bluuebunny/crossref_metadata_2025 huggingface dataset:
Gibberellin Inhibits Fruit Abscission Following Seed Abortion in Peach
Authors: Stutte G.W. , Gage J.
Published: January 2019

Seed coats of developing fruit of peach [Prunus persica (L.) Batsch cvs. Redkist, Redskin, and Loring] were punctured at 31, 33, and 38 days after full bloom (DAFB), respectively. Injections of water, 390 mg GA3/liter, or 390 mg GA4+7/liter were made immediately following seed puncture. Seed puncture and water injection following puncture resulted in abscission of all fruit. Injection of GA3 and GA4+7 delayed abscission of `Redkist' and `Redskin' fruits of punctured seeds by 6 to 10 days. Both GA treatments resulted in normal growth into Stage II and increased fruit retention through Stage III in `Loring'. About 100 μl of 250, 500, or 1000 mg GA3/liter was injected into the locule of `Loring' fruits following seed puncture at 30, 40, or 50 DAFB. GA treatments at 30 DAFB resulted in≈ 75% fruit set in comparison to seeded control fruit, while fruit treated at 40 and 50 DAFB abscised by the end of Stage II. Increasing GA concentration from 250 to 1000 mg·liter-1 had no additional effect. Movement of the GA was examined by injecting 3H-GA1 into the locule following the puncture treatment. More than 97% remained in the fruit after 96 hours. The percentage of 3H recovered in the seed cavity decreased over time, whereas recovered label increased in both endocarp and mesocarp. The results suggest a potential regulatory role for seed-produced gibberellins during early Stage I of development. We have identified an apparent change in tissue sensitivity to gibberellin induction of seedless fruit development between 30 and 40 DAFB in `Loring' peach.
Effect of Photoperiod and Shoot Decapitation on Flowering of Leucospermum `Red Sunset'
Authors: Malan Daniel G. , Jacobs Gerard
Published: January 2019

Incandescent light night break (NB) and day continuation (DC) prevented flower formation in Leucospermum R.Br. cv. Red Sunset. Natural short days (NSD) during winter were inductive for flowering of intact shoots until 28 Aug. (Southern Hemisphere), but only until 24 July for decapitated shoots. Vegetative axillary buds released from correlative inhibition by shoot decapitation were less responsive to inductive short days (SD) than distal axillary buds on intact shoots. At least 42 inductive SD cycles were required for normal flowering after cessation of shoot growth. The effective length of the NB depended on the length of the NSD of winter. A 2-hr NB prevented flowering in vegetative buds released from correlative inhibition by shoot decapitation on 3 Mar., but was inadequate for axillary buds on shoots decapitated on 1 May. When the NB was begun during winter and discontinued before natural day (ND) lengths became too long in spring, the flowering time was delayed.
Leaf Color Retention, Dark Respiration, and Growth of Red-leafed Japanese Maples Under High Night Temperatures
Authors: Deal D.L. , Raulston J.C. , Hinesley L.E.
Published: January 2019

Red- and purple-leafed seedlings and clonal material selected for superior color and growth under northern climatic conditions may exhibit progressive color loss and reduced growth rates when exposed to the hot summers and high night temperatures of more southern climates. Studies were conducted to characterize the color loss associated with red-leafed seedlings of Acer palmatum Thunb. (Japanese maple), and to determine to what extent night temperatures affect the dark respiration, growth, and anthocyanin expression of A. palmatum `Bloodgood'. The percentage of seedlings within each of five color classes was determined for five dates from spring to early fall. Significant shifts in class distribution occurred on every evaluation date tested. The class changes contributing the most to these shifts varied with age of leaf material and date. Dark respiration rates increased by 0.09 mg CO2/g leaf dry weight per hour for every 1C rise in temperature, regardless of exposure duration. Dark respiration rates of 0.69 and 1.73 mg CO2/g per hour were found at 14 and 26C, respectively. The greatest amount of growth occurred during weeks 6 through 8 at a night temperature of 14C. Plant growth during this period increased by an average 51%, compared to that at warmer night temperatures. Ultimately, total plant growth at 14C decreased 7%, 19%, and 32% as night temperatures increased from 18 to 22 to 26C. Leaf redness index values at 14 or 18C were from two to seven times greater than those at warmer night temperatures.
Association of Epicuticular Sugars with Aphid Resistance in Hybrids with Wild Tomato
Authors: Goffreda J.C. , Steffens J.C. , Mutschler M.A.
Published: January 2019

Behavioral studies have shown that aphid resistance in Lycopersicon pennellii (Corr.) D'Arcy is due to the presence of sugar esters in glandular exudate of the type IV trichomes. In this study, various methods for the estimation of epicuticular sugar ester concentrations were examined. There was a significant negative relationship between the concentration of sugar esters on the leaf and the level of potato aphid infestation in a segregating L. esculentum × L. pannellii F2 population. Selection for sugar ester accumulation should be an efficient selection technique for the aphid resistance of L. pennellii and other species that synthesize epicuticular sugar esters.
Establishment and Yield of Asparagus as Influenced by Planting and Irrigation Method
Authors: Sterrett S.B. , Ross B.B. , Savage C.P.
Published: January 2019

