bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographical Profiles of Alkalinity Levels in Greenhouse Irrigation Waters
Authors: Reddy Shiv K. , Madore Michael A.
Published: February 2019

Alkalinity of irrigation water affects pH of the plant growing media. High alkalinity water raises media pH and affects nutrient availability to plants and, thus, plant growth. Alkalinity levels in irrigation water vary in different regions. Knowledge of alkalinity levels would help growers and advisors in modifying cultural practices to suit the levels. To find out how the levels vary in different states, we searched our database of thousands of water analyses from across the country. Overall, 38% of the waters had <100 ppm CaCO3, a level not considered to be a concern for even small pots. About 74% of the waters had <200 ppm CaCO3, a level considered to be safe for large pots. The majority of the waters in the states along the eastern seaboard had <150 ppm CaCO3. In waters in the interior states, alkalinity levels varied. Pacific Northwest had most waters <150 ppm CaCO3. Detailed results—bar charts showing percent of waters at different alkalinity levels in each state and in the country will be shown.
Painted Containers: A New Method for Paclobutrazol Application
Authors: Pasian Claudio C. , Struve Daniel K.
Published: February 2019

The effectiveness of two application methods of the growth regulator paclobutrazol on the growth of Chrysanthemum plants, Dendranthema ×grandiflora (Ramat) (cv. `Fina' and `Cream Dana') were compared. Plants were grown in containers with their interior covered by a mixture of flat latex paint and several concentrations of paclobutrazol (0, 5, 10, 20, 40, 80, 100, 150, 160, and 200 mg·L–1) or were treated with a soil drench of the growth regulator according to label recommendations (59 ml/container of paclobutrazol solution at 4 mg·L–1). Plants grown in containers with the paint–paclobutrazol mix at concentrations >80 mg·L–1 were shorter than plants given the control and paint only treatments but taller than plants given the drench treatment. Increasing paclobutrazol concentrations in paint from 100 to 150 and 200 mg·L–1 did not produce proportionately shorter plants. Paint alone had no effect on growth and development. Plants subject to growth regulator treatments appeared greener than the control plants. None of the plants given treatments with paint with or without paclobutrazol showed any sign of phytotoxicity. These results suggest the possibility of a new application method for systemic chemicals with the potential of reducing or eliminating worker protection standard restricted entry intervals and reducing the release of chemicals to the environment. Chemical name used: beta-[(4-chlorophenyl)methyl]-α-(1,1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol).
Growth and Development of Euphorbia pulcherrima `Freedom' and Lilium longiflorum `Nellie White' in Sphagnum Peat- and Coir Dust-based Substrates
Authors: Waber Andrew A. , Evans Michael R.
Published: February 2019

Euphorbia pulcherrima `Freedom' (poinsettia) were grown in coir dust, sphagnum peat, and perlite at the following ratios (respectively) 20:0:80, 40:0:60, 60:0:40, 80:0:20, 0:20:80, 0:40:60, 0:60:40, and 0:80:20 (v/v) substrates. Days to anthesis were not significantly different between substrates. Heights were greater for plants produced in 80% coir compared to plants grown in 80% peat. Overall, plants grown in coir-based substrates were taller than plants grown in peat-based substrates. Plants grown in 60% coir had a greater number of lateral shoots, increased shoot fresh weight and increased bract area compared to plants grown in 60% peat. Overall, plants grown in coir-based substrates had greater shoot fresh weights compared to plants grown in peat-based substrates. Lilium longiflorum `Nellie White' (lily) plants were grown in 40:0:20:40, 0:40:20:40, 0:57:14:28, 0:73:9:18 (v/v sphagnum peat: coir dust: loam: perlite) substrates. As the proportion of coir in the substrate increased, height, and shoot and root fresh weights increased. Nodes to flower, days to flower, and number of flowers were not significantly affected by substrate.
Effect of Media Containing Processed Fiber, Micronutrient Application, and Mixing Ratio of Processed Fiber with Perlite on Plant Appearance and Growth of Pansy Plants
Authors: Gu Sanliang , Bonney Tera M. , Fuchigami Leslie H.
Published: February 2019

Effect of media containing processed fiber (methane digested cow manure) as a substitute for peatmoss, micronutrient application, and medium mixing ratios of processed fiber with perlite were investigated in pansy cv. Maxima mix plants (Viola ×wittrockiana). Neither medium components nor micronutrients significantly influenced plant growth and appearance when plants were potted in medium containing either 60% processed fiber and 40% perlite, 100% processed fiber, or 60% peatmoss and 40% perlite and supplemented with either N–P–K or N–P–K with micronutrients. The plant size and biomass production of leaves increased with increasing proportion of perlite in the mixtures containing processed fiber while the number and biomass of flowers were not affected. Water content of leaves or flowers was not influenced by mixes of processed fiber and perlite. The processed fiber, either alone or mixed with other media components, was satisfactory for the production of pansy plants with or without micronutrient application.
Effect of Media Containing Processed Fiber, Fertilization, and Fumigation on Appearance and Growth in Containerized Woody Perennial Plants
Authors: Gu Sanliang , Fuchigami Leslie H. , Sahakian Victor
Published: February 2019

