bluuebunny/crossref_metadata_2025 huggingface dataset:
178 Response of Valencia Orange Trees to the Foliar Application of Different Potassium Salts: Their Effects on the Vegetative Growth, Leaf Miner Infestation, and Leaf Mineral Contents
Authors: Stino G.R. , Aziz A.E. Abou , Elezaby A.A. , Elmoneim E.A. Abd
Published: February 2019

Valencia orange trees [Citrus sinensis (L.) Osb.], budded on sour orange (C. aurantium) rootstock, were sprayed with four different potassium salts during 1995 and 1996. Twenty 5-year-old trees were sprayed once per month with one of the following material. K0: distilled water, K1: potassium green (a compound of different potassium salts, 35% K2O), K2: potassium nitrate (35% K2O), K3: potassium citrate (35% K2O), or K4: potassium sulfate (51% K2O). The vegetative growth occurred in three distinct successive cycles, i.e., spring, summer, and autumn. These cycles differed in time of commencement, duration and termination with respect to season. All potassium treatments significantly increased the shoot length and number of leaves/shoot for the three growth cycles. However, potassium green was superior overall other treatments. Percentage of leaf miner infestation was reduced at all potassium treatments. Potassium applications significantly increased leaf contents of N, P, K and decreased Ca and Mg levels.
181 Studies on Fruit Thinning and Growth in Apple Cultivars
Authors: Costa Guglielmo , Grappadelli Luca Corelli , Bucchi Fabrizio
Published: February 2019

Experiments were carried out for 3 years on `Gala' and `Fuji' apple cultivars. The efficacy of the compounds applied during blooming (ATS, Armothin) and at 10 mm king fruit diameter (BA, CPPU, and NAA) was studied. Results showed a poor efficacy of the chemicals applied during bloom, while compounds applied at fruit set showed interesting results. Among the new chemicals, citokinins were the most effective, although their effects were related to the cultivar: BA performs better than CPPU on `Fuji' while vice versa on `Gala'. In addition, both chemicals induced a slightly higher °Brix content, and acidity level showed the tendency to increase L/D ratio of the fruits as compared to controls. Fruit thinning and the strategies to enhance fruit size are applied early in the season and the problem remains, to assess their effectiveness as early as possible in order to adapt the management techniques (e.g., further thinning, if applicable, or fine-tuning of nutrition and irrigation, etc.) to enable the fruit to reach their maximum potential development. A modelling approach proposed by Lakso et al. (1995) postulates that apples grow in weight according to an equation termed “expolinear” (Goudriaan and Monteith, 1990) because after an initial phase of exponential growth (cell division), the apple enters a phase of linear growth (cell expansion) lasting up to harvest. The effectiveness of a thinning agent can therefore be evaluated-and explained-in terms either of the number of cells of the cortex tissue, or of their volume, or both. In addition, assessing the slope of the linear phase as early as possible might provide a prediction tool to evaluate size at harvest. This paper presents data from apple thinning trials on several cultivars. The effectiveness of these applications has been evaluated via an analysis of the cell parameters (number, volume and intercellular spaces) of the fruit's parenchyma cortex tissue. Also, fruit growth data have been used to test the possibility to predict fruit size at harvest once the fruit reaches the phase of linear growth.
185 Effects of Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots
Authors: Croker Steve J. , Hedden Peter , Rademacher Wilhelm
Published: February 2019

Prohexadione-Ca (BAS 125 W) is a new growth retardant for the inhibition of excessive vegetative growth in apple and other plant species. From work with enzyme preparations, it is known that prohexadione-Ca mimics 2-oxoglutaric acid, the co-substrate of dioxygenases, which catalyze late steps in gibberellin (GA) biosynthesis. As a result, the formation of growth-active GAs is reduced. In order to have a better understanding of its effects in intact plants, we have analyzed the GA status of treated and untreated apple plantlets. In a typical experiment, the following results were obtained: Plants (cv. Jonagold on M9 at 19 cm of new shoot growth) were sprayed until run-off with an aqueous preparation containing 25 ppm of active ingredient. After 22 days of cultivation under greenhouse conditions, total new shoot growth of the controls and the treated plants was 55 cm and 44 cm, respectively. In the apical part of this material the following GAs (roughly ordered in biosynthetic sequence) were detected at the following levels (control/treated in microgram per kilogram dry weight): GA19 (31/62), GA29 (24/36), GA20 (11/20), GA1 (4/3), and GA8 (8/3). These results clearly demonstrate that prohexadione-Ca blocks primarily the hydroxylation of GA20 into GA1. This leads to reduced levels of the highly active GA1 and of GA8, its inactive metabolite, whereas GA20 and the other inactive precursors accumulate. The data support older observations obtained in vitro, which indicate that GA20 3β-hydroxylase and related dioxygenases are the primary targets of prohexadione-Ca and similar compounds.
190 Growth Response of Four Tree Species to Fertilization and Humate Additives to CU Soil
Authors: Grabosky Jason , Bassuk Nina
Published: February 2019

