bluuebunny/crossref_metadata_2025 huggingface dataset:
634A PB 527 INSECT PEST MANAGEMENT THROUGH A CABBAGE-INDIAN MUSTARD COMPANION PLANTING
Authors: Bender David A. , Morrison William P.
Published: February 2019

Indian mustard (Brassica juncea) has been reported to be a preferred host for diamondhack moth (Plutella xylostellu) and other insect pests when interplanted with cabbage (Brasssica oleracea var. capitata). A cabbage-Indian mustard companion planting study was conducted to determine the seasonal occurrence of cabbage insects and the potential for using a trap-crop system to reduce insecticide applications to cabbage in West Texas. Three-row plots of cabbage 9 m long were transplanted with and without sequentially seeded borders of Indian mustard in three seasons. Harmful and beneficial insects were counted at roughly weekly intervals. Insecticides were applied when insect populations in individual plots reached predetermined thresholds. Indian mustard did not appear to be more attractive than cabbage to lepidopterous pests, but did preferentially attract hemipterans, particularly harlequin bugs (Margantia histrionica). The mustard trap crop eliminated two insecticide` applications in one trial by reducing harlequin bug pressure on the cabbage.
639 PB 369 RELATIONSHIP BETWEEN THE SURFACE WAX OF APPLE FRUIT AND SOOTY BLOTCH DISEASE
Authors: Belding R.D. , Sutton T.B. , Blankenship S.M.
Published: February 2019

Apple sooty blotch (SB) is a disease complex caused by Gloeodes pomigina (Schw.) Colby, Leptodontidium sp. and other fungi. This study was undertaken to determine if G. pomigena and Leptodontidium sp. utilize some portion of the apple epicuticular wax as a carbon source for growth. Two isolates of G. pomigena and two of Leptodontidium sp. were used. Isolates were cultured on water agar coated with a thin layer of either nonacosane, ursolic acid, or complete apple wax and an uncoated control. Radial colony growth over a 30-day period was used to assess growth. Preliminary results suggest that G. pomigena differs from Leptodontidium sp. in carbon source preference. Gloeodes colonies were larger when ursolic acid and apple wax were used as a carbon source compared to nonacosane. Leptodontidium isolates grew best on apple wax. Also, growth was greater on nonacosane than ursolic acid. results from laboratory studies were compared to SB severity (percent surface area covered) in the orchard on cultivars of apples where the wax composition was determined. Although fungal genera were not detailed in the orchard, SB severity was positively correlated with the concentration of ursolic acid (r2=0.69) and nonacosane (r2=0.34).
640 PB 372 FALL COLE CROP PRODUCTION FOLLOWING TOBACCO
Authors: Clements A.M. , Weston L.A.
Published: February 2019

Fall cole crops of exceptional quality and high market value are produced in Kentucky. Tobacco is an integral part of agriculture in the southeastern states and production of fall cole crops following tobacco may increase diversification and Potential profits. A float system was utilized for transplant production. Field plots were established with broccoli and cabbage grown conventionally, planted into killed sudex cover, cultivated tobacco stubble and directly into tobacco stubble. Data were collected on soil fertility, insect and weed populations, crop quality and yield. Periodically, foliar samples were analyzed for nitrate, total nitrogen, phosphorus, potassium and calcium content. Fall cole crops grown conventionally or in killed sudex cover produced comparable results and head size. Insect pressures were reduced in killed sudex covers. Total yield and quality were reduced when seedlings where planted directly into tobacco stubble.
641 PB 375 CHALLENGES IN IMPLEMENTING A BIOINTENSIVE IPM PROGRAM IN DIVERSE-CROP GREENHOUSES
Authors: Stack Philio A. , Drummond Francis A.
Published: February 2019

A biointensive IPM program began in 1991 in UM's 12,000 ft2 research/teaching greenhouses. Efficacy, economics and practicality of multiple natural enemy releases to control greenhouse arthropod pests in diverse-crop ranges were assessed in 1991-93. Both UM lab-reared and commercial insectary-produced natural enemies were used. Environmental constraints, natural enemy quality, daylength and short crop cycles limited biocontrol. Predators and parasites were most effective when compatible environmental parameters, cultural practices and biorational pesticides were used. Informing greenhouse users about natural enemy recognition and conservation were also important considerations. Rearing and release techniques and compatible systems are discussed.
645 PB 407 FIELD STUDY OF BLACK SPOT RESISTANCE IN ROSE
Authors: Black William A. , Byrne David H. , Pemberton H. Brent
Published: February 2019

Forty-five rose genotypes including modem cultivars and rose species were evaluated in a field trial for resistance to black spot caused by Marssonina rosae. The trial was designed as a randomized block with four replications at two sites. The plots were planted at College Station (East Central Texas) and Overton (Northeast Texas). Ratings were done for the percentage of leatlets with black spot lesions and for leaf defoliation. These ratings were taken four times during the growing season from May to October 1993. Preliminary results indicate a high degree of resistance in the ten species studied, Modem cultivars were equally divided into moderate resistance, low resistance, and susceptible with only four showing high resistance. Disease pressure was higher and occurred earlier in the season at the Overton site. Disease pressure was highest at both sites in late spring and again in fall. Pressure was lowest in August after a prolonged period without rain. Introduction during the growing season of a previously unseen race of the pathogen was observed by the performance of the cultivar Sunbright.
648 PB 416 MINIMAL USAGE OF CARBAMATE FUNGICIDES IN FIELD PRODUCTION OF SPINACH AND POSTHARVEST REMOVAL OR RESIDUES BY WASHING TECHNIQUES
Authors: Gonzalez Alfredo R. , Carrel James C. , Motes Dennis
Published: February 2019