Applicability of processed fiber (methane digested cow manure) as a substitute for peatmoss for production of various containerized perennial woody plant species with various fertilization and fumigation practices was investigated in this study. Liner plants of five species and rooted cuttings of 41 species were potted in various media containing processed fiber as the replacement of peatmoss with or without fertilization and fumigation, with commercial mix as control. Plants varied in their responses to the media, fertilization, and/or fumigation. Most plant species performed well in the media containing processed fiber. The physical and chemical properties of processed fiber, either alone or mixed with other media components, were satisfactory for producing woody perennial species even with less fertilization and no fumigation.
Foliar Variation of Black and Sugar Maples Indigenous Near the 43°N Latitude from Maine to Iowa
Authors: St. Hilaire Rolston , Graves William R.
Published: February 2019

Its more westerly native range and apparent xeromorphic foliar traits have led to speculation that black maple (Acer nigrum Michx.f.) is more drought resistant than sugar maple (Acer saccharum Marsh.). We examined differences in morphology and anatomy of leaves of trees of these species indigenous near the 43°N latitude in the midwestern and eastern United States. Leaves were collected during July, Aug., and Sept. 1995, from 10 trees in each of 24 sites at longitudes of 71°W in Maine to 94°W in Iowa. Density of trichomes on abaxial surfaces and lamina surface area showed quadratic relationships with longitude and were greatest for leaves from westerly sites in Iowa. The percentage of total lamina surface area partitioned in the two most basipetal lobes increased linearly with longitude. Abaxial surfaces had 6 to 960 trichomes/cm2, lamina surface area was 28 to 176 cm2, and surface area partitioned in basipetal lobes was 5% to 9%. A quadratic regression function related increases in trichome density to decreasing mean annual rainfall at collection sites. Specific leaf mass ranged from 3.5 to 7.6 mg·cm–2 and did not relate to longitude. Scanning electron microscopy showed leaves throughout the range had similar trichome morphology, and light microscopy is being used to examine variation in leaf anatomy and stomatal traits.
Urban Mesoclimate Effects on Winter Survival and Damage of Ornamental Species in Fort Worth, Texas
Authors: Harp Derald A. , McWilliams Edward L.
Published: February 2019

Urban areas are typically 2 to 3°C warmer than surrounding rural areas throughout the year. Winter minimum temperatures are often 4 to 5 °C warmer in the city and, during extreme episodes may exhibit differences of 12 to 13°C. Because the USDA Hardiness Maps compile readings from individual stations in an area, temperature differences may not be apparent at the local scale. This study was conducted to compare ornamental plant damage during Winter 1995–96 in Fort Worth, Texas. AVHRR 1-km thermal satellite imagery was used to determine the warmest and coolest portions in Fort Worth, Texas. Each temperature area was divided into five 0.5-km blocks on the basis of similar landscape features and plant types. During Mar. 1996, these areas were evaluated on the basis of plant damage to several species. Asian jasmine (Trachelospermum asiaticum), indian hawthorn (Raphiolepis indica), St. augustine turf (Stenotaphrum secundatum), southern magnolia (Magnolia grandiflora), and Live Oak (Quercus virginiana) were the primary species damaged. Asian jasmine and St. Augustine turf were either completely killed or severely damaged in the coldest areas but suffered only moderate or light damage in the warmest areas. Indian hawthorn, live oak, and southern magnolia suffered leaf and stem damage in the coldest areas but little to no damage in the warmer areas.
Clopyralid Uptake, Translocation, and Ethylene Production in Resistant and Susceptible Yellow Starthistle (Centaurea solstitialis) Plants
Authors: Valenzuela-Valenzuela Juan , Lownds Norman K.
Published: February 2019

Resistance to the auxin-like herbicide picloram has been reported in a yellow starthistle population growing in Washington. In addition, this population is cross resistant to clopyralid, another auxin-like herbicide. To understand the mechanism of resistance to clopyralid, studies were was conducted to determine uptake and translocation and to characterize clopyralid-induced ethylene production in the susceptible (S) and resistant (R) biotypes. R and S yellow starthistle plants were grown under ambient greenhouse conditions until full rosette stage and then transferred to a growth chamber (14-hour photoperiod, 25°C, 200 mol·m–2·s–1) 48 hours before treatment. Radiolabel solutions were prepared from 12C and 14C-clopyralid. Each treatment in the uptake experiment contained 0.009 Ci (20,000 dpm) and in the translocation experiment 0.225 Ci (500,000 dpm). Clopyralid 11.7 mm (420 g a.e./ha) solutions were applied as six 0.5-L droplets to the adaxial surface of completely expanded leaves using a microsyringe. Radioactivity was quantified by Liquid Scintillation Spectrometry. Uptake was determined at specified times after treatment. Almost all clopyralid uptake occurred within the first 2 hours, with no significant differences between the two biotypes. The amount of picloram translocated was 2.4%, 40.2%, and 50.7% of that absorbed at 2, 24, and 96 hours after treatment, respectively, but was not different between biotypes. Clopyralid induced about ten times greater ethylene production in S than in R. Ethylene production was followed by epinasty and chlorosis but appears to play only a small role in the resistance mechanism.
Wine and Table Grape Cultivar Evaluation in Missouri
Authors: Kaps Martin L. , Odneal Marilyn B. , Moore James F.
Published: February 2019

Wine and table grape vineyards were planted at Mountain Grove in 1985. Twenty-seven wine and 10 table grape cultivars were evaluated in respective 12 and 18 vine plots, replicated five times. Vineyard management practices were single curtain cordon training, dormant season balance pruning, protective spray program according to Missouri recommendations, grass sod row middles with preemergence herbicide applied underneath the trellis, and fertilization according to soil and petiole analysis. Cluster thinning and shoot positioning were done as needed. Productivity data was measured yearly and included: pruning weight, yield, cluster and berry weights, and juice °Brix, titratable acidity, and pH. Disease evaluation data was also taken on these cultivars. Based on these data and current market trends, two wine grape cultivar groups were identified: recommended, `Catawba', `Cayuga White', `Chambourcin', `Norton', `Seyval blanc', `Vidal blanc', and `Vignoles'; not recommended, `Aurore', `Baco noir', `Bellandais', `Chancellor', `Chelois', `Couderc noir', `DeChaunac', `Delaware', `Horizon', `LaCrosse', `Leon Millot', `Marechal Foch', `Melody', `Missouri Riesling', `Niagara', `Rayon d'Or', `Rougeon', `Ventura', `Villard noir', and `Vivant'. Three table grape cultivar groups were identified: recommended, `Mars' and `Reliance'; recommended for limited planting, `Canadice', `Vanessa', and `Vinered'; and not recommended, `Challenger', `Einset', `Festivee', `Himrod' and `Venus'. This information is used by growers to make cultivar decisions and also serves as a benchmark for comparing new grape germplasm coming into the state.
Effects of Gibberellic Acid Treatments on Fruit and Seed Development of Muscadine Grapes
Authors: Lu J. , Lamikanra O.
Published: February 2019

Gibberellic acid, a plant growth regulator commonly sprayed for seedless bunch grape cultivars, was used to spray on the seeded muscadine grape cultivars `Carlos', `Fry', `Higgins' and `Triumph'. GA3 at 100 to 300 ppm were sprayed on leaves and fruit clusters before and after anthesis. The flower/fruit clusters also were dipped into a much higher concentration (1000 ppm) in addition to the sprayed concentration of GA3. Berry weight significantly increased in all the sprayed vines, with a maximal increase up to 50%. Early and more uniform ripening was observed in the cultivar `Triumph'. More than 20% of seedless berries also were found on the GA3-sprayed `Triumph' vines. However, the latter two responses (early ripening and seedlessness) did not occur in other cultivars tested. Similar results also were obtained in the dipping treatments. The results indicated that the seeded muscadine grapes responded well to the GA3 treatments in general, but genotype variation is obvious.
A Single Basal Application of MEISTER (Polyolefin-coated Urea) to the Strawberry Greenhouse Soil in Kumamoto, South Japan
Authors: Suenaga Y. , Takamori K. , Nishimot F. , Miyoshi S. , Higashi T.
Published: February 2019

It is not uncommon that tipburns, deformation, and poor coloring of strawberries, delaying of differentiation of flowering buds and flowering, etc., occur reflecting rapid changes in soil solution concentrations by repeated applications of conventional fertilizers. These physiological disorders contribute to lowering the yield and quality of strawberries to a significant extent. Polyolefin coated urea called “MEISTER” is one of the excellent controlled availability fertilizers whose dissolution is primarily controlled by temperature. Therefore, blended materials of a few MEISTER products can supply N matching the plant demand for the long growing season (8 months). This results in contributing to the prevention of occurrences of the physiological disorders described above. Treatment plots using blended materials of MEISTER products were early dissolution, even dissolution, and late dissolution and were fertilized with a single basal application. Compared with the conventional plot, the late dissolution plot was most suitable for strawberry growth, producing the largest yield of high quality. The new fertilization using MEISTER will contribute to decreasing the amount of fertilizer to apply, eliminating topdressing, saving labor cost, etc.
Commercial Evaluation of Five Almond Cultivars in Northwestern Mexico
Authors: Grijalva-Contreras Raul L. , Lopez-Carvajal Arturo , Valenzuela-Ruiz Manuel J. , Juarez-Gonzalez Rogelio A. , Robles-Contreras Fabian
Published: February 2019

The total shell almond production in northwestern area in Mexico is ≈80 tons per year; therefore, almond fruit tree would be a potential fruit crop in this agricultural area. Also, this crop offers some advantages with lower costs than other fruit crop, and the water requirement needs for almond trees is low in support to the limited water availability. Our objective was to test new five almond cultivars of low chilling requirement. Almond cultivars were grafted on Nemaguard rootstock and planted during 1990. The data were collected from the almond orchard using the inshell kernel. The average yield during 1993 and 1994 were 970, 602, 552, 419, and 388 kg·ha–1 for `R-633', `Cavaliera', `Constantini', `Um El Fahm', and `Rane', respectively. `Cavaliera' and `Um El Fahm' showed good inshell percent and kernel weight. `Cavaliera' was harvested early in last week of June compared to the other cultivars that were harvested in mid-July.
Long-range Yield of High-density Apple Orchard on Seedling Rootstock
Authors: Devyatov A.S.
Published: February 2019

Apple orchard was planted in 1963 with treatments of 8, 6, or 4 m between rows and 8, 6, 5, 4, 3, and 2 m between trees in the row. Pruning of trees corresponded to the space requirement imposed by each treatment. Spherical canopy seldom formed in treatments of 8 × 2,3,4, or 5 m and the size of canopy was equal to the distance between trees. In treatment of row spacing 6 or 4 m the size of the canopy across the row was 3 or 2 m, respectively, with the length of the canopy equal to the distance between the trees. Tree height was 3 m in all treatments. The cultivar was `Antonovka' on Malus sylvestris rootstock. There were four replications. Fruiting in all treatments begun at the age of 8 years. During the 25 years of productive time of the orchard, there were 7 years without fruit. During the 33 years of orchard operations fruit yield was in treatments (in t·ha–1) 8 × 8 = 301, 8 × 4 = 417, 6 × 3 = 508, 4 × 3 = 612. Yield efficiency, based on crosssection of trunks in 1995 did not depend on orchard density or orchard design.
Fresh Market and Long Shelf Life Tomato Response to Rowcover Treatments in a Dry Temperate Climate
Authors: Rubeiz I.G. , Freiwat M.M. , Chehab A.M.
Published: February 2019

