bluuebunny/crossref_metadata_2025 huggingface dataset:
Internal Ethylene Levels and Maturity of ‘Delicious’ and ‘Golden Delicious’ Apples Destined for Prompt Consumption
Authors: Blankenship Sylvia M. , Unrath C.R.
Published: August 2022

Internal ethylene levels, fruit firmness, soluble solids content, and starch–iodine reaction in ‘Delicious’ and ‘Golden Delicious’ apples (Malus domestica Borkh.) were measured weekly for 6 to 8 weeks during fruit maturation for 3 years. Internal ethylene level did not consistently correlate with minimum maturity as judged by agricultural inspection or optimum maturity as judged by a taste panel in either cultivar. Internal ethylene levels ranged from 0 to 26 μl·liter−1 in ‘Delicious’ and 0 to 41 μl·liter−1 in ‘Golden Delicious’ on taste panel harvest dates. Decreases in fruit firmness and increases in starch conversion and soluble solids content were observed prior to any increase in internal ethylene in both ‘Delicious’ and ‘Golden Delicious’. Thus, internal ethylene concentration is not a reliable index of maturity for harvest determination for immediate sale on the fresh market. The combination of fruit firmness decrease, soluble solids increase, and conversion of starch seem to be more closely tied to perception of maturity by both the agricultural inspectors and taste panel.
Flooding Duration and Seasonal Effects on Growth and Development of Young Rabbiteye Blueberry Plants
Authors: Crane Jonathan H. , Davies Frederick S.
Published: August 2022

The response of 3-year-old ‘Woodard’ rabbiteye blueberry (Vaccinium ashei Reade) plants to 0, 5,15, 25, and 35 days of flooding during spring and summer of 1984 and 1985 was studied under field conditions. Soil oxygen diffusion rate (ODR) and redox potential (Eh) of flooded plots were significantly lower than those of unflooded plots within 2 days of flooding. After plots were released from flooding, soil Eh recovered to control levels within 10 days but ODR did not. Almost 100% of the plants survived flooding treatments in 1984, whereas plant survival decreased to 83% after 25 days of spring and 67% after 5 days of summer flooding in 1985. Stem elongation and leaf expansion were inhibited after about 15 days of spring and 7 days of summer flooding. The number of flower buds formed during the fall was reduced by about 30% and 70% after as little as 5 days of summer flooding in 1984 and 1985, respectively. Fruit set decreased by 13% and 29% after 25 days of spring flooding in 1984 and 1985, respectively. Yields were not consistently affected by spring flooding, but decreased significantly after 35 days in 1984 and 25 days in 1985.
Response of Blueberry Species to Excessive Manganese
Authors: Korcak R.F.
Published: August 2022

The response of blueberries (Vaccinium spp.) to added Mn was studied in soil, solution, and sand cultures. Weekly additions of up to 0.8 mg Mn to Berryland sand soil (4.3 kg/pot) for 7 months produced the most growth in highbush blueberries, and additions of 6.4 mg Mn/week resulted in growth reductions but no visual toxicity symptoms. Solution culture- (800 ml/bottle) grown ‘Blueray’ highbush blueberries tolerated Mn additions up to 96 μg·ml−1 without significant growth reductions. Under similar conditions, a lowbush clone grew best at high added Mn and had higher foliar Mn concentrations than did ‘Blueray’, the rabbiteye cultivar ‘Tifblue’, or a selection of Vaccinium elliotti Chapman. Lowering solution Ca, Mg, and NO3 levels sharply increased foliar or stem Mn concentrations of all species. Growth of three genetically diverse hybrid blueberry progenies were not signficiantly affected by relatively high levels of applied Mn or Al when grown in sand culture. Increasing Al had a greater effect on increasing root Mn concentrations than did an increase in Mn levels. There were no visual Mn toxicity symptoms expressed in any of the three media from excessive Mn levels.
Effects of Root Pruning at Four Levels of Severity on Growth and Yield of ‘Melrose’/M.26 Apple Trees
Authors: Schupp James R. , Ferree David C.
Published: August 2022

Vigorous 15-year-old ‘Melrose’/M.26 apple (Malus domestica Borkh) trees were mechanically root-pruned annually for 4 years at full bloom on two sides of the trunk at a distance of 60 or 80 cm and to a depth of 25 or 50 cm at each distance. Compared to unpruned controls, trees that were root-pruned had reduced trunk cross-sectional area, shoot length, leaf size, pre-harvest fruit drop, fruit size, and pruning time. Although fruit yield was unaffected, yield efficiency, fruit color, and soluble solids were increased by root pruning. Canopy light penetration was increased, as was spur quality. Generally, pruning 60 cm from the trunk had a greater effect than pruning at 80 cm, while pruning depth had no influence.
Effects of Dissolved Oxygen Concentrations in Aero-hydroponics on the Formation and Growth of Adventitious Roots
Authors: Soffer Hillel , Burger David W.
Published: August 2022

Cuttings of Ficus benjamina L. and Chrysanthemum × morifolium(Dendranthema grandiflora tzvelev.) were rooted in aero-hydroponics to study the effect of dissolved oxygen concentrations in the range of 8 mg·liter. (ambient saturation) to 0 mg·liter−1. The results of this study indicate that dissolved oxygen is essential to root formation and root growth. Woody (Ficus) and herbaceous (Chrysanthemum) cuttings responded similarly. Lowering the dissolved oxygen concentration increased the time required to form adventitious roots, reduced rooting percentages, reduced numbers of roots formed per cutting, and reduced average root lengths. Comparisons between stirred and unstirred water suggested the development of an area of depleted oxygen concentration (boundary layer) at the stem-water interface on cuttings immersed in unstirred water. Cuttings in water stirred constantly rooted sooner and formed more roots than did those in unstirred water. Maximum rooting occurred in misted (high dissolved oxygen concentrations) sections of cuttings suspended in the aero-hydroponics chambers. Chemical name used: potassium salt of lH-indole-3-butyric acid (K-IBA).
Carbohydrate Relationships of Citrus jambhiri Inoculated with Glomus fasciculatum
Authors: Dixon R.K. , Garrett H.E. , Cox G.S.
Published: August 2022