New Jersey `Syn 4' asparagus (Asparagus officinalis, L.) was grown on a sandy loam soil to compare plant survival and yield of asparagus grown from crowns and transplants under four irrigation treatments: sprinkler (SPR), surface trickle (ST), subsurface trickle (SST), and no irrigation (NI). While plant survival of crowns was not appreciably influenced by any irrigation treatment, survival of transplants was significantly increased by SST. Total and marketable yields from crowns and transplants were similar in the first harvest season (year 3). However, in years 4 and 5, the yield of crowns was higher than that of transplants. Subsurface trickle increased yield from transplants in years 4 and 5 and increased yield from crowns in year 5. All irrigation methods significantly increased both spear production (spear/ha) and average spear weight. Subsurface trickle irrigation resulted in the largest increase over NI in total yield and spear production.
Response of Easter Lily Bulbs to Peat Moisture Content and the Use of Peat or of Polyethylene-lined Cases during Handling and Vernalization
Authors: Prince Timothy A. , Cunningham Maria S.
Published: January 2019

Lining of shipping cases with low-density polyethylene (PE) greatly reduced moisture loss from packing media and bulbs of Lilium longjlorum Thunb. `Nellie White' during shipping, handling, and case vernalization (CV). Three years of studies showed that use of PE liners accelerated floral sprout emergence above the growing medium, floral bud initiation, and flowering date. Effects of case lining became more pronounced as the initial water content of the spagnum peat packing was lowered. Case lining sometimes increased apical meristem diameters measured immediately after vernalization, or 2 or 4 weeks after bulb planting, but flower bud number was never significantly increased. Root growth during the first 4 weeks after planting was not affected by case lining. Bulb scale and basal plate water contents at planting were greater in lined than nonlined cases and when packed in peat of relatively high moisture content. Handling and vernalization of bulbs in PE-lined cases without a packing medium resulted in similar bulb forcing characteristics as in bulbs held in PE-lined cases packed with sphagnum peat.
Thinning of Spur `Delicious' Apples by Shade, Terbacil, Carbaryl, and Ethephon
Authors: Byers R.E. , Barden J.A. , Carbaugh D.H.
Published: January 2019

Terbacil applied to whole-spur `Delicious' apple (Malus domestica Borkh.) trees reduced photosynthesis and fruit set. The addition of the surfactant X-77 to terbacil sprays increased fruit thinning and leaf injury. Terbacil sprays applied to leaves only (fruit covered with foil) were as effective as when applied to leaves plus fruit. Dipping fruit alone in a terbacil solution did not cause abscission. Shading trees for 4 days with 92% polypropylene shade material reduced fruit set =50%. Spraying trees with carbaryl reduced fruit set by 25%. The combination of shade + carbaryl spraying reduced fruit set by 89%. Chemical names used: l-naphthalenyl methylcarbamate (carbaryl); 3-tert- butyl-5-chloro-6-methyluracil (terbacil); 2-chloroethylphosphonic acid (ethephon); alkaryl polyoxyethylene alcohols (X-77).
Growth and Productivity of Vigorous `Northern Spy'/MM.106 Apple Trees in Response to Annually Applied Growth Control Techniques
Authors: Elfving D.C. , Cline R.A.
Published: January 2019

Beginning in 1982, daminozide (DZ) was applied annually for 5 years to whole, 5-year-old `Northern Spy'/MM.106 (Malus domestics Borkh.) trees: a) shortly after bloom, b) together with ethephon (ETH) 6 to 7 weeks after bloom, or c) after harvest. Controls were unsprayed. One-half of the trees receiving each growth regulator treatment were summer-pruned after terminal-bud formation each year. Postharvest DZ reduced shoot numbers, mean shoot length, trunk enlargement, and fruit size, but had little or no effect on bloom, fruit set, or yield. Postbloom DZ, summer DZ plus ETH, and summer-pruning reduced vegetative growth and time required for dormant-pruning, but only postbloom DZ and summer DZ plus ETH increased spur density in the tree. Postbloom DZ and summer DZ plus ETH increased both flowering and cropping in 3 of the 5 years, with little effect on fruit set. Fruit size was reduced only in years when cropping was enhanced. Total yields (1982-86) were increased 34% and 36% by postbloom DZ and summer DZ plus ETH, respectively. Summer-pruning had no effect on fruit size in any year, but reduced yields in 1984 and 1986. Year-to-year fluctuation in yield was unaffected by any treatment. Growth-control treatments had no direct effect on foliar or fruit macronutrient concentrations. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); 2-chloroethylphosphonic acid (ethephon).
Variation in and Relationship of Biomass, Growth Rate, Harvest Index, and Phenology to Yield of Common Bean
Authors: Scully B.T. , Wallace D.H.
Published: January 2019

A diverse set of 112 common bean (Paseolus vulgaris L.) accessions were evaluated for variation in eight traits related to yield over a 2-year period. Days to flower, days of pod fill, and days to maturity ranged from 25 to 66, 44 to 83, and 70 to 133, respectively, in upstate New York: Yield and biomass ranged from 81 to 387 and 270 to 1087 g•m-2, respectively. Harvest index ranged from 12% to 65%. The biomass (biomass/days to maturity) and seed (yield/days of pod fill) growth rates ranged from 3.2 to 9.3 and 1.2 to 9.5 g•m-2 -day-1, respectively. The economic growth rate (yield/days to maturity) extended from 0.6 to 5.7 g•m-2 -day-1. The growth rates, biomass, and days of pod fill were linearly and positively related to yield. Biomass and the growth rates explained a large amount of the variation in yield, with r2 values between 0.71 and 0.84; days of pod fill explained the least, with r2 = 0.09. Yield followed a curvilinear relationship with days to flower and days to maturity; yield was maximized at 48.5 days to flower and 112.2 days to maturity. Yield was a quadratic function of harvest index and maximized at 57.2%. Among these three curvilinear traits, days to flower explained 80% of the variation in yield, while days to maturity and harvest index accounted for 25% and 12.5%, respectively. The “ideal” genotype for New York was defined at these maximum values for harvest index, days to maturity, days to flower, and at 63.7 days of pod fill. Additionally, a simple equation is proposed to aid breeders in the selection of common bean accessions with strong sink strength. It is defined as “relative sink strength”: RSS = seed growth rate/biomass growth rate. Values > 1.0 implied strong sink capacity in common beans.
Seed Germination of Fraser Fir: Timing of Irradiation and Involvement of Phytochrome
Authors: Henry Paul H. , Blazich Frank A.
Published: January 2019