A study was conducted to test alternative production practices that lessen the use of carbamate fungicides in the field and post-harvest washing techniques that help to reduce carbamate residues in canned spinach. Five spinach genotypes showed a high degree of resistance to white rust, the predominant field disease. The fungicide Ridomil used alone or combined with copper or Maneb provided the best control in susceptible cultivars. Maneb alone or combined with copper controlled white rust but not as efficiently as Ridomil. The most efficient washing methods to remove Maneb residues were washing with a detergent solution plus water or ozonated water or a triple wash with detergent, water and ozonated water. The lowest residue levels of ethylenethiourea (ETU), a carcinogenic carbamate derivative, detected in the washing treatments was in the range of 0.15 to 0.45 ppm. ETU in the non-washed controls fluctuated from 0.85 to 2.31 ppm.
649 PB 419 UTILIZATION OF XYLEM FLUID DURING DEVELOPMENT BY THE LEAFHOPPER VECTOR, HOMALODISCA COAGULATA
Authors: Brodbeck Brent V. , Andersen Peter C. , Mizell Russell F.
Published: February 2019

Homalodisca coagulata (Say) is a xylem feeding leafhopper that is the principal vector of many economically-important diseases resulting from infection by Xylella fastidiosa (i.e., plum leaf scald, phony peach disease, Pierce's disease). Xylem fluid consists primarily of dilute concentrations of amino acids, organic acids and inorganic ions, and thus provides less nitrogen and carbon for herbivorous insects than any other plant tissue. Despite these nutritional constraints, H. coagulata is highly polyphagous. To assess how H. coagulata subsists on this dilute food source we examined host utilization by different instars on Lagerstroemia indica L. (preferred adult food source) and Euonymus japonica Thumb. (preferred ovipositional site).

Different instars survived and utilized nutrients at varying rates on the two hosts. Second instar nymphs survived at higher rates on E. japonica and utilized nitrogen more efficiently than on L. indica, yet assimilated nitrogen was less as a result of lower feeding rates. Adults on L. indica were more successful than those on E. japonica, used carbon more efficiently, and assimilated higher quantities of both carbon and nitrogen. Efficiencies of nutrient utilization were high for E. coagulata compared to other types of insects with assimilation efficiencies of specific compounds often exceeding 90%.
653 PB 031 ENHANCEMENT OF NUTRIENT UPTAKE IN LACTUCA SATIVA BY THIAMIN APPLICATIONS
Authors: Martens D. A. , Sanchez C.
Published: February 2019

Incorporation of specific vitamins such as thiamin to the rooting media has been reported to stimulate root and shoot growth. Thiamin is involved in the Kreps cycle decarboxylation of pyruvate to citrate as a coenzyme in the pyruvate decarboxylase enzyme complex. Axenic and soil glasshouse studies were conducted to determine the tissue nutrient concentrations (ICP analysis), especially Ca, in response to low application rates of thiamin. In a 50 d axenic “Grand Rapids” lettuce study, thiamin (5 mg mL-1 0.5 N Hoagland's) stimulated shoot length (25%), root length (23%), Ca (8%), K (14%), and P uptake (18%) compared with control values (no thiamin added). Soil glasshouse “Grand Rapids” lettuce studies showed that thiamin (6 mg kg-1 soil) stimulated N (72%), Ca (58%). K (12%), and P uptake (11%) compared with control values. Additional glasshouse-soil-thiamin form studies with “Black seeded Simpson” lettuce (20 mg each form kg-i soil) showed thiamin compounds increased Ca tissue levels from 3 to 10% and organic C content from 5 to 30%. The prospect of using these compounds to reduce tipburn in lettuce is being investigated in follow-up studies.
654 PB 034 EVALUATION OF CHLOROPHYLL METER READINGS FOR ASSESSING THE N STATUS OF LETTUCE
Authors: Wilcox M. , Sanchez C.A. , Blackmer T.M.
Published: February 2019

Several studies in the midwestem United States have shown that chlorophyll meter readings (Minolta SPAD 502) are useful in determining the N status of corn (Zea Mays L.), and show promise as a tool for the efficient N management of corn. Studies were conducted to evaluate the potential of the `chlorophyll meter for evaluating N deficiencies in lettuce (Lactuca sativa L.). Data for chlorophyll meter readings, midrib nitrate-N, lettuce growth rate, and marketable lettuce yield were collected in five N fertility experiments in 1993 and 1994. Chlorophyll meter readings not only varied among lettuce types (butter, cos, leaf, crisphead), but also among cultivars of the crisphead type. Chlorophyll meter readings were generally poorly correlated to midrib nitrate-N levels and marketable lettuce yield. Lettuce leaves have more color variation than corn leaves, and perhaps this variation in relation to the small sensor size on the SPAD 502 confounded readings. The observation that subtle N deficiencies in lettuce are usually manifested in growth rate reduction rather than abrupt color changes may also limit the usefulness of the chlorophyll meter for lettuce.
656 PB 040 PHOSPHORUS FERTILIZER ALTERS DEPTH OF ROOT SYSTEM DEVELOPMENT IN FOUR POTATO CULTIVARS
Authors: Warncke Darryl D. , Evans William B.
Published: February 2019

Phosphorus applications can increase potato yields in Michigan soils with over 400 kg·ha-1 Bray-Kurtz P1 extractable P. Four potato cultivars (Onaway (On), Kennebec (Ke), Russet Norkotah (RN), and Snowden (Sn)) were planted on 7 May 1993 to study P fertilizer effects on root growth and development. Each plot received adequate N & K, and either 0 or 50 kg·ha-1 P. Two minirhizotrons (5 cm i.d.) were set 1.1 m deep at 45° to the soil surface into each plot. P treatment did not influence tuber yield. At 65 days after planting, root counts for On, RN and Sn averaged 72, 44 and 58%. respectively, of those in Ke plots. The P treatment did not significantly influence total root counts within or across cultivars on any of five sampling dates. More visible roots were produced in the first 0.4 m of soil by plants receiving P than by plants not receiving P. Below the first 0.4 m, plants not fertilized with P produced more visible roots than those receiving P.
658 PB 066 EVALUATION OF PREPLANT AND FERTIGATED NITROGEN ON YIELD OF DRIP-IRRIGATED BELL PEPPERS
Authors: Tietien W.H. , Nitzsche P. , Cowgill W.P.
Published: February 2019

