bluuebunny/crossref_metadata_2025 huggingface dataset:
Foliar Nitrogen Fertilization of Citrus in Florida
Authors: Bondada B.R. , Syvertsen J.P. , Albrigo L. , Alva A. , Petracek P.
Published: February 2019

Foliar applications of urea nitrogen (N) is a relatively new practice in Florida citrus production resulting from applied research and changes in citrus fertilizer management philosophy. The present study investigated the effect of leaf age and surface morphology on leaf wettability as measured by contact angles, and absorption efficiency of foliar-applied N. Young leaves (0.25 and 1 month) were more efficient than old leaves in the absorption of foliar-applied N. Contact angles of water, urea-, and triazone-N solutions were low in the young leaves. The adaxial surfaces had lower contact angles than abaxial surfaces in each leaf age group. Inefficient N absorption and large contact angles in old leaves (3 and 6 months) were related to surface wax deposition and cuticle thickness, which increased with leaf age. 15N- and 14C-labeled urea are being used to determine precisely how the cuticle and wax affect foliar N absorption in citrus leaves.
Fertilization of Young `Hamlin' Orange Trees with Controlled-release Fertilizer
Authors: Ferguson J.J. , Davies F.S.
Published: February 2019

Young `Hamlin' orange trees [Citrus sinensis (L.) Osbeck] were fertilized six times/year with water-soluble N fertilizer at recommended rates (0.20, 0.34, and 0.38 kg N/tree per year) and with controlled-release fertilizer one time/year [Osmocote, IDBU, and a 44.5% urea-N fertilizer coated with a sulfonated ethylene-propylene-diene polymer (Sherritt, Inc.)] at 0.04, 0.06, and 0.08 kg N/tree per year for years 1, 2, and 3, respectively. There were no differences in trunk diameter, tree height, or tree rating among treatments in any year, although there was a slight reduction in tree rating for some trees with biuret symptoms in the Sherritt treatment in year 2. Leaf nitrogen content was acceptable for all treatments in all 3 years, except for the Osmocote treatment in year 2, which had low to deficient levels. Levels of other nutrients were all within acceptable ranges, except for low potassium levels for the Osmocote in year 2. There were no significant differences in yields of young trees in year 3, the first bearing year. Given its 44.5% N analysis, the total amount of Sherritt controlled-release fertilizer applied to young citrus trees was 4% that of the standard, water-soluble fertilizer and from 39% to 45% that of the two other controlled-release fertilizers in years 1, 2, and 3.
Assessment of Nitrogen Uptake Capacity in Mature Alternate-bearing Pistachio (Pistacia vera) Trees
Authors: Rosecrance Richard C. , Weinbaum Steve A. , Brown Patrick H.
Published: February 2019

The interrelationships between crop load, root growth, and nutrient uptake in mature, pistachio trees were examined in this study. Nutrient uptake was determined during the spring, summer, and fall using labeled nitrogen (15N) and boron (10B) and by differences in whole-tree accumulation between tree harvests for other nutrients (e.g., P, K, Ca, Zn). Nitrogen and boron uptake were double in fruiting compared with nonfruiting trees in the spring. Most of the labeled N was found in the developing fruits and leaves. Total labeled N recovery during the spring flush period, however, was low, indicating that much of the N in the fruit came from N reserves from within the tree rather than uptake from the soil. In contrast, significant amounts of N were taken up from the soil during the summer uptake period. Thus, our data support the hypothesis that sink demand (i.e., fruit development) conditions N uptake in pistachio. The relationship between root growth and N uptake was also examined in this study. Root observation chambers were constructed, and root growth determined by tracing roots growing up against the glass windows. Root length, root growth rate, relative root growth rate, and total tree fine root weight were all greater in nonfruiting compared to fruiting trees during the fruit development period (late May to mid-July). Surprisingly, fruiting trees had less root growth, but greater N uptake than nonfruiting trees during this period. This evidence suggests that N uptake is decoupled from root growth in mature pistachio trees.
Effect of Pollen of Five Different Male Palm Trees on the Chemical Characteristics of Jiroft Mazafati Date
Authors: Talaie A. , Panahi B.
Published: February 2019

The type of pollen of date palm trees could affect the chemical characteristics of the fruit, and determine the quality and quantitative aspects. Careful selection of proper pollen for pollination of date palm is very important. This research was conducted for the selection of the best pollinizers and to study the effects of five varieties of male trees from the Shahdad area on the chemical characteristics of `Jiroft Mazafati' date. A completely random block was used for analysis of the 2 years of data (1991–1993). The study sight was in the Jiroft area of Kerman Province, Iran. Samples of fruit were collected after the pollination process and the required information recorded. Total dry matter, fruit moisture, total sugar content, fruit ash, and fruit pH were measured. Statistical calculations analysis and compound variations and evaluations of the treatments by Duncan's test indicate that, statistically, the different treatments have no effect on the fruit pH, and the difference are not significant. There are statistically significant effects on the other chemical characteristics of the fruit.
Effect of Urea, Some Micronutrients, and Growth-regulator Foliar Sprays on the Yield, Fruit Quality, and Some Vegetative Characteristics of `Washington' Navel Orange Trees—Vegetative Growth and Mineral Leaf Content
Authors: Akl Ahmed M. , Eid Abdel-Fattah M. , Hegab Mohamed Y.
Published: February 2019