Floating rowcover (R), Dupont's “Lawn and Garden Blanket”, with 75% to 80% light transmittance, was applied on black plastic mulch (M) and over transplanted seedlings of tomato (Lycopersicon esculentum). Peto Seed's fresh market (F) `Al Wadi' and long shelf-life (L) `PSX 19392' were transplanted on 11 Apr. 1995 to drip-irrigated beds that were covered with M or not covered (C). The R was removed 4 (R1) or 5 (R2) weeks after its application. The climate is temperate with ≈200 days frost-free and 400 mm rainfall. Each cultivar was grown in a field with the treatments randomized in a complete block with four replications. Fruit harvest was done weekly for 6 weeks. Yield of the first 2 weeks was considered indicative of earliness. Yield earliness was enhanced by the shorter period treatment (R1) with the L cultivar showing more response to R1 (P < 0.05) than the F cultivar. Early average fruit weight was comparable among all treatments (P > 0.05) in both cultivars, but total average fruit weight was increased by R1 in L cultivar. (P<0.05). Total yield was comparable among the treatments in F cultivar (P > 0.05) and was lowest under M treatment in the L cultivar (P < 0.05). We recommend using R for shorter periods on tomato grown in a dry temperate climate, where clear skies can cause excess heat build up under rowcovers during day time.
Establishing Bumble Bees as a Supplementary System for Honey Bees in the Pollination of Watermelon, Citrullus lanatus (Thunb.)
Authors: Stanghellini Michael S. , Ambrose John T. , Schultheis Jonathan R.
Published: February 2019

The effectiveness of bumble bees, Bombus impatiens, and honey bees, Apis mellifera, on the pollination of watermelon, Citrullus lanatus (Thunb.), was compared at the individual bee level. Correlations between the number of bee visits a flower received and the resultant seed set and fruit abortion rates were established. Using `Royal Jubilee' watermelon, B-impatiens-visited flowers resulted in higher seed sets than A. mellifera when compared at equal bee visit numbers. This difference between bee types was highly significant. With respect to fruit abortion rates, no statistical difference between bee types was detected. However, bee visit count was significant. Increasing the number of bee visits received by a flower resulted in a lower percentage of aborted fruit.
Nitrogen Management of Drip-iIrrigated Peppers
Authors: Bierman Peter , Wall Tom
Published: February 2019

Inadequate N can reduce growth and yield, but excess N can be uneconomical and environmentally harmful. Our objective was to investigate the potential for using fertigation and on-farm plant-nutrient monitoring to improve the efficiency of N fertilizer use by bell peppers (Capsicum annuum L.). Two N fertilizer treatments were compared: 1) all N applied preplant and 2) one-third of the N applied preplant and the remainder injected into the drip-irrigation lines throughout the growing season. Total application rates were N at 118 kg·ha–1 for both treatments. Data were collected for total yield, marketable yield, and fruit size. Leaf and petiole samples were collected every 2 weeks and were used to monitor plant N status throughout the growing season. A Horiba/Cardy nitrate meter was used to measure nitrate concentrations in freshly-pressed petiole sap. A SPAD chlorophyll meter was used to measure leaf chlorophyll content and give an indirect measure of leaf N concentrations. Subsamples of leaves and petioles also were saved for conventional laboratory analyses. Whole (aboveground) plant samples were collected every 2 weeks, analyzed, and used to calculate differences in N accumulation. Suction cup samplers were installed at the 24-in soil depth and water samples collected every 1 to 2 weeks for nitrate analysis. Except for early in the growing season, petiole sap nitrate and leaf chlorophyll were higher in the fertigation treatment. Plant dry matter and total N accumulation also were much larger, but fertigation did not increase yield. Nitrate leaching was greater early in the season with 100% preplant N, but later in the season it was greater with fertigation. Data suggested that adequate plant N, reduced nitrate leaching, and equivalent yields are possible with fertigation at reduced N-rates compared to 100% preplant fertilizer applications.
Nitrogen, Phosphorus, and Soil pH Effects on Goldenseal (Hydrastis canadensis L.) Growth, Root Yield, and Quality
Authors: Davis Jeanine M.
Published: February 2019

Goldenseal was grown in pots of forest soil under a wood-lath structure for 3 years. Soil treatments consisted of four pH levels (4.5, 5.5, 6.5, and 7.5) and four rates of P and N (P or N at 0, 0.1, 0.2, and 0.3 kg·m–3 of soil) arranged as a RCB factorial with eight replications. Final root weights were highest with pH 5.5 and 6.5. Although response to N and P rates varied from year to year, final root weights showed no response to P and decreased with increasing N. Increase in fresh weight from initial weight of the planting stock to final total root weight ranged from 5.7× (pH 4.5, P at 0 kg·m–3, and N at 0.3 kg·m–3 treatment) to 28.5× (pH 5.5, P at 0.2 kg·m–3, and 0 N treatment). Flowering, fruit set, plant height, leaf number, and fibrous roots: rhizome ratio were highest at pH 5.5 and 6.5 and not influenced by P or N rates. Preliminary analysis suggest that root alkaloid content was also affected by soil pH.
Comparisons of Chemical Controls for Thrips (Frankliniella occidentalis) on Greenhouse-grown Gerbera (Gerbera jamesonii L.)
Authors: McIntyre Julie A. , Hopper Douglas A. , Cranshaw W.S.
Published: February 2019