Environmental concerns about nitrate contamination of groundwater have prompted renewed interest in optimizing fertilizer rates. A field study was initiated to study the influence of preplant and drip fertigation rates of nitrogen on the yield of hell peppers grown on Quakertown (QkB) silt loam soil. Preplant nitrogen rates of 0, 56.7, and 113.5 kgha were incorporated into the plots before transplanting. The three fertigation rates (0, 17 and 34 Kg/mulched hectare) were injected through the drip irrigation starting one week after transplanting and repeated at three week intervals.

Proplant nitrogen applications variably influenced early pepper yield. and did not significantly influence total yield. Early pepper yield was not influenced by drip fertigation rate, however, total yield increased as the fertigation rate increased. The dry weather conditions of the 1993 growing season may have influenced the responsc of pepper yield to the fertilizer treatments. Further studies are required to determine the optimum fertilization program for bell peppers grown under Northern New Jersey's edaphic conditions.
661 PB 075 POLYMORPHIC DNA PROFILES AID IN DISTINGUISHING PETUNIA SPECIES
Authors: Cerny Teresa A. , Starman Terri W.
Published: February 2019

Our overall objective was to use DNA Amplification Fingerprinting (DAF) to determine the relationships between Petunia × hybrida and four wild petunia species,P. axillaris, P. inflata, P. parodii, and P. violacea. This research was to optimize the DAF amplification reaction for petunias, check for variability in the fingerprints among different seedlings of the same species and screen primers to be used for Identifying polymorphisms between cultivars of P. × hybrida end the four wild species. Optimization of the DAF procedure was accomplished by varying concentrations of DNA template (O - 10 ng), MgCl2(0 - 10 mM), and primers (0 - 30 μM). Optimum concentrations were found to be 1.0 ng DNA template and 2.0 mM MgCl2. Clearly resolved banding patterns were produced using primer concentrations from 3.0 μM to 30 μM. When separate seedlings of each wild species from the same seed source were fingerprinted, profiles were consistent. Seeds from other sources are presently being collected to investigate variation between sources. Twenty-five heptamer and octomer primers varying in GC content were screened and ten produced clear banding patterns for the Petunia species. These primers have produced polymorphic profiles between the pink-flowering species and the white-flowering species. Several primers have shown distinct polymorphisms between P. axillaris and P. parodii, the two white-flowering species, which have very similar morphological traits. Similarities in the banding patterns have been found between P. × hybrida and these wild species.
664 PB 104 AGROBACTERIUM INFECTION OF WHITE ASH (FRAXINUS AMERICANA L.)
Authors: Bates Sharon A. , Preece John E. , Yopp John H.
Published: February 2019

Both greenhouse-grown white ash plants derived from tissue culture and rooted microshoots in high humidity trays were inoculated with 11 tumor-inducing Agrobacterium strains. Eight strains stimulated mutative gall formation. Plants inoculated with strain A281 exhibited a higher frequency of callus formation (greenhouse-22.2%; microshoots-18.8%) than other strains at the site of the wound. Therefore, strain A281 was used to inoculate seed and seedling explants in vitro. Explants were placed on MS medium containiner no plant growth regulators and inoculated at 0, 3, 5, 7, or 10 days after initiation. Plants inoculated at 10 days showed a higher frequency of callus formation (16.4%) than with earlier inoculations. Also, rewounding of the explant at inoculation resulted in a higher frequency of callus formation (11.3%) compared to not rewounding the explant (3.9%).
668 PB 116 Genetic Linkage Mapping in Prunus
Authors: Foolad M.R. , Arulsekar S. , Bliss F.
Published: February 2019

A genetic linkage map of Prunus has been constructed using an interspecific F2 population generated from self-pollinating a single F1 plant of a cross between a dwarf peach selection (54P455) and an almond cultivar (Padre). This map consists of approximately 80 markers including 10 isozymes. 12 plum genomic, 19 almond genomic and 40 peach mesocarp specific cDNA clones. The backbone map will be used for identifying the genomic locations and characterization of genes governing important economic traits in the genus Prunus. Of particular interests are those genes associated with fruit ripening and mesocarp development in peach and almond.
670 PB 142 PHYLOGENETIC RELATIONSHIPS OF CULTIVATED PRUNUS SPECIES FROMAN ANALYSIS OF HYPERVARIABLE CHLOROPLAST DNA
Authors: Badenes Maria L. , Parfitt Dan E.
Published: February 2019

Chloroplast DNA (cpDNA) mutations in 7 cultivated Prunus species were compared to establish the phylogenetic relationship among them. Mutations were detected in 3.2 kb and 1.5 kb regions of hypervariable cpDNA, amplified and cut with 21 and 10 restriction endonucleases, respectively, to reveal polymorphisms. Parsimony and cluster analyses were performed. Two groups of species, P. persica and P. dulcis and P. domestica and P. salicina were completely monophyletic. The subgenus Cerasus was the most recently derived, while the subgenus Amygdalus was the most ancestral and somewhat separate from the rest of Prunus. The results also suggest that the rate of mutation in the Cerasus chloroplast genome is significantly greater than for the other subgenera sampled.
671 PB 145 GENETIC LINKAGE MAPPING IN PEACH
Authors: Rajapakse S. , Belthoff L. E. , Ballard R. E. , Scorza R. , Baird W.V. , Monet R. , Abbott A. G.
Published: February 2019