This investigation was carried out during the experimental seasons of 1991–92 and 1992–93 on 25-year-old `Washington' navel orange trees grown in an orchard at Beni Suef (≈120 km south of Cairo). This part of the investigation studied the effect of foliar spraying urea (0.5%), a mixture of Zn (0.4%), Mn (0.3%), Fe (0.5%), and Cu (0.3%) in sulfates from 23% Zn, 28% Mn, 19% Fe, and 30% Cu, respectively, and two growth regulators (GA3 at 25 ppm and α-NAA at 10 ppm) on some vegetative aspects and leaf content of some macro- and micronutrients. The investigation also included the effect of number and date of spraying (one spray 3 weeks before flowering, one spray 4 weeks after fruit set, and two sprays at the two dates) on the studied traits. The results showed that the overall treatments included two sprays of urea, micronutrients (Zn, Mn, Fe, and Cu) and NAA at 10 ppm achieved the highest values for average leaf area and shoot diameter in both seasons. The treatment on shoot length was more effective when GA3 replaced NAA. Leaf analysis showed that the application of any of the nutrients was responsible for a pronounced increase in leaf content of that element, but reduced the contents of others. Growth regulator treatments lowered leaf content of the determined elements. However, all other treatments in this study reduced leaf content of P and K.
Nitrogen Fertilization Effects on Growth, Yield, and Quality of Lettuce (Lactuca sativa) Transplants
Authors: Soundy Puffy , Cantliffe D.J. , Hochmuth G.J. , Stoffella P.J.
Published: February 2019

`South Bay' lettuce transplants were grown in F392A styrofoam Speedling® flats at different levels of N to evaluate the effect of N on transplant quality and subsequent yield and head quality in the field. Plants were irrigated eight times over a 4-week growing period by floating flats for 30 min in nutrient solution containing eight 0, 15, 39, 45, or 60 mg·liter–1 N supplied from NH4NO3. Dry shoot mass, leaf area, and plant height increased linearly with increasing N rates and dry root mass and stem diameter increased in a quadratic fashion. Transplants with the greatest plant biomass were, therefore, produced with 60 mg·liter–1 N. Plants from the 15, 30, 45 and 60 mg·liter–1 N treatments were planted in sandy soil in plastic-mulched beds under drip irrigation. To optimize lettuce head maturity among the treatments, plants from the N treatments were harvest 53, 56, and 59 days after transplanting (DAT). The optimum time to harvest was determined to be 56 DAT. There was no yield response (measured in terms of head mass) or quality response (measured in terms of head height, head diameter, head compactness or core length) to N applied during transplant production. This indicated that transplants produced with 15 mg·liter–1 N gave equally good yield to those produced with 30, 45, or 60 mg·liter–1 N when N was applied via flotation irrigation.
Carbon Partitioning as Affected by Shoot Type and Light Exposure in Peach
Authors: Corelli-Grappadelli L. , Ravaglia G. , Asirelli A.
Published: February 2019

Carbon partitioning and translocation in 1-year-old fruiting limbs of the peach cultivar Elegant Lady was studied, as affected by source [leaves on actively growing extension shoots (EXT), or on lateral shoots emerging from nodes with (F) or without (NF) fruit], five times during the season [2, 4, 7, 11, 17 weeks after full bloom (WAFB)]. Growing shoot apices were the strongest sinks early in the season (2 WAFB), with the EXT apices capable of attracting more C, and over longer distances, than the NF or F ones. The major source of newly synthesized carbohydrates for fruit growth 2 WAFB was the F lateral shoot; i.e., the most-important C contributor for fruit growth well into stage II (11 WAFB in this study). EXT shoots began contributing to fruit growth before the NF ones: 4 WAFB on, they exported to the fruit in amounts similar to the F shoots. This contribution was even larger 17 WAFB, when the F shoots retained more C than the other two shoot types. The NF shoots exported to the growing apices 2 WAFB, but this export decreased 4, 7, and 11 WAFB, compared to the other treatments. Seventeen WAFB, they contributed to fruit growth in the same amounts as the EXT shoots, and more than the F ones. Shade did not consistently affect patterns of carbon partitioning within limb components, except for the F treatment, where it diminished C export to the fruit in the first four treatment dates. Partitioning within fruit components (mesocarp, endocarp, and seed) followed the fruit growth curve, with more C allocated to endocarp tissues at 11 WAFB (stage II).
RAPDs are Useful for Genetic Analysis of Xylella fastidiosa and for Development of Strain-specific PCR Primers
Authors: Pooler Margaret R. , Hartung John S.
Published: February 2019

Xylella fastidiosa is a fastidious gram-negative, xylem-limited leafhopper-transmitted bacterium that has proven to be the causal agent of many economically important horticultural plant diseases, including Pierce's disease of grapevine and citrus variegated chlorosis. Genetic relationships among 11 X. fastidiosa strains isolated from mulberry, almond, ragweed, grape, plum, elm, and citrus were determined using randomized amplified polymorphic DNA (RAPD). Twenty-two 10-base primers amplified a total of 77 discrete polymorphic bands. Phenetic analysis based on a similarity matrix corresponded well with previous reports on RFLP-based similarity relationships, indicating that RAPD-PCR amplification products can be used as a reliable indicator of genetic distance in X. fastidiosa. RAPD products have been cloned and sequenced, and pairs of 21-nucleotide PCR primers have been developed that detect X. fastidiosa in general and the causal agent of citrus variegated chlorosis specifically.
Effects of Dicyandiamide on Blueberry Uptake and Soil Transformations of Nitrogen
Authors: Throop Philip , Hanson Eric
Published: February 2019

Absorption of 15N-enriched fertilizer by young `Bluecrop' bushes was compared following application of the nitrification inhibitor dicyandiamide (DCD). Ammonium sulfate solutions containing 7.9 g N (10.2 atom % 15N) were applied to the soil surface. Treated plants received 0.6 g of DCD and were compared to fertilized untreated controls. Fruit was collected during the growing season and bushes were excavated at the end of the season. The bush was partitioned into root stems and current season's growth (shoots, leaves, fruit). Tissues were dried, ground, and analyzed for 15N and 14N by mass spectrometry. No significant differences in N absorption were observed. Available soil fertilizer nitrate and ammonium content is presently being analyzed for effects of DCD.
Soft Sour Cherries—What's the Problem?
Authors: Mandujano Mario , Dennis F.G. , Guyer D.E. , Timm E. , Brown G.K.
Published: February 2019

Michigan growers often have severe problems with soft `Montmorency' sour cherries. Causal factors may include weather conditions, orchard practices, harvesting methods, and conditions during hold of fruits prior to processing. In this study, efforts were concentrated on orchard practices, including shading to reduce solar radiation, irrigation, nutrient level, and application of growth regulators, especially ethephon and gibberellin. Fruit firmness decreased as maturity approached, then stabilized. Significant fruit softening occurred only during mechanical harvesting. No treatments, including sprays of calcium and potassium, consistently increased firmness, but firmness was reduced in 1993 by spraying with ethephon. Firmness varied among orchards, but no “soft” fruit, as defined by industry standards, were observed in harvested fruit. Softening appeared to be caused by excessive bruising, and was always associated with mechanical damage. Advanced maturity and heavy cropping appear to predispose the cherries to greater bruise damage.
Improvement of `Fuji' Apple Color and Fruit Size using Reflective Materials
Authors: Andris Harry L. , Crisosto Carlos
Published: February 2019

Soil-applied reflective materials significantly improved the red color development, fruit size, and early harvestability of `Fuji' apple grown under hot climate conditions of the the San Joaquin Valley of California. Red surface color was significantly improved from 7.35% in the control to 14.27% where 60-inch-wide silver polypropylene o 48-inch-wide crinkled foil on cloth backing were applied to the soil between rows of `Fuji' apple grown on a Lincoln trellis. The weight per apple was also significantly increase where the reflective materials were used. There was no significant difference in soluble solids, acidity, pH, pounds firmness, or starch content. Packinghouse records showed a 33% increase in first harvest pack-out where the reflective materials were used. Total pack-out in the larger sizes was improved in the extra-fancy and US#1 grades, while the utility-grade fruit was reduced by using these materials. Ground color was shifted from green to yellow where the reflective materials were used.
Influence of Environmental Factors on Pecan Oil Composition and Nut Quality
Authors: Sistrunk Laurence , Chapman Dan , Storey J. Benton
Published: February 2019

Four cultivars of pecan [Carya illinoinensis (Wangenh.) K. Koch] were selected for the study (`Cheyenne', `Mohawk', `Pawnee', and `Osage'). The influence of total climatic heat units, during nut filling, on nut quality was compared from 14 geographic locations over a 3-year study. Nut quality parameters included nut size by weight, kernel percentage by weight, kernel color by Hunter Color Difference Meter, fatty acid profile by GC, and total oil by NMR. Nuts were harvested at shuck split, dried to 3% moisture, and stored at –20C prior to analysis. Monounsaturated fatty acids (MUFA) and total oil increased, and polyunsaturated fatty acids (PUFA) decreased in `Mohawk' 2 out of 3 years with increased heat units. Fatty acids in `Pawnee' responded the same as in `Mohawk' in 1992, but were variable in 1991. In 1993, `Pawnee' kernel whiteness and total oil decreased with increased heat units. Higher heat units caused the testas of `Cheyenne' to be darker in all 3 years. MUFA of `Cheyenne' increased with increased heat units 1 out of 3 years. The PUFA content of `Cheyenne' decreased with increased heat units in 1993. `Osage' showed a reversal of MUFA and PUFA with increased heat units. High negative correlation between oleic and linoleic acid were obtained for all cultivars.
Root-zone Temperature Effects Onion Content of Tomato, Muskmelon, and Honey Locust
Authors: Klock Kimberly A. , Taber Henry G. , Graves William R.
Published: February 2019

Horticultural species vary in growth response to high root-zone temperature (RZT), but little is known about the effects of RZT on nutrient uptake. We determined P, K, Ca, Mg, Zn, and Mn total plant content of tomato (Lycopersicon esculentum Mill. cv. Jet Star), muskmelon (Cucumis melo L. cv. Gold Star), and honey locust (Gleditsia triacanthos L. var. inermis Willd.) grown in nutrient solution kept at 24, 27, 30, 33, and 36C. RZT effects on plant dry mass gain and gain in nutrient per plant varied by species. Honey locust and tomato total plant gain in P decreased linearly with increasing RZT, while melon P content increased linearly to 36C. Trends in total Mg and Mn content will be presented, as well as results from further research on correlations between supraoptimal RZT, root respiration, and shoot and root P content of tomato.
Effect of Different Nitrogen–Sulfur Ratios on 2-Phenylethyl isothiocyanate (PEITC) Levels in Watercress
Authors: Palaniswamy Usha Rani , McAvoy Richard , Bible Bernard , Singha Suman , Hill Dennis
Published: February 2019

A study was initiated to identify cultural conditions that optimize the production of important chemopreventive agents in watercress. Chemopreventatives are chemical compounds that reduce or prevent diseases such as cancer. Watercress (Nasturtium officinale) contains phenylethyl glucosinolate that, on hydrolysis, yields PEITC, and PEITC is one of the most-important anti-carcinogens among the cruciferous chemopreventatives tested. Watercress was grown in closed hydroponic systems containing 200 ppm nitrogen and either 64, 128, and 192 ppm sulfur to yield N:S ratios of 1:0.3, 1:0.6, and 1:0.9. The experiment was laid out as RCBD in the greenhouse with six replications. PEITC levels in leaf and stem tissue was assayed using gas chromatograph. After 36 days in the treatment solutions, watercress grown at a N:S ratio of 1:0.6 produced 90.1% and 65.3% (in repeated experiments) more PEITC than plants grown at a N:S ratio of 1:0.3. Plants grown in nutrient solution with a N:S ratio of 1:0.9 produced 57.4% and 24.2% greater PEITC than those grown with a N:S ratio of 1:0.3. Plants grown in a nutrient solution with a N:S ratio of 1:0.9 produced 17.2% to 24.2% less PEITC than those grown with a N:S ratio of 1:0.6. Leaves contained 54% to 70% more PEITC per unit dry mass than stems, suggesting that the leaf is the major site of synthesis and storage of PEITC.
Influence of Nitrogen and Phosphorus Rates and Soil pH on Growth and Yield of Goldenseal
Authors: Davis Jeanine M.
Published: February 2019

Goldenseal (Hydrastis canadensis L.) is a widely used medicinal herb that is commonly collected from forests in North America. An increasing demand for goldenseal has put intense pressures on wild populations and increased the interest in cultivation. Cultural information on goldenseal, however, is limited and contradictory. A 3-year study was initiated to examine the effects of soil pH (4.5, 5.5, 6.5, and 7.5) and four rates of P and N (0, 0.1, 0.2, and 0.3 kg P or N/m3 of soil) on growth and development of goldenseal. In Spring 1993, small rhizome pieces were planted in pots of forest soil and grown under a wood-lath structure. Plant growth, flowering, and fruiting are monitored throughout each growing season. The plants are brought into an underground storage facility for overwintering. In late winter, roots are weighed, evaluated, and replanted. After one season of growth, root weights were highest with pH 5.5 and 6.5 and no additional P or N. During the second season of growth, the greatest plant growth and fruiting were obtained with pH 5.5 and 6.5 and with the two highest rates of phosphorus.
The Earth Box—A Sustainable Production System
Authors: Geraldson C.M.
Published: February 2019

The Earth Box is made of recycled plastic and designed to maintain a water table. A nutritional gradient is initiated with N–K fertilizer applied on the surface of the soil or media contained in the box. The box is designed to facilitate the functioning of a nutritional procedure known as the gradient concept. Basically, the concept synchronizes the nutrient/water input with removal, providing stability and nutritional predictability to the ionic composition of the soil solution. Crop response (yields and, especially, quality) with the Earth Box has been most positive, indicative of an optimal nutritional precision. The positive response is also evident in the field—average tomato yields in Florida more than doubled with the inception of the gradient-mulch system (1970s). the gradient as the dominant nutritional component eliminates the soil (type and/or quantity)–plant–season as nutritional variables. The Earth Box with minimal water, minimal pollution, minimal management, and the potential for a minimal unit cost could be the basis of a globally sustainable production system.
Postharvest Cullage of `Anjou' Pears
Authors: Kupferman E.M. , Sanderson Peter
Published: February 2019

Fruit cullage due to postharvest-expressed diseases and disorders of `Anjou' pear amounted to $1.4–2.4 million annually to northwest growers in 1991–93. Fungal diseases, including Penicillium spp., Botrytis cinerea, and Mucor spp. accounted for the majority of losses. Scald, skin speckling, and scuffing are listed by packinghouse managers as major contributing disorders. A 3-year study has examined reasons for losses and methods to reduce losses through improved postharvest handling. Maturity at harvest, fruit nutrient status, time of packing, temperature management, and improved handling practices provide the basis for cullage.
Early Response of High-density Peaches in Sod to Different Irrigation and Fertilizer Treatments
Authors: Layne Richard E.C. , Tan Chin S. , Hunter David M. , Cline Robert A.
Published: February 2019

Seven high-density (606 trees/ha) management systems for peach [Prunus persica (L.) Batsch cv. Harrow Beauty/Bailey] were compared on Fox sand in southwestern Ontario. Each system had an irrigation component (N = none D = drip, M = microsprinkler) and a fertilizer placement component (B = banded, L= low-rate fertigation, H = high rate fertigation). NB (nonirrigated, banded fertilizer) and DB (drip-irrigated) are commonly used systems in Ontario, while the other five treatment combinations were experimental. Trunk cross-sectional area (TCA) was generally greatest for DH and DB systems, smallest for ML and NB systems, and intermediate for the other three. No symptoms of N or K deficiency or excess were noted for any of the fertilizer treatments. The seven management systems each had similar cumulative yield efficiencies for the first 4 cropping years However, total marketable yields for the 4 years were highest for MB (58.7 t·ha–1), followed in descending order by DB (56.8 t·ha–1), DH (56.6 t·ha–1), MH (53.9 t·ha–1), DL (50.6 t·ha–1), ML (49.8 t·ha–1), and NB (47.5 t·ha–1). Each of the irrigated treatments outyielded the nonirrigated check (NB) and ranged from 4.8% to 23.6%. Only one of the irrigated treatments (MB) outyielded the irrigated check (DB), and by only 3.3%. There was no clear advantage for either the drip or microsprinkler system of irrigation. Banded application of N and K appeared to promote higher yields than by fertigation equivalent to the banded rate, while yields at the low rate of fertigation were lower than for either the high rate of fertigation or the banded application. It appeared that banded fertilizer combined with either microsprinkler (MB) or drip irrigation DB provided the most-effective of the management systems in the first 4 cropping years.
Nimblewill Ground Cover for Biocontrol of Ring Nematode in Peach Orchards
Authors: Olien William C.
Published: February 2019

Benefits of nimblewill (Ms = Muhlenbergia schreberi), a warm-season, perennial grass, as an orchard ground cover are: 1) it is not competitive with tree growth and 2) it reduces ring nematode (Cx = Criconemella xenoplax) soil population, even in the presence of a tree fruit host. Ms is difficult to establish in orchards in warm fruit-growing regions. In field studies, we found that Ms establishment was decreased by chemical mowing relative to seeding only. Successive years of reseeding at 22 kg seed/ha per year, mechanical mowing, and control of winter annuals gave best establishment of Ms in peach orchards. An orchard microplot study was established to evaluate effects of five Ms densities and two Ms sources on Cx population and on growth of `Redhaven'–Lovell trees (10 replications). Cx numbers were reduced hyperbolically in response to Ms density. Ms cover of 5 g dw/m2 (planted at 9 kg seed/ha) reduced Cx from 200 (control) to the accepted threshold of 50 Cx/100 cc soil. Maximum Cx reduction to 26 Cx/100 cc was obtained at 34 g dw/m2 Ms (planted at 40 kg seed/ha). Cx response to Ms density was not affected by Ms source.
Evaluation of Incorporated Slow-release Fertilizers for Two-year Container Production Systems.
Authors: Calkins James B. , Swanson Bert T.
Published: February 2019

Media fertility, nutrient availability, and subsequently plant nutrition are critical factors that can be modified by growers to produce quality container-grown plants. The trend in container fertility has been toward incorporation of slow-release fertilizers; however, fertility release curves are variable and fertilizer longevity for many fertilizers is limited. Seventeen slow-release fertilizers were compared for longevity and plant performance over a 2-year production cycle using deciduous and evergreen plant materials. Plant growth was quantified based on height, volume, branching, dry weight, and quality. Soil fertility levels based on leachates were followed. Nutrient release for the incorporated fertilizers evaluated was variable. Fertility treatment effects were species-dependent. Several incorporated, slow-release fertilizers, especially those high in nitrogen and having extended release curves, including Nutricote 20–7–10, Scotts Experimental 24–6–10 and 26–6–11, Scotts Prokote Plus 20–3–10, Sierra 17–6–10, Sierra High N 24–4–6, Sierra Experimental 24–4–8, Woodace 21–4–10, Woodace 23–7–12, and Woodace Briquettes 23–2–0, show promise for use in 2-year container production systems.
Breeding Tomatoes for Attractiveness to Pollinating Insects
Authors: Robinson Richard W.
Published: February 2019

Bumblebees are commercially used to improve fruit set of greenhouse tomatoes, but they seldom pollinate tomatoes outdoors if not confined in a no-choice situation. Bumblebees frequently pollinated L. peruvianum and other self-incompatible (SI) Lycopersicon species, but not tomato plants, in the field at Geneva, N.Y. Bumblebees were very efficient pollinators of Sl Lycopersicon species, averaging only 5 s to pollinate one flower and fly to the next. Transfer of this attractiveness to pollinating insects to the tomato could improve fruit set of tomatoes grown in greenhouses with introduced bumblebees. It could also improve fruit set in the field, especially when conditions are poor for pollination. It has potential use for producing F1 hybrid seed, but associated problems make hybrid tomato seed production by insect pollination impractical now. Attractiveness to pollinating insects is being introgressed from L. peruvianum, L. hirsutum, and L. pennellii in the tomato breeding program at Geneva, N.Y. Several floral characteristics were found to be of importance for attracting pollinators, including the reaction to ultraviolet light. Flowers of SI species absorbed UV, whereas tomato flowers reflected UV light.
Determination of Cavitation Response in Stems of Apple Rootstocks and Hawthorn Seedlings with a Pressure Chamber
Authors: Remmick Michael D. , Fuchigami Leslie H.
Published: February 2019

Stems of 1-year seedling Washington hawthorn (Crataegus phaenopyrum) and 1-year layers of apple rootstocks M.9 and M.26 EMLA were subjected to positive air pressures in a double-open-end pressure chamber to determine the cavitation response of each taxon. Inferences regarding relative desiccation tolerance of the taxa can be made by comparing the range of applied pressures over which air-seeding and subsequent reduction of water flux through xylem conduits is induced. M.9 rootstock maintained higher levels of water flux relative to M.26 EMLA or Washington hawthorn at pressures between 3.0 to 4.0 MPa, suggesting greater resistance to water stress-induced air-seeding in the former compared to the latter two taxa. The cavitation responses of M.26 EMLA and Washington hawthorn were indistinguishable from each other. Inferences regarding water stress-induced cavitation response will be discussed relative to this technique.
Influence of Irrigation System and Frequency on Plant Growth, Root Distribution, and Water-use Efficiency
Authors: Morvant Jaime K. , Dole John M. , Cole Janet C.
Published: February 2019

Euphorbia pulcherrima `Gutbier V-14 Glory' were grown with 220 mg·liter–1 N (20N–4.4P–16.6K) using ebb-and-flow (EF), capillary mat (CAP), microtube (MIC), and hand-watering (HAN) and were irrigated either daily (pulse - P) or as needed (regular - R). For all irrigation systems, pulse irrigation produced the greatest total dry weight. HAN-R produced lower total dry weight than all other irrigation systems and frequencies. Root dry weight was highest with pulse subirrigation (EF and CAP). MIC-P, EF-P, and EF-R were the most water-efficient treatments. The experiment was repeated twice with similar results. In a second experiment, Pelargonium ×hortorum `Pinto Red' root balls were sliced into three equal segments; top, middle, and bottom. For all irrigation systems, root counts were lowest in the top region. EF root counts were greatest in the middle region, while MIC root counts were greatest in the bottom region. The two subirrigation systems had higher average root counts than the two top-irrigated systems (HAN and MIC). In general, there was less difference in EC between regions for top-irrigated than for subirrigated root balls. The EC was lowest in the bottom and middle regions of EF and the bottom region of MIC and CAP. For subirrigation, the highest EC was in the top region. For all systems, pH was lowest in the bottom region.
Comparison of Drought-induced Chitinase Expression Between Wild and Cultivated Tomatoes
Authors: Yu Long-Xi , Greer Ann. F. , Tabaeizadeh Zohreh
Published: February 2019

We have carried out a comparative study on chitinase gene expression and enzyme activity in Lycopersicon chilense (a drought-tolerant wild tomato) and L. esculentum under water stress. Both enzyme assay and Northern blot analysis revealed that chitinase expression was differentially induced by drought among the different genotypes. Higher induction of chitinase was found in tolerant species compared to the sensitive one. Among genotypes examined, L. chilense LA2747 presented the highest level of the chitinase induction, while the lowest level was found in L. esculentum HR86. Leaves of drought-stressed plants showed the highest expression and roots showed the lowest, with stems being intermediate. Chitinase activity was detected in flowers of both drought-stressed and control plants. The measurement of leaf water potentials of different genotypes revealed a correlation between drought tolerance and the level of chitinase expression during water stress. Our results suggest that the chitinase might be involved in drought tolerance of L. chilense.
Use of Paper Sludges as a Partial Constituent of Substrate Mixtures in Horticulture
Authors: Norrie Jeffrey , Gosselin André
Published: February 2019

Waste residues arising from paper production, either from recycled (deinking) or virgin wood (primary) fibers, are composed primarily of lignin, cellulose and hemi-cellulose. Large quantities of such residues are usually landfilled or burned. In a joint project with the company “Les Composts du Quebec Inc.',” this study examined the use of deinking and primary paper sludges as partial constituents of substrate mixtures, used as organic soil amendments for the growth of several grass and tree species. In a strip-split-plot design, mixtures of paper sludge (0% to 50%), sand (50%) and organic soil (0% to 50%) were prepared with or without a base-fertilization (strip-plot) before planting. Base fertilizations were given to improve N, P, and K availability and C/N and C/P ratios based on the nutrient status of substrate mixtures before incorporation into the soil. Results over both years indicated that unfertilized treatments with a higher percentage of paper sludge (by dry volume) generally displayed poorer growth. Grass plots exhibited decreased ground cover and stand quality. Shrubs showed some deficiency symptoms, but not until late in the season of each year. However, few differences were found between sludge treatments for grass or shrub species if substrates were given a base-fertilization of N, P, and K (to 0.5%, 0.13%, and 0.33%, respectively). Again, during the 2nd year, few differences were found between sludge-amended plots that were base-fertilized the year before. In short, our results indicate that paper sludge amendments can maintain or improve the growth of grass and shrub species if an adequate base fertilization is given to overcome nutrient immobilization. Several, more-precise base-fertilizer treatments are currently being examined for turfgrass culture.
Plant Growth Regulators for Crop Management in Tea
Authors: Manivel L. , Kumar R. Raj , Marimuthu S. , Venkatesalu V.
Published: February 2019

Growth regulators are used in tea plantations from planting to productivity. Paclobutrazol at 500 ppm applied on foliage, 1 month after planting, promotes lateral production, besides feeder root proliferation. Triacontanol at 2 ppm applied in mature tea improves productivity through enhanced photosynthesis, favorable partition of assimilates, and water-use efficiency. Hydrogen cyanamide applied on the pruned frame at 0.5% improves budbreak. Antitranspirants based on long-chain polymers impart drought-tolerance in young and mature tea. Thus, use of PGR for cost-effective management of tea plantations, without affecting the quality of made tea or bush health, has been standardized.
Packingsheds Harvest Date and Seasonal Effects on Texas Grapefruit Destined for Fresh Market
Authors: Fucik John E.
Published: February 2019

Uniform samples of Texas grapefruit, harvested in December, January, February, and March, were run through five Rio Grande Valley packingsheds, then stored for 30 days at 65C and 80% RH. The tests were done in 1987, 1988, and 1989 (December only). Data evaluated were degreening effectiveness, water loss, spoilage, and juice analysis. There were no degreening differences between sheds. Analyses of the parameters of time in storage × water loss regressions for sheds and harvest dates showed fruit harvested in the warmer months tended to have the higher percentage of water loss. Water loss differences between sheds was inconsistent, varying with month and season. The correlation between average fruit weight and percentage of water loss was very inconsistent. Harvest date rather than sheds had the most influence on spoilage. While the variations in the physical characteristics and chemical treatments of each packing line probably underlay the packingshed × harvest date interaction for water loss, no simple cause and effect hypothesis involving all these factors could be constructed.
Using Subirrigation to Root Stem Cuttings: Comparison to Mist and Effects of Nutrition
Authors: Zhang Hongvi , Graves William R.
Published: February 2019

Use of subirrigation to root stem cuttings was compared to using mist, and effects of fertilization during subirrigation were determined. All cuttings of Dendranthema ×grandiflorum (Ramat.) Kitamura `Charm' and Coleus ×hybridus Voss. rooted, but misted D. ×grandiflorum `Charm' had a higher mean root mass than subirrigated cuttings. Percentage rooting and mean root mass of subirrigated Acer rubrum L. `Franksred' were 95% and 321 mg, whereas mean root mass of the 21% of cuttings that rooted with mist was 38 mg. Percentage cuttings with callus, mean callus diameter, rooting percentage, and mean root mass of Syringa retuculata (Blume) Hara were 77%, 124 mm, 21%, and 52 mg with subirrigation and 45%, 63 mm, 0%, and 0 mm with mist. Subirrigation with <7 mol N/m3 improved rooting of Impatiens hawkeri Bull. `Celebration Bright Scarlet' and A. rubrum `Franksred'. Subirrigation can replace mist, and effects of fertilizer in subirrigation solution vary among taxa.
A Propagation and Reintroduction Strategy for the Neches River Rose Mallow, Hibiscus dasycalyx
Authors: Smith Erin , Creech David
Published: February 2019

Hibiscus dasycalyx is known from less than 10 locations along the Neches River. A many-stemmed, woody-based, narrow-leafed perennial to 4 ft, the species displays showy white-petaled, 3-inch blooms in summer and fall. The species is federally endangered due to loss of habitat and interspecific hybridization with the Soldier Rose Mallow, Hibiscus militaris, a species that encroaches into the range of the Neches River Rose Mallow. A 1994 seed propagation study included nine collection dates (late July to late October) and stratification at 0, 2, 4, and 6 weeks prior to planting. Germination percentages were low; only the 7/22 and 9/10 collection dates exhibited a germination rate above 25% and stratification did not improve germination percentages. In late Fall 1994, container-grown plants exhibited an almost universal tendency to enter dormancy in a greenhouse maintained above 70F and provided with long-days via supplemental lighting. In two cutting propagation trials, cuttings collected 8/23 rooted at 65%; a 11/22 cutting collection failed to root. Seedling variation in leaf shape and growth rate is high. The results of 1995 cutting propagation trials will be presented. A reintroduction strategy for the species under the umbrella of the Stephen F. Austin State Univ. Arboretum includes establishing a sustainable planting of the species in the Arboretum and reintroduction into Mill Creek Gardens, a Nacogdoches county conservation easement.
Influence of Velvetbean on Southern Root-knot Nematode When Used As Part of the Crop Rotation in Low-input Vegetable Production in Southern Georgia
Authors: Brunson Kathryn E. , Phatak Sharad C. , Gay J. Danny , Sumner Donald R.
Published: February 2019

Velvetbean (Mucuna deeringiana L.) has been used as part of the crop rotation in low-input vegetable production in southern Georgia to help suppress populations of root-knot nematode (Meloidogyne incognita) for the past 2 years. Over-wintering cover crops of crimson and subterranean clovers were used the low-input plots and rye was the plow-down cover crop in the conventional plots. Tomatoes, peppers, and eggplant were the vegetable crops grown in these production systems. Following the final harvest in 1992, use of nematicides in the low-input plots was discontinued and velvetbean was then planted into the low-input plots and disked in after 90 days. Results from the 1993–94 soil samples taken before and after velvetbean showed a continuing trend of reduced nematode numbers where velvetbean had been, while most conventional plots that had nematicides applied resulted in increases in nematode populations.
Insect Pests, Beneficial Insects, and Cover Crops of Biological Vegetable Farmers
Authors: Caldwell J.S. , Amirault J.P. , Christian A.H.
Published: February 2019

Eighty-two vegetable growers responded to a survey on pests, beneficial insects, and cover crop use sent in Winter 1993–94 to 314 members of the Virginia Assn. for Biological Farming (VABF) and participants at the 1993 Virginia Sustainable Agriculture Conference. Respondents reported 68 occurrences of insect pests on 99 vegetable crops and herbs. Six insects (flea beetle, squash vine borer, stink bug, cucumber beetles, and Mexican bean beetle) comprised 70% of the occurrences. Squash vine borer and cucumber beetles on cucurbits comprised 24% of all pest occurrences. Insect pests attacked summer squash on 57% and cucumber on 49% of the farms. Average severity of squash vine borer damage was 3.8 (range 0–4, where 0 = no damage and 4 = death or destroyed). Average severity of cucumber beetle damage was 3.0 (severe). Squash vine borer was not observed by farmers on non-cucurbit alternate hosts. Cucumber beetles were observed on horse nettle (10%) and wild nightshades (6%), but on no other plants in most cases (61%) when found on cucurbits. The most frequently observed beneficial insects were lady beetles (64% of the farms), preying mantises (42%), wasps (29%), assassin bugs (18%), and spiders (15%). Only 29% of the farms had purchased beneficial insects, with assassin bugs (10%) and lady beetles (7%) the most common types. Vetches, clovers, rye, and buckwheat comprised 69% of the responses on 23 types of cover crops and mulches used.
Evaluating Fall Cover Crops Following Early Harvested Vegetables
Authors: Stivers-Young Lydia
Published: February 2019

