bluuebunny/crossref_metadata_2025 huggingface dataset:
Genotypic Differences in the Effect of Temperature on CO2 Assimilation and Water Use Efficiency in Blueberry
Authors: Moon J.W. , Hancock J.F. , Draper A.D. , Flore J.A.
Published: August 2022

To determine if the net CO2 assimilation and water use efficiency (WUE) of highbush blueberry under high temperature can be improved genetically, gas exchange determinations were made for a selection of Vaccinium darrowi Camp (Florida 4B), a highbush cultivar (Bluecrop) (V. corymbosum L.), their F1 hybrid (US75), and two crosses of the F1 hybrid to another improved genotype (US239 and US245). All genotypes responded parabolically to increasing temperature at vapor pressure deficits <1 kPa. Maximum CO2 assimilation of US75 (15 µmol·s–1·m–2) was 30% to 40% higher than either parent. Carbon dioxide assimilation of US75 and Florida 4B was optimum at 30°C and that of ‘Bluecrop’ at 20°. The optimum for US239 was similar to ‘Bluecrop’, and that of US245 to Florida 4B. Florida 4B had higher WUEs than ‘Bluecrop’ at both 20° (5.64 µmol CO2/mmol H2O to 4.01) and 30° (3.73 to 2.53). US239 and US245 had significantly (P < 0.05) higher WUEs at 30° than did ‘Bluecrop’. Residual conductance to CO2 (gr) decreased in ‘Bluecrop’ when temperature was raised from 20° to 30°, but increased in all other genotypes. Due to the favorable gas exchange properties of US75 and US245 at 30°, we suggest that the high temperature tolerance of V. darrowi may be heritable and that US245 may be used to improve the heat tolerance of highbush blueberry.
Glucosinolates in Crucifer Vegetables: Broccoli, Brussels Sprouts, Cauliflower, Collards, Kale, Mustard Greens, and Kohlrabi
Authors: Carlson Diana G. , Daxenbichler M.E. , VanEtten C.H. , Kwolek W.F. , Williams P.H.
Published: August 2022

Correlation coefficients based on relative concentrations of 13 glucosinolates in the edible parts of 30 cultivars were determined. Brussels sprouts (Brassica oleracea L. gemmifera group), cauliflower (B. oleracea L. botrytis group), and either marrow-stem or smooth-leafed kale (B. oleracea L. acephala group) had similar glucosinolate patterns based on significant correlations (P < 0.01). The glucosinolates of ‘Morris Heading’ collards [(B. oleracea L. acephala group (var. sabellica)] were highly correlated with those of curly kale [B. oleracea L. acephala group (var. selensia)]. Mustard greens [B. juncea (L.) Czern. & Coss. var. rugosa Bailey] and the corresponding seeds were the most highly correlated of the 17 cultivars for which the edible parts and seeds were compared. Seed analyses indicated relationships among the cultivars somewhat similar to those seen for the edible portions.
Growth and Cropping of ‘Redhaven’ Peach Trees Following Soil Application of Paclobutrazol
Authors: Marini Richard P.
Published: August 2022

Paclobutrazol was applied to soil around 5-year-old ‘Redhaven’ peach [Prunus persica (L.) Batsch] trees at rates of 0, 1.1, 2.2, and 4.4 g a.i./tree in Dec. 1982. Trunk and shoot growth suppression in 1983 were related to application rate, but there was no treatment effect in 1984 or 1985. Yield and fruit size were not influenced in 1983 by treatment, but treated trees produced less fruit than control trees in 1985. Rate of defoliation was negatively related to concentration in 1984, and bloom development was positively related to concentration in 1985 following a single treatment in 1982. Chemical names used: β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-l,2,4-triazole-1-ethanol (paclobutrazol).
Osmotic Potential and pH of Fluid Drilling Gels as Influenced by Moisture Loss and Incorporation of Growth Regulators
Authors: Amador Adolfo Minero , Stewart Katrine A.
Published: August 2022

A seaweed extract (Cytex) was incorporated at 0%, 1%, 2%, and 3% (v/v) into four carrier gels used for fluid drilling. The gels were: magnesium silicate (Laponite), starch acrylate polymer (Liquagel), potassium copolymer (Viterra Agrigel), and a starch (Water lock B-100). When moisture was not lost, the pH values were significantly different among diluted gels (1 gel : 1 water, v/v) and ranged from 6.8 to 9.2. Incorporation of the seaweed extract significantly decreased the pH of the gels. Osmotic potential values of all the gels were close to 0 MPa, with potassium copolymer having a significantly lower osmotic potential (−0.03 MPa) than that of starch acrylate polymer (−0.007 MPa). Incorporation of the seaweed extract signficantly decreased the osmotic potential of the gels between −0.12 and −0.16 MPa. When gels were dehydrated to simulate water stress conditions (0% to 50% water evaporation), pH values were decreased further (ranging from 4.6 to 6.8). Osmotic potential decreased in all the gels to a range between −0.22 and −0.36 MPa with increasing moisture loss.
Evaluation of Irrigation Scheduling Methods for Sweet Corn
Authors: Braunworth William S. , Mack Harry J.
Published: August 2022

Accurate irrigation scheduling for sweet corn can reduce irrigation costs and ensure meeting of yield goals. Three scheduling methods, evaluated in a 2-year study, included: a) irrigation when 46% and 57% of available water was depleted in 1984 and 1985, respectively, as measured by a neutron meter; b) irrigation when 50% of available water was depleted as estimated by the Food and Agriculture Organization modified Penman equation; and c) irrigation at three growth stages. Irrigation water applied for the neutron meter, modified Penman, and growth stage method was 367, 279, and 269 mm, respectively, in 1984 while in 1985 these methods resulted in application of 500, 368, and 366 mm of irrigation water. Yields of total unhusked ears in 1984 for the growth stage and modified Penman methods were significantly lower than the yields of the neutron meter method but were not significantly different from one another. In 1985, there were no significant differences in total unhusked or husked processable ear yields among the three scheduling methods. Quality factors, which included ear length, kernel moisture content, and ear weight did not vary significantly with irrigation scheduling methods. Since total unhusked, husked processable yields, and quality differences were minor, irrigation scheduling by any of these methods would appear to be satisfactory.
Low Pollen Production as a Cause of Fruit Malformation in Strawberry
Authors: Gilbert Cynthia , Breen Patrick J.
Published: August 2022

The differential tendency to form misshapen fruit and anther quality and pollen production were determined in ‘Benton’, ‘Totem’, ‘Olympus’, and ‘Tyee’ strawberries (Fragaria × ananassa Duch.) in field trials in 1983 and 1984. All flowers had a full set of anthers; however, the proportion of anthers that appeared unhealthy (dull yellow, brown, or black) varied. Usually the proportion of unhealthy anthers was higher in primary than in secondary or tertiary flowers of an inflorescence. Primary flowers often contained only unhealthy anthers. This condition was found in 90% of the primaries of ‘Benton’ in 1983 and in all those of ‘Tyee’ in both years. ‘Tyee’ released ≤6000 pollen grains per flower. When 75% or more of the flowers at a ranking had at least some healthy anthers, pollen production averaged ≥240,000 grains per flower. ‘Tyee’ had the highest incidence of misshapen fruit (18–19%) in both years. Comparable values were ‘Benton’, 14–17%; ‘Olympus’, 10–11%; and ‘Totem’, 7%. From 42% to 70% of the primary fruit of both ‘Tyee’ and ‘Benton’ were malformed each season. Low pollen production in ‘Tyee’ and ‘Benton’, a result of anther failure, likely contributed to the high incidence of malformation in primary fruit.
Factors Affecting Hedgerow Peach Orchard Establishment
Authors: Allison M.L. , Overcash J.P.
Published: August 2022

A hedgerow peach [Prunus persica (L.) Batsch.] orchard was established in 1980 at Pontotoc, Miss. to evaluate effects of cultural treatments on precocity of trees spaced 1.8 × 4.3 m (1292 trees/ha). Treatments were a trellis-trained, six-scaffold horizontal palmette tree or a central-leader tree both at two initial tree heights—0.6 m or 1.8 m—using Ca(NO3)2 or Sta-Green Super Nursery Mix at two rates. Two cultivars (Harbelle and Canadian Harmony) on ‘Lovell’ rootstock were used. Training systems did not affect growth or yield. Tall stock of ‘Canadian Harmony’ produced more fruit in 1981 than was produced on short stock. Central-leader tall stock of ‘Canadian Harmony’ with the high rate of Ca(NO3)2 produced the highest yield at 6.9 t·ha-1 in the 2nd year (1981). Calcium nitrate maintained soil pH at 6.6, but Sta-Green decreased it to 6.0. Calcium nitrate increased leaf Ν and Ca. Sta-Green increased leaf P, K, B, and Mn.
Growth Retardant Use with Potted Anemone and Ranunculus
Authors: Albrecht Mary Lewnes
Published: August 2022

Ranunculus asiaticus L. ‘Tecolote Giant White’ and Anemone coronaria L. ‘The Bride’ tubers were forced as spring pot crops in 1983 and 1984. Daminozide, ancymidol, and flurprimidol were used as preplant tuber dips or as foliar sprays. Foliar sprays were applied when the flower buds had grown to plant canopy height. A. coronaria ‘The Bride’ was not responsive to growth retardant treatment. Foliar application of ancymidol at 0.5 mg a.i./plant and daminozide as a 0.5% foliar spray were effective with R. asiaticus ‘Tecolote Giant White’ in reducing peduncle height without delaying time to anthesis. Daminozide as a 0.5% solution tuber dip provided an inadequate reduction in peduncle length at anthesis for either species. When ancymidol was used as a 1-min preplant tuber dip in the range of 10–25 mg a.i./liter of solution, excessive stunting and delay of anthesis resulted. Flurprimidol in the range of 3.0–10.0 mg a.i./liter as a preplant tuber dip and in the range of 0.1–10.0 mg a.i./plant as a foliar spray was effective in reducing peduncle length at anthesis. However, plants were considered unmarketable because of a slight delay in reaching full bloom and extreme growth reduction. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (anycmidol); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); and α-(1-methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol).
The Response of Rose Plants to Different Night Temperature Regimes
Authors: Zieslin N. , Khayat E. , Mor Y.
Published: August 2022

Four rose cultivars (‘Mercedes’, ‘Sonia’, ‘Visa’, and ‘Golden Times’) were grown under four night temperature regimes: 1) constant 18°C; 2) constant 14°; 3) 18° until midnight followed by 14° until 1 hr before sunrise; and 4) 18° alternated every 2 hr by 14°. A minimal temperature of 18° was maintained from 1 hr before sunrise in all treatments. Low temperature regimes resulted in an increase in the time period required for flower development and the number of flowers produced was lowest under the constant low temperature regime. The number of flowers produced under the two partial heating regimes was similar to the constant high temperature in 3 of the cultivars examined. Alternating the temperature every 2 hr stimulated the flower production of ‘Golden Times’. Under this regime, 28% more flowers were produced in comparison to a constant temperature of 18°.
Carbohydrate Changes in Sweet Potatoes During Curing and Storage
Authors: Picha David H.
Published: August 2022