We have constructed a genetic linkage map of peach consisting of RFLP, RAPD, and morphological markers, based on 78 F2 individuals derived from the self-fertilization of four F1 individuals originating from a cross between `New Jersey Pillar' and KV 77119. This progeny set was chosen because parental genotypes exhibit variation in canopy shape, fruit flesh color, and flower petal color, size, and number. The segregation of 81 markers comprised of RFLP, RAPD and morphological loci was analyzed. Low copy genomic and cDNA probes were used in the RFLP analysis. The current genetic map for the WV family contains 57 markers assigned to 9 linkage groups, which cover 520 cM of the peach nuclear genome. The average distance between two adjacent markers was 9 cM. Linkage was detected between Pillar (Pi) and double flowers (Dl). RFLP markers loosely linked to Pi, flesh color (Y), and white flower (W) loci were found. Twenty-four markers remain unassigned.
674 PB 154 DEVELOPMENT OF AN RFLP MAP FOR WALNUT
Authors: Fjellstrom Robert G. , Parfitt Dan E.
Published: February 2019

32 cloned probes from a walnut (Juglans sp.) PstI random genomic library were used to develop a linkage map for walnut. Low copy number walnut random genomic DNA probes were constructed and hybridized to restriction endonuclease digested DNA from parent walnut trees from a backcross of (J. hindsii × J. regia) with J. regia to identify parental polymorphism. 63 backcross progeny were analyzed to determine the inheritance and linkage of 48 RFLP loci. 66% of the probes detected duplicated, but unlinked loci. 42 of the RFLP loci could be placed on 12 linkage groups. The other 6 loci could not be placed on common linkage groups. (Theoretical maximum number of linkage groups is 16.) A Poisson probability method for estimating genome size was utilized to calculate the approximate walnut genome length as 1660 cm and to estimate that 138 markers would be needed to cover 95% the walnut genome within 20 cM of each marker.
676 PB 160 IDENTIFICATION AND CLASSIFICATION OF PISTACHIO (Pistacia vera L.) CULTIVARS WITH RAPD MARKERS
Authors: Hormaza J.I. , Dollo L. , Polito V.S.
Published: February 2019

The Random Amplified Polymorphic DNA (RAPD) technique was used to characterize 15 cultivars of pistachio (Pistacia vera L.). A total of 37 polymorphic markers were considered in this study. Each cultivar exhibited a unique molecular phenotype and, as a consequence, can be uniquely fingerprinted. A similarity and cluster analysis based on the amplified fragments produced two distinct groups which are consistent with the known geographical origin of the cultivars. Our results suggest that RAPD analysis can provide a new alternative for cultivar identification and classification of pistachio.
679 PB 189 USE OF RAPDS IN ANNONA SPECIES
Authors: Ronning Catherine M. , Schnell Raymond J. , Gazit Shmuel
Published: February 2019

The native American genus Annona contains many species that are cultivated in the tropics and subtropics for their edible fruit, including the custard apple (A. reticulata), soursop (A. muricata), cherimoya (A. cherimola), sugar apple (A. squamosa), and the interspecific hybrid, Atemoya. Random Amplified Polymorphic DNA (KAPD) analysis of the A. cherimola cultivars `Jete' and `Campa, 1A. squamosa `Lessard', and the Atemoya cultivars `Ubranitzki', `Mallali', and `Kaspi' resulted in very distinctive patterns, indicating that RAPD markers are an easy, efficient method of fingerprinting Annona species. Thirteen of 15 primers gave repeatable, polymorphic patterns. An F1 population of `Jete' × `Lessard' as well as selfed populations of `Jete' and of `Lessard' were analyzed to determine the inheritance of the KAPD banding patterns. The results indicate that PAPD analysis can be used in genetic and phylogenetic studies of Annona species.
681 PB 195 MOLECULAR CHARACTERIZATION OF A cDNA THAT ENCODES 5-AMINOLEVULINIC ACID DEHYDRATASE IN TOMATO
Authors: Polkinz Gary F. , Hannapel David J. , Gladon Richard J.
Published: February 2019

Tomato fruit ripening is characterized by a decrease in chlorophyll content and an increase in lycopene synthesis. We are interested in the role of chlorophyll metabolism as it relates to tomato fruit ripening. 5-Aminolevulinic acid dehydratase (ALAD) is the first committed enzyme in the chlorophyll biosynthetic pathway, and it catalyzes the conversion of two 5-aminolevulinic acid molecules into porphobilinogen. We have isolated a full-length tomato ALAD cDNA clone from a tomato fruit library. Sequence analysis showed that this tomato ALAD was highly homologous to ALAD found in spinach and pea, and the analysis predicted a protein of 46.8 kDa. Southern analysis indicated that 1 to 3 copies of the ALAD gene are present in the tomato genome. Northern analysis suggested that the gene is expressed constitutively throughout tomato fruit development. Currently, we are subcloning the fragment into an E. coli expression vector in order to obtain protein for antibody production for Western analysis.
682 PB 198 NICOTIANA FIXATION FOR IMMUNO-LOCALIZATION OF IPTASE
Authors: Rogers Greg S. , Frett John
Published: February 2019

A problem in immunocytochemistry is obtaining acceptable fixation of tissue while retaining antigenicity. Two concentrations (1% and 2.5%) of glutaraldehyde, with and without secondary fixation in 1% Osmium Tetroxide (OsO4) and varying fixation times were used.

Fixation in 1% glutanddehyde for 3 h was adequate to preserve the tissue. Some loss of fine structure was visible under an electron microscope. A solution of 2.5% glutaraldehyde was more effective in preserving fine structure. At 2 h fixation the tissue was well preserved and only slight loss of tine detail was observed. A longer fixation results in better ultrastructural preservation, but can cause loss of antigenicity.

