bluuebunny/crossref_metadata_2025 huggingface dataset:
CYTOLOGICAL EXPRESSION OF ms MUTANT IN WATERMELON
Authors: Zhang X. P. , Rhodes B. B. , Skorupska H.
Published: April 2024

Cytological studies on a male-sterile, female-fertile mutant ms in watermelon were done to determine differences in gene expression and stage of microsporangium development between male-sterile and male-fertile genotypes. Anthers of male-sterile (msms) and normal (Ms) plants of a line G17AB were compared using a single-staining procedure for sporopollenin, a double-staining procedure for nucleic acid and polysaccharides and a triple-staining procedure for DNA, protein and polysaccharides with bright field and fluorescent microscopy. No distinguishable features were observed between sterile and fertile plants at the microsporogenous stage. By microsporocyte stage, tapetum surrounding the sporocytes was differentiated and enlarged in normal plant anthers. There was no tapetum differentiation in ms mutant, and sporangium wall consisted of 5-7 layers of small cells. Ontogeny of microsporocytes of msms stopped at telophase II. The tetrad stage was not observed in the male-sterile plant. As maturