weekly individual learning objectives and assignments. Students, in turn, develop their own action plans, upon which evaluation is based. Interactive group meetings replace formal lectures for more effective instructional delivery. Knowledge retention is enhanced as lessons are experienced, not only heard and read. Technical hands-on experiences of design, display, advertising, recordkeeping, sales, and merchandising sharpen abilities. Professional skills, such as time management, interpersonal communication, leadership, and creative problem solving are also developed and fostered by all members of the class. Practicum instruction, as an example of effective collaborative learning, allows a creative and realistic approach to teaching horticulture.
376 COOPERATIVE LEARNING IN AN HERBACEOUS ORNAMENTAL PLANTS IDENTIFICATION CLASS
Authors: Needham Douglas C. , Dobbs Steven
Published: February 2019

Twenty-three students of HORT 2212: Herbaceous Ornamental Plants divided into five teams, each selecting one of the ground beds at the television studio gardens of Oklahoma Gardening to design with the aid of MacDraw II and Macintosh computers. The team approach promoted cooperative learning, where those who were skilled in design worked cooperatively with those individuals more skilled at developing the theme gardens' cultural pamphlets. This project encouraged individual students to develop various communication skills to support their team's thematic garden-visual, in the form of a CAD plot of the garden design; written, in the form of a garden pamphlet; and telecommunication, in the form of Oklahoma Gardening television segments.

The students and OBGA Ambassadors started the seeds and, then, planted the gardens, resulting in a very practical experience. This design and installation project not only prepared students for the cooperative efforts that they are likely to encounter in the ornamental horticulture and landscape design and maintenance industries, but also imparted pride in their work, which was viewed by over 150,000 television viewers and visitors weekly.
378 ME, USE THE TEACHING PORTFOLIO? BUT I'M PREDOMINANTLY A RESEARCHER!
Authors: Decoteau Dennis R. , Wilkinson T. Ross
Published: February 2019

Public scrutiny about faculty time commitment have brought professor accountability to the front page of the daily newspapers. Many faculty in agricultural colleges at Land Grant Universities have split appointments in either research, teaching or extension. Effectiveness has been traditionally demonstrated in research by listing of publications, grants, graduate students. and presentations; but these measures are not necessarily appropriate measures for teaching. The need to better document teaching is imperative and a simple listing of classes taught and number of student contact hours can no longer be sole measures of teaching effectiveness. The Teaching Portfolio is a factual description of a professor's strengths and accomplishments. It includes documents and materials that collectively suggest the scope and quality of a professor's teaching performance. The Teaching Portfolio is an important tool for all Land Grant faculty, regardless of their teaching responsibilities. As pan of a ESCOP/ACOP Leadership Program at Clemson University, we have been reevaluating how university faculty are evaluated. We will discuss our experiences in introducing and using the Teaching Portfolio as part of a new evaluation process.
382 PRECISION SEEDING STUDIES ON SNAP BEANS
Authors: Price H.C. , Taylor A. G.
Published: February 2019

Field studies were. conducted in 1992 and 1993 to evaluate vacuum planters with respect to precision placement of seeds and to separately study plant spacing and emergence uniformity on stand establishment and yield. All studies were. performed with Bush Blue Lake 47. In 1992, a cooperative study was conducted with the Experiment Station and ten growers in Upstate New York representing four makes of commercial planters. No planter was able to precision seed, and seedling emergence revealed a large tendency to clump plant, with less errors made in the form of misses or skips. In 1993, tractor planting speed was studied as a variable from 3.4 to 12.3 KPH (2.1 to 7.6 MPH) on spacing uniformity and yield. The average number of seedlings per meter of row was similar for all treatments, however, the variation in spacing between plants generally increased as planter speed increased. In research plots, in-rowspacing and emergence uniformity were studied. Plant population was held constant and three in-row spacings were. developed (1 plant 5 cm apart, 2 plants 10 cm apart or 3 plants 15 cm apart). There were. no differences in yield in this study. Daily emergence was recorded and seedlings were grouped into three categories based on their time to emergence (early, medium or late). Yield was more than twice as much from early than late emerging seedlings, while the medium group was intermediate with respect to yield.
383 SPECIALTY/HEIRLOOM BEAN VARIETY EVALUATIONS IN THE LOWER SACRAMENTO VALLEY OF CALIFORNIA
Authors: Murray Mike , Temple Steve
Published: February 2019

Significant industry interest exists for evaluating the lower Sacramento Valley as a production region for specialty dry beans. This interest is being driven by erratic or inconsistent production in the existing commercial production regions, mostly in the Pacific Northwest and the Mid-West regions. The environmental conditions in the Sacramento Valley are favorable for producing consistent yields of high-quality dry beans. Specialty beans are generally typified by limited markets and relatively high producer returns, and offers an attractive rotation crop for local growers.