Two experiments investigated the relationship of light and temperature in seed germination of Fraser fir [Abies fraseri (Pursh) Poir.]. Irradiation during the warm portion of 9/15 hr thermoperiod of 20/10C and 30/20C increased germination percentages after 42 days, and the degree of stimulation depended on the timing of the light exposures. A 1-hr exposure was most effective during the latter part of the warm portion of the thermoperiods, and varying the time of irradiation had the greatest effect at 20/10C. The involvement of phytochrome in this photomorphogenic response was ascertained by demonstration of red/far-red reversibility.
Evaluation of Moving Mean and Border Row Mean Covariance Analysis for Error Control in Yield Trials
Authors: Fernandez George C.J.
Published: January 2019

The effectiveness of using moving mean covariance analysis (MMCA) rather than randomized complete-block design (RCBD) in experimental error control was compared in a large-scale mungbean [Vigna radiata (L.) Wilczek] yield trial. The MMCA was superior to the RCBD, since it significantly reduced the experimental error and the coefficient of variation (cv). Inclusion of five neighboring plots in the moving mean computation provided better error control. However, the estimation of optimum number of neighboring plots to be used and moving mean calculations were tedious. The feasibility of using border-row measurements such as mean plant height at 50% flowering or mean seed yield/m of row as a covariate in an analysis of covariance (BRMCA) was examined in a separate mungbean yield trial in which border rows were planted with a check cultivar. Both border-row measurements were equally effective in reducing the experimental error. However, plant height measurements were simpler than measuring seed yield. Because border-row measurements could be readily used as covariate in analysis of covariance without a need for moving mean computation from the response variable, BRMCA could be advantageous for error control in row crops yield evaluation.
Prolonged Storage of Lemons Using Individual Seal-packaging
Authors: Cohen E. , Lurie S. , Shapiro B. , Ben-Yehoshua S. , Shalom Y. , Rosenberger I.
Published: January 2019

`Eureka' lemons [Citrus limon (L.) Burro. f.] treated for commercial storage were held for 6 months at 13C. One-half of the fruits were individually sealed in high-density polyethylene (HDPE) plastic film and half not sealed. The HDPE-seaIed lemons showed little change in the water relations characteristics, while unsealed lemons lost weight and decreased in water potential throughout the storage period. The maturity indices in the two treatments were generally similar during the first 3 months of storage, after which maturation of wrapped fruit was slower than that of the control. The overall marketable quality of the fruit was higher in HDPE-sealed lemons than in unsealed. From these results, it appears feasible to introduce seal packaging in packing lines where lemons will be placed in extended storage.
Production and Postproduction Irradiance Affects Acclimatization and Longevity of Potted Chrysanthemum and Poinsettia
Authors: Nell Terril A. , Leonard Ria T. , Barrett James E.
Published: January 2019

Production irradiance levels on growth, light compensation point (LCP), dark respiration (DR), and interior longevity of potted chrysanthemum (Demfranthema grandiflora Tzvelev. cvs. Iridon and Mountain Peak) and poinsettia (Euphorbia pulcherrima Wind. cvs. Annette Hegg Dark Red and Gutbier V-10 Amy) were determined. LCP and DR were measured at anthesis and during acclimatization to interior conditions (10 μmol·s-1·m-2). Days to flowering, inflorescence diameter, total chlorophyll, and interior longevity of chrysanthemum increased when maintained at a mean maximum photosynthetic photon flux density (PPFD) of 500 μmol·s-1·m-2 compared to plants shifted to 300 or 100 μmol·s-1·m-2 8 weeks after planting. LCP and DR were highest at anthesis and were reduced 38% and 49%, respectively, for chrysanthemum and 19% and 42%, respectively, for poinsettia within 3 days in interior conditions. Chrysanthemum plants shifted to 300 μmol·s1·m-2 during production had lower LCP and DR rates at anthesis and throughout time in interior conditions compared to plants maintained at 500 μmol·s-1·m-2. The acclimatization of chrysanthemum to reduced production PPFD is of little significance because interior longevity is reduced. No differences were found in the LCP or DR of poinsettia or chrysanthemum cultivars that differ in interior performance, demonstrating that these physiological characteristics are not good indicators of interior longevity for chrysanthemum and poinsettia.
Strain and Rootstock Effects on Spur Characteristics and Yield of `Delicious' Apple Strains
Authors: Warrington Ian J. , Ferree David C. , Schupp James R. , Dennis Frank G. , Baugher Tara A.
Published: January 2019

The characteristics of 1-year-old vegetative spurs growing on 2-year-old branches were measured on 28 `Delicious' apple (Malus domestica Borkh.) strains growing on M.7 rootstocks at Clarksville, Mich., and on 23 strains of `Delicious' on M.7a rootstocks at Kearneysville, W.Va. Spur-type strains typically had densities >20 to 21 spurs/m, and high spur leaf numbers, leaf areas per spur, leaf areas per leaf, and terminal bud diameters, whereas values for standard strains were generally lower. However, for most spur quality characteristics, there was a continuous range of values between the extremes rather than any distinct grouping into either spur or standard type. At both sites, spur density was significantly and positively correlated with yield efficiency. In a related study, the spur characteristics of `Starkspur Supreme' were measured on nine rootstocks: M.7 EMLA, M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC 9, MAC 24, OAR 1, and Ottawa 3. Spur leaf number and spur leaf area were both high with vigorous rootstocks, whereas spur density was low. The rootstocks MAC 9, M.9, and M.9 EMLA had the highest yield efficiencies.
Growth of Transplants and in Vitro-cultured Clones of Asparagus in Response to CO2 Enrichment and Supplemental Lighting
Authors: Desjardins Yves , Gosselin André , Lamarre Michel
Published: January 2019