OsO4 fixes lipids and acts as an electron dense stain. OsO4 has a negative effect on antigenicity. The use of OsO4 had little effect upon the preservation of ultrastructural detail and-did not improve staining; therefore, it was omitted in later fixations. Based on this experimental evidence, initial localization experiments will utilize tissue fixed in 1% glutaraldehyde for 3 h.
683 PB 221 IDENTIFICATION OF MOLECULAR MARKERS LINKED TO LOW-TEMPERATURE RESPONSES
Authors: Teutonico Rita A. , Palta Jiwan P. , Osborn Tom C.
Published: February 2019

Identification of the genes involved in freezing tolerance in oilseed Erussica could lead to genetic improvement of winter survival of this crop and other species, as well as provide greater understanding of the basis of cold stress tolerance in plants. We developed a genetic linkage map for B. rapa using restriction fragment length polymorphisms (RFLPs) and identified molecular markers which are linked to genes controlling vernalization requirement and freezing tolerance. We mapped the location of a group of cold-regulated (`cor') genes from Arabidopsis thaliana in this population and determined their association with freezing tolerance and vernalization requirement. We developed genetically fixed, recombinant inbred lines of B. rapa to assay the physiological processes involved in these cold responses. Specifically, we measured the differences in lipid composition of the plasma membranes of acclimated and nonacclimated plants of a subset of this population. We will determine if the genes involved in the physiological responses to cold temperature are also associated with the acquisition of freezing tolerance.
683 PB 236 WATER STRESS REDUCES ASPARAGUS GROWTH
Authors: Drost Dan
Published: February 2019

In 1992, a long term study was initiated to determine water use of asparagus and to assess water stress effects on asparagus growth. Asparagus (Syn 4-56) crowns were planted and maintained at soil moisture levels near field capacity during the first year. In 1993, irrigation treatments based on 60, 40, and 0 percent of evapotranspiration (ET) were applied to asparagus during the fern growing period (mid-June to October). Soil moisture, shoot and root growth, and fern water potentials were measured throughout the year. Prior to the irrigation treatments, asparagus had 39 buds per plant with a shoot and root fresh weight of 573 and 270 grams, respectively. Soil moisture in the root zone (0 to 60 cm) approached the permanent wilting point in the 40%. and 0% of ET treatments by mid-August. A decrease in irrigation rate from 80 to 0% of ET had no effect on fern fresh weight at the end of the growing season. However, as irrigation rate decreased from 80 to 0% of ET, root fresh weight (586, 533, 415 grams) and bud number (78, 59, 53) decreased linearly. These results suggest yield and growth may be reduced in 1994.
690 PB 262 EFFECT OF IRRIGATION ON THE YIELD AND YIELD COMPONENTS OF TOMATO
Authors: Smeal Daniel , Gregory E.J. , Arnold R.N. , Tomko J.
Published: February 2019

A single sprinkler line-source was used to provide irrigation treatments to three tomato (Lycopersicon escu Mill.) varieties (`Baja', `Rowpac', and `Roza') during 1988 and 1989 in northwestern New Mexico. In both years, marketable fruit yield (Y) of all varieties increased linearly with increased irrigation (1). However, the regression coefficients describing the Y vs. I relationship differed with variety and year. In 1989, `Rowpac' Y ranged from 40.3 to 114.2 Mg ha-1 at levels of 31.5 and 62.5 cm, respectively. Yields of `Baja' and `Roza', while similar to those of `Rowpac' at low I levels, were 59% and 71% of `Rowpac' Y, respectively, at the highest level of irrigation. At any given I level, Y was lower in 1988 than in 1989. While average weight per fruit (wt/fruit) and number of fruit per plant (no/plant) increased with increasing I level in all varieties, increased Y in `Rowpac' had a higher positive correlation with no/plant (40 to 90) than with wt/fruit (85 to 120 g). Increasing Y in `Baja' on the other hand, correlated much better with increased wt/plant (100 to 195 g) than no/plant (20 to 45).
691 PB 265 DRIP IRRIGATION AND FERTIGATION MANAGEMENT CAN MINIMIZE NITRATE LEACHING LOSSES
Authors: Hartz T.K.
Published: February 2019

Trials were conducted under California field conditions examining the impact of drip irrigation and nitrogen fertigation regime on in-season NO3-N leaching losses. Six field studies were conducted, 4 on tomato and 2 on pepper. Seasonal fertigation ranged from 0-440 kg N/ha; irrigation was applied 3X per week, with leaching fractions of 10-25% of applied water. NO3-N leaching losses were estimated both by suction lysimetry and the use of buried anion resin traps. A similar pattern was seen in all trials. From transplant establishment until early fruit set soil solution at 0.8 m had relatively high NO3-N concentration (>30 mg/liter), which declined as the season progressed; in the month before harvest soil solution NO3-N at 0.8 m was consistently below 10 mg/liter (tomato) and 15 mg/liter (pepper) in appropriately fertilized plots. Seasonal NO3-N leaching estimates were generally below 25 kg/ha (tomato) and 35 kg/ha (pepper), with only modest differences among fertigation regimes. These results suggest that well managed drip irrigation can minimize in-season NO3-N leaching.
693 PB 271 ROOT DISTRIBUTION OF MATURE ORANGE TREES FOLLOWING CONVERSION FROM FLOOD TO PRESSURIZED IRRIGATION
Authors: Wright G. C. , Roth R. L. , Gardner B. R.
Published: February 2019

Mature `Campbell Nucellar Valencia' trees were converted from border flood irrigation to four pressurized irrigation systems. A border flood irrigation treatment was included as a control. Four years later, roots were collected from 62 holes (10 cm diameter × 120 cm) on a 60 cm grid on one side of each treated tree. For trickle irrigated trees, the highest concentration of roots was found around the emitters, particularly at 30 to 90 cm deep, but some roots appeared to be located below the 120 cm depth. Root distribution was similar for the basin irrigated trees, but the highest concentration of roots was found in a larger wetted area near the tree trunk. This treatment had the highest root concentrations, compared to all other treatments. Root distribution of trees irrigated by spray irrigation was similar to the basin treatment, except that root spread was not as extensive. Roots of trees irrigated by sprinkler and flood were distributed more randomly, and were more likely to extend past the drip line, compared to the other treatments. Root concentrations also declined with increasing depth.
694 PB 270 DESICCATION AVOIDANCE OF APPLE TREES WITH N-2001 ANTITRANSPIRANT
Authors: Guak Sung H. , Shin Charles C. , Fuchigami L. H.
Published: February 2019