CU soil is a material primarily composed of clay loam soil and crushed stone designed for use under pavement to promote street tree root growth in a durable pavement section, such as sidewalks or parking lots. One concern is the low total soil fraction from which tree roots can meet nutritive demands. At issue is the long-term nutrient management of street trees once the root zone has been rendered inaccessible due to the pavement wearing surface, although in 3-year field tests, there were no differences found between a CU soil material and an agricultural field control. CU soil treatments were produced in a factorial design with a patent applied for processed humate additive, and a nursery production fertilization treatment. Bare-root seedlings of Salix nigra Marsh, Platanus × acerifolia Willd., Ginkgo biloba L., and cell plugs of Ficus benjamina L. were grown in treatment containers for 5 months. A Minolta SPAD-502 was used to evaluate relative chlorophyll content as an indication of leaf tissue nutrient levels. Plant growth as a function of new growth dry weight was calculated. Soil samples were collected at the end of the study and were analyzed to evaluate the impact of humate admixes in nutrient availability. The fertilization treatments positively influenced leaf color and growth for all species. The CU soil control plants displayed significantly lower chlorophyll levels, but overall growth differences were less dramatic—insignificant in some cases. The humate additive did not consistently affect leaf color. The humate additive alone did not affect plant growth, but a significant positive interaction with the fertilizer treatment was evident for Platanus and Ficus. The positive interaction was insignificant in Salix and non-existent in Ginkgo.
208 Physiological and Anatomical Evaluation of Chilling-tolerant Sweetpotato Genotypes
Authors: Izekor Ehiorobo , Garner James O.
Published: February 2019

Selected physiological and anatomical characteristics of four chilling-tolerant sweetpotato genotypes were evaluated. Although the genotypes were considered highly tolerant to chilling, it was proposed that differences in their mechanism for tolerance existed. A genotype temperature interaction for chlorophyll fluorescence ratio was observed when the plants were exposed to 5 °C. Genotype differences were found for electrolyte leakage and peroxidase activity. There were no differences found for fatty acid percentage composition of the glycolipid or the phospholipid fraction from leaf samples. There were no differences in diffusive resistance and transpiration rate among the genotypes; however, stomata density, leaf shrinkage, and specific leaf weight differed among the genotypes. Differences were also found among the genotypes for percent leaf dry weight, leaf thickness, and cellular structure of the leaf. It was concluded that the basis or mechanism for chilling tolerance was not the same for the four genotypes tested; therefore, combining traits for tolerance could lead to higher tolerance levels.
225 Growth and Aesthetic Evaluations of Container- and Field-grown Atlantic White Cedar, Chamaecyparis thyoides (L.) B.S.P.
Authors: Sandrock David R. , Williams-Woodward Jean , Dirr Michael A.
Published: February 2019

Fifty-four taxa of Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.] were assembled and maintained. A protocol for propagation of Atlantic white cedar was established. Plants were grown in containers and in a replicated field plot. Height and width data were recorded from container- and field-grown plants and all taxa were evaluated for growth habit, growth rate, and summer and winter color. Color descriptions of foliage are provided based on the Royal Horticultural Society colour chart. Exceptional taxa were identified based on needle color, texture, growth habit, and growth rate. Superior green forms include Dirr Seedlings 1 and 2, `Emily', `Rachel', and `Okefenokee'. The superior variegated form is `Webb Gold'. Superior blue forms include `Blue Sport', `Glauca Pendula', and `Twombly Blue', and superior slow-growing forms include `Andelyensis', `Meth Dwarf', `Red Star', and `Heatherbun'. These taxa are recommended to growers, landscapers, and gardeners for production and use.
237 Evaluation of Green Snap Bean Varieties in Northwestern Mexico
Authors: Araiza-Celaya Gerardo , Liñeiro-Celaya Eduardo , Grijalva-Contreras Raúl L. , López-Vilchez Francisco , Salvador-Rivas Victor , Robles-Contreras Fabián
Published: February 2019

Vegetable production in the Caborca area is about 6500 ha, and the main crops are asparagus, muskmelon, watermelon, and pea. However during 1999, some growers tested green snap beans as a new crop for this area. The objective of this experiment was to evaluate five green snap beans with round podded (`Benchmark', `Landmark', `Jade', `Probe', and `Prosperity') and two densities (14 and 28 seeds/m) on subsurface drip irrigation system. The sowing was on beds of 2.0 m with two rows separated 60 cm. The date sowing was on 7 Sept. 1999. The first cutting were between 65 and 70 days after sowing in all varieties; in this case `Benchmark' was the earliest. The cumulative yield were 330, 140, 87, 63, and 20 boxes/ha (30 lb/box), respectively, in four harvests. On the other hand, the high population yielded 14.4% more than the low population. All varieties were damaged by frost that ocurred on 22 and 23 Nov. `Prosperity' was more susceptible to mosaic virus and `Benchmark' more tolerant. The pod quality distributions were 19.9%, 21.5%, 26.1%, and 21.0% for classes 1, 2, 3, and 4, respectively. We have not seen any important insect pests during this trial.
240 Sudden Tree Decline and Death of Pecan
Authors: Wood Bruce W. , Reilly Charles C.
Published: February 2019