Asparagus (Asparagus officinalis L.) transplants and in vitro-cultured clones were grown and acclimatized under two photosynthetic photon flux (PPF) conditions (ambient and ambient + 80 μmol·s-1·m-2) and three atmospheric CO2 concentrations (330, 900, and 1500 ppm). Short- and long-term effects were measured in the greenhouse and after two seasons of growth in the field, respectively. In the greenhouse, CO2 enrichment (CE) and supplemental lighting (SL) increased root and fern dry weight by 196% and 336%, respectively, for transplants and by 335% and 229%, respectively, for clones. For these characteristics, a significant interaction was observed between SL and CE with tissue-cultured plantlets. In the absence of SL, CE did not significantly increase root or shoot dry weight. No interaction was observed between CE and SL for transplants, although these factors significantly improved growth. It was possible to reduce the nursery period by as much as 3 weeks with CE and SL and still obtain a plant size comparable to that of the control at the end of the experiment. Long-term effects of SL were observed after two seasons of growth in the field. Supplemental lighting improved survival of transplants and was particularly beneficial to in vitro plants. Clones grown under SL were of similar size as transplants after 2 years in the field.
Fertilizer Salts Reduce Hydration of Polyacrylamide Gels and Affect Physical Properties of Gel-amended Container Media
Authors: Bowman Daniel C. , Evans Richard Y. , Paul J.L.
Published: January 2019

Hydration of three commercial hydrophilic polyacrylamide gels in deionized water ranged from 340 to 420 g per gram of gel. Hydration was progressively inhibited by fertilizer salt concentrations from 0 to 20 meq·liter-1. Hydration of the gels in the presence of divalent cations (Ca2+ and Mg2+) and monovalent cations (K+ and NH4+) at 20 meq·liter-1 was reduced to ≈10% and 20% of maximum, respectively. The valence of the accompanying anion did not affect hydration. Gel hydration was unaffected by urea over the range of 2 to 20 mm. Sequential rinses of the hydrated gels with deionized water completely reversed the inhibition due to the monovalent, but not the divalent, cations. The electroconductivity (EC) of the external solution increased during gel hydration. In the presence of fertilizer salts, the physical properties of a 2 redwood sawdust : 1 sand (v/v) container mix were unaffected by hydrophilic gel additions of 1.2 and 2.4 kg·m-3 (1 × and 2 × the recommended rate, respectively).
Ripening of Mangos Following Low-temperature Storage
Authors: Medlicott A.P. , Sigrist J.M.M. , Sy O.
Published: January 2019

The effects of harvest maturity of mangos (Mangifera indica L.) on storage tinder various low-temperature regimes and the influence of storage on quality development during subsequent ripening at higher temperatures were investigated. The capacity for storage of mango fruit depended on harvest maturity, storage temperature, and the time of harvest within the season. Development of peel and pulp color, soluble solids concentration, pH, and softening in `Amelie', `Tommy Atkins', and `Keitt' mangos occurred progressively during storage for up to 21 days at 12C. Based on the level of ripening change that occurred during 12C storage, immature fruit showed superior storage capacity than fruit harvested at more-advanced stages of physiological maturity. On transfer to ripening temperatures (25C); however, immature fruit failed to develop full ripeness characteristics. Mature and half-mature fruit underwent limited ripening during storage at 12C, the extent of which increased with progressive harvests during the season. Ripening changes during storage for 21 days were less at 8 and 10C than at 12C. Chilling injury, as indicated by inhibition of ripening, was found at all harvest stored at 8C, and in early season harvests stored at 10C. Fruit from mid- and late-season harvests stored better at 10 than at 12C, with no apparent signs of chilling injury. Flavor of mangos ripened after low-temperature storage was less acceptable than of those ripened immediately after harvest. Suggestions are made for maximizing storage potential by controlling harvest maturity and storage temperature for progressive harvests throughout the season.
Seasonal Changes of Membrane Lipids in Apple Shoots
Authors: Wang Shiow Y. , Faust Miklos
Published: January 2019

Composition changes in galactolipids, phospholipids, and sterols in apple shoots (Malus domestica Borkh. cv. Red Delicious) from August to April were determined. The predominant fatty acids in the membrane lipids of apple shoots were palmitic acid (C16:0), linoleic acid (C18:2), and linolenic acid (C18:3). The major galactolipid components in apple shoots were monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG). The amount of MGDG and DGDG increased from autumn to spring. Galactolipids contained highly unsaturated fatty adds, mainly linoleic (18:2) and linolenic (18:3) acid. The major individual phospholipids were phosphatidylcholine (PC) and phosphatidylethaeolamine (PE). β -Sitosterol and sitosteryl ester were the predominant sterols. The phloem contained higher amounts of galactolipids, phospholipids, and sterols than did the xylem tissue. There was a significant increase in the content of galactolipids and phospholipids and onsaturation of their fatty acids during cold acclimation. A decrease in the ratio of free sterols to phospholipids also occurred in apple shoots toward cold winter months. Composition changes in galactolipids, phospholipids, and sterols that were associated with growth cessation, defoliation and cold acclimation from fall to winter, were mostly reversed following deacclimation in spring.
Inhibition by NaCl of Net CO2 Fixation and Yield of Cucumber
Authors: Drew Malcolm C. , Hold Pamela S. , Picchioni Geno A.
Published: January 2019