The quantity and pattern of carbohydrate change during curing and storage differed among 6 sweet potato [Ipomoea batatas (L.) Lam] cultivars. ‘Travis’ contained the most total sugar and ‘Whitestar’ the least on a dry weight basis. Sucrose, the major sugar in raw sweet potatoes, sharply increased during curing (10 days at 32°C; 90% RH), and generally continued to increase in 4 orange-flesh cultivars during 46 weeks of 15.6° storage. Sucrose concentration decreased in 2 white-flesh cultivars after curing, followed by an increase after 14 weeks of storage. Glucose concentration was slightly higher than fructose in all cultivars except ‘Centennial’, which had similar monosaccharide concentrations. The pattern of monosaccharide change during curing and storage varied with cultivar, but generally increased during curing and the first 4 weeks of storage, followed by stabilization or a slight increase. Alcohol-insoluble solids (AIS) decreased with increasing lengths of storage in the 4 orange-flesh cultivars, which was attributed to continuous starch degradation. AIS increased during the first 4 or 14 weeks of storage in the 2 white-flesh cultivars, followed by a decrease during longer periods of storage.
Effect of Seasonal Soil Waterlogging on Vegetative Growth and Fruiting of Apple Trees
Authors: Olien William C.
Published: August 2022

Soil waterlogging imposed for 6-week periods in the spring, summer, or fall reduced vegetative growth and fruit yield of ‘Macspur’/Malling 26 apple (Malus domestica Borkh.) trees over their 7th to 9th growing seasons. Shoot and trunk growth were reduced most by spring and summer waterlogging. The relative decrease in shoot growth of summer-waterlogged trees increased over the three treatment years. Excavation of the trees in 1985 revealed that root dry weight was reduced markedly by summer waterlogging, but shoot dry weight was not affected by treatment. Average fruit yield was reduced severely by spring waterlogging (52%). Yield reductions increased with successive years of stress for all treatments, with the most marked trend over years associated with summer waterlogging. Decrease in yield was paralled by increased return bloom. There were no marked effects on fruit quality.
Rootstock and In-row Spacing Effects on Growth and Yield of Spur-type ‘Delicious’ and ‘Golden Delicious’ Apple
Authors: Archbold D.D. , Brown G.R. , Cornelius P.L.
Published: August 2022

The effects of in-row spacing (1.8, 3.0, and 4.3 m) and rootstock [seedling, Mailing Merton (MM) 111, MM 106, and Mailing (M) 7] on growth and yield of ‘Redspur Delicious’ (RS) and ‘Goldspur Golden Delicious’ (GS) apple (Malus domestica Borkh.) were studied over 14 years. Close in-row spacing generally reduced annual yield per tree of all scion-stock combinations. However, increased estimated yields per hectare resulted from close tree spacings, which compensated for the reduced yield per tree. RS/MM 106 generally had greater yield per tree than the others and exhibited greatest precocity. RS/seedling initially exhibited the lowest production per tree, although it eventually performed well. Of GS combinations, GS/M 7 generally performed best and GS/seedling poorest, although in early years the latter did well. Although a spacing × rootstock interaction on yield per tree or per hectare was not found in any year, significant spacing effects were first evident on clonal rootstocks (RS/MM 106, RS/M 7, GS/MM 111, GS/M 7). Cumulative production efficiency was affected by rootstock but not by spacing. RS and GS on MM 106 and M 7 were the most efficient, nearly twice that on seedling. Trunk cross-sectional area in 1984 was less on clonal than on seedling rootstocks. All combinations had smallest trunk size at the closest spacing.
Modification of the Water Stress-induced Floral Response in ‘Tahiti’ Lime
Authors: Southwick S.M. , Davenport T.L.
Published: August 2022

Treatments that inhibit production of citrus flowers, such as the presence of fruit, gibberellic acid (GA3) spray, and branch pruning, were examined on container-grown ‘Tahiti’ lime (Citrus latifolia Tan.) trees induced to flower by severe water stress lasting from 2 to 5 weeks. The presence of (or effects of recently removed) fruit located at the apex of branches inhibited production of new shoots as well as expression of the vegetative and floral nature of those shoots in basipetal lateral buds. Fruit ranging in size from 0.76 to 5.0 cm in equatorial diameter inhibited the shooting response. Shoot production and floral expression were normal on other branches. Fruit size or the amount of time fruit were present on branches were associated with the reduction in shoot and flower production. Aqueous GA3 sprays at 10−3 m concentration, applied at the onset or end of the floral inductive water stress treatment, inhibited expression of both vegetative and floral shoots. This inhibitory response dissipated as time elapsed after treatment. Pruning three branches from each tree replicate did not modify the flowering response in nonpruned water-stressed branches. The shooting response of branch units on these small trees responded independently to the presence or absence of fruit, GA3 treatment, and branch pruning.
Influence of Photoperiod on Crop Productivity and Form of Begonia × semperflorens-cultorum Grown as Bedding Plants
Authors: Hershey David R. , Merritt Richard H.
Published: August 2022

Seedlings of Begonia × semperflorens-cultorum Hort. ‘Scarletta’ were grown in a greenhouse at a plant density of 193 plants/m2. Crop productivity (grams of dry matter produced per day per square meter of crop) and crop productivity efficiency (percentage of the photosynthetic photon flux incident on the crop that is stored in the form of crop dry matter as energy of combustion) did not increase when the photoperiod was extended from 9 to 13 hr with incandescent lights. However, stem and petiole length did increase under 13- compared to 9-hr photoperiods. Crop productivity of begonia was less than maximum values reported for some other bedding plants. However, when crop growth was expressed in terms of fresh weight rather than dry weight, begonia crop growth exceeded that reported for other bedding plants. This increased growth seemed to be due to the low dry weight to fresh weight ratio in wax begonia of 0.03.
Growth of Three Native Prairie Perennials as Influenced by Phosphorus Fertilization, Potting Media, and Mycorrhizae
Authors: Zajicek Jayne M. , Albrecht M.L. , Daniels Hetrick B.A.
Published: August 2022