This study reports on sudden death (or decline) of mature and apparently healthy pecan trees [Carya illinoinensis (Wangenh.) K. Koch]. Observations suggest that death and damage is due to winter cold injury (although the season's low was only -5 °C). The severity of this cold injury-like form of sudden death is closely associated with nut crop load (i.e., grams of kernels per square centimeter of trunk cross-sectional area) and premature defoliation. Both dead and declining trees not only produced relatively heavy crops, but also exhibited substantial premature pest-induced defoliation the previous autumn. The near absence of sugars and starch in roots and shoots of dead or declining trees at budbreak and the relatively high levels in healthy trees indicates that diminished assimilate reserves during the dormant season were the key factor causing death or decline. The diminished assimilate reserves prevented the accumulation of assimilate reserves necessary for maintaining live roots throughout the dormancy and prevented proper cold acclimation of shoot tissues. Distinct symptoms of sudden tree death or decline compared to typical cold damage are: a) a distinct top-to-bottom gradation of tree damage, with an increased proportion of dead shoots and shoots supporting abnormally small foliage being near the base of the canopy; b) dessicated and tan appearance of inner bark and phloem of the main trunk rather than brown coloration so typical of classical cold injury; c) death of roots by time of budbreak; and d) absence of resprouting from the trunk or root collar. These observations indicate that pecan trees can suddenly die due to being overly stressed for assimilates and that economic losses previously attributed to injury by severe winter cold sometimes may be due to depleted assimilate reserves during the dormant season as a result of overcropping and premature defoliation.
252 Effect of Harvesting Technique and Genotype on Cut Flower Production of Alstroemeria
Authors: Olate Eduardo , Bridgen Mark
Published: February 2019

The effect of harvesting procedures on the production of cut flowers of Alstroemeria was determined by growing six different cultivars from three different response groups with three different harvesting techniques. The orchid-type cultivars tested were `Parigo Red' and `Parigo Pink', the butterfly-type cultivars were `FreedomP', `PatriotP', and `Patricia Lynn', and the hybrid-type cultivar was `Sweet LauraP'. The different harvesting treatments were “cutting,” “pull,” and “no harvesting” (control). Cultivars and treatments were evaluated for date of harvest, number of florets per flowering stem, stem length and number of flowering stems produced per plant. The harvest period covered week 14 to week 34 of 1999. The number of florets produced per inflorescence was not affected by any harvesting treatments. The average length of the flowering stems with butterfly-type and hybrid-type cultivars of Alstroemeria decreased over the period of harvest. These two types of cultivars did not differ from each other as a result of the harvesting technique, but did differ from the control plants that were not harvested. The stems from control plants of the butterfly-type and hybrid-type cultivars were longer than those of the harvested plants. The orchid-type cultivars did not exhibit this “short stem effect” as the other two types of cultivars. In both orchid-type cultivars (`Parigo Red' and `Parigo Pink') and in the hybrid-type cultivar (`Sweet LauraP') the total number of flowering stems that were produced was greater with the “cutting” technique than with the “pulling” technique of harvest. In the case of butterfly-type cultivars, there was no difference of the number of flowering stems produced between the two harvesting systems, but they differed from the control plants.
254 Stem Extension and Subsequent Flowering of Plugs Grown Under A Far-red-deficient Film
Authors: Runkle Erik S. , Heins Royal D.
Published: February 2019

Environments with a low red (R, 600 to 700 nm) to far-red (FR, 700 to 800 nm) ratio (e.g., with high plant density) promote stem elongation, and a high R: FR suppresses it. While FR light promotes stem extension, it is also required for rapid, uniform flowering of many long-day plants. We investigated how a new FR filter [creating a FR-deficient (FRd) environment] influenced plug growth and subsequent flowering of pansy (Viola ×wittrockiana `Crystal Bowl Yellow'), petunia (Petunia ×hybrida `Carpet Pink'), impatiens (Impatiens wallerana `Accent Rose'), snapdragon (Antirrhinum majus `Liberty Scarlet'), and tomato (Solanum lycopersicon `Beefmaster'). One-week-old seedlings were placed under three filter treatments with 16-h photoperiods: the FRd filter, a neutral-density filter (N) that transmitted a similar PPF, and transferring plugs from the N to the FRd filter when leaves of each species began to touch (7 to 11 days later). The predicted phytochrome photoequilibria under the FRd and N filters was 0.80 and 0.72, respectively. After 25 to 35 days at 20 °C, node number and stem (or petiole for pansy) length were collected. Twenty plants of each species and filter treatment were then transferred to 4-inch pots and grown under natural photoperiods (14 to 15 h) at 20 °C until flowering. Compared to plants continually under the N filter, stem length under the FRd filter was significantly reduced in impatiens (by 11%), pansy (by 18%), petunia (by 34%), snapdragon (by 5%), and tomato (by 24%). Flowering of plants from plugs under the FRd filter was delayed by 2 to 3 days for snapdragon, petunia, and pansy. Filter treatment of plugs had no significant effect on flower number or plant height at flower.
260 Temperature Change during Development Affects Flowering in Cyclamen persicum
Authors: Karlsson Meriam , Werner Jeffrey
Published: February 2019

Cyclamen persicum (`Miracle Deep Salmon') was grown at 16 or 20 °C starting at transplant (70 d from seeding). Plants were maintained at the initial temperature of 16 or 20 °C for 3, 6, 9 weeks, or until flowering. Plant development was faster at 20 than 16 °C. Average time at 20 °C was 42 d to color appearance in the flower buds and 68 d to first open flower. At 16 °C, the average time was 58 d to flower bud color and 84 d for first open flower. Plants at 3 weeks of 16 °C flowered at a similar time as plants grown at 20 °C for 9 weeks or throughout. Three initial weeks at 20 °C resulted in similar time to flower as 16 °C throughout although flower color was recorded 9 d earlier for the plants initially at 20 °C. Time between flower bud color and open flowers averaged 26 d at both 16 and 20 °C. Significantly slower development from flower bud color to open flower was recorded with 3 or 6 initial weeks at 20 °C followed by 16 °C.
263 Photoselective Films Influence Flowering of Photoperiodic Species
Authors: Cerny Teresa A. , Rajapakse Nihal C. , Oi Ryu
Published: February 2019