Cucumber (Cucumis sativus L. cv. Fidelio) grown in sand culture in the greenhouse was trickle-irrigated with nutrient solution containing 0, 10, or 50 mm NaCl. Gas exchange of Individual leaves was measured by a portable infrared gas analyzer et saturating photosynthetic photon flux. Salt at 10 mm had no detectable effect on plant performance, but exposure to 50 mm NaCl caused net CO2 fixation to decline by 33% and 48% in the eighth and ninth oldest leaves, respectively. Stomatal conductance and transpiration rate were also reduced (≈ 50%) In these leaves. These differences, as well as lower leaf water potentials, were associated with a 60% reduction in fruit fresh weight. The relationship between net CO2 fixation and intercellular (substomatal) CO2 concentrations was determined for individual, attached leaves of plants with roots exposed to various concentrations of NaCl in hydroponics. With 50 and 100 mm NaCl, a nonstomatal contribution to the inhibition of photosynthesis at the chloroplast level was Indicated by strong inhibition of CO, fixation at a saturating CO2 concentration. Salt-induced inhibition of CO2 fixation was associated with accumulation of Na+ and Cl-, and lower K+ in the individual leaves examined.
A Model for Net Photosynthesis of Rose Leaves as a Function of Photosynthetically Active Radiation, Leaf Temperature, and Leaf Age
Authors: Lieth J.H. , Pasian C.C.
Published: January 2019

A mathematical description for the relationship between the rate of rose (Rosa hybrida L.) leaf net photosynthesis and photosynthetically active radiation, leaf temperature, and leaf age is developed. The model provides a tool for the prediction of these rates for leaves growing in a rose crop canopy.
Inheritance of Physico-chemical Seed Characters Related to Culinary Quality in Dry Bean
Authors: Wassimi N.N. , Hosfield G.L. , Uebersax M.A.
Published: January 2019

Culinary quality in dry bean (Phaseolus vulgaris L.) depends on attributes of seeds prevailing at harvest and is determined by the genetic architecture of cultivars and by unpredictable environmental factors. Variation among genotypes for culinary quality has been shown to be heritable; however, the efficacy of selection depends on a knowledge of the genetic control of the measured traits. A diallel mating design was used to estimate the combining ability of parents and determine the inheritance of nine culinary quality traits important to processors and consumers. Genetic variability among eight parents, 56 F2, and 56 F3 progenies was confirmed by significant mean squares from analyses of variance. Significant variability detected between F2 and F3 progenies for soaked bean weight (SBWT), soaked bean water content (SBWC), and clumps (CLMP) was due to inbreeding effects. General combining ability (GCA) components were highly significant and overshadowed specific combining ability (SCA) components in the F2 and F3 for SBWT, SBWC, split beans (SPLT), and the washed-drained weight coefficient (WDWTR), indicating that additive variance predominated. Ratios of GCA: SCA components were equal to or less than unity for CLMP, washed-drained weight (WDWT), and texture (TEXT), indicating that both additive and nonadditive effects contributed to trait expression. Significant SCA effect variances were noted for `Sanilac', `San Fernando', `Nep-2', and `A-30' for WDWT and TEXT, implying that progeny from crosses of these parents had higher or lower mean values for the traits titan the average expected on the basis of GCA. Graphs of the regression of Vr on Wr showed that genes controlling WDWT and TEXT were completely dominant in most cases. Recurrent selection, which seeks to concentrate favorable alleles with additive effects in populations, may he an effective breeding procedure to improve the culinary quality of dry beans. It is not feasible to breed for TEXT and WDWT simultaneously because of a negative correlation between the traits.
Lime and Phosphorus Effects on American Ginseng: I. Growth, Soil Fertility, and Root Tissue Nutrient Status Response
Authors: Konsler T.R. , Shelton J.E.
Published: January 2019

Soil applications of dolomitic limestone and P fertilizer before seeding American ginseng (Panax quinquefolium L.) affected root weight (RW) gain during the first 4 years of growth. At the end of each growing season, root size was greatest with the intermediate liming rate and with the high P rate. Lime resulted in positive linear responses in soil pH, K, Ca, and Mg and in root N, P, Ca, and Mg and curvilinear responses in soil Mn and Zn and in root K, Mn, and Zn. Applied P had a positive linear effect on soil Na and on root N, Ca, and Fe and a curvilinear effect on soil P and on root P and Ca. Terminal RW was positively correlated with soil pH, K, Ca, Mg, and Na and with root P, K, Ca, and Mg; RW was negatively correlated with root Mn and Zn. Regression analyses implicated only soil Ca and Na and root Mg and Zn as significant terms in prediction equations,
Yield of Trickle-irrigated Tomatoes as Affected by Time of N and K Application
Authors: Dangler James M. , Locascio Salvadore J.
Published: January 2019