Antitranspirant N-2001 (10%), Great Lakes Chemical Corporation, was applied as a soil drench to `Fuji'/EMLA7' apple plants growing in 15 cm pots in a 25/22±3°C (D/N) greenhouse. After bringing pots to field capacity, chemical application was made and water was withheld thereafter. One hour after chemical application, stomatal conductance of treated and control plants was 0.25 and 0.70 cm/sec, respectively. Stomatal conductance of treated plants was maintained at approximately 0.25 cm/sec throughout the test period (28 days). Stomatal conductance of the control plants decreased to 0.25 cm/sec 13 days after treatment due to desiccation. The stem xylem water potential of the treated and control plants was -2.0 and -5.5 MPa, respectively, 28 days after treatment. The relative water content of leaves of treated plants was 45% greater than controls. The average loss of water via transpiration of treated plants was 32% less than the control plants.
697 PB 303 POINSETTIA WATER USE INFLUENCED BY ENVIRONMENTAL CONDITIONS AND NUTRIENT SOLUTION CONCENTRATION
Authors: McAvoy Richard J. , Bible Bernard B. , Yang Xiusheng
Published: February 2019

Poinsettias were grown in a closed hydroponic system with a modified Hoagland's solution concentration of either 1 or 3 mS·cm-1. Water use and whole plant fresh mass were measured gravimetrically at 2 to 3 day intervals over an eleven week period (initial break development through full bract development). At two week intervals, poinsettias were harvested and the fresh and dry mass of leaves, bracts stems, and roots were determined, and total laminar surface area was measured. Leaf temperature (LT), root-zone solution temperature (RZT), and at canopy level, air temperature (CAT), VPD, and photosynthetic photon flux (PPF) were monitored at 1 mm intervals and mean values recorded each 30 mm using a 21X micrologger (Campbell Scientific, Logan Utah). Water use (ml·dm-2·day-1) averaged 15% higher for poinsettias grown in the 1 mS·cm-1 solution than in the 3 mS·cm-1 nutrient solution. Simple linear regression of daily water use with PPF, or VPD, or CAT, while significant, accounted for less than half of the daily fluctuation in water use (r2; PPF= 0.47, VPD=0.21, CAT=0.30). However, multiple regression involving daily PPF, VPD, CAT, RZT and LT accounted for up to 82% of the variation in daily water use.
698 PB 306 WETTABILITY AND SURFACE TENSION OF FRUIT SURFACES
Authors: Cisneros-Zevallos L. , Saltveit M. E. , Krochta J. M
Published: February 2019

Nettability is an important factor to be considered in postharvest treatments such as washing, aqueous dippings, coatings, etc. Pome fruits (ten apple and four pear cultivars) and stone fruits (nectarine and plums) were evaluated for wetting behavior and surface tension at room temperature. Nettability was assessed by measuring contact angles of water. Surface tension was calculated by measuring contact angles of methylene iodide and water or by a series of pure surfactants using Zisman's method. Wetting behavior on apple fruits depended on cultivar, with water contact angles ranging from 75° to 131°. For pear fruits, wetting also depended on cultivar. Calculated surface tensions of pear fruits were in general higher than most apple cultivars tested. In stone fruits, plums presented a high water-repellency with a contact angle of 137°.

The wetting of fruit surfaces seems to be governed by the nature of the chemical groups exposed on the surface of the cuticle and also by the surface roughness, as evidenced by tire high values of some contact angles.
699 PB 309 THE MODE OF CO2 ACTION ON ACC OXIDASE AND ITS ROLE IN INHIBITION OF ETHYLENE BIOSYNTHESIS
Authors: Gorny James R. , Kader Adel A.
Published: February 2019

Ethylene biosynthesis of Golden Delicious apple fruit at 20°C is rapidly inhibited by a controlled atmosphere of air + 20% CO2. However, in vitro ACC oxidase activity and ACC content were not significantly different between air and air + 20% CO2 treated fruit, To determine the in vivo effects of CO2 treatment, both in vivo and in vitro enzyme activity essays were performed in en atmosphere of air or air + 20% CO2. Western blots were also performed to quantify the amount of ACC oxidase protein present in the air and air + 20% CO2 treated fruit.

We believe that in vivo cytosolic pH changes, induced by CO2, may reduce the in vivo catalytic capacity of ACC oxidase, end hence significantly reduce ethylene biosynthesis in climacteric tissue,
703 PB 341 THE RELATIONSHIP BETWEEN FRUIT ELASTICITY, INTERNAL CARBON DIOXIDE AND STANDARD MATURITY INDICES FOR APPLE FRUIT ATTACHED TO THE TREE
Authors: Beaudry Randolph , Armstrong Paul , Brown Galen
Published: February 2019

Elasticity, internal C2H4, CO2, and O2, diameter, firmness, and starch index were determined for ripening `McIntosh', `Red Delicious' and `Golden Delicious' apple fruit. Elasticity, measured by the acoustic impulse response of the apple, has previously been found to correlate with fruit firmness after harvest (Armstrong and Brown, 1992) and was studied as a possible index of apple harvest maturity because it is a rapid, non-destructive measurement that could be adapted for field use. However, elasticity did not correlate with firmness or other maturity parameters for fruit attached to the tree. Fruit temperature influenced internal gas levels, probably due to its effect on metabolic activity. An increase in the temperature-compensated internal CO2 level occurred for fruit having an elevated internal C2H4 concentration (> 0.02 μl/L), which suggested that the climacteric respiratory increase associated with ripening occurred while fruit were attached to the tree.
704 PB 344 EFFECT OF METHYL JASMOMATE ON ETHYLENE PRODUCTION AND VOLATILE SYNTHESIS DURING RIPENING OF `SUMMER RED' APPLES
Authors: Fan Xuetone , Mattheis James P.
Published: February 2019