Chemical and physical methods were tested to determine their effectiveness in controlling Western Flower Thrips, Frankliniella occidentalis (Pergande), in greenhouses. Comparisons were made between abamectin (Avid); Spinosyn A and D, formulated from the soil Actinomycete, Saccharopolyspora spinosa (Spinosad); azadirachtin (Margosan-O); and diatomaceous earth, a physical control aimed at deterring pupation. Results based on the number of thrips counted in gerbera (Gerbera jamesonii L.) flowers indicate that the chemical treatments were significantly more effective in reducing populations than the diatomaceous earth. Over time, the population of thrips in both the Avid and Spinosad treatments was reduced to zero. Diatomaceous earth treatments reduced populations almost 50% as compared to the control, while reductions from Margosan-O ranged 50-90%.
Growth Retardants Control Height of Herbaceous Perennials
Authors: Hamaker Cheryl , Carlson William H. , Heins Royal D. , Cameron Arthur C.
Published: February 2019

Twenty species of perennials were trialed to determine the effectiveness of five growth retardants on final plant height and flowering. Growth retardant treatments consisted of five sprays: 100 ppm ancymidol, 1500 ppm chlormequat, 5000 ppm daminozide, 30 ppm paclobutrazol, or 15 ppm uniconazole. Also included for comparison were two drenches of 15 ppm paclobutrazol or 7.5 ppm uniconazole. Spray treatments consisted of one application every 10 days until anthesis. Drench treatments consisted of one application only. Data for days to visible bud and anthesis, bud number, and final height were collected. Plant response varied significantly between growth retardant treatments. Sprays of ancymidol, chlormequat, daminozide, paclobutrazol, and uniconazole effectively controlled the height of 4, 3, 13, 4, and 12 species, respectively. Daminozide and uniconazole were the most effective sprays at controlling height on a broad range of species. However, daminozide delayed anthesis compared to control treatments of at least 5 species. Drench treatments of paclobutrazol and uniconazole were effective on 14 and 15 species, respectively. The number of responsive species increased significantly when paclobutrazol was used as a drench rather than a spray. All species tested were responsive to at least one growth retardant treatment.
Post-pollination Signaling in Carnation Flowers
Authors: Jones Michelle L. , Woodson William R.
Published: February 2019

In Dianthus caryophyllus flowers the pollinated stigma gives rise to signals that are translocated throughout the flower and ultimately result in corolla senescence. Pollination leads to a rapid increase in ethylene production by the pollinated styles followed by ethylene biosynthesis from the ovaries, the receptacle tissue, and lastly the petals. The accumulation of ACC in these floral tissues also correlates with the sequential pattern of ethylene production. Ethylene production by the pollinated style can be defined temporally by three distinct peaks, with the first peak detected as early as 1 hour after pollination. In a carnation flower with multiple styles it is also possible to detect ethylene production from an unpollinated style on a pollinated gynoecium by 1 hour after pollination. This finding provides evidence for very rapid post-pollination signaling between styles. ACC synthase expression is induced in pollinated styles as early as 1 hour after pollination, but no message is detected in pollinated ovaries. ACC synthase enzyme activity is also absent in the pollinated ovaries despite the accumulation of large amounts of ACC in the ovary after pollination. This indicates that ACC must be translocated between organs after pollination. When a pollinated styles is removed from the flower at least 12 hours after pollination the corolla will still senesce. This indicates that the pollination signal has exited the style by this time. Evidence in carnations suggests that ACC and ethylene may both be involved in aspects of post-pollination signaling.
Influence of Gibberellic Acid and Long Days on Flowering Time of Antirrhinum majus L.
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: February 2019

Gibberellic acid (GA3) and photoperiod were used in combination in an effort to reduce generation time of Antirrhinum majus L. Four commercial inbred lines of A. majus were started from seed and grown in a glasshouse in winter 1993-94. GA3 was applied as a foliar spray every 2 weeks at 0, 144, 289, 577, or 1155 μm starting 5 weeks after seeds were sown. Supplemental lighting (60 μmol·m–2·s–1) from 0600 to 2000 hr and night interruption from 2300 to 0300 hr was used throughout the experiment. Data were collected weekly on plant height and leaf count from the start of GA3 treatments through anthesis. Time to flowering was determined as days from seed sowing to anthesis. GA3 treatment of A. majus under a long-day photoperiod increased time to flowering, plant height and leaf count. It would appear that long-days may have overridden the floral induction effects of GA3.
Flower Bud Load Influences Blueberry Vegetative and Fruit Development
Authors: Maust B.E. , Williamson J.G. , Darnell R.L.
Published: February 2019

A field experiment was conducted in Gainesville, Fla., with two southern highbush blueberry cultivars, `Misty' and `Sharpblue', to investigate the influence of varying flower bud load on the timing and extent of vegetative and reproductive development. Flower bud load was adjusted on three different canes on ten plants by removing none, one-third, or two-thirds of the flower buds. Vegetative budbreak, leaf area, fruit number, and fruit fresh weight and dry weight were measured. Vegetative budbreak was delayed with increasing flower bud load. Vegetative budbreak, leaf area, and leaf area: fruit ratio decreased with increasing flower bud load. Fruit maturity was delayed and average berry fresh weight and dry weight declined with decreasing leaf area:fruit ratio. Responses were similar for both cultivars although `Misty' was more adversely affected by high flower bud load and low leaf area: fruit ratio.
Flower Bud Organogenesis and Development in Blackberry Cultivars
Authors: Takeda F. , Strik B. C. , Clark J. R.
Published: February 2019