Seedlings of blue wildindigo [Baptisia australis (L.) R. Br.], rough gayfeather (Liatris aspera Michx.), and butterfly milkweed (Asclepias tuberosa L.) were grown in either a 1 soil : 1 sphagnum peat : 1 perlite (by volume) or 1 soil : 1 sand medium (v/v), amended with 0.00, 0.29, or 0.58 kg P/m3, and inoculated with Glomus etunicatum Becker and Gerd., G. fasciculatum (Thax. sensu Gerd.) Gerd. and Trappe, G. macrocarpum Tul. and Tul., G. mosseae (Nicol. and Gerd.) Gerd. and Trappe, or remained noninoculated. The objective was to determine whether vesicular-arbuscular mycorrhizal (VAM) fungi can establish and enhance plant growth, and how this would be affected by soil amendments. Replications were transplanted into the field to determine whether VAM pretransplant inoculation increased host growth and flowering. In the greenhouse, total dry weight of the three wildflower species grown in 1 soil : 1 sand (v/v) medium with no P was significantly improved by addition of most mycorrhizal species tested, but the response varied among plant species. At 0.29 kg P/m3, fewer mycorrhizal growth responses were evident. No growth responses were evident at 0.58 kg P/m3. B. australis was the only species that benefited from mycorrhizal inoculation in the 1 soil: 1 sphagnum peat: 1 perlite (by volume) medium at 0.00 and 0.29 kg P/m3. There were no differences in tissue P content within the three species when VAM-inoculated plants at 0.00 kg P/m3 were compared to noninoculated controls. At 0.29 kg P/m3 in the 1 soil : 1 sand medium, inoculated seedling tissue P increased, but in the 1 soil : 1 sphagnum peat : 1 perlite medium, noninoculated controls had significantly higher tissue P contents compared to inoculated seedlings. In the field, height and inflorescences per plant for the wildflowers were improved by VAM inoculation during the 2nd growing season.
Influence of Inoculum Placement Depth on Endomycorrhizal Fungal Infection and Perennial Ryegrass Shoot Growth
Authors: Frank J.B. , Petrovic A.M. , Mudge K.W.
Published: August 2022

Effects of several vesicular-arbuscular mycorrhizal (VAM) fungi on shoot growth and mycorrhizal development in ‘Citation’ perennial ryegrass (Lolium perenne L.) were studied as a function of inoculum placement depth. Soil columns were layered with inoculum at 0, 5, 10, or 20 cm prior to seeding. Three inocula were tested: 1) chopped roots and soil from sorghum (Sorghum bicolor L.) plants previously infected with the VAM fungus Glomus macrocarpus Tul. and Tul. var. macrocarpus; 2) a mixed inoculum from plants infected with G. macrocarpus var. macrocarpus; G. mosseae (Nichol. and Gerd.), G. faciculatum (Thaxter) Gerd. and Trappe, Gigaspora margarita Becker and Hall; 3) roots and soil from noninoculated sorghum plants. Shoot growth was greatest when VAM inoculum was placed at the surface, and declined progressively with deeper placement. Greatest mycorrhizal fungal infection of the root system occurred at the site of inoculum placement regardless of depth. The effectiveness of the surface-applied inoculum on enhancing the initial shoot growth (70 days) of perennial ryegrass in this study suggests that inoculation with VAM fungi might prove useful in low maintenance turfgrass culture.
A Conceptual Model Of Changes In Deep Supercooling of Dormant Sweet Cherry Flower Buds
Authors: Andrews Preston K. , Proebsting Edward L. , Sweet Lee Gail
Published: August 2022

A conceptual model of sweet cherry (Prunus avium L.) flower-bud deep supercooling during dormancy is presented. The extent of deep supercooling exhibited by the flower buds is expressed as the temperature of the median low-temperature exotherm (LTE50). The model calculates the LTE50 hourly, using air temperature, chill unit accumulation, and the previously calculated LTE50 in the decision pathways. An initial and updated LTE50 are determined experimentally by differential thermal analysis (DTA) in order to start the model at the beginning of the dormant season and to update it at periodic intervals. The model has been tested and validated. This model will overcome the delay in direct measurement and provide orchardists with a method of estimating critical flower-bud cold-hardiness temperatures for use in freeze-protection decisions.
Growth of ‘Thompson Seedless’ Grapevines: II. Nitrogen Distribution
Authors: Williams Larry E.
Published: August 2022

Nitrogen content and concentration were determined on field-grown ‘Thompson Seedless’ grapevines in the San Joaquin Valley of California. Individual vine replicates were harvested throughout the growing season over a 3-year period. There was a linear increase in vine N content from budbreak to 1000 growing degree days (GDDs) later. During this time, the accumulation of N was primarily in the stems and leaves. Subsequent to 1000 GDDs, the increase in vine N was due to the accumulation of N in the clusters. Throughout the season, N concentration in all vine parts decreased. The increase in cluster N content did not appear to occur at the expense of N remobilization from the vegetative structures measured in this study. On a single date, the N concentration of leaves varied throughout the canopy—the outer layer of leaves contained 3.2% N, while leaves in the interior of vine contained 2.4% N. The loss of N from the vine through leaf fall and cane pruning was about 20 and 15 g, respectively. The data were similiar from year to year with regards to both N concentration and content in leaves, stems, and clusters when plotted vs. GDDs. The approximate requirement of N for current season’s growth of ‘Thompson Seedless’ grapevines used for raisin production was 75 g/vine, or 84 kg·ha-1.
Carbohydrate Composition of Vascular System Exudates and Characterization of Their Uptake by Leaf Tissue of Pecan
Authors: Wood Bruce W.
Published: August 2022