Vegetable growers in the northeastern United States who want to use cover crops are limited by the relatively short growing season and by a lack of cover crop species options. Seven cover crops that winter-kill under NE US conditions were evaluated in on-farm trials for their suitability for following early harvested vegetables. Plots of oilseed radish (Raphanus sativus), white senf mustard (Brassica hirta), phacelia (Phacelia tanacetifolia), oats (Avena sativa), and a bare control were planted on 25 Aug. and 8 Sept. 1993, following a lettuce crop. In the early planting, oilseed radish, white senf mustard, and phacelia produced more than 3000 kg·ha–1 dry matter in 11 weeks, while oats produced just more than 2000 kg·ha–1. A smaller proportion of the accumulated biomass from these cover crops remained on the surface in the spring compared to oats. In the first planting, 80–107 kg·ha–1 N were accumulated in the above-ground biomass of the cover crops. On 3 and 16 Sept. 1994, plots of oilseed radish, white senf mustard, oats, yellow mustard (Brassica hirta), forage kale (Brassica oleracea), forage turnip (Brassica rapa), canola (Brassica napus cv. Sparta), and a bare control were established following potatoes. All cover crops except kale produced more than 3800 kg·ha–1 dry matter by late November in the early planting.
Fruiting and Ripening Characteristics of Actinidia arguta Hardy Kiwi
Authors: Kempler Chaim , Kabaluk J.T.
Published: February 2019

In 1989, 2-year-old A. arguta varieties Geneva, Annaysana, Dumburton Oaks, Fairchild, National Arboretum, 74-7', 74-8, and the self-fertile variety Issai, were planted in Agassiz, B.C., on a well-drained soil site. The plants were grown with a single trunk to 1.8-m with permanent cordons, and fruiting laterals trained on a 2.1-m-wide winged T-bar trellis support. Plant spacing was 2.75 m within the row and 4.8 m between rows. Staminate varieties (Meader and 74-6) were planted at a 1:6 ratio of male: female for pollination. Fruiting canes were renewed every 2 years by winter pruning. All plants began to bear harvestable yields by 1991. A. arguta vine required 622 heat units from bud break to full bloom and the average flowering date was 29 May. Fruit begin to mature during September, depending on the variety. `Geneva', `Annaysana', and `Issai' were the most suitable for commercial production. In 1993, they produced a yield of 26, 38, and 26 kg/vine, with average fruit weight of 7.7, 6.3, and 4.8 g, respectively. `Geneva' was the earliest to mature, followed by `Annaysana' and `'Issai'. A. arguta ripen very unevenly and, at harvest, a certain proportion of the fruit are over-ripe. Fruit are best harvested early when they are firm. Storing the fruit at 1C improved ripening uniformity.
Software for Design of Modified-atmosphere Packages for Fruits and Vegetables Incorporating Respiration Rate Variation
Authors: Talasila P. Chowdary , Cameron Arthur C.
Published: February 2019

Modified-atmosphere (MA) packages for fruits and vegetables are traditionally designed by matching product respiration rate with permeation of the packaging film to achieve a desired gas composition in the package. However, this design procedure is adequate only in ideal situations. We have previously shown that actual O2 partial pressures were distributed around targeted levels due to variation in product respiration rate and film permeability. In some cases, injurious levels of O2 were generated as a result of this variation. We have developed a procedure that incorporates variation of product respiration rate and uses a statistical approach to predict appropriate target levels. This approach includes a user-based decision as to how many packages with O2 partial pressures below the lower O2 limit for product injury can be tolerated. We have incorporated this approach into a user-friendly computer software using turbo pascal in MS DOS environment. This software is menu-driven and has graphical support. Use of the software will be demonstrated with examples.
Application of an Ethanol Biosensor to Identify Low-O2 Injury of Fruits and Vegetables in MA Packages
Authors: Talasila P. Chowdary , Cameron Arthur C. , Beaudry Randolph M.
Published: February 2019

In modified-atmosphere (MA) packaging of fruits and vegetables, there is a risk of generation of excessively low, injurious O2 levels due to improper package design, temperature abuse, and/or product respiration rate variation. When exposed to injurious O2 levels, product quality deteriorates and off-flavors develop. Also, there is increased production of ethanol and other fermentative volatiles. For blueberries, off-flavors were positively correlated with tissue ethanol level when the product was exposed to a range of O2 partial pressures (0 to 18 kPa) and temperatures (0 to 25C). A biosensor that measures ethanol level in package headspace will be useful for easy identification of the packages containing injured products. Biosensors that measure ethanol in aqueous solutions by a color change reaction are commercially available. We have found a positive correlation between the color (hue) of the sensor and headspace ethanol levels in packages containing cut broccoli at 22C. The utility of the biosensor in quality assurance (QA) based on the identification of low-O2 injury of the packaged products will be discussed.
Impact of Storage Temperature Fluctuation on Modified-atmosphere Packaging of Fresh Produce
Authors: Tano K. , Lee L.Z. , Castaigne F. , Arul J.
Published: February 2019

Use of modified atmosphere (MA) as an adjunct to low temperature can be effective method for prolonging the shelflife of fresh fruits and vegetables. However, if storage temperature fluctuates, anoxic conditions can result and, consequently, the fresh produce quality can deteriorate rapidly. The objective of this investigation was to evaluate the effects of temperature fluctuation on the atmosphere inside the package and on the quality of packaged produce. Mushrooms (A. bisporus, U3 Sylvan 381) were packaged in rigid containers (4 liters) fitted with diffusion windows to obtain an atmosphere of 5% O2 and 10% CO2 at 4C. Temperature fluctuation had a major impact to the atmosphere inside package. During the first fluctuation sequence, O2 level depleted to 1.5% and CO2 increased to 18%. When the temperature returned to 4C during the next sequence, CO2 level fell back to 10%, but O2 level remained at 1.5%. The quality of mushrooms stored under temperature-fluctuating conditions was severely affected, as indicted by the extent of browning, loss of texture, and level of ethanol in the tissue compared to mushrooms stored at constant temperature. It was clear from this experiment that under temperature fluctuation, even it occurs once, can seriously compromise the benefits of MA packaging and safety of the packaged product. It is thus necessary that MA packaging compensate for the additional permeability required that is caused by storage temperature fluctuations.