Western trailing blackberries (e.g., `Boysen' and `Marion') are grown in Oregon. USDA-released semi-erect thornless blackberries (e.g., `Chester Thornless') and erect, thorny blackberries (e.g., `Cherokee') from Arkansas are grown across the United States from the mid-Atlantic coast region to Oregon. Flower bud development in several blackberry cultivars growing at three sites (Arkansas, Oregon, and West Virginia) was studied. In buds of `Boysen' and `Marion' blackberries from Oregon, sepal primordia were first observed in September and November, respectively. Further floral bud development continued into January. Sepal development in `Cherokee' buds occurred in November in Oregon and in December in Arkansas. At all subsequent sampling dates, the development was more advanced in Oregon than in Arkansas. Buds of `Chester Thornless' blackberry from all three sites remained undifferentiated until spring. Preliminary findings indicated that the time of flower bud initiation varied considerably among the cultivars examined. The results suggest that floral bud development in blackberry, once initiated, is continuous, but periods of low temperature can arrest bud development.
Early Pruning and Delayed Hydrogen Cyanamide Application Improve Budbreak Uniformity of `Superior' Grapevines
Authors: Osorio-Acosta Guadalupe , Siller-Cepeda Jorge
Published: February 2019

Cane pruning of `Superior' grapevines grown on Hermosillo valley vineyards is normally done between 5 and 10 Jan., with cyanamide application right after pruning. However, hand labor to tie the canes on the wires and rainy days occurring at that time makes it difficult to apply cyanamide right after pruning, resulting in uneven budbreak. Four-year-old `Superior' grapevines were pruned on 17 Dec. (PD1) and 27 Dec. (PD2) 1994 and 6 Jan. 1995 (PD3), and hydrogen cyanamide (5% Dormex) was applied on 7 Jan. Budbreak was evaluated on three segments of the canes. Total budbreak of vines pruned on 17 Dec. was 71%, 90%, and 80% on the first, second, and third segment of the canes, while on plants pruned on 27 Dec., the response was 39%, 50%, and 79% budbreak on the three segments of the canes, respectively. On vines pruned on 6 Jan., budbreak was 71%, 79%, and 88% on the first, second, and third segment of the canes. Response on cluster number was similar to budbreak, improving when the plants were pruned early (PD1). Number of cluster on PD1, PD2, and PD3 were 7.1, 4.5, and 4.8, respectively. Cluster distribution on PD1 among the canes were 1, 2.4, and 3.7 on the first, second, and third segments; on PD2, 0.3, 2, and 2.2; and on PD3, 0.8, 2, and 2 clusters, respectively.
Date and Intensity of Topping before Spur Pruning Alters Budbreak of Primary Buds in `Flame Seedless' Grapevines
Authors: Osorio-Acosta Guadalupe , Siller-Cepeda Jorge , Avlos Jorge
Published: February 2019

In the Sonoran desert, vines are forced to break with early pruning and cyanamide application. Usually topping of the canes (leaving canes 50 cm long) is done on 10 Dec. to facilitate spur pruning and cyanamide application after 20 Dec. However, budbreak is irregular over the years. There is no reason why date and intensity of topping is done that way. The objective of this work was to evaluate budbreak at different dates and intensity of topping. Five-year-old `Flame Seedless' vines were prune topped on three dates (21 Nov., 1 Dec., and 11 Dec.) and at three different intensities (leaving canes 25, 50, and 75 cm long). A control block was also included without top pruning. Spur pruning and cyanamide application (Dormex 7%) was done on 24 Dec. Budbreak on canes left 50 cm long before spur pruning was 83%, 84%, and 58% on 21 Nov., 1 Dec., and 11 Dec., respectively, while nontop-pruned plants break only 58% of the buds. Number of clusters per plant in the same order were 52, 42, 39, and 26, respectively. There was an interaction of date and intensity of topping with the cluster number, since slight topping (leaving 75 cm long canes) on 1 and 11 Dec. improved the number of clusters per vine up to 47 and 60, respectively.
Abnormal Anther and Pollen Development in Sweet Cherry Cultivars Resulting from Lack of Winter Chilling
Authors: Weis K.G. , Southwick S.M. , Rupert Michael E.
Published: February 2019

Lack of pollen dispersal was noted in various sites and cultivars of sweet cherry (Prunus avium) following one of California's warmest recorded winters (≈550 hours @ 7°C in the Central Valley). `Bing' cherry is thought to require 850 to 880 hours for adequate budbreak and bloom development. Cross pollination is required by most sweet cherry cultivars for fruit set, including `Bing'. Complete anther dehiscence averaged 13% in `Bing' trees sampled, compared to 52% in `Rainier', 65% in `Brooks', 84.5% in `Burlat', 33% in Van, 23% in `Larian', and 86% in `Black Tartarian'. A range of degree of dehiscence from none to half-open was widely apparent, again by cultivar. Many partially dehiscent anthers did not shed pollen normally but appeared to have the mass of pollen completely adherent inside the pollen sacs. `Black Tartarian', `Larian', and `Burlat' shed pollen readily, however, pollen from dehiscent anthers of other cultivars generally appeared to stick together on the everted locule walls and required direct manipulation to be withdrawn from the pollen sac. Anther morphology ranged from normal size to half normal size, anthers appearing to be without pollen altogether that shriveled on drying, and lobes that were aborted. Pollen germination was low overall: 19% `Bing', 18% `Rainier', 20% `Brooks', 57% `Burlat', 14% `Van', 48% `Larian', and 48% `Black Tartarian'. Poor fruit set in low chill years is often attributed to lack of bloom overlap with pollenizers, however, inadequate chilling also may contribute to low fruit set by inhibiting anther and pollen growth and development. The implications of a critical chilling requirement for normal floral differentiation are that in cherry-growing areas where low chill years are common, pollen may not be viable or transferrable from pollenizers and female gametophytic development also may be impaired.
Root System Characteristics of Papaya Plants Grown on a Slope
Authors: Marler Thomas E. , Discekici Haluk M.
Published: February 2019