Growth chambers constructed from photoselective plastic films were used to investigate the effects of light quality on height manipulation and flowering of photoperiodic plant species. Three types of treatment films were used; control, a far-red light intercepting film (YXE-10) and a red light intercepting film (SXE-4). The red (600-700 nm):far-red (700-800 nm) ratios and phytochrome photoequilibrium estimates for the control, YXE-10 and SXE-4 films were 1.0 and 0.71, 1.5 and 0.77, and 0.71 and 0.67, respectively. The photosynthetic photon flux was adjusted to uniformity among chambers using neutral density filters. Spectral filters did not effect minimum and maximum air temperatures. Experiments were conducted using quantitative long day (Antirrhinum majus and Petunia × hybrida), quantitative short day (Zinnia elegans and Dendranthema × grandiflorum) and day-neutral (Rosa × hydrida) plant species under natural short-day conditions. Plants produced under the YXE-10 filters were significantly shorter than the control plants, while plants produced under the SXE-4 films had similar or increased height compared to the control plants. However, both height response and flowering times varied with the crop species. Flowering time of Rosa × hybrida plants was uniform among all treatments. Flowering of quantitative long-day plants was delayed by at least 10 days under the YXE-10 film and was most responsive to the filtered light. Flowering of quantitative short-day plants was delayed by 2 days under the YXE-10. Days to flower for plants produced under the SXE-4 film were similar to the control plants for all species tested.
266 Response of Winter-injured Peach Trees to Pruning
Authors: Miller Stephen S. , Byers Ross E.
Published: February 2019

When temperatures reach -26 °C and lower, even for brief periods of time, damage to fruit buds and woody tissue of the peach tree is common. Low temperature injury on peach can lead to bark damage, gummosis, increased incidence of perennial canker, partial or complete crop losses, reduced shoot growth and/or tree death. In Jan. 1994 the Eastern Panhandle of West Virginia and surrounding states experienced three successive nights of temperatures at -28 °C or lower. Beginning in Apr. 1994, 7-year-old `Blake'/Lovell peach trees were subjected to four pruning levels (none, light, heavy, and dehorned) each at three times (April, May, and June) in a replicated factorial arrangement. Specific pruning treatments were applied only in 1994; a local commercially recommended level and time of pruning were applied to all trees from 1995 through 1998. Treatments had a significant effect on canopy volume and fruit yields. Trees receiving no pruning or dehorned trees and trees pruned in June had lower yields in 1995 than trees pruned in April or May or trees receiving a light or heavy pruning. These treatments also produced fewer large fruit at harvest. Lower yields and smaller fruit led to reduced dollar returns per hectare in 1995. Yields from 1996 through 1998 were lower for trees that were dehorned pruned in 1994 although there were little or no differences in fruit sizes between treatments. Time and/or level of pruning had effects on the number of cankers and number of large (>5.1 cm) cankers.
280 Production of Carrots Suitable for Cut-and-peel Processing in Ontario, Canada
Authors: McDonald M.R. , Janse S. , Kooi K. Vaner
Published: February 2019

Production of carrots for cut-and-peel processing has increased to >400 ha in the past 5 years in the Holland/Bradford Marsh area (44°5' N, 79°35' W) of Ontario. To provide carrots best suited for the new industry, growers needed information on the best cultivars and production practices. Trials with cultivars from four seed companies were conducted on muck soil (60% organic matter, pH 6.0) for 3 years (1997-1999) and on mineral soil (5% organic matter, pH 7.2) for 2 years (1998-1999). Carrots were seeded on raised beds at three seeding rates—25, 40, and 55 per foot—at two or three seeding dates and were harvested at two or three dates at 15-day intervals. Plant stand was always less than the seeded rate because of hot, dry growing conditions during the years of the trials. Carrots were hand-harvested and assessed for total yield, marketable yield, oversized carrots (>0.75 in diam.), length, width, and uniformity. The seeding rate of 55 seeds/ft and harvest 100 to 110 days after seeding resulted in the highest yield of carrots suited for cut-and-peel processing. Cultivar HM03 consistently had the highest score for quality, but low yields. Other cultivars, such as `Indiana', `Caro Pride', and `Vita Treat', also had high scores for quality. Carrots grown on mineral soil were longer than those grown on muck soil; however, yields were higher for the muck-grown carrots.
288 Use of Transplants, Rowcovers, and Black Plastic to Improve Yield and Earliness of Butternut and Calabaza Squash
Authors: Carter A. , Rulevich M.
Published: February 2019