Tomatoes (Lycopersicon esculentum Mill.) were grown on polyethylene-mulched beds of an Arredondo fine sand during two seasons to evaluate the effects of trickle-applied N and/or K, percentages of trickle-applied N and K (50%, 75%, and 100%), and schedules of N and K application on fruit yield, and leaf and shoot N and K concentrations. The daily irrigation requirement, calculated at 47% of the water evaporated from a U.S. Weather Service Class A pan (Epan), was met by the application of 4.6 mm to 7.2 mm water/day. Fertilizer was injected weekly in a variable (2% to 12.5% of the total amount weekly) or constant (8.3% of the total amount weekly) schedule during the first 12 weeks of each season. Trickle-applied nutrients and trickle-applied percentage of nutrients interacted in their effects on early, midseason, and total marketable fruit yields. When N + K and N were trickle-applied, the mean early total marketable fruit yield decreased linearly from 25.3 t·ha-1 to 16.3 t·ha-1 as the trickle-applied percentage of nutrients increased from 50% to 100%; but when K was trickle-applied (100% preplant-applied N), yields were not affected by the trickle-applied percentage (mean 26.3 t·ha-1). The weekly schedule of N and K injection had no effect on fruit yield or other characteristics. Higher leaf N and K concentrations early in the season were obtained when the respective nutrient was 50% to 100% preplant-applied than when the respective nutrient was 75% to 100% trickle-applied; but late in the season, higher concentrations were obtained when the respective nutrient was trickle-applied. Higher yields, however, were associated with higher early season leaf N concentrations rather than with higher late-season leaf N or K concentrations.
Gene B Influences Susceptibility to Chilling Injury in Cucurbita pepo
Authors: McCollum T.G.
Published: January 2019

The effects of gene B on susceptibility to chilling injury (CI) in two types of summer squash (Cucurbita pepo L.) were investigated. Two pairs of near-isogenic lines with (BB) and without (B+ B+) gene B were included in the study: `Caserta' (B+ B+) and `Precocious Caserta' (BB) of the vegetable marrow type, and `Benning's Green Tint' (B+ B+) and `Benning's Yellow Tint' (BB) of the scallop type. Respiration and ethylene evolution at nonchilling temperature were consistently higher in marrows than in scallops. Gene B had no influence on respiratory rates at nonchilling temperatures; however, the presence of gene B enhanced the chilling-induced stimulation of respiration in both marrows and scallops. Temporal differences in the patterns of chilling-induced stimulation of ethylene evolution indicated a greater sensitivity to chilling in marrows than in scallops and in both types in the presence of gene B. Electrolyte leakage was decreased by storage at chilling temperature in both marrow genotypes and was not influenced by storage temperature in B+ B+ scallops, but was increased by storage at chilling temperature in BB scallops. Therefore, electrolyte leakage was not a good CI index for these summer squash.
Flower and Pod Abscission Due to Heat Stress in Beans
Authors: Monterroso Victor A. , Wien H. Chris
Published: January 2019

The effect of high temperature on abscission of bean (Phaseolus vulgaris L.) flowers and pods was studied under growth chamber and greenhouse conditions. Experiments investigated stages at which flowers are sensitive to heat stress, the period when reproductive structures abscise, and sensitivity of male and female flower parts to heat stress. Heat treatments (2 days at 35C, 10 hours per day) were applied through flower ontogeny, from 8 days before anthesis until anthesis. The flower bud stages were defined by correlating the pedicel length with days to reach anthesis. The prefertilization period showing highest sensitivity to heat stress extended from ≈ 6 days before anthesis to anthesis. We found that 82% of heat-stressed structures abscised as small pods (< 2 cm in length), even when the stress was applied at various flower bud stages. Reciprocal crosses made with pollen from heated plants or on heat-treated flowers indicated that pollen was more affected by heat stress than by female structures.
Salt Effects on Growth and Ion Uptake of Pistachio Rootstock Seedlings
Authors: Picchioni G.A. , Miyamoto S. , Storey J.B.
Published: January 2019

The degree of salt resistance of Pistacia spp. grown in the western United States is not adequately known. This study evaluated seedling growth and ion uptake characteristics of two Pistacia spp. and one hybrid in outdoor lysimeters for two seasons. After 12 weeks, seedling stem elongation of P. atlantica Desf., P. terebinthus L. (three selections), and P. integerrima Stewart × atlantica (referred to as Gold II) was reduced by an average of 33% at soil solution salinity of 12.6 dS·m-1 (or 8.0 dS·m-1 in the saturation extract). Gold II was the most vigorous genotype and produced the greatest biomass in control and high-salt solutions. Decreases in root and stem growth (average of all seedlings combined) occurred at soil solution salinity of 13.8 dS·m-1 (or 8.7 dS·m-1 in the saturation extract). Increasing salinity resulted in a higher root to stem ratio, which was most pronounced in P. terebinthus. Comparatively small but significant differences in leaf Na and Cl concentrations between species and selections occurred. All species limited Na transport to leaf tissue up to 125 meq Na/liter in soil solution, storing the greatest amount in roots. Chloride concentrations on a dry-weight basis were substantially higher in leaves than in roots. Increasing salinity did not affect leaf K and Mg concentrations, whereas Ca was significantly reduced. Leaf Na and Cl concentrations of P. atlantica and P. terebinthus had significant correlation with Na and Cl concentrations in soil solutions (r = +0.83 to +0.94).
Association of Pedicel Length and Diameter with Fruit Length and Diameter and Ease of Fruit Detachment in Pepper
Authors: Setiamihardja Ridwan , Knavei Dean E.
Published: January 2019