Jasmonic acid and its methyl ester (methyl jasmonate), regarded as putative plant growth regulators, are naturally occurring in higher plants and present in a variety of plant organs including apple fruit. Pre- and post-climacteric `Summer Red' apples were exposed for 12 hrs to a low concentration (25ul/4L) of atmospheric methyl jasmonate. Ethylene and volatile production were measured with GC/MS at harvest and through 15 days at 20°C after treatment. Forty eight headspace volatile compounds were identified and quantified. Results showed that methyl jasmonate effects depended on stage of fruit development. Methyl jasmonate stimulated ethylene, ester, alcohol, and acid productions in preclimacteric fruits while no significant effects were observed on postclimacteric fruits. Ketone and aldehyde volatile evolutions were not significantly affected by methyl jasmonate regardless of harvest date.
709 PB 359 SPECTROPHOTOMETRIC CHARACTERIZATION OF STORAGE SCALD DISORDER IN BARTLETT, PACKHAM'S TRIUMPHED `ANJOU' PEAR FRUIT VARIETIES
Authors: Zoffoli Juan P. , Richardson Daryl , Sugar David , Chen Paul
Published: February 2019

The brown color development on the skin of three varieties of pears (Bartllet, Packham's T. and Anjou) was characterized between 200 and 300 nm from hexane extracts of pear peel discs, with and without the application of the antioxidant Ethoxyquin (2700ppm) during -1°C storage and 20°C ripening. All the varieties presented a main peak at 232nm (afarnesene), which decreased in the storage as scald increased.

Absorbance at 259, 269, and 280nm (conjugated trienes) were characteristic of Anjou and Packham's Triumph fruits susceptible to the disorder. Bartlett fruits had a major peak at 259nm without the other secondary peaks.

The application of ethoxyquin reduced the oxidation of a farnesene, the formation of the conjugated trienes and intensity of scald in Packham's Triumph and Anjou fruits. However in Bartlett fruits this antioxidant was not very effective to reduce the scald.
711 PB 385 EFFECTS OF TEMPERATURE, GAS COMPOSITION, AND STORAGE ON THE O2CONSUMPTION OF `RED GOLD' NECTARINES
Authors: Omary Maria B. , Testin Robert F. , Rajapakse Nihal C.
Published: February 2019

The influence of 3 temperatures (1, 10 and 25°C). 9 combinations of initial O2 (5, 10 and 20%) and CO2 (0, 10 and 20%) concentrations, and 3 storage durations at 1°C (2, 13 and 24 days) on the O2 consumption of `Red Gold' nectarines was investigated. Fruits were sealed in glass jars, flushed with respective gas mixtures and stored in dark incubators maintained at 1, 10 or 25°C. Head space O2 concentration was monitored at selected intervals until it dropped down to 1% or less. The oxygen consumption rate decreased significantly with decrease in temperature and initial O2 concentration. The O2 consumption rate increased as storage duration increased. The range of initial CO2 concentrations used in this study had no effect on O2 consumption rate. An empirical model was developed to estimate O2 consumption rate of `Red Gold' nectarines as a function of temperature, initial O2 and CO2 concentrations and storage duration.
712 PB 388 PACKINGHOUSE OPERATIONS AFFECT PEACH QUALITY DURING STORAGE
Authors: Rodriguez-Felix Armida , Araiza-Lizarde Evelia , Villegas-Ochoa Monica A. , Brineas-Taddei Elsa
Published: February 2019

`Flordaprince' peach quality characteristics were evaluated during cold storage after passing thru different packinghouse operations. Fruits were sampled at three points in a commercial packinghouse as follows: (A) upon arrival at a peach packinghouse, (B) after hydrocooling, and (C) after grading and sorting. After sampling, fruits were stored at 2 C (90 % R.H.) for 0, 15, and 30 days. Following the cold storage periods, fruits were transferred to 20 C. Quality characteristics evaluated during cold storage or marketing conditions consisted of weight loss, firmness, skin color (hue), total soluble solids, titratable acidity, respiration rate, and ethylene production. Peaches stored for 27 days at 2 C had up to 40% weight loss. Additional weight loss was observed during marketing conditions at 20 C (up to 70 % weight loss). Selected peaches after grading and sorting (point C) had the highest weight loss during storage at 2 C, as compared to the other two sampling points. Flesh firmness decreased significantly after 3 days storage at 20 C in all representative points. Weight loss and firmness were the quality attributes that mainly affect peach storage life.
713 PB 391 RELATIONSHIP OF MACRO-MINERAL NUTRITION ON FRUIT POSTHARVEST PERFORMANCE IN `HAYWARD' KIWIFRUIT
Authors: Gu Sanliang , Johnson R. Scott , Christo Carlos H. , Cochran Robert C. , Garner David
Published: February 2019

Fruit from 8 `Hayward' kiwifruit vineyards in central California were harvested at 2 week intervals after soluble solids content (SSC) reached 6% and subjected to 4 and 6 months of storage at 0°C in an ethylene free environment. Macro-nutrients were analyzed from leaf and fruit tissues. Leaf petiole N and NO3--N were 2 to 3 times higher for vines that had softer fruit after long-term storage. Where the correlations were significant, fruit firmness and SSC were correlated negatively with N, P, K, Cl, and N/Ca and positively with Ca and Mg of leaf and fruit tissues. The significance of the correlations depended on the harvest maturity and growing locations. Soil nitrogen application increased Mg and reduced Ca and Cl in lamina but did not influence macro-nutrients in fruit tissues.
716 PB 400 THE EFFECT OF PACKING DELAYS ON THE FRUIT QUALITY OF VALENCIA ORANGES
Authors: Gottlieb M. L. , Arpaia M. L.
Published: February 2019