The population of Puerto Ricans and Dominicans in Massachusetts is ≈6% of the total state population. Latinos have begun to request certain commodities native to their culture at Farmers' Markets and retail stores. One of these commodities is a winter squash [Cucurbita moschata (Duchene Poir)] called calabaza in Puerto Rico and auyama in the Dominican Republic. Calabaza has also been found in Asian markets. In order to have the crop ready for market by August in the Northeast, cultural practices which hasten maturity would need to be used. Eight treatments were tested: 1) direct seeded in bare ground, 2) direct seeded in black plastic, 3) direct seeded in bare ground with rowcover, 4) direct seeded in black plastic with rowcover, 5) transplanted in bare ground, 6) transplanted in black plastic, 7) transplanted in bare ground with rowcover, 8) transplanted in black plastic with rowcover. Calabaza was compared to butternut squash. Three weeks after seeding or transplanting, the transplants on black plastic were just beginning to vine and those transplants on black plastic and covered with rowcover were vining and in flower. Direct-seeded plants were in the second- or third-leaf stage. Treatment effects on early growth in the spring translated to differences in earliness and yield at the end of the season. Overall, the use of transplants improved yield by 30%, black plastic improved yield 15%, and the use of rowcover improved yields by 12%. There were no significant differences among the treatments where transplants were used along with plastic, rowcover or both. Significant differences were found in the number of fruit available for harvest in August. Direct-seeded plants on bare ground or on plastic did not have any harvestable fruit in August. The transplant, plastic and rowcover treatment had 300 to 500 boxes/acre depending on the year. Even the use of transplants on bare ground yielded an August-harvested crop.
304 Effects of Calcium and Magnesium on Growth, Fruit Yield, and Quality of Greenhouse Tomato Grown in Rockwool
Authors: Hao Xiuming , Papadopoulos Athanasios P.
Published: February 2019

Tomato (Lycopersicon esculentum Mill.) cv. Trust was grown in rockwool in summer and fall 1999 and 8 calcium/magnesium nutrient treatments, formed by two levels of calcium (Ca: 150 and 300 ppm) and four levels of magnesium (Mg: 20, 50, 80, and 110 ppm), were applied to investigate the effects on growth, fruit yield and quality. High calcium (300 ppm) increased overall fruit yield and size, reduced incidence of blossom-end rot and fruit cracking. However, high calcium also reduced the dry-matter content, soluble solid content and firmness of tomato fruit, and increased fruit russetting. Magnesium did not affect early growth or fruit production. However, 2 months after applying the treatments, the plants grown under 20 ppm Mg started to show Mg-deficient symptoms (leaf chlorosis), and Mg-deficient leaves lost more than 50% of their photosynthetic capability. The Mg concentration required for achieving high yield of firm fruit with high soluble solids and dry-matter content increased as the plant aged; i.e, 50 ppm in early stage of fruit production and 80 ppm in later stage of fruit production. At the end of experiment, the plants grown with 80 ppm of Mg also had the best root systems. Therefore, for both better yield and quality, a concentration of 300/50-80 ppm Ca/Mg may be recommended. Mg concentration may be started at 50 ppm and gradually be increased to 80 ppm in the later stage of fruit production.
316 Environmental Effect on Polyembriony of Two Citrus Rootstocks
Authors: Andrade-Rodrìguez Marìa , Villegas-Monter Angel , Gutièrrez-Espinosa M. Alejandra
Published: February 2019

Polyembryony is an important characteristic for citrus that allows them to be propagated clonally through seed. Even when it is genetically controlled by a quantitative trait, the environment in which the seed is developed can affect it. The aims of this investigation were to evaluate polyembriony in two citric rootstocks in two harvest cycles and embryo germination of polyembrionic seeds. Embryos of 300 seeds of Citrus volkameriana and C. amblycarpa were counted and measured in Summer-Fall and Winter 1998 and 1999, respectively; embryo of 50 seeds of both rootstocks were germinated in vitro. The number of embryos per seed was 1.9 and 1.6 in C. volkameriana and 4.7 and 5.7 in C. amblycarpa. In C. volkameriana, we observed 42% of monoembryonic seeds during summer-fall and 67% in winter, whereas in C. amblycarpa 5.0 and 4.1% were detected, respectively. Only embryos that were larger than 1 mm long germinated. Even when germination takes similar time (5 to 6 days), further growth is faster in larger embryos (5 to 10 mm) than smaller ones. Therefore, size of embryos would need to be considered for propagation purposes.
323 Vegetative Propagation of Spigelia marilandica (Indian Pinks) from Shoot-tip Cuttings
Authors: Foster Susan , Kitto S.L.
Published: February 2019

Wild populations of Spigelia marilandica, a clump-forming perennial, are being destroyed because of its recent popularity and the plant is now becoming rare in its native habitat. The effect of the stock plant environment on the rooting capability of Spigelia marilandica cuttings is the primary focus of this research. Cuttings were obtained from greenhouse (GH) grown plants on a monthly basis, and from plants maintained in outside field beds (FB), season permitting. Cuttings were dipped in Hormodin 1 (1000 IBA), placed in a perlite:peat mix, and put under mist for 8 weeks. During the experiment, 91% rooting of cuttings obtained from GH-grown plants and 35% rooting of cuttings obtained from FB-maintained plants was observed. Cuttings from GH-grown plants averaging 39 roots/cutting (average FW/cutting = 1.243 g, average DW/cutting = 0.1574 g) were compared to cuttings obtained from FB-maintained plants averaging 9 roots/cutting (average FW/cutting = 0.6041 g, average DW/cutting = 0.0663 g). A statistically significant difference was found between the two stock plant environments, with the cuttings from the GH-grown plants having an advantage over the cuttings obtained from the FB-maintained plants. A separate comparison was made of the cuttings obtained from the GH-grown plants over the 12 months of the experiment and the analysis showed no significant difference in the average FW/cutting, DW/cutting, and the number of roots/cutting.
330 Plant Regeneration via Organogenesis and Embryogenesis from Different Tissues of Sweetpotato
Authors: Park S.O. , Chen L.H. , Dhir S.K. , Bhagsari A.S.
Published: February 2019