Root exudation patterns and carbohydrate composition of roots and leaves of Citrus jambhiri Lush, were examined during the period of initial colonization by Glomus fasciculatum (Thaxt.) Gerd. and Trappe. Exudation of reducing sugars and amino acids from seedling roots decreased as soil and root P increased. Comparison of vesicular-arbuscular mycorrhizal (VAM) seedlings to nonmycorrhizal seedlings of similar size and P nutrition revealed root exudation in VAM plants decreased following fungal colonization. Root reducing sugars increased and root starch content decreased in VAM seedlings during the infection process. Following establishment of symbiosis, leaves of VAM seedlings had greater levels of total soluble sugar, sucrose, reducing sugars, and starch relative to nonmycorrhizal controls. Colonization of C. jambhiri roots by VAM fungi apparently alters the balance of carbohydrates within leaves and roots.
Effect of Pruning System on Yield Components of Two Summer-bearing Raspberry Cultivars
Authors: Nehrbas Stanley R. , Pritts Marvin P.
Published: August 2022

Effects of annual pruning, alternate-year mowing, and primocane suppression on yield and its components for ‘Titan’ and ‘Royalty’ summer-bearing raspberries (Rubus idaeus and R. neglectus) were measured for 2 consecutive years. Cumulative yield was highest for primocane suppression and lowest for alternate-year mowing. Path analysis revealed that cane number per plant and number of fruitful laterals per cane were the most important yield components for both cultivars. Alternate-year mowing plots had higher cane numbers per plant than other treatments, but fewer fruitful laterals in the bottom and middle thirds of the canes. Annual primocane suppression increased numbers of fruitful laterals in the bottom and middle thirds of canes, resulting in increased yield compared to other treatments. Productivity was related to the amount of photosynthetically active radiation entering the canopy.
Controlled Atmosphere Storage of Ontario-grown Celery
Authors: Smith Richard B. , Reyes Andres A.
Published: August 2022

Total weight loss of < 10% over a 10-week period was achieved by storing celery in atmospheres containing 1% O2 combined with 2% or 4% CO2 at 0°C. Significant increases in marketable celery resulted when C2H4 was scrubbed from some atmospheres. A combination of 1% or 2% O2 and 2% or 4% CO2 prevented black stem development during the storage period. Improved visual color, appearance, flavor, and increased marketable celery justifies the use of 4% CO2 in celery storages.
Relationship of Endogenous Gibberellin and Cytokinin Levels in Shoot Tips to Apical Form in Four Strains of ‘McIntosh’ Apple
Authors: Looney N.E. , Taylor J.S. , Pharis R.P.
Published: August 2022

Shoot tips collected in June from ‘Summerland Red McIntosh’ (nonspur), ‘Macspur’, ‘Morspur’, and ‘McIntosh Wijcik’ apple (Malus domestica Borkh.) were examined for polar and less-polar gibberellins (GAs) and for cytokinin-like bioactivity. The latter three strains are increasingly compact and spurry, with ‘McIntosh Wijcik’ exhibiting a distinctive columnar growth habit. ‘McIntosh Wijcik’ shoot tips exhibited significantly lower levels of polar GAs, but the levels of less-polar GAs were similar in all four strains. Conversely, ‘McIntosh Wijcik’ displayed higher levels of cytokinin-like substances than the other three strains. These results are discussed in relation to the physiology of the spur-type growth habit of ‘McIntosh Wijcik’ apple and its progeny.
Supercooling in ‘Darrow’ Blackberry Buds
Authors: Warmund Michele R. , George Milon F. , Cumbie Billy G.
Published: August 2022

Differential thermal analysis (DTA) experiments, viability tests, and anatomical studies were conducted to investigate the biophysics of freezing in ‘Darrow’ blackberry (Rubus spp.) buds at selected stages of development from Nov. 1985 through Sept. 1986. As many as four low-temperature exotherms (LTEs) associated with the crystallization of supercooled water were detected in DTA experiments on buds collected 16 Nov. 1985. Anatomical observations revealed seven to nine floral initials present at that date. On 16 Jan. 1986, buds were morphologically similar to those examined in November, with four to 10 LTEs per bud. By 2 Mar., the size of the floral initials increased and distinct floral parts were evident. One to 10 LTEs were observed per bud at this date. Five to seven floral initials were observed in buds collected on 23 Sept. 1986, but floral parts were not evident. DTA experiments conducted in September revealed one or no LTE per bud. The median LTEs for November, January, March, and September buds were −20.5°, −28.0°, −22.0°, and −16.5°C, respectively. T50 values calculated from viability tests were within 4.5° of the median LTEs at all test dates. These results indicate that injury to the entire floral region is associated with a single freezing event when ‘Darrow’ blackberry buds are at an early stage of development. However, as floral differentiation progresses, individual primordia supercool, freeze, and are injured independently.
Scion Water Relations During Union Development in Colorado Blue Spruce Grafts
Authors: Beeson R.C. , Proebsting W.M.
Published: August 2022