In an effort to identify the primary transfer carbohydrates and to describe their characteristics of uptake by pecan [Carya illinoensis (Wangenh C. Koch)] leaf disks, it was discovered that the major carbohydrates in pecan xylem and phloem exudate and leaf free space leachate were sucrose, fructose, glucose, and inositol. Sucrose was the primary component of each of these systems. Uptake of sucrose, glucose, and fructose by leaf tissues was biphasic with a saturable active (sensitive to CCCP) carrier-like component and a nonsaturating passive (insensitive to CCCP) diffusion-like component. Uptake by the saturable component predominated at levels below 8 and 14 mM for fructose and glucose, respectively, and up to at least 40 mM for sucrose. The observations of a preponderance of sucrose in the free space of leaf disk and a sucrose Vmax an order of magnitude greater than for fructose or glucose suggests that sucrose is the major uptake carbohydrate moving from the leaf free space into the cytoplasm. The observation that uptake of any of these three sugars was noncompetitively inhibited by the other two sugars and that their uptake was unequally influenced by metabolic inhibitors suggests the possible presence of a separate carrier for each sugar. Sucrose uptake also appeared to be without hydrolysis and was coupled to the co-transport of protons with uptake diminishing with decreasing apoplastic proton levels.
The Role of Cell Wall-degrading Enzymes in the Formation of Gum Ducts in Almond Fruit
Authors: Morrison Janice C. , Greve L. Carl , Labavitch John M.
Published: August 2022

Cell wall-degrading enzymes were extracted from the cell wall free space of mesocarp tissue from immature almonds [Prunus dulcis(Mill.)D.A. Webb, ‘Nonpareil’]. The activities of several of these enzymes were found to correlate with the development of gum ducts in this tissue. Polygalacturonase (EC 3.2.1.15) and 1,3-β-D-glucanase (EC 3.2.1.39) activities rose sharply at, or just prior to, the early schizogenous stage of duct initiation, while increases in α-galactosidase (EC 3.2.1.22), β-galactosidase (EC 3.2.1.23), α-arabinosidase (EC 3.2.1.55), and α-mannosidase (EC 3.2.1.24) activities were correlated with the later lysigenous stage of duct formation. Cell wall analysis of almond mesocarp tissue sampled the week preceding gum duct formation determined that the predominant noncellulosic sugars present in the mesocarp cell walls are arabinose, galactose, xylose, and glucose, with smaller amounts of rhamnose and mannose also present. The walls also contain a high percentage of galacturonic acid and trace amounts of glucuronic acid. Methylation analysis of the cell walls confirmed that many of the specific glycosidic linkages that are cleaved by the enzymes tested are present in the mesocarp cell walls immediately prior to gum duct formation.
Salinity Effects on Asparagus Yield and Vegetative Growth
Authors: Francois L.E.
Published: August 2022

The effect of salinity on germination, first-year growth, and spear and fern yield of asparagus (Asparagus officinalis L.) was determined in germination dishes, crocks, and field plots, respectively. Saline treatments were imposed by irrigating with water that contained equal weights of NaCl and CaCl2. Spear yield was reduced 2.0% for each unit increase in salinity above 4.1 d S · m−1. Yield reduction was attributed primarily to a reduction in individual spear weight. Mature asparagus plants would be considered the most salt-tolerant crop commercially available. Asparagus possessed nearly the same salt tolerance for germination and spear production with soil salinities <7.2 d S·m−1. Above 7.2 dS·m−1, germination was less salt-tolerant. First-year growth was significantly more salt-sensitive than growth in subsequent years.
Effects of Apple Rootstocks and Nematicides on Pratylenchus penetrans Populations and Apple Tree Growth
Authors: Costante J.F. , Mai W.F. , Aleong J. , Klein R.M.
Published: August 2022

‘Rogers Red McIntosh’ (Malus domestica Borkh.) on Mailing Merton (MM)111, MM 106, Mailing (M) 26 and M 7a were planted within an old apple orchard site. The trees were trickle-irrigated and the sandy soil was treated with the nematicides Telone (C-17), Vorlex, or Nemacur 3. In 1984, data were collected from trees excavated at 50, 100, and 156 days after planting and from permanent trees in 1985 from plots treated with nematicides prior to planting. The numbers of Pratylenchus penetrans [(Cobb) Filipjev & Schuurmans-Stekhoven] in soil and rootstocks from nematicide treatments and controls were well below reported damage levels and not considered a problem on this test site. M 111 and MM 106 roots and ‘McIntosh’ scion growth were superior to M 26 and M 7a counterparts regardless of soil treatment in 1984, while only the scions on MM 111 were larger than those on M 26 in 1985. ‘McIntosh’ scions grew 36% larger on Telone C-17-treated soil and 19% larger on Vorlex-treated soil than on untreated soil. Leaf and soil analyses showed no interaction with rootstocks and minor differences between soil treatments in both years. A soil replant bioassay revealed disease factor(s), including P. penetrans, present in untreated soil.
Influence of Drought Stress and Mycorrhizae on Growth of Two Native Forbs
Authors: Zajicek Jayne M. , Hetrick B.A. Daniels , Albrecht M.L.
Published: August 2022