`Red Lady' papaya transplants were planted on a slope with a 30% to 35% grade and grown for 5 months. Excavation was used to determine root distribution on the uphill and downhill sides of the plants. Roots were separated into the taproot system and lateral roots on the uphill and downhill sides. The line intersect method was used to determine length of the lateral roots, and length of the taproot system was measured directly. All roots were dried at 70°C. The taproot system accounted for 2% of the total root length and 66% of the total root mass. Of the 130-m of lateral roots, 71% were located on the downhill side. Similarly, 69% of the dry mass of the lateral root system was located on the downhill side. Primary lateral roots on the uphill side of each plant developed horizontally, but some secondary lateral roots developed against gravity to maintain a portion of the root system close to the surface of the slope. Some of these lateral roots developed at angles of 55° to 60° above the horizontal.
Reduced 5'-Methylthioadenosine Nucleosidase and 5-Methylthioribose Activities and Ethylene Biosynthesis in Nonripening Tomato Mutants `Rin' and `Nor' Relative to Ripening Tomato `Rutgers'
Authors: Xiao Chunlin , Kushad Mosbah M.
Published: February 2019

5'-methylthioadenosine (MTA) nucleosidase (EC.2.2.2.28) and 5-methylthioribose (MTR) kinase (EC.2.7.1.100) activities were evaluated in `rin', `nor', and `Rutgers' tomato fruit during development and ripening. Changes in the activities of these enzymes were compared to ethylene biosynthesis. MTA nucleosidase and MTR kinase activities in `rin' and `nor' were ≈30% and 22%, respectively, lower than `Rutgers' during the first 2 weeks of fruit development. In `Rutgers', activities of these enzymes declined sharply until fruit maturity. Shortly before climacteric rise in ethylene synthesis, MTA nucleosidase, and MTR kinase activities increased, reaching a maximum level before peak ethylene synthesis then declined when fruit started to approach senescence. Whereas, `rin' and `nor' mutants exhibited no climacteric rise in ethylene synthesis and no change in MTA nucleosidase or MTR kinase activities, following their decline after 2 weeks of growth. A rapid increase in ethylene synthesis was observed when mature green `rin' and `nor' fruit were wounded. This increase in ethylene was paralleled by an increase in MTA nucleosidase and MTR kinase activities. However, increase in wound ethylene, MTA nucleosidase, and MTR kinase activities in `rin' and `nor' was ≈40% less than what we had previously reported in `Rutgers'. Relationship of MTA and MTR kinase activities to fruit growth, development, ripening, and natural and wound ethylene biosynthesis will be described.
The Role of Auxin in Enhanced Root Growth of Trichodermacolonized Sweet Corn
Authors: Blanchard Lisa M. , Björkman Thomas
Published: February 2019

Sweet corn roots colonized with the T-22 strain of the common rhizosphere fungus grow substantially faster than roots of plants not so colonized. We tested whether this growth enhancement was a consequence of the fungus affecting auxin regulation of cell elongation. In corn roots, auxin acts an inhibitor of growth, maintaining the rate below its short-term maximum potential. The first hypothesis was that the fungus secretes an auxin inhibitor, and thereby reduces the auxin limitation of growth. Apical segments (5 cm) were incubated in media conducive to elongation, supplemented with 0.1 μm indole acetic acid (IAA), a T-22 culture filtrate (5%), or both. IAA inhibited growth by 69%, and the culture filtrate inhibited by 16% with no interaction. The action of T-22, therefore, is not through a secreted antiauxin. The second hypothesis was that the fungus metabolizes or otherwise reduces the effectiveness of auxin, which was tested by measuring growth of colonized and uncolonized seedlings after a half-hour incubation of the root tips in 0.1 μm IAA. Auxin inhibited growth by 42%, whereas colonization increased growth by 27%. Again, there was no interaction, a result inconsistent with the antiauxin model. The third experiment further tested the antiauxin hypothesis by maximizing acid growth (normally regulated by auxin) by incubating the root tips in 1 μm fusicoccin (FC). Colonization increased growth by 10% without FC but by 42% with it. FC alone increased growth by 11%. The significant positive interaction is not consistent with a change in the auxin sensitivity but is consistent with an increase in the maximum sustainable growth rate.
Distribution of Horseradish Peroxidase in Horseradish Plants
Authors: Kushad Mosbah M. , Abbasi Nadeem A. , Xiao Chunlin , Bratsch A.
Published: February 2019

Peroxidases are an enzyme family that displays a wide range of forms, functions, and distribution in the plant kingdom. Peroxidase extracted from horseradish is one of a few enzymes that had been widely used in industrial and clinical research. Horseradish peroxidase (HRP, EC 1.11.1.7, donor: hydrogen-peroxide oxidoreductase) has been used to estimate the levels of other enzymes, in immunoassay, bio-bleaching processes, and in lignin degradation for fuel production. Despite its extensive use, little is known about HRP distribution in horseradish plants. Four commercial horseradish cultivars (IL-647, IL-1069, IL-1573, and IL-1590) were evaluated for HRP activity in the main root, lateral roots, leaves, and leaf blades. HRP activity was highest in the main root followed by lateral roots. However, only a trace amount of HRP activity was detected in leaf blade and leaf petiole. IL-1573 has the highest HRP activity, while IL-647 has the lowest activity. Site of HRP synthesis and its distribution during horseradish plant growth and development will be described.
Climacteric Fruit Produce a Diminished Respiratory Climacteric When Ripened on the Plant
Authors: Saltveit M.E.
Published: February 2019