The objective was to determine optimum conditions for embryogenic callus, embryo, organogenesis, and embryogenesis developed from leaf, petiole, stem, and tip tissues of the sweetpotato `Jewel' cultivar and from subcultured callus. Embryogenic callus was developed from stem and tip tissues on MS medium containing combinations of BA and NAA only under light conditions. Plant regeneration via organogenesis was developed from stem and tip tissues on medium including 1, 3 and 4 mg/L BA under dark and light conditions, while no plant regeneration via organogenesis was developed from leaf and petiole tissues. Frequencies for plant regeneration via organogenesis from the tissues were very low. No plant regeneration via embryogenesis was developed from the four tissues on medium having any combinations of BA+NAA and of kinetin+NAA. Embryogenic callus was observed in the subculture of callus developed from petiole and tip tissues on medium containing 0.2 and 2 mg/L 2,4-D only under dark conditions. Embryo was found in the subculture of callus from the tissues on medium containing 0.2 mg/L 2,4-D only under both conditions. Plant regeneration via embryogenesis was obtained in the subculture of callus from the tissues. Plant hormones and other factors affecting plant regeneration from the four tissues of the `Jewel' cultivar and other elite cultivars are currently being investigated at our lab for its application in transformation.
351 Nitrogen-fixing Water Fern Azolla as Biofertilizer for Hot Pepper (Capsicum chinense var. Scotch Bonnet)
Authors: Prasad Devi , Potluri S.D.P.
Published: February 2019

Scotch Bonnet pepper is a valuable commodity for Jamaica and the Caribbean, both for local consumption and for export because of its unique flavor and pungency. It is a valuable cash crop for small farmers who supply most of the fruit needed for processing and export. Azolla is a small water fern that grows on the surface of water bodies or on moist soil. Due to the presence of the nitrogen-fixing cyanobacterium Anabaena azollae, it fixes molecular nitrogen. This fern is used as biofertilizer for rice in millions of hectares in Asia. In the present work, experiments were carried out to determine the suitability and usefulness of both fresh and dried Azolla as biofertilizer for Scotch Bonnet pepper. A control without any fertilizer and a fertilizer control with 100 kg N/ha, supplied as ammonium sulfate, were used in 2-m2 plots, with three replicates for each treatment. Fertilizer was supplied in three split doses. Fresh Azolla was spread at the base of each plant and the soil was kept moist for the duration of the study. Dry Azolla was spread like a mulch around the base of the plant and used as a split treatment similar to inorganic fertilizer. Both the fresh and dry Azolla increased the marketable fruit yield over the control without fertilizer. Dry Azolla resulted in a similar yield as the fertilizer treatment [80%] while the fresh Azolla had a 60% increase in the yield over the control. In addition, dry Azolla resulted in early anthesis by 3 days over the fertilizer control. The dry weights of the whole shoot also showed increases similar to fruit yield. The dry Azolla also helped to improve the soil conditions and retained moisture for long periods. The results suggest that dry Azolla can be successfully substituted for chemical fertilizer for pepper. The cost of preparing Azolla to be used as fertilizer is calculated to be about 10% to 15% of the cost of chemical fertilizer for small farmers.
359 Irrigation Rate and Nitrogen Concentration Affect Plant Growth and Leaf Senescence of Citrus Rootstock Seedlings
Authors: Scholberg J.M.S. , Parsons L.R. , Wheaton T.A.
Published: February 2019

The interactive effects of irrigation rate and nitrogen concentration of the irrigation water on the growth of seedlings of two citrus rootstocks were studied. Four-month old seedlings of Swingle citrumelo [Citrus paradisi Macf. × Poncirus trifoliata (L.) Raf.] and Volkamer lemon (C. volkameriana Ten. & Pasq.) were grown for ≈10 months in square citripots filled with a Candler fine sand. Plants were irrigated at 0.5, 0.75 or 1.0 times the evapotranspiration rate. Irrigation was applied using water containing 0, 7, 21, or 63 ppm nitrogen. Plant growth increased with irrigation rate and nitrogen concentration. Evapotranspiration rates, as determined from weight losses of reference plants, increased with nitrogen rate. Overall plant growth and weekly evaporation rates were greater with Volkamer than with Swingle. Leaf senescence of Swingle was more pronounced at low irrigation rates and/or low nitrogen concentrations than it was with Volkamer. Increasing nitrogen concentration of the irrigation water during the winter months reduced leaf senescence of both Swingle and Volkamer seedlings, and also promoted continuous growth in Volkamer. Leaf growth of Swingle ceased during the winter months, regardless of the nitrogen concentration of the irrigation water.
360 The Relationship of Mineral Nutrients in the Rhizoplane, Rhizosphere, and Bulk Soil during the Gorwth of Apple Rootstock Seedlings
Authors: Dong Shufu , Shu Huairui
Published: February 2019