Seedlings of Baptisia australis (L.) R. Br. and Liatris aspera Michx., grown in prairie soil with no additional P, benefited significantly from inoculation with Glomus etunicatum Becker and Gerd., regardless of whether they were adequately watered or moderately or severely drought-stressed. In the presence of additional P, growth of severely droughted inoculated seedlings for both plant species was not significantly greater than noninoculated plants. When the influence of four Glomus species on growth of the two forbs was compared under drought-stress conditions with no supplemental P, growth of both plant species was signficantly improved by all fungal species compared to noninoculated controls. Preinoculated seedlings of both plant species were transplanted into disturbed-site soils with indigenous vesicular-arbuscular mycorrhizal (VAM) fungi present and subjected to severe moisture stress. After 12 weeks, inoculated seedlings were significantly larger than noninoculated seedlings for all soil types, with or without additional fertilizer (0.15 kg P/m3 + 0.075 kg N/m3). Under conditions of drought stress and low fertility, preinoculated seedlings of both B. australis and L. aspera grew significantly larger than noninoculated seedlings.
Effect of Extended Photoperiod on Budbreak, Overwinter Survival, and Carbohydrate Levels of Acer rubrum ‘October Glory’ Rooted Cuttings
Authors: Smalley Timothy J. , Dirr Michael A. , Dull Gerald G.
Published: August 2022

Acer rubrum L. ‘October Glory’ cuttings taken on 15 June 1984 were subjected to short day (SDT) (800-1700 HR) or short day plus night interruption treatments (NIT) (800-1700 plus 2200-200 HR) from 25 July until 22 Oct. 1984. Additional cuttings taken on 14 Aug. were subjected to the same photoperiod treatments from 10 Sept, until 22 Oct. For the 15 June cuttings, the NIT treatment induced significantly greater percent budbreak than the SDT, but did not induce significantly greater overwinter survival. Cuttings of 15 June that broke bud under NIT had significantly greater stem length and dry weight than cuttings that broke bud under SDT. SDT and NIT cuttings of 15 June that broke bud had significantly greater percent root carbohydrates, total grams of carbohydrates, and percent overwinter survival then cuttings that did not break bud. For the 14 Aug. cuttings, 1% of the cuttings broke bud, yet 95% (SDT) and 90% (NIT) of the cuttings survived the winter, and no difference in cutting carbohydrate levels, except stem starch, existed between the two treatments.
Effects of Maturity, Harvest Date, and Storage Time on Postharvest Quality of Red Raspberry Fruit
Authors: Sjulin Thomas M. , Robbins JoAnn
Published: August 2022

‘Meeker’ red raspberry (Rubus idaeus L.) fruit harvested at three maturity stages [inception (IN), red ripe (RR), and processing ripe (PR)] on four harvest dates at weekly intervals were held 0, 3, 6, and 9 days at 0°C and 90-95% RH. Fruit retention strength, firmness, and titratable acidity decreased with increasing maturity, while berry weight, total anthocyanin concentration, pH, and postharvest rot incidence increased. Fruit were darker visually with increasing maturity when compared to color standards. Soluble solids differences among stages of maturity were not consistent for all harvest dates. During storage, fruit at all stages of maturity increased in pH, total anthocyanin concentration, and postharvest rot incidence, but decreased in titratable acidity and darkened visually. The rate of increase in anthocyanin concentration and visual darkening was greater for IN and RR fruit than PR fruit. Total anthocyanin concentration accounted for 85% of the variation in visual darkness. Changes in red hues during storage, and differences in red hues among stages of maturity, were not consistent for all harvests and were not related to total anthocyanin concentration. Firmness increased during storage for the first harvest date, but decreased for the remaining three harvests. Berry weight, firmness, and titratable acidity decreased for all stages of maturity with later harvest dates, while postharvest rot incidence increased. This decrease in berry weight was greater for RR fruit than IN or PR fruit. Harvest date affected pH and rate of weight loss of all maturity stages and fruit retention strength of IN and RR fruit, but not PR fruit. Total anthocyanin concentration increased with later harvest dates of PR fruit, but did not change in IN or RR fruit. Soluble solids decreased linearly with harvest date in IN and PR fruit, but changed nonlinearly in RR fruit.
Influence of Root Temperature During Dormancy on Respiration, Carbohydrates, and Growth Resumption in Apple and Peach
Authors: Young Eric , Motomura Yoshie , Unrath C. Richard
Published: August 2022

Apple (Malus domestica Borkh.) (‘MM 111’ rooted layers) and peach (Prunus persica L. Batsch) (‘Lovell’ seedlings) trees were subjected to two root temperatures (5° and 16°C) in a cold room during dormancy with the shoot maintained at 5°. Trees were removed after specific cold treatments (5°), ranging from 0 to 1870 hr. Respiration and carbohydrate fractions were determined on shoots and roots immediately upon removal from the temperature treatments. A second set of trees treated identically were placed in a greenhouse for 30 days, and respiration, budbreak, new root number, and new root and shoot dry weights were determined. Warm (16°) root temperature reduced total soluble carbohydrates and respiration in roots of apple and peach after removal from the cold room, and this response did not change with additional chilling. Root starch levels of both species decreased with increased chilling time, but were not affected by root temperature. After 30 days in the greenhouse, budbreak, new shoot dry weight, and new root number and weight were significantly higher in apple trees that had their roots chilled as compared to those with unchilled roots. These parameters were independent of root temperature in peach. Respiration rates showed greater increases during the greenhouse phase, with increased shoot chilling in peach and root and shoot chilling in apple after the chilling requirements were surpassed. Shoot and root respiration rates did not rise in apple when the roots were not chilled.
Factors Affecting Exotherm Detection in the Differential Thermal Analysis of Grapevine Dormant Buds
Authors: Wolf Tony K. , Pool Robert M.
Published: August 2022