Genetic correlations for pedicel length and diameter, fruit length and diameter, and fruit detachment force (FDF) were determined in three pepper (Capsicum annuum L.) families from crosses of `Serrano Chili' (low FDF) with three cultivars (`Anaheim Chili', `Keystone Resistant Giant', and `Red Cherry Small') characterized by high FDF and different fruit characteristics. Pedicel and fruit length means of F1 generations were nearly intermediate, while pedicel and fruit diameter means were shifted toward `Serrano Chili'. Progeny distributions in F2 generations were continuous and F2 means slightly less than the F1 means. Generation mean analyses indicated gene effects for pedicel and fruit length to be mostly additive. Gene effects for pedicel and fruit diameter were also mostly additive. Pedicel length was positively correlated genetically with fruit length, and pedicel diameter was positively correlated with fruit diameter. FDF means were positively correlated with pedicel and fruit length and diameter in most segregating generations. In BCP2 (`Serrano Chili' × `Red Cherry Small'), FDF was negatively correlated with pedicel and fruit length. Pendant fruit in BCP2 (`Serrano Chili' × `Red Cherry Small') were longer and narrower than upright fruit and FDF decreased with increased length of both pedicel and fruit.
Long-term Performance of Pecan Trees when Nitrogen Application is Based on Prescribed Threshold Concentrations in Leaf Tissue
Authors: Worley Ray E.
Published: January 2019

A threshold of 2.75% N was most practical for the low end of the sufficiency range when lower thresholds of 2.25%, 2.50%, 2.75%, and 3.00% were tested on old `Stuart' pecan [Carya illinoensis (Wangenh.) C. Koch] trees. Application of 224 kg N/ha annually reduced nut size when compared with application of 112 kg/ha made only when leaf N dropped below 2.25%, 2.50%, 2.75%, or 3.00%. Yield and tree growth were similar when 112 kg·ha-1 was applied only when leaf N dropped below 2.75% and when 224 kg·ha-1 was applied annually. No N application was necessary to meet the 2.75% threshold for 3 of the 16 years.
Gas Exchange Characteristics of Apple and Peach Leaves Infested by European Red Mite and Twospotted Spider Mite
Authors: Mobley Kendrick N. , Marini Richard P.
Published: January 2019

Greenhouse-grown `Imperial Delicious' apple (Malus domestics Borkh.) and `Redhaven' peach (Prunus persica Batsch.) trees were inoculated during the summer with three densities of European red mite (ERM) (Panonychus ulmi Koch) and twospotted spider mite (TSM) (Tetranychus urticae Koch). As ERM- and TSM-days increased, net photosynthesis (Pn), transpiration (Tr), and total chlorophyll content (TCHL) of apple leaves decreased linearly. At similar densities, TSM was more damaging than ERM to apple leaf gas exchange. Water-use efficiency (WUE) of apple declined similarly with increasing mite-days for both mite species. Specific leaf weight (SLW) of apple increased with TSM-days. Pn, Tr, TCHL, and WUE of peach declined linearly with increasing ERM- and TSM-days, and the rates of decline were similar for both mite species. Mites did not affect peach SLW. These results indicate that greenhouse-grown peach is more tolerant than apple to mite feeding.
Foliar Application of Calcium Chloride Delays Postharvest Ripening of Strawberry
Authors: Chéour F. , Willemot C. , Arul J. , Desjardins Y. , Makhlouf J. , Charest P.M. , Gosselin A.
Published: January 2019

Effects of CaCl2 preharvest treatment on postharvest strawberry (Fragaria × ananassa) ripening and gray mold development were assessed. Two experiments were carried out in 1987 on two sites. In the first experiment, the effects of rate of application of CaCl2 and degree of fruit maturity at treatment were studied with the conventional cultivar Kent. In the second experiment, the influence of concentration and frequency of application of CaCl2 was investigated with day-neutral `Tribute'. Calcium treatment caused a significant increase in fruit and leaf Ca contents, which were closely correlated. The degree of fruit maturity at application and the frequency of treatment did not affect Ca concentration in the tissues. Several maturity criteria were measured during fruit storage in air at 4C. Anthocyanin and free-sugar contents and tissue electrical conductivity increased, while titratable acidity and firmness decreased. In both experiments, Ca treatment delayed ripening and gray mold development. The delay increased with increasing Ca concentration.
Changes of Membrane Lipids in Apple Buds During Dormancy and Budbreak
Authors: Wang Shiow Y. , Faust Miklos
Published: January 2019

The changes of membrane lipids in apple (Malus domestics Borkh. cv. Delicious) auxillary and terminal buds from August to April were determined. The predominant lipids were monogalactosyl diglyceride (MGDG), digalactosyl diglyceride (DGDG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). An increase in membrane polar lipids was associated with budbreak and bud growth from August to April. Linolenic acid was the predominant fatty acid in MGDG, DGDG, and PC, while linoleic acid was predominant in PE. Phosphatidylglycerol (PG) and phosphatidylinositol (PI) contained a high amount of palmitic acid. The ratio of (18:2 + 18:3) to 18:1 fatty acids in galactolipids in apple buds increased from August to April. ß-Sitosterol and sitosteryl ester were the predominant sterols in apple buds. An increase in sitosterol, a decrease in sitosteryl ester, and a decline in the ratio of free sterols to phospholipids occurred during budbreak in spring. A decrease in sitosterol was associated with bud expansion in spring.
Developmental Changes in Translocation and Localization of 14C-labeled Assimilates in Grapefruit: Light and Dark CO2 Fixation by Leaves and Fruit
Authors: Yen Chung-Ruey , Koch Karen E.
Published: January 2019