Malus hupehensis Reld apple rootstock seedlings and the rhizobox technique were used in this study. The seeds were collected from healthy mature trees at the Wanshougong Forest Farm in Shandong, China, stratified at 0 to 2 °C for 60 days, sown into growing medium with 1/3 loam soil+1/3 silt sand+1/3 compost manure, grown until the three-leaf stage, and then transplanted into rhizoboxes with four plants in each box. The rhizoboxes were inserted into the ground with the top of the boxes levelled with the soil surface. After the root mattress formed in the center of the box, plants were harvested by carefully dividing each box into rhizoplane, rhizosphere, and bulk soil, and mineral nutrients in each part were analyzed. The relationships were tested between the rhizoplane, rhizosphere, and bulk soil for each nutrent. Significant correlations were found for NH +4, NO –3, K, Mg, Zn, and Cu in the rhizoplane, rhizosphere, and bulk soil. There were significant relationships for P and Ca between the rhizoplane and rhizophere, but not between the rhizoplane or rhizosphere and bulk soil. Fe in the rhizoplane closely related to Fe in the rhizosphere but not to Fe in bulk soil. No correlation was found between the rhizoplane and either rhizosphere or bulk soil, but close correlation existed between rhizosphere and bulk soil for Mn.
385 Survey of Technical Information Requirements for Hispanic Nursery Employees
Authors: Mathers Hannah
Published: February 2019

At least 90% or more of the Oregon nursery industry workforce is composed of Hispanic employees who understand little English, with Spanish their primary language. Currently, most of the technical information available to the nursery industry is in English. A Spanish translation of the OSU/ODA Nursery Newsletter to Hispanic workers began in Aug. 1999. The first newsletter contained a questionnaire to determine the foremost technical topic interests. Surveys were also conducted at the Spanish sessions at the Ornamentals Northwest Seminars and of 40 Hispanic employees during visits to five Oregon nurseries. In total, 340 surveys were conducted with 158 respondents. At the Ornamental Northwest seminars, 57% of those attending the Spanish sessions answered the survey. Eighty-seven percent replied that insect control information was their leading technical information interest, 81% disease and 80% weeds. Other interests were nutrition at 73% and propagation and plant identification, both at 67%. Twenty-one percent of newsletter readers responded to the questionnaire. Like the seminar respondents, newsletter readers indicated pest control information was very important to them; however, 91% found all the information presented of value and 97% wanted to continue to receive future issues. This finding was consistent with responses from nursery visits where respondents indicated their delight to receive technical information in Spanish.
386 Employment Trends Within the Illinois Horticultural Industry
Authors: Waliczek T.M. , O'Rourke P.D.
Published: February 2019

Horticulture crops are a multi-million dollar industry in Illinois, providing employment opportunities as well as strengthening many local economies. To help establish a “green-goods” industry basis for Illinois, ≈300 surveys were mailed to members of the Illinois Nurserymen's Association, including owners and operation managers of retail and wholesale nurseries, greenhouses and garden centers. The focus of the questionnaire was on the horticultural products and services provided and the value of these sales and services to residents of Illinois. Questions were included regarding the pool of available labor, the total number of industry employees, including full and part-time employees, and the starting and average salaries for employees. A 25% response rate was achieved with 76 surveys returned and analyzed. Results examined fundamental predictors in gaining industry employment such as education and experience, employee demographics and average compensation for those employed at various levels. Provided that survey responses were indicative of the overall Illinois horticulture industry, responses provided evidence that the horticulture industry contributes approximately $67 million in salary and wages to the Illinois economy. While universities are reporting an increase in the number of female horticulture graduates, respondents indicated that 74.8% of their employees were male. Businesses reported an average of 28 employees including sales and office staff. However, very few businesses had hired people with disabilities or were aware of the services the state can provide to businesses hiring people with disabilities. Businesses employed an average of 2.5 managers with an approximate annual salary of $48,000, and an average of 15 laborers with an approximate annual salary of $21,000. Correlations provided insight into which areas of the industry hired persons with horticulture degrees and the types of experience most valued by the industry.
391 C-factor Research on Horticultural Crops for Erosion Prediction: Philosophy and Methodology of Data Collection
Authors: Panicker G.K. , Weesies G.A. , Al-Humadi A.H. , Sims C. , Huam L.C. , Harness J. , Bunch J. , Collins T.E.
Published: February 2019

Even though research and education systems have transformed agriculture from a traditional to a high-technology sector, soil erosion still remains as a major universal problem to agricultural productivity. The Universal Soil Loss Equation (USLE) and its replacement, the Revised Universal Soil Loss Equation (RUSLE) are the most widely used of all soil erosion prediction models. Of the five factors in RUSLE, the cover and management (C) factor is the most important one from the standpoint of conservation planning because land use changes meant to reduce erosion are represented here. Even though the RUSLE is based on the USLE, this modern erosion prediction model is highly improved and updated. Alcorn State Univ. entered into a cooperative agreement with the NRCS of the USDA in 1988 to conduct C-factor research on vegetable and fruit crops. The main objective of this research is to collect plant growth and residue data that are used to populated databases needed to develop C-factors in RUSLE, and used in databases for other erosion prediction and natural resource models. The enormous data collected on leaf area index (LAI), canopy cover, lower and upper biomass, rate of residue decomposition, C:N ratio of samples of residues and destructive harvest and other gorwth parameters of canopy and rhizosphere made the project the largest data bank on horticultural crops. The philosophy and methodology of data collection will be presented.
397 Assessment of Community Tree Planting Project Reveals Social and Psychological Benefits
Authors: Catanzaro Christopher , Ekanem Enefiok
Published: February 2019