Differential thermal analysis was evaluated as a means of determining the cold hardiness of excised dormant buds of Vitis vinifera L. cv. Chardonnay grapevines. The manner in which buds were excised and cooled affected the freezing characteristics of bud primordia. Buds excised with 1 to 2 mm of subjacent nodal tissue exhibited both high temperature exotherms (HTEs) and low temperature exotherms (LTEs). HTEs apparently resulted from freezing of supercooled moisture in bud scales and/or in the subjacent nodal tissue and occurred at inconsistent temperatures. Cooling similarly excised buds on a water-saturated substrate caused HTEs to occur at −4° to −8°C and did not affect the occurrence of LTEs, which were consistently associated with primordia death. Median LTEs associated with primary bud death were 1.5° to 2.0° warmer than LT50s derived from temperature/survival freezing tests of similar buds. Buds killed by freezing did not supercool appreciably when refrozen. Bud cold hardiness increased when single-node cuttings were exposed to a step-wise cooling cycle; however, the ability to detect exotherms decreased under these conditions. The decreased detection of exotherms was due to increased bud death and, presumably, a decrease of freezable (and thus detectable) moisture in the supercooled primordia of viable buds. DTA provides a useful and reliable means of determining grapevine bud cold hardiness when conducted in a standardized fashion.
Use of Nitrogen Isotopes and a Light-textured Soil to Assess Annual Contributions of Nitrogen from Soil and Storage Pools in Mature Almond Trees
Authors: Weinbaum S.A. , Klein I. , Muraoka T.T.
Published: August 2022

Mature almond trees [Prunuis dulcis (Mill) D.A. Webb] growing on a very light-textured soil (Delhi sand) were “pulsed” in 1980 with a soil application of 15N-depleted ammonium sulfate. Leaching of labeled N from the soil and dilution (with unlabeled N carriers) of residual label in the soil minimized uptake of labeled N from this soil in subsequent years. The percent annual depletion (PAD) of labeled N in tissue samples was 50% and represented the percent annual influx of tree N from the soil N pool. Nitrogen assimilated in previous years also represented 50% of total tree N. The fractional contribution of N absorbed in any prior year, relative to the total pool of storage N, may be expressed as 1/(2)x, where x represents the number of years prior to the current year. The PAD, as measured in tissue samples, was greater in trees growing in the Delhi sand than among comparable trees growing in a heavier-textured soil (Yolo silty clay loam). A hyperbolic depletion function was fitted to the data to predict endpoints of tissue labeling. These endpoints were estimated to be 8.5 and 86.1 years on the light- and heavy-textured soils, respectively.
Nucleotide Metabolism in ‘Washington’ Navel Orange Fruit: I. Pathways of Synthesis and Catabolism
Authors: Tomlinson Patricia Tolson , Lovatt Carol J.
Published: August 2022

The capacity of ‘Washington’ navel orange fruit [Citrus sinensis (L.) Osbeck] to synthesize and catabolize purines and pyrimidines was assessed. De novo biosynthesis of purine nucleotide was demonstrated by [14C] bicarbonate incorporation into purine nucleotides, blockage of this process by four known inhibitors, and assimilation of radiolabeled carbon from formate, both carbons of glycine, and carbon-3 of serine into the adenine ring. De novo synthesis of pyrimidines via the orotate pathway in young fruit was demonstrated by incorporation of [14C] bicarbonate and [6-14C]orotic acid into uridine nucleotides, release of 14CO2 from [7-14C]orotic acid, and blockage of these processes by 6-azauridine. Synthesis of purine and pyrimidine nucleotides via salvage reactions was demonstrated by incorporation of radiolabeled bases and ribonucleosides into nucleotides and into nucleic acids. Release of 14CO2 from radiolabeled adenine, adenosine, hypoxanthine, and xanthine, uric acid, urea (purines), uracil, and uridine (pyrimidines) provided evidence the pathways for catabolism (degradation) of purines and pyrimidines in navel orange fruit are similar to those found in microorganisms and animal tissues. To the best of our knowledge, this report is the first to assess the capacity of anabolic and catabolic pathways of purine and pyrimidine nucleotide metabolism in fruit of any species. De novo synthetic activities in orange fruit permit increases in the pools of purine and pyrimidine nucleotides using simple precursors. Further, the patterns of salvage and catabolism suggest riboside pools are reused predominantly as nucleotides, while the majority of base pools are degraded to permit recycling of carbon and nitrogen into other metabolites.
Endogenous Gibberellins and Cytokinins in Spear Tips of Asparagus officinalis in Relation to Sex Expression
Authors: Ombrello Thomas M. , Garrison Stephen A.
Published: August 2022

Endogenous gibberellins (GA) and cytokinins (CK) were extracted from asparagus (Asparagus officinalis L.) spear tips, purified, and determined by lettuce hypocotyl and amaranthus bioassays, respectively. There was no quantitative difference in GA-Iike activity between heterogametic male and female spears. The major GA fraction in asparagus spears has 1 OH group. Asparagus spears contain 3 major fractions of CK-like activity. Fraction 1 eluted from Sephadex LH-20 and C18 HPLC columns with or before zeatin-riboside. Fractions 2 and 3 eluted in a similar pattern to IPA-riboside and IPA, respectively. There were higher levels of CK fraction 2 and trends toward higher levels of fraction 1 and total CK in female than in heterogametic male spears. There were also higher CK:GA ratios in female than in heterogametic male spears. The data support the hypothesis that sex in asparagus is controlled in part by CK levels or by CK:GA ratios.
Genotype × Environment Interactions in Sweet Potato Yield and Quality Factors
Authors: Collins Wanda W. , Wilson L. George , Arrendell Susan , Dickey Lynn F.
Published: August 2022

Genotype (G) x environment (E) interactions were measured in sweet potatoes (Ipomoea batatas L.) for yield (seven genotypes, six locations, 3 years) and selected quality factors (nine genotypes, six locations, 2 years). Yield of all grades of roots and all quality factors tested were affected significantly by genotype, environment, and G × E interactions. Quality factors were less affected by G × E interactions than yield factors. Broad-sense heritability estimates ranged from 75% to 92% for yield factors and 94% to 99% for quality factors. Estimates of variances of clonal means with varying years, locations, and replications suggest that 2 years, four locations, and four replications would provide reliable test data for yield and quality factors.
Effect of Fertilization Rates and Sources on Rabbiteye Blueberry
Authors: Spiers J.M.
Published: August 2022

Rabbiteye blueberries (Vaccinium ashei Reade) were fertilized with various sources and rates of nutrients over a 4-year period. There were no positive differences in plant growth responses to fertilizer source or rate. At the 80 g/plant rate, plants fertilized with Ca(NO3)2 were chlorotic and lower in plant height and vigor than control (no fertilizer) plants. Plants treated with 160 g of either 13N-6P-11K fast release, (NH4)2SO4, or Ca(NO3)2 fertilizer were shorter than control plants. Plants fertilized with cottonseed meal, 14N-6P-12K slow release, and NH4NO3 did not differ from control plants, regardless of application rate. Fruit yield was highest at the 40 g/plant rate regardless of fertilizer source.
Growth and Survival of the Highbush Blueberry in Response to Root Zone Flooding
Authors: Abbott John D. , Gough R.E.
Published: August 2022

Flooded, 2-year-old highbush blueberry plants (Vaccinium corymbosum L. ‘Bluecrop’) survived 30 months of continuous flooding, but vegetative growth was suppressed after ≈4 months. Plants continuously flooded for 4 months and subsequently placed in the field recovered partially. The greatest number of plants died when flooding began in April and the least number when it was begun in December.
Response of Perennial Cultured Strawberries to Fall Planting
Authors: Caldwell J.D. , Grimes L.W.
Published: August 2022

Certified, fresh-dug plants of ‘Apollo’ and ‘Earlibelle’ strawberry (Fragaria × ananassa Duch.) were set in single plant rows on 23 Sept., 7 Oct., 21 Oct., and 5 Nov. 1982 at in-row spacings of 7.5, 15, 22.5, and 30 cm. Leaf, inflorescence, flower and fruit number per plant, and fruit size and yield were determined in Spring 1983. The highest yield and fruit numbers were obtained from the 23 Sept. plantings. Yields decreased with each delay in planting through 21 Oct., but the affected yield components varied with planting date, plant spacing, and cultivar. Total yield increased as plant spacing decreased for each planting date. Plant spacing had no effect on fruit size.
Improvement of Gibberellin Efficiency in Prolonging the Citrus Harvest Season by the Surfactant L-77
Authors: Greenberg J. , Monselise S.P. , Goldschmidt E.E.
Published: August 2022

L-77, a nonionic organo-silicone block copolymer surfactant, significantly increased [14C]GA3 uptake and physiological effects of GA3 on ‘Marsh’ seedless grapefruit, as compared with the commonly used surfactant Triton B 1956. Effects on fruit strength at harvest were assessed by testing rheological parameters and evaluating peel color. Corroborating results also were obtained in field trials with ‘Minneola’ tangelo and ‘Clementine’ tangerine. Using L-77, even one single fall application of 1 ppm GA3 proved commercially effective.
Effects of Parthenocarpy on Fruit Quality in Tomato
Authors: Diaz A.V. Casas , Hewitt J.D. , Lapushner D.
Published: August 2022

Two parthenocarpic tomato (Lycopersicon esculentum Mill.) lines segregating for male sterility were grown in the field in three plantings. Male-fertile plants produced both seeded (showing more than five seeds when cut in half transversely) and low-seeded (showing 0-5 seeds) fruit, whereas male-sterile plants produced only parthenocarpic fruit. The objective of the experiment was to compare the compositional quality of seeded and low-seeded fruit from male-fertile plants with parthenocarpic fruit from male-sterile plants. Young fruit were thinned from male-fertile plants so that they would have fruit loads similar to the male-sterile plants. Parthenocarpic fruit were found to have higher percent soluble solids than low-seeded fruit, which, in turn, had higher values than seeded fruit. In general, parthenocarpic and low-seeded fruit had higher pH values than seeded fruit. Only seeded and parthenocarpic fruit were used to compare total solids, the ratio of water insoluble solids : total solids (WIS:TS), titratable acidity, and color. Parthenocarpic fruit, in general, had significantly higher total solids than seeded fruit. No consistent differences between fruit types were observed for WIS:TS ratio, titratable acidity, or color.
Effect of Seed Treatment and Planting Method on Tabasco Pepper
Authors: Sundstrom F.J. , Reader R.B. , Edwards R.L.
Published: August 2022

In the laboratory, gibberellic acid (GA3) applied to Tabasco pepper (Capsicum frutescens L.) seed at 1000 ppm for 48 hr and priming in 2.75% KNO3 for 144 hr significantly stimulated seed germination performance (a function of germination rate and percent germination). In the field, GA3-treated and primed seed treatments were direct-seeded or plug-mix planted and were evaluated for germination, emergence, and yield. In addition, a pregerminated plug-mix seed treatment and a transplanting treatment also were evaluated. Seed priming and GA3 treatment significantly decreased field emergence of both direct-seeded and plug-mix planted treatments. Seedling emergence percentages of untreated seed that was direct-seeded, and pregerminated seed that was planted in plug-mix were significantly higher than other treatments. Greatest stand percentage was observed in the pregerminated seed treatment. Mean rates of emergence increased in primed and pregerminated seed treatments. Total fruit yields of Tabasco were increased by transplanting or pregerminated seed treatments; red fruit yields were greater in pregerminated seed treatments.