Respiration (i.e., carbon dioxide production and oxygen consumption) increases as ripening is initiated in a group of harvested fruit called climacteric. This group includes many horticulturally important fruit crops, such as apples, avocados, bananas, melons, peaches, pears, and tomatoes. Other fruit, which includes cherries, citrus, and strawberries, do not exhibit an increase in respiration as they ripen and are called nonclimacteric. Measurements of carbon dioxide production by ripening apples, melons, and tomatoes revealed a well-defined climacteric, but only in harvested fruit. The respiratory climacteric was greatly diminished or absent from these fruit when they ripened while attached to the plant. Fixation of respired carbon dioxide through photosynthesis or into organic acids was insufficient to account for the diminished amount of carbon dioxide evolved from ripening attached climacteric fruit. Unlike the respiratory climacteric, an increase in ethylene production occurred in both attached and harvested climacteric fruit. Ethylene stimulates respiration in most plant tissues. The rapid rise in respiration as soon as attached ripening climacteric fruit were harvested or abscised suggests that an inhibitor of ethylene-stimulated respiration may be translocated from the plant and prevent the climacteric rise in respiration in attached ripening fruit.
Alternative Practices for Almond
Authors: Connell Joseph H.
Published: February 2019

Improving almond orchard management by integrating cultural practices, pest and disease controls, and vegetation management has been a goal of Univ. of California research and extension efforts for more than 25 years. Alternative cultural practices related to orchard floor management, fertilizer applications, and pest and disease control are currently important components of the almond production system. Nontillage, with or without a seeded cover crop, has improved potassium uptake and reduced pest problems. In-season fertilizer applications reduced the potential for nitrate pollution of groundwater. Minimizing dust, early harvest, and destruction of overwintering refugia are all cultural practices that reduce crop damage caused by pests. New methods of pest and disease monitoring using pheromone traps, egg traps, or a better understanding of disease life cycles have reduced unnecessary chemical applications. Degree-day phenology models have improved the timing of needed sprays. Expanded use of selective spray materials, such as narrow-range oils and Bacillus thuringiensis, reduce impacts on non-target species while natural predators and parasites are encouraged. Augmentative releases of beneficial insects are currently being evaluated as an additional alternative to in-season spraying. Cultivar and rootstock choices for new plantings present alternatives that can help avoid pests or diseases. Planting pattern affects productivity and is another factor to consider when evaluating alternative production practices for almond as new orchards are established.
Selection and Characterization of Resistance in Mango Embryogenic Cultures to Colletotrichum gloeosporioides Penz. Phytotoxin
Authors: Subramanian Jayasankar , Litz Richard E , Schnell Raymond J.
Published: February 2019

Anthracnose, caused by Colletotrichum gloeosporioides, is the most serious production and postharvest problem of mango. Most mango cultivars are highly susceptible to this disease. Embryogenic nucellar cultures of two cultivars, `Hindi' and `Carabao', were recurrently selected with either the purified phytotoxin or the crude culture filtrate produced by the fungus. Mycelium growth was suppressed in dual cultures involving the recurrently selected lines. Enhanced extracellular production of proteins was observed in the embryogenic cultures and in regenerants, including a newly expressed acidic chitinase isozyme (`Hindi') and greater expression of two other chitinase isozymes (`Hindi' and `Carabao'). Activity of α-1,3-glucanase was also substantially increased in the recurrently selected lines. Resistant lines were characterized using RAPDs on the basis of polymorphisms generated by eight different primers. In most cases, the differences involved the absence of RAPD markers in resistant lines.
Plant Nutrition and Heavy Metal Aspects of Compost Use
Authors: Chaney Rufus L.
Published: February 2019

Depending on the materials used to produce a compost, it will contain lower or higher levels of nutrients and metals. If composts have been appropriately matured, nutrients are in plant-available forms for crop production, and the compost pH will be near neutral. After 25 years of research and development of regulations and advice for biosolids and compost utilization, pretreatment of industrial wastes allows biosolids composts, and composts prepared from biosolids mixed with municipal solid wastes or yard debris to contain levels of microelements needed for plant nutrition but not high levels that could cause phytotoxicity. Composts can supply N, P, K, Ca, Mg, Fe, Zn, Cu, Mn, B, Mo, and Se required by plants or animals. When used in potting media, supplemental N fertilization is usually required, depending on crop requirements. Use of compost can replace other forms of microelements used as fertilizers in media or fields. Detailed evaluation of potential food chain transfer of Cd, Pb, and other elements in composts clearly shows that consumption of 60% of garden foods produced on pH 5.5 soils with 1000 t compost/ha would not comprise risk over a lifetime of consumption, nor would ingesting the composts at 200 mg/day for 5 years. Potentially toxic organic compounds are either destroyed during composting, or bound very strongly by the compost so that plant uptake is trivial. Compost use can be a safe and wise choice for both home and commercial use to replace peat or uncomposted manures, etc. Many states have developed regulatory controls to assure that pathogenic organisms are killed during composting, and that product quality standards are attained that allow marketing for general use in the community.