The role of scion water relations was studied using Colorado blue spruce (Picea pungens Engelmann ‘Hoopsi’) scions on Norway spruce [Picea abies (L.) Karst.] rootstocks grown either in a greenhouse or in a covered, unheated lath house. In greenhouse-grown grafts, total water potential (ψT) and relative water content (RWC) of the scions declined rapidly the first 2 weeks. Thereafter, both ψT and RWC were maintained or gradually increased in successful grafts. With scion budbreak, ψT rapidly increased to −1.0 MPa. This increase occurred 1 to 2 weeks after tracheid connections matured, based on dye movement through the graft union. At the same time, the ψT and RWC of unsuccessful grafts declined rapidly. Osmotic potentials (ψw) increased 3 weeks prior to budbreak in successful grafts. However, ψπ declined in unsuccessful grafts more rapidly than ψT, resulting in increased calculated turgor pressures with graft failure. Lath house-grown grafts had higher scion ψT and higher graft success than those in the greenhouse, but required more time for union development. Based on this data and previous work, an hypothesis relating changes in ψT, maturation of connecting tracheids, and scion budbreak to graft success or failure is presented.
Aviary and Field Evaluations of Sweet Corn Resistance to Damage by Blackbirds
Authors: Dolbeer R.A. , Woronecki P.P. , Mason J.R.
Published: August 2022

Each of 11 cultivars of sweet corn (Zea mays L.) was presented to red-winged blackbirds (Agelaius phoeniceus L.) in an aviary under no-choice conditions in 1985. This evaluation was repeated in 1986 with eight cultivars, five of which had been tested in 1985. In both years, there were significant differences in damage among cultivars; the damage rankings of the cultivars tested in both years were correlated. Total husk weight and husk weight beyond the cob tip individually explained 68% to 69% of the variation in damage among cultivars. Husk characteristics were more important than kernel characteristics in determining the amount of damage a cultivar received. Six of the cultivars evaluated in a field test near a blackbird roost showed differences in damage similar to that found in the aviary. In the field test, the most- and least-resistant cultivars had 16% and 76% of the ears damaged, respectively. Resistance is a viable approach to reduce damage in situations where sweet corn is grown near concentrations of blackbirds.
Performance of ‘Hamlin’ Orange on 30 Citrus Rootstocks in Southern Florida
Authors: Wutscher Heinz K. , Bistline Fred W.
Published: August 2022

‘Hamlin’ orange, Citrus sinensis (L.) Osbeck, was grown on 30 rootstocks for 8 years in an area between Florida's east coast and Lake Okeechobee. There were eight five-tree replications in randomized blocks, with 3×6-m spacing. Yield and fruit quality were determined at four harvests and tree size (trunk cross sectional area) and tree losses were recorded. In general, tree on trifoliate orange [Poncirus trifoliata (L.) Raf.], trifoliate hybrids, and tangelo (C. paradisi Macf. × C. reticulata Blanco) rootstocks survived better than trees on mandarin, C. reticulata, and sour orange (C. aurantium L.) rootstocks. Most of the losses were due to tristeza virus and phytophthora root rot. The largest trees were on Volkamer and rough lemon (C. limon L. Burm. f.), F 80-18 citrumelo, C. paradisi × P. trifoliata, Troyer citrange, C. sinensis × P. trifoliata, and Sampson tangelo. Fruit production (kg/tree) was best on Volkamer lemon, Swingle, and F 80-18 citrumelo, and hybrid FF 1-131-20 (C. reticulata × P. trifoliata). In terms of kilograms of solids/tree, trees on Swingle and F 80-18 citrumelo, on hybrid FF 1-131-20, and on Sunshine tangelo were the most productive. Average juice content was low because of two late harvests, but other fruit characteristics were normal. Rind color was exceptionally good on Alamoen shaddock (C. paradisi).
Influence of Leaf Removal, Root Pruning, and Soil Addition on the Growth of Greenhouse-grown Strawberry Plants
Authors: Chandler Craig K. , Miller Diane Doud , Ferree David C.
Published: August 2022

Experiments were conducted to examine strawberry (Fragaria × anannassa Duchesne) plant renovation practices, singly and in combination, for effects on vegetative growth of greenhouse-grown, potted strawberry plants. The major results of these experiments were as follows: a) most of the plants that were both defoliated and root-pruned after fruit harvest died; b) there was a negative linear relationship between the number of leaves removed and the number of new leaves and runners produced; c) root, leaf, and total plant dry weights were negatively correlated with the severity of root pruning; and d) soil addition after fruit harvest decreased the shoot : root ratio of multiple-crown plants, but had no effect on single-crown plants.
Yield and Quality Responses of Celery and Crisphead Lettuce to Excess Boron
Authors: Francois Leland E.
Published: August 2022

The boron tolerance of celery [Apium graveolens L. var. dulce (mill.) Pers.] and lettuce (Lactuca sativa L.) was determined in large, outdoor sand cultures. Boron treatments were imposed by irrigation with culture solutions that contained 1.0, 3.0, 6.0, 9.0, 12.0, or 15.0 mg B/liter in 1984-85 and 0.5, 1.0, 5.0, 10.0, 15.0, or 20.0 mg B/liter in 1985-86. Relative yields of celery and lettuce were decreased 3.2% and 1.7% with each unit (mg·liter−1) increase in soil solution B (Bsw) above 9.8 and 1.3 mg B/liter, respectively. Celery plants harvested from treatments > 10.0 mg B/liter were immature, bitter tasting, and not of marketable quality. Leaf margin injury on lettuce was confined to the outer wrapper leaves, which were removed at harvest.
Numerical Expression for Estimating the Minimum Ethylene Exposure Time Necessary to Induce Ripening in Banana Fruit
Authors: Inaba Akitsugu , Nakamura Reinosuke
Published: August 2022