Distribution of radiolabeled assimilates was examined at various intervals after 1 hour of light or dark 14CO2 fixation by leaves or developing fruit of grapefruit (Citrus paradisi Macf.) so that the fate of assimilates from each source could be assessed at sequential stages of fruit growth. Exported products of both light and dark 14CO2 fixation in leaves were deposited primarily in juice tissues of fruit even during periods of substantial dry weight accumulation by peel. Fruit photosynthesis, however, gave rise to assimilates that remained almost entirely in the peel (flavedo and albedo) even 7 days later, regardless of dry matter increases by other tissues. Products of dark 14CO2 fixation by intact fruit were recovered in all tissues but predominated in the peel of young fruit vs. juice tissues at later stages of growth. Comparison of dry matter gains and 14C-labeled assimilate distribution indicated that fruit photosynthesis likely contributed substantially to development of peel but not juice sacs. Data on dark 14CO2 fixation were consistent with its suggested involvement in organic acid synthesis by juice sacs.
Shade and Nitrogen Influence Gas Exchange and Growth of Cocoyam (Xanthosoma sagittifolium)
Authors: Valenzuela Hector R. , Schaffer Bruce , O'Hair Stephen K.
Published: January 2019

Net gas exchange and growth were determined for cocoyam [Xanthosoma sagittifolium (L.) Schott] growing in 30%, 50%, and 100% sunlight and fertilized with 0 or 475 mg N/kg nutrient solution. Interactions between N and shade were observed for lamina area per plant, top : corm ratio, corm weight, transpiration (E), stomatal conductance (g,), and lamina N and chlorophyll concentrations. When N treatments were pooled, shade-grown plants (30% and 50% sunlight) had greater lamina areas, lamina and petiole biomass, top: corm (fresh weight) ratios, and corm fresh weights than plants grown in full sunlight. All of these criteria also had higher values for plants that received the N-fertilizer solution (+ N) than for plants that received the N-free solution (- N), when shade treatments were pooled. When N treatments were pooled, 100%-sunlight plants had greater net CO2assimilation (A) rates than shade plants. Water-use efficiency (WUE), A, g., and E for 100%-sunlight-grown plants were higher for + N than for - N plants. For shade plants, however, A and E were similar between N treatments. When N treatments were pooled, shade plants had a greater lamina chlorophyll concentration on a dry-weight basis than 100%-sunlight plants, whereas content on an area basis was similar among shade treatments. Among shade treatments, chlorophyll contents on an area and dry-weight basis were higher for + N than for - N plants. Plants grown in 100% sunlight had higher lamina N concentrations (area and dry-weight bases) than shade plants. The interactions between N and shade showed that cocoyam response to N depends on incident photosynthetic photon fluxes during growth.
Resistance Responses of Plants Regenerated from Peach Callus, Cultures to Xanthomonas campestris pv. pruni
Authors: Hammerschlag F.A.
Published: January 2019

A detached-leaf bioassay was used to evaluate peach [Prunus persica (L.) Batsch] regenerants derived from zygotic embryo callus cultures of cultivars Sunhigh (susceptible to leaf spot) and Redhaven (moderately resistant to leaf spot) for resistance to Xanthomonas campestris pv. pruni [(E.F. Sm.) Dews], the causal agent of bacterial leaf spot. Regenerants obtained from calli produced on two `Sunhigh' embryos, #61 and #156, and on three `Redhaven' embryos were evaluated. Sixty-four percent of the regenerants derived from `Sunhigh' embryo #156 and 13% of the regenerants derived from `Sunhigh' embryo #61 demonstrated significantly greater spot resistance than `Sunhigh'. Regenerants with resistance greater than `Redhaven' were also obtained from both `Sunhigh' embryos. The frequency of variation in the `Sunhigh' seedling population, with respect to the response to bacterial leaf spot, was not so great as that exhibited by the regenerants derived from `Sunhigh' embryo #156. None of the `Redhaven' seedlings or any of the regenerants derived from `Redhaven' embryos were more resistant than `Redhaven'. These studies suggest that the frequency of somaclonal variation is genetically determined and that screening for somaclonal variation may be a feasible approach to obtaining leaf spot-resistant peach plants.
Comparison of Sod, Mulch, Cultivation, and Herbicide Floor Management Practices for Grape Production in Nonirrigated Vineyards
Authors: Pool R.M. , Dunst R.M. , Lakso A.N.
Published: January 2019

In two 4-year studies, `Concord' (Vitis labruscana, Bailey) cane pruning weight, yield, and soluble solids content were similar for vines growing under herbicide and cultivation treatments. In a vineyard with shallow soil, vines grown under mulch had a significantly greater increase in cane pruning weight than did vines grown with sod middles. Growth suppression of sod-managed vines occurred only in relatively dry years. While there was annual variation in vine response to herbicide and cultivation treatments, the cumulative responses over the 4-year study were similar for these treatments. A second vineyard where soil was less restrictive for root growth did not respond to the replacement of clean cultivation with herbicide treatments. In both experiments, there was no apparent advantage of two instead of a single herbicide application, and there was no difference between the budbreak, as opposed to bloom timing, of herbicide application.
Yield of Successively Cropped Polyethylene-mulched Vegetables as Affected by Irrigation Method and Fertilization Management
Authors: Clough G.H. , Locascio S.J. , Olson S.M.
Published: January 2019

Broccoli (Brassica oleracea L. var. italica), followed by tomato (Lycopersicon esculentum Mill) or squash (Cucurbita pepo L. var. melopepo), and then broccoli were produced in succession re-using the same polyethylene-mulched beds at two locations with different soil types. First-crop broccoli yield was earlier and greater with drip than with overhead irrigation and increased as N-K rate increased from 135-202 to 270-404 kg·ha-1. On a tine sandy soil, yields of second and third crops produced with residual or concurrent fertilization increased with an increase in N-K rate. On a loamy fine sandy soil, yields also increased as the rate of residual N-K increased; yields of second and third crops did not respond to rate of concurrently applied N-K, but were higher with concurrent than with residual fertilization, except total tomato yields were similar with either application time. With drip irrigation and concurrent weekly fertigation, yields equalled or exceeded those obtained with preplant fertilization and overhead irrigation.