A community tree planting project was conducted on the border of an urban Nashville, Tenn., neighborhood in Autumn 1994. In Jan. 2000, a written survey was developed to assess residents' perception of this site. Responses were gathered voluntarily and anonymously following a community meeting. Photographs of the site taken before the planting and again recently were available to respondents. Descriptions of the site's appearance prior to planting (turf only) included barren, boring, and lacking character. Comments regarding the site with trees suggest that trees provide cover and shade, are aesthetically pleasing, and represent positive human involvement. The average rating of the site's appearance prior to planting was “fair,” while its recent appearance was rated “very good.” Among three tree species included in the planting, Southern magnolia was strongly preferred over Canadian (Eastern) hemlock and Eastern redbud. Respondents valued magnolia's size, unique flowers and leaves, and evergreen nature. Most respondents did not use the area for any specific purpose. Despite that fact, respondents stated that they benefitted from the soothing aesthetics of the landscaped site, and that the site added value to the neighborhood and implied the qualities of belonging and leadership. An unintended outcome of the survey was its educational aspect. Nearly two-thirds of respondents did not live in the area when this site was landscaped, and most of them were not aware that the neighborhood had conducted the project. Nearly one-half of all respondents expressed interest in additional landscaping at this site or nearby high-visibility, high-use sites.
399 Use of Conservation Tillage and Cover Crops for Sustainable Vegetable Production
Authors: Hruska H.J. , Cline G.R. , Silvernail A.F. , Kaul K.
Published: February 2019

Research began in 1999 to examine sustainable production of bell peppers (Capsicum annuum L.) using conservation tillage and legume winter cover crops. Tillage treatments included conventional tillage, strip-tillage, and no-tillage, and winter covers consisted of hairy vetch (Vicia villosa Roth), winter rye (Secale cereale L.), and a vetch/rye biculture. Pepper yields following the rye winter cover crop were significantly reduced if inorganic N fertilizer was not supplied. However, following vetch, yields of peppers receiving no additional N were similar to yields obtained in treatments receiving the recommended rate of inorganic N fertilizer. Thus, vetch supplied sufficient N to peppers in terms of yields. Pepper yields following the biculture cover crop were intermediate between those obtained following vetch and rye. When weeds were controlled manually, pepper yields following biculture cover crops were similar among the three tillage treatments, indicating that no-tillage and strip-tillage could be used successfully if weeds were controlled. With no-tillage, yields were reduced without weed control but the reduction was less if twice the amount of residual cover crop surface mulch was used. Without manual weed control, pepper yields obtained using strip-tillage were reduced regardless of metolachlor herbicide application. It was concluded that a vetch winter cover crop could satisfy N requirements of peppers and that effective chemical or mechanical weed control methods need to be developed in order to grow peppers successfully using no-tillage or strip-tillage.
408 Potential Use of Typha latifolia for Bioremediation of Metalaxyl and Simazine
Authors: Wilson C. , Klaine S. , Whitwell T.
Published: February 2019

This research focused on the potential use of common cattails (Typha latifolia) for removing metalaxyl and simazine residues from contaminated water. Specifically, it established toxicity thresholds to the herbicide simazine and characterized the uptake and distribution of simazine and metalaxyl by the plants. Simazine tolerance levels were determined by exposing plants to a series of six concentrations (0 to 3.0 mg/L) in aqueous nutrient media for 7 days. Metalaxyl toxicity was not evaluated because other studies indicated it was relatively non-toxic to plants. Toxicity endpoints measured included fresh mass production after 7 days exposure and 7 days post-exposure. Pesticide uptake and distribution were determined by growing plants in nutrient media amended with C-14-ring-labeled metalaxyl (0.909 mg/L) or simazine (0.242 mg/L) for 1, 3, 5, or 7 days. Plants were dissected and tissues were combusted and analyzed by liquid scintillation counting. Cattail fresh mass production was reduced 84% and 117% at 1.0 and 3.0 mg/L simazine, respectively, after 7 days of exposure. Metalaxyl and simazine activity in solution was reduced 34% and 65%, respectively, after 7 days. By day 7, activity from both pesticides was detected predominantly in the leaves. Uptake of each pesticide was correlated with water uptake throughout the 7 days. These results suggest that the common cattail may be a good candidate for incorporation into a phytoremediation scheme for metalaxyl and simazine.
409 Reintroduction and in Situ Conservation of `Chococito' Maize Race in Anchicaya River, Buenaventura, Colombia
Authors: Reyes Luz M. , Martinez Orlando , Martinez Nubia
Published: February 2019

Variability of `chococito' maize cultivars (Zea mays L.), have been decreased in the Anchicaya river area, because new crops were established there. Process of recuperation, promotion, and conservation under in situ and ex situ conditions were proposed to the community of the area. Using participatory research methodologies, memory and uses were recuperated for four varieties through the Exchange Seed Interchange Fund (ESIF), established just for maize. The study was carried out in two components: social and agronomic. The social component was development in three phases: i) diagnosis; ii) establishment of the ESIF, and iii) socialization. The agronomic characterization was performed with members of the community through the development of the crop. Twenty-six variables, both quantitative and qualitative, were registered. The cultivars were appropriated for extreme conditions of the Anchicaya river area, high temperatures (30 °C) and high level of precipitation (6000 mm/year). During the process of cropping, it was found that the “to cut and to decay” system is the most common used in this region. Using multivariate analyses of quantitative and qualitative variables, the relationships between materials of `Chococito” race were found. The dendograms for these cultivars had shown differences among them. As a complement of the in situ conservation done by compromise of the Anchicaya's community, a duplicate under ex situ conditions was established at the Genetic Resources Laboratory, belonged to the Agronomy Dept. of National Univ. of Colombia.