A numerical expression for the minimum treatment time (MTT) for ethylene necessary to induce ripening in banana [Musa (AAA group, Cavendish subgroup) ‘Giant Cavendish’] fruit was determined using the concentration of applied ethylene, fruit temperature, and a number of fruit variables. The content of sugars, organic acids and ACC, and the activity of the ethylene-forming enzyme (EFE) in the fruit just prior to ethylene treatment were measured as fruit variables. In a linear regression analysis between MTT determined at 30°C with 1000 μl·liter−1 ethylene and each fruit variable, significant correlations were found with ACC (r = −0.84) and individual sugar content. MTT (y hours) in banana fruit treated with a selected ethylene concentration (x μl·liter−1) at a given temperature (t °C) could be estimated from their initial ACC content (k nmol·g−1) by the following equation: y = (0.202 − 0.238k)t2 − (11.92 − 13.1k)t + 185.8 − 190.7k − (0.02t2 − 1.3t + 22)log10x. When the calculated values for MTT were compared with the observed values, this equation adequately represented the MTT for Japanese commercial bananas. Chemical name used: 1-aminocydopropane-1-carboxylic acid (ACC).
Harvest Indices, Dessert Quality, and Storability of ‘Jonagold’ Apples in Air and Controlled Atmosphere Storage
Authors: Lau O.L.
Published: August 2022

Starch index (SI) was correlated negatively with starch content and positively with internal ethylene concentration (IEC) and logarithm to the base 10 of IEC (loglEC) in ‘Jonagold’ (Malus domestica Borkh.) apples. The initial rapid increase in SI, loglEC, and yellow ground color coincided with one another and occurred ≈20 days before the increase in IEC and incidence of watercore (WC). In 1984, 1985, and 1986, the first acceptable picking date for British Columbia-grown ‘Jonagold’ was about 10 Oct., when the fruit had attained an acceptable amount of color (50% to 85% area greater than No. 2 red color and 4.0-4.5 yellow color units on a 0-10 scale) and a good level of firmness (73-76 N), soluble solids (13.5% to 14.5%), starch (SI of 6.5-7.0 on a 0-9 scale), and acids (661-782 mg malate/100 ml of juice), but without much WC (2% to 13%) or ethylene (0.3-1.5 μl·liter−1 IEC; 5% to 40% of fruit with IEC > 1 μl·liter−1). Fruit picked on 20 Oct. were softer, lower in acids and storage potential, and more susceptible to WC, coreflush (CF), and breakdown (BD) than those picked 10 Oct. Fruit harvested from mature trees stored well at 0°C in air until February and in controlled atmosphere (CA, 1.5% O2 + 1.5% CO2) until June. Fruit from young trees were large and developed BD in air storage as early as November; fruit afflicted with BD were lower in Ca and higher in K : Ca ratio than those free of the disorder. Dessert and sensory ratings were higher in ‘Jonagold’ than in ‘McIntosh’, ‘Golden Delicious’, ‘Spartan’, and ‘Delicious’ and were also higher in fruit from CA than from air storage.
Postharvest Glyphosate Application Reduces Toughening, Fiber Content, and Lignification of Stored Asparagus Spears
Authors: Saltveit Mikal E.
Published: August 2022

Standing freshly harvested 21-cm asparagus spears (Asparagus officinalis L.) in 50 ml of 1 mg·liter−1 to 10 g·liter−1 aqueous glyphosate solutions significantly decreased toughening and the amount of fiber and lignin in spears stored at 2.5°C for 10 or 20 days. The effect increased with storage time and concentration, but decreased with distance from the cut end. Depending on the time of harvest and length of storage, 1 g·liter−1 glyphosate increased the usable portion of the spear from 40% to 60%. Chemical name used: N-(phosphonomethyl)glycine (glyphosate).
Compositional Changes in Ginger Rhizomes During Storage
Authors: Paull Robert E. , Chen Nancy Jung , Goo Theodore T.C.
Published: August 2022

Compositional changes in ginger (Zingiber officinale Rosc.) rhizome stored at 22° or 12.5°C were studied. The rhizome surface Hunter “b” value increased from 9.2 to 18 in 4 weeks. Water loss did not become significant until 12 weeks of storage at 22°. There was little increase in dry matter of rhizomes stored at 12.5°. Rhizome crude fiber content, oil percentage, total phenols, and protein content did not change significantly. Rhizome total sugar increased significantly during storage at 12.5° for 32 weeks with pungency increasing 5-fold, as measured by gingerol content. No significant volatile flavor changes were noted, with rhizome variation being greater than storage effect. The changes in rhizome surface color did not lead to a significant loss in quality. The increase in pungency could be regarded as a favorable improvement in the fresh ginger market. The loss of water and increase in dry matter percentage significantly decrease overall appearance and quality of rhizomes stored at 22°.
Screening Interspecific Blueberry Seedling Populations for Drought Resistance
Authors: Erb W. Alan , Draper Arlen D. , Swartz Harry J.
Published: August 2022

Open-pollinated species, interspecific hybrid seedling populations, and selected clones propagated by softwood cuttings and tissue culture were used to further evaluate the use of dry soil to screen blueberry seedlings for drought resistance. These different propagation types of Vaccinium (subgenus Cyanococcus) were screened for drought resistance in a Galestown fine sandy loam soil. The soil was permitted to dry to progressively higher soil tension levels to a maximum of 0.8 MPa. The plants were evaluated by scoring them on a 1 to 9 shoot damage rating scale and by determining the fraction of total biomass partitioned as roots. Drought resistance in blueberries is heritable and there is a high degree of genetic diversity within and among Vaccinium spp. for resistance to water deficits. Southern species (Vaccinium darrowi Camp, V. elliottii Chapman, and V. ashei Reade) were more drought-resistant than northern species (V. corymbosum L., V. vacillans Torrey, and V. myrtilloides Michaux), which demonstrated the reliability of this soil screening method. Clones with half their germplasm from southern species were usually drought-resistant. This screening method can be used to select for shoot and root vigor and drought resistance in 6- to 7-month-old blueberry seedlings.
Stability in Fruit Yield, Soluble Solids, and Citric Acid of Eight Machine-harvested Processing Tomato Cultivars in Northern Ohio
Authors: Berry S.Z. , Uddin M. Rafique , Gould W.A. , Bisges A.D. , Dyer G.D.
Published: August 2022