Variety evaluations including many of the most popular or likely candidates for a local specialty bean industry were conducted in 1991 and 1993. Parameters evaluated included plant architecture, flowering dates, pod set and retention, maturity dates and seed yield. Additional qualitative evaluations to determine varietal quality were also conducted. Many varieties were identified that had both acceptable yield and seed quality potential.
384 AGRONOMIC TRAITS OF 19 TEPARY BEAN LINES
Authors: Debaene Jan E. Paul , Robison Laren
Published: February 2019

Tepary beans (Phaseolus acutifolius A. Gray) are native to north America and are considered drought and heat tolerant. Teparies are not commonly grown commercially, so little is known about their field performance. This study compared agronomic traits of 19 tepary bean lines to two pinto bean (P. vulgaris) varieties. The beans were evaluated under field conditions in a randomized complete block design with three replications. Traits examined included time to germinate, time to first trifoliate leaf, time to flower, height, seed protein content, and yield. Tepary yields ranged from 1593.0 to 656.4 kg/ha with three lines averaging 63.7 to 76.8% more than the average pinto bean yield. Tepary protein content ranged from 17.1 to 29.7% and averaged 24.7%. Tepary beans have great potential for adaptation to dry conditions while producing adequate yields and protein content.
387 FIELD PERFORMANCE COMPARISON OF TWO EXPERIMENTAL TRANSGENIC SUMMER SQUASH LINES AND THEIR PARENTAL LINE
Authors: Arce-Ochoa Juan Pablo , Dainello Frank , Pike Leonard M. , Quemada Hector , Drews David
Published: February 2019

Two of Asgrow's experimental virus resistant transgenic lines, XPH-1719 and XPH-1739, and their parental line, Pavo, a commercially grown virus susceptible hybrid, were tested for field performance at the Texas A&M University Experimental Farm in the summer of 1993. The two transgenic squash lines possessed the desired fruit and plant characteristics of Pavo plus resistance to ZYMV and WMV2 (XPH-1719), and resistance to ZYMV, WMV2 and CMV (XPH-1739). Under the conditions of this test it was determined that the two transgenic hybrids, were equally effective in producing high quality marketable fruits/ha with 89.64 % and 86.84 % respectively and marketable yields with 13,762 kg/ha and 16,525 kg/ha respectively. XPH-1719 and XPH-1739 also demonstrated their outstanding virus resistance by producing only 3.44% and 14.35% symptomatic plants/ha, and 0.00% and 7.17% infected fruits/ha respectively compared to 53.55% symptomatic Pavo plants/ha, and 25.73% infected Pavo fruits/ha.
389 EFFECT OF PLANTING DENSITY ON PRECOCIOUS PALM HEART YIELD OF PEJIBAYE IN HAWAII
Authors: Clement Charles R , Manshardt Richard M.
Published: February 2019

The pejibaye (Bactris gasipaes, Palmae) is being evaluated in Hawaii as a source of fresh hearts of palm. Nine open-pollinated progenies from the Benjamin Constant population of the Putumayo landrace are planted at three densities: 1.5 × 2 m (3333 plants/hectare); 1 × 2 m (5000 pl/ha, the commercial density in Costa Rica); 1 × 1.5 m (6666 pl/ha). Harvest started at 15 months after planting and four months later 25% of the plants had been harvested, with 25%, 30% and 21% at 3333, 5000, and 6666 pl/ha, respectively. Mean heart diameters were unaffected by density (mean±SD = 3.2±0.4 cm). Heart lengths were similar (24±5 cm, 23±6 cm, 26±5 cm, respectively), as were heart weights (200±41 g, 187±44 g, 224±42 g, respectively). This relative uniformity was unexpected, as density effected all of these yield components in earlier experiments in Latin America. Potential yields were different (667±136 kg/ha, 835±221 kg/ha, 1491±275 kg/ha, respectively), and are comparable to yields reported from Costa Rica. Actual precocious yields, however, were not different (167 kg/ha, 278 kg/ha, 385 kg/ha, respectively).
390 USE OF HARDENING TEMPERATURES ON SEVERAL SPECIES OF SEED-PROPAGATED HERBACEOUS PERENNIAL PLUGS PRIOR TO FREEZING
Authors: Engle Beth E. , Cameron Arthur C. , Heins Royal D. , Carlson William H.
Published: February 2019

Storage of perennial plugs at subfreezing temperatures could be a valuable production tool since plants could be removed over relatively long periods for forcing. Several species of seed-propagated perennial plugs were pretreated at 0 and 5C under continuous 50 μmol·s-1m-2 PPF for 0, 2, 4, or 8 weeks. After each pretreatment period, plugs were placed into 4-mil polyethylene bags that were then sealed and placed at -2.5C for 0, 2, or 6 weeks. Plugs were then removed from the bags and placed into a 24C greenhouse for two weeks under ambient light levels and daylength, after which time they were rated for percent survival and general regrowth quality. Regrowth was not influenced by pretreatment temperature. Regrowth of Limonium dumosumtatarica, and Campanula carpatica `Blue Clips' following -2.5C storage was excellent with or without a pretreatment. Regrowth of Achillea filipendulina `Cloth of Gold,' Gaillardia grandiflora `Goblin,' and Iberis sempervirens `Snowflake' was improved on plugs given the 0 or 5C pretreatment. Hibiscus × hybrida `Disco Belle Mixed' regrowth was poor, regardless of pretreatment.