A major outlet for California Valencia orange fruit is the export market. Transit time to Pacific Rim markets varies from ca. 20 to 40 days. This coupled with delays in packing and cooling ranging from 1 to 3 days may negatively affect fruit quality at the destination market. A study was conducted which examined cooling/packing delays (6, 24, 48, 72 hrs), storage temperature (5, 11C) and duration (3, 6 wks) following packing to evaluate the effect of these factors on the postharvest quality of Valencia orange. The following parameters were monitored: peel penetration force, peel color (L*, Chroma, Hueo), weight loss, external appearance (0-5), decay, and changes in carton pack height. Weight loss prior to packing was directly related to the duration of the prepack delay. This relationship, however, did not continue through storage and simulated marketing. Fruit subjected to delayed packing, however, had lower pack heights and higher external ratings following storage. Storage at 11C resulted in decreased penetration force, higher levels of decay and greater color development and weight loss. Storage for 6 weeks resulted in decreased penetration force, higher weight loss and greater color development.
721 PB 435 EFFECT OF ANAEROBIC CONDITIONS ON VOLATILE COMPOUNDS OF RIPENING BANANA
Authors: Chantrachit Theeranuch , Richardson Daryl G.
Published: February 2019

Ripening bananas (color stage 5) were placed in closed jars held at 20°C. Nitrogen (99.99%, 100 ml/min) or air were flowed through the jars. SPME (Solid Phase Micro Extraction) was used for sampling dynamic headspace and analyzed by GC-MS and GC-FID. Several volatile compounds decreased with time in the nitrogen treatment. Production of isobutyl butyrate, 3-methyl-1-butanol, methyl heptanoate, pentyl acetate, and 2-pentanol which were present in air treatments, were absent in the nitrogen treatment. Ethanol rapidly increased until the last day. Off-flavors were detected by most panelists after three days of N2 treatment and off-flavors increased in the following days. Reversibility of off-flavor after exposing the bananas to air was not detected by panelists. Correlations were low between the main compounds in the nitrogen treatment and the off-flavor score.
731 PB 501 INTERGRATING MICROWAVE FOOD PROCESSING INTO PLANTAIN UTILIZATION
Authors: Smith-Kayode O.
Published: February 2019

Plantain (Musa parasidiaca), a staple among estimated 70 million Africans and popular item in the tropics is emerging as specialty ethnic food product in developed countries. It is suitable as menu item for food service particularly in the ripe form when deep oil fried. The perishability of the fruit is a major constraint to wide spread use and distribution. To expand the utilization base in the food service industry, microwave heating process was applied to tempering and cooking of frozen pre-fried slices. The purpose of this is to determine the effect of the process on warmed over properties and acceptability of fried plantain. Large surface area and spherical shape were critical physical factors in the heating thus providing good quality product from taste, texture and appearance standpoint
735 PB 029 SORGOLEONE: A PHOTOSYSTEM II INHIBITOR PRODUCED BY SORGHUM BICOLOR
Authors: Weston Leslie A. , Gonzalez Verónica M.
Published: February 2019

Sorgoleone, the oxidized quinone form of a hydrophobic p-benzoquinone was first isolated from Sorghum root exudates. Sorgoleone is a potent inhibitor of growth in several annual weed species and causes tissue bleaching at concentrations of <25 μ M. These investigations were designed to determine if soreoleone's allelopathic activity was related to an inhibition of photosynthetic electron transport. The effect of sorgoleone versus DCMU (diuron) on inhibition of O2 evolution by broken wheat thylakoids, and in oxygenevolving PSII membranes containing QA and QB primary and secondary electron acceptors in PSII was determined. Sorgoleone was a potent inhibitor of O2 evolution in this system with ∼ 0.04 and 0.78 μ M concentrations required for 50 and 100% inhibition as compared to -0.11 and 2.0 μ M DCMU, respectively. Sorgoleone caused no significant inhibition of PSI mediated photooxidation of ascorbate/dichlorophenolindophenol, establishing that the locus of inhibition by sorgoleone was within the PSII complex. The effect of trypsin treatment of chloroplasts and PSII membranes on sensitivity to inhibition by DCMU and sorgoleone was examined. The comparison of DCMU and sorgoleone upon the formation and decay of flash-induced chlorophyll a variable fluorescence indicates that sorgoleone specifically inhibited the oxidation of QA by QB.
744 PB 076 IDENTIFICATION OF BOTH ACID AND NEUTRAL INVERTASE ACTIVITY IN DEVELOPING STRAWBERRY FRUIT
Authors: Pomper Kirk W. , Breen Patrick J.
Published: February 2019

Invertase (INV) may influence sugar levels and assimilate transport in strawberry fruit. Several groups, including our own, have only detected acid INV (optimum pH 4.6) in strawberry fruit, however, recently Hubbard et al. (Physiol. Plant. 82:191-196, 1991) reported the presence of a neutral INV (pH 7.5). Since dissimilar isolation protocols may have contributed to the different findings, we re-examined our work with developing `Brighton' strawberry using the extraction procedure of Hubbard et al. Neutral INV activity per gFW (pH 7.5-8.0) increased many fold as fruit developed from green to the red ripe stage. Acid INV activity decreased markedly from green-white to the red stage. In addition, when fruit extracts were precipitated with cold acetone, a pellet contained 60% of the acid INV activity, and a surface coagulation of protein contained 60% of the neutral INV activity. This allowed easy separation of these two enzymes. Extraction methodologies affect isolation of neutral INV activity from strawberry fruit.