Stability and variation of fruit yield, soluble solids, and citric acid content of eight tomato (Lycopersicon esculentum Mill.) cultivars over 6 years were investigated. The cultivar Ohio 7814 exhibited above-average yield and yield stability. The cultivars showed a wide range of variation for percent soluble solids and citric acid. The cultivar Ohio 7870 was least variable in soluble solids, and ‘Heinz 2653’ most variable. Regarding citric acid, ‘Heinz 722’ had the largest seasonal variation, whereas ‘Ohio 7814’ had the least. A linear relationship between fruit yield and percent soluble solids was not detected on the basis of 6 years of data.
Relationship Between Achene Number, Achene Density, and Berry Fresh Weight in Strawberry
Authors: Strik Bernadine C. , Proctor John T.A.
Published: August 2022

Field-grown genotypes (Fragaria × ananassa Duchesne) were studied in two seasons to determine the relationship of primary berry fresh weight to the total number of achenes per berry and the number of achenes/cm2 of receptacle tissue. Within genotypes grown in matted rows (1985), berry fresh weight was correlated with the total number of achenes per berry. In the hill system (1986), berry weight was correlated with the number of achenes and the number of achenes/cm2. Genotypic variation in berry weight in the matted row was related to the total number of achenes. In the hill system, there were no differences in the total number of achenes per berry between high- and low-yielding genotypes, but the highest-yielding genotype had fewer achenes/cm2.
Freezing Woody Plant Stems Produces Acoustic Emissions
Authors: Weiser Russell L. , Wallner Stephen J.
Published: August 2022

Freezing woody stem segments of supercooling and non-supercooling species resulted in acoustic emissions in characteristic reproducible patterns. In the supercooling species examined (Fraxinus americana, Malus × ‘Dolgo’, Pyrus communis, and Fraxinus pennsylvanica), many acoustic emissions began after extracellular freezing, but before freezing of the supercooled fraction, and ended near −40°C. Acoustic emissions also occurred in species that did not supercool (Pinus edulis, Pinus ponderosa, and Cornus sericea), but to a much lesser extent. Cavitation of water within the cells during freezing is discussed as a source of acoustic emissions and possible cause of freezing injury.
Influence of Herbicides on Bermudagrass Greens Overseeded With Perennial Ryegrass
Authors: Johnson Billy J.
Published: August 2022

Two field experiments were initiated to determine the effects of herbicides on turfgrass quality and spring to summer transition from overseeded perennial ryegrass (Lolium perenne L.) back to ‘Tifway’ bermudagrass [Cynodon transvaalensis Burtt-Davy × Cynodon dactylon (L.) Pers.]. Pendimethalin applied at 3.3 kg·ha−1 in early March hastened the transition from ryegrass to bermudagrass in one of two years, but 1.7 kg·ha−1 applied in each of two applications did not. A single application of pronamide at 0.28 kg·ha−1 hastened the transition of overseeded ryegrass to bermudagrass without severely injuring either turfgrass. Oryzalin, oryzalin + benefin, or paraquat severely reduced the quality of ryegrass, while oxadiazon at 3.3 kg·ha−1, oxadiazon + benefin, glyphosate, metribuzin, or MSMA did not affect transition from overseeded ryegrass to bermudagrass when compared with nontreated turfgrass. This study illustrates the potential for some herbicides to enhance the transition from perennial ryegrass to bermudagrass. Chemical names used: N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine (benefin); dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA); (±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate (ethofumesate); N-(phosphonomethyl)glycine (glyphosate); N-[2,4-dimethyl-5-[[(trifluoromethyl) sulfonyl]amino]phenyI]acetamide (mefluidide); 4-amino-6-(1,1-dimethylethyl)-3-(methylthiol)-1,2,4-triazin-5(4H)-one (metribuzin); monosodium salt of MAA (MSMA); 4-(dipropylamino)-3,5-dinitrobenzene-sulfonamide (oryzalin); 3-[2,4-dichloro-5-(1-methylethoxy)-phenyl)-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one-(oxadiazon); 1,1'-dimethyl-4,4'-bipyridinium salts (paraquat); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzamine (pendimethalin); and 3,5-dichloro(N-1,1-dimethyl-2-propynyl)benamide (pronamide).
Tomato Production and Weed Control in Notillage Versus Conventional Tillage
Authors: Shelby Paulus P. , Coffey David L. , Rhodes G. Neil , Jeffery Larry S.
Published: August 2022

Field studies were conducted in 1983 and 1984 to evaluate the feasibility of growing fresh-market tomatoes (Lycopersicon esculentum Mill. ‘Floradade’) in no-tillage or conventional tillage systems and to evaluate the efficacy of postemergence herbicides under both tillage systems. In 1983, marketable fruit yields in no-tillage were nearly twice those from conventional tillage. In 1984, there were no statistical differences in marketable yields among herbicide treatments or between tillage systems. Yields were higher in 1984 than in 1983, largely due to more favorable growing conditions. In both years, metribuzin provided good broadleaf weed control. In 1983, annual grasses were better controlled in no-tillage with a sequential metribuzin application for fluazifop following metribuzin than with a single metribuzin application. Marketable yields were highest in plots where annual grasses were adequately controlled. Sequential metribuzin applications provided good broadleaf weed control and postemergence grass herbicides each provided excellent annual grass control in 1984. Chemical names used: (±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop); 4-amino-6-(1,1-diemthylethyl)-3-(methyIthio)-1,2,4-triazin-5(4H)-one (metribuzin).
Phosphorus Concentration and Application Interval Influence Growth and Mycorrhizal Infection of Tomato and Onion Transplants
Authors: Waterer Douglas R. , Coltman Robert R.
Published: August 2022

Transplants of ‘Healani’ tomato (Lycopersicon esculentum Mill.) and ‘Yellow Granex’ onion (Allium cepa L.) inoculated with the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus aggregatum (Schenck and Smith emend. Koske) were grown in peat-vermiculite fertilized with solutions containing 4, 16, 64, or 256 mg P/liter, applied daily or every 4 or 8 days. Increasing the total amount of P available to the transplants by either increasing the P concentration or by decreasing the interval between applications increased plant total fresh weights (TFW) and shoot P concentrations, but decreased root VAMF infection. Inoculation reduced tomato TFW when P availability was high. Inoculation increased onion shoot P concentrations and TFW only when P availability was very low. Frequent applications of solutions low in P produced larger transplants with higher levels of VAMF infection than did similar total amounts of P supplied less frequently but at higher concentrations. Different combinations of P concentration and application intervals were required for the production of vigorous mycorrhizal tomato and onion transplants.
Axillary Shoot Abscission in Pecan and Its Relationship to Growth Regulators
Authors: Wood Bruce W.
Published: August 2022

The relatively low incidence of axillary shoot development in pecan [Carya illinoensis (Wangenh.) C. Koch] and its detrimental impact on nut productivity prompted: 1) an evaluation of methods to induce axillary shoot morphogenesis, and 2) estimation of levels of endogenous phytohormones in abscising and nonabscising axillary shoots. Retention of developing shoots from 1-year-old terminals was increased three-fold by ringing. Application of benzyladenine (BA) delayed, but did not prevent, shoot abscission, whereas abscisic acid (ABA), indoleacetic acid (IAA), and gibberellic acid (GA3) applications had no detectable effect. Normal morphogenesis of axillary shoots was independent of the presence of developing catkins. Phytohormones tentatively identified in pecan axillary shoots and catkins were IAA, ABA, dihydrozeatin riboside (DHZR), t-zeatin riboside (ZR), trans-zeatin (Z), and dihydrozeatin (DHZ). A possible influence of these substances on budbreak and shoot morphogenesis is discussed. Axillary shoots eventually abscising exhibited a substantially higher level of IAA-like and ABA-like substances than did shoots completing morphogenesis. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine(BA); abscisic acid (ABA); 1H-indole-3-acetic acid (IAA); gibberellic acid (GA,).
Ripening of Mature-green Tomato Fruit Slices
Authors: Mencarelli Fabio , Saltveit Mikal E.
Published: August 2022

Equatorial 7-mm-thick slices of mature-green tomato fruit (Lycopersicon esculentum, Mill., cv. Castlemart) ripened normally, and changes in the concentrations of lycopene, soluble solids content, and titratable acids and in pH were analogous to, although in some cases significantly different from, changes in whole fruit that were harvested when mature-green and ripened. An untrained taste panel scored ripened slices acceptable to good, and no off-flavors were detected. Slices of mature-green tomato fruit can be ripened to an acceptable level of quality, and could provide an additional outlet for fresh-market tomatoes to the home and institutional markets.
Genetic Analysis of Isozyme Polymorphism in Grape
Authors: Weeden Norman F. , Reisch Bruce I. , Martens Mary-Howell E.
Published: August 2022

Genetic analysis of 11 allozyme polymorphisms was performed on the progeny of ‘Cayuga White’ × ‘Aurora’, two complex interspecific grape (Vitis) hybrids. Segregation for most of the polymorphisms closely approximated monogenic Mendelian ratios, and eight new isozyme loci were defined for grape. Joint segregation analysis among the isozyme loci revealed three multilocus linkage groups. These results demonstrate that sufficient allozyme polymorphism exists in grape to establish many multilocus linkage groups and that this genetic analysis can be accomplished using extant progeny or progeny readily produced from highly heterozygous clones.
Ethylene-induced Defoliation in Ficus Species and Ethylene Depletion by Soil Bacteria in Peat-amended Media and in Vitro
Authors: Turner Melanie A. , Reed David W. , Morgan David L.
Published: August 2022

Ficus benjamina L. and F. stricta Miguel. were exposed to various concentrations of ethylene gas and ethephon to determine their sensitivity to defoliation. F. stricta was more sensitive to ethephon, whereas F. benjamina was more sensitive to ethylene gas. Plants growing in medium exposed to ethylene gas depleted ethylene from the ambient atmosphere. Double-autoclaving the peat : perlite growing medium prevented ethylene depletion, indicating soil microbes as the source of depletion. Bacterial isolates from the medium depleted ethylene in vitro; fungal isolates did not deplete ethylene. The eight species of bacteria isolated into pure culture depleted 9% to 46% of the ethylene from the flask atmosphere over 5 days, with two Enterobacter spp. and one Pseudomonas sp. being the most effective depleters. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).
Modeling and Simulation of Tree Wraps and Microsprinkler Irrigation for Young Citrus Freeze Protection: II. Factors Affecting Protection
Authors: Rieger Mark , Smerage Glen H. , Davies Frederick S. , Jackson Larry K.
Published: August 2022

Computer simulation was used to study factors affecting freeze protection of young citrus trees using tree wraps and microsprinkler irrigation. Simulation results suggest tree wraps provide 1° to 2°C more freeze protection when air temperature decreased linearly rather than exponentially with time toward a minimum value. Tree wraps provided greater freeze protection when air temperature decreased rapidly (0.75°/hr) than slowly (0.5° or 0.25°/hr). Thus, variation in rate and pattern of air temperature decrease among freeze nights may be responsible for inconsistent levels of freeze protection observed with tree wraps. Changing irrigation water temperature from 12° to 7° or 17° produced changes in trunk temperature under radiative, but not advective, freeze conditions. Simulated positioning of the microsprinklers to maximize coverage of the wrap surface with water provided better freeze protection than positioning that resulted in increased water interception. Increasing windspeed from 0 to 10 m·s−1 reduced temperature of an irrigated wrapped trunk by 5°. Without irrigation, temperature of a wrapped trunk was largely unaffected by windspeed. Reducing humidity from 80% to 20% had a negligible effect on trunk temperature of irrigated wrapped trees under radiative and advective freeze conditions.
Effect of Storage Temperature, Duration, and Gibberellic Acid on the Flowering of Zantedeschia elliottiana and Z. ‘Pink Satin’
Authors: Funnell Keith A. , Tjia Benny O. , Stanley C. Jill , Cohen Daniel , Sedcole J. Richard
Published: August 2022

Tubers of Zantedeschia elliottiana (Watson) Engl. and the hybrid Z. ‘Pink Satin’, a Z. rehmannii Engl.-like selection, were stored at 5°C. Over a 3-month period they were transferred to incubators at 12°, 18°, or 24° for 2, 4, 6, 8, or 12 weeks of holding. One-third of these tubers were planted in moist media during this time; the remaining tubers were stored dry and on removal were sprayed with either gibberellic acid (GA3) at 50 mg·liter−1 or distilled water before planting and transfer to a greenhouse. The proportion of flowering of dry-stored tubers of Z. elliottiana was reduced by prolonged storage at 5°. Subsequent storage at 12° did not reduce this proportion, but, at 18° and 24° flowering was reduced further. Tubers of Z. ‘Pink Satin’ were less sensitive to the duration of dry storage at 5°, but increasing time of storage at all subsequent temperatures caused a progressive decrease in the proportion of tubers that flowered. The proportion of moist-stored tubers of both selections that flowered was greater than that for tubers stored dry for an equivalent time. A preplant treatment with GA3 enabled almost total compensation for reduced flowering except after the longest period of storage.
Sulfur-coated Urea as a Slow-release Nitrogen Source for Onions
Authors: Brown Bradford D. , Hornbacher Albert J. , Naylor Denny V.
Published: August 2022

Field studies with onions (Allium cepa L. cv Monarch) were conducted in 1980 and 1981 to compare preplant-banded sulfur-coated urea (SCU) with preplant-banded and split applications of urea. Treatments were evaluated at two N rates, 56 and 224 kg·ha−1. Root NO3-N and soil NO3-N concentrations in bed centers indicated slower release of N from SCU than from urea. Nevertheless, total and large bulb (> 76 mm in diameter) yields and N uptake in onion bulbs and leaves from SCU were significantly higher under low-N conditions than with preplant urea, but did not differ significantly from split urea treatments.
Aerobic–anaerobic Respiratory Transition in Pear Fruit and Cultured Pear Fruit Cells
Authors: Boersig Michael R. , Kader Adel A. , Romani Roger J.
Published: August 2022

The extinction point (EP), defined as the lowest O2 concentration at which alcohol production ceases, was a useful concept in early interpretations of the Pasteur effect in fruit. However, ethanol is now known to be a normal constituent of many fruits under aerobic conditions. Therefore, we propose an alternative concept, the anaerobic compensation point (ACP), defined as the O2 concentration at which CO2 evolution is minimum. After 2 to 4 hr under various O2 concentrations, the ACPs of mature-green pears (Pyrus communis L.) and pear cell cultures are 1.6% to 1.7% and 1.1% to 1.3% O2, respectively. The ACP shifts to lower O2 concentrations upon extended exposure of the cells to low-O2 atmospheres and to higher O2 concentrations as pear fruit mature physiologically or as the diffusion coefficient of cell suspensions is decreased. With O2 diffusion coefficients of 4.4, 3.7, and 2.5 × 10−6 cm2·s−1, the ACP effect is observed just below 1.3%, 3.0%, and 5.0% O2, respectively. Analogies between the responses of intact fruit and suspension-cultured cells to limiting O2 are illustrated and use of the latter in assessing the response of pear cells to changing coefficients of diffusion is discussed.
Evaluation of Storage Methods for ‘Granex’ Onions
Authors: Smittle Doyle A.
Published: August 2022

‘Granex’ onions were stored in an air-conditioned room at 27°C, at 5° in air, 5% CO2−3% O2 or 10% CO2−3% O2, and at 1° in air or 5% CO2−3% O2. Relative humidity of storages at 5° and 1° was maintained at 70% to 85%. The quantity of marketable bulbs decreased 12% to 25% per month when stored at room temperature. Virtually all onions were marketable after 7 months of storage at 1° in 5% CO2−3% O2. More than 92% of these bulbs remained in a marketable condition after an additional 3 weeks in air at room temperature. Bulb quality of these sweet onions decreased during storage, as indicated by lower sugar concentrations and greater pungency. Bulb quality decreased most rapidly when onions were stored in air at 1° and least rapidly when onions were stored in 5% CO2−3% O2 at either 1° or 5°.
Changes in Carbohydrates and Osmotic Potential during Rhythmic Expansion of Rose Petals
Authors: Evans Richard Y. , Reid Michael S.
Published: August 2022

Rhythmic pulses of irreversible petal expansion in rose (Rosa hybrida L. ‘Sonia’) petals cause diurnal changes in the rate of flower opening. Time-lapse cinematography revealed a transient increase in the rate of rose flower opening that commenced shortly before the onset of a light period and lasted for a few hours. Petal expansion, which occurred sequentially from the outer to the innermost whorl, involved rhythmic increases in fresh and dry weights. The amount of expansion was greatest in the distal portion of each petal and least near the petal base. Periods of rapid expansion were accompanied by decreases in starch and increases in soluble sugars in the petals, but the total carbohydrate content of the petals remained constant during a light–dark cycle. During expansion, the osmotic potential of the outer petal increased from −790 to −690 kPa. Starch hydrolysis during petal growth appears to be important for maintenance of cell size, but it is not the factor controlling cell expansion.
Salinity Can Enhance Freeze Tolerance of Citrus Rootstock Seedlings by Modifying Growth, Water Relations, and Mineral Nutrition
Authors: Syvertsen J.P. , Yelenosky George
Published: August 2022

Seedlings of ‘Pineapple’ sweet orange [Citrus sinensis (L.) Osbeck] (Swt), Cleopatra mandarin (C. reshni Hort ex Tan) (Cleo)], and trifoliate orange [Poncirus trifoliata (L.) Raf.] (Tri) were grown from seed for 10 months in 2-liter containers of native Candler fine sand in a glasshouse, watered two times per week, and fertilized weekly with a complete nutrient solution. NaCI at 0, 15, 30, or 60 mM was added to the watering solution for 2 additional months. Increases in salinity decreased hydraulic conductivity of roots, transpiration rate, leaf water potential, and root growth. The effect of salinity on mineral composition of tissues was rootstock-dependent. High salinity leaves of Tri had the highest N, K+, and Cl− but the lowest Na+, whereas Tri roots had the highest Na+ at the highest salinity. High-salinity Cleo leaves had the lowest Cl− and K. All seedlings survived −4°C for 6 hr in a controlled freeze test. Salinity decreased leaf loss, except in the deciduous Tri, in which 60 mM NaCI may have been excessive. Thus, moderate salinity treatment can reduce growth and modify water and mineral nutrient relations so as to increase cold hardiness of certain Citrus species.
Selection for Virus Tolerance in Strawberry Seedlings in Relation to Virus Source and Plant Age
Authors: Robbins JoAnn , Sjulin Thomas M.
Published: August 2022

Strawberry (Fragaria × ananassa Duch.) seedlings were planted in a greenhouse at 3- to 4-week intervals and simultaneously inoculated at ages 80, 101, 129, or 157 days with either of two naturally occurring virus sources each of which contained a mottle, mild yellow edge, and crinkle virus complex. Inoculation by aphids with either virus source reduced vigor, petiole length, leaflet width, stolons per plant, and vegetative dry weight of plants in the greenhouse. The tendency of virus inoculation to reduce vigor and petiole length was inversely proportional to increasing seedling age. In the field, inoculated seedlings were also less vigorous than control seedlings. Virus source effects and seedling age interactions with virus source were not significant. Selection for virus tolerance, based on greenhouse vigor, petiole length or leaflet width measurements, increased the frequency of seedlings subsequently classified as virus-tolerant in the field in both 80- and 101-day-old seedlings. Selection based on greenhouse vigor or petiole length increased the frequency in 129-day-old seedlings. No greenhouse selection method evaluated was effective in 157-day-old seedlings.
Identification of Pineapple Cultivars by Isozyme Genotypes
Authors: DeWald Maria G. , Moore Gloria A. , Sherman Wayne B.
Published: August 2022

Starch gel electrophoresis of leaf tissue samples was used to distinguish pineapple [Ananas comosus (L.) Merr.] cultivars. Isozyme genotypes at two peroxidase and three phosphoglucomutase loci allowed the unique identification of 15 of the 27 cultivars examined. The hypotheses that some cultivars originated as either sports or hybrids were confirmed by the allozyme data.
Genetic Transformation and Foreign Gene Expression in Walnut Tissue
Authors: Dandekar Abhaya M. , Martin Lori A. , McGranahan Gale
Published: August 2022

A system was developed to transform walnut cultivars using the natural gene transfer system of Agrobacterium tumefaciens. We report the infection of English walnut (Juglans regia L.), northern California black walnut (Juglans hindsii), and their F1 hybrid ‘Paradox’ with A. tumefaciens carrying various recombinant derivatives of the tumor-inducing (Ti) plasmids, pTiA6 and pTiB6S3. The three walnut species, each represented by a single micropropagated clone, were found to be equally susceptible to Agrobacterium-induced tumor formation in vitro. Stable lines were established from tumors induced on each clone, and, unlike normal stem callus, these tumor cells grew rapidly in culture media without exogenous plant hormones. High-voltage paper electrophoretic analysis revealed the presence of opines in the walnut tumor tissue. The presence of a foreign gene was demonstrated by expression of a chimeric bacterial gene that encodes resistance to the antibiotic kanamycin, and also by the presence of foreign DNA sequences in genomic DNA isolated from tumors.
Quality of ‘Tifblue’ Rabbiteye Blueberries and Efficiency of Machine Harvesting at Different Times of Day
Authors: Patten Kim D. , Neuendorff Elizabeth W. , Nimr Gary
Published: August 2022

Fruit from 7- and 8-year-old ‘Tifblue’ rabbiteye blueberry [Vaccinium ashei (Reade)] plants were harvested at 0600, 0900, 1200, and 1500 hr. Harvests occurred twice a season for each of 2 years. Fruit cullage after machine harvesting averaged ≈30% of total fruit harvested. The first machine harvest in a season had 6% to 16% less cullage than the last harvest. The number of mature fruit remaining on the plants after harvesting decreased with later harvest times during the day. Thus, an increase in harvester efficiency corresponded to decreased leaf water potential. The effect of harvest time during the day on packout and fruit quality after storage was inconsistent between and within years. There was no optimum time of day to machine-pick blueberries when fruit were promptly sorted and cooled after harvest.
Combining Ability Estimates for Early Blight Resistance in Tomato
Authors: Maiero Marisa , Ng Timothy J , Barksdale Thomas H.
Published: August 2022

Six inbred tomato (Lycopersicon esculentum Mill.) genotypes and 13 hybrids among them were evaluated at two locations for resistance to early blight (Altemaria solani). The breeding lines 71B2, C1943, and NC EBR-1 were the most resistant, while ‘Castlejay’ was consistently the most susceptible. Hybrid means for area under the disease progress curve (AUDPC) generally were intermediate to their parental values, indicating quantitative genetic control. Five of the parents were included in a diallel mating design to obtain estimates of general combining ability (GCA) and specific combining ability (SGA) for the resistance trait. Both GCA and SCA were highly significant; the GCA component accounted for 88.2% of the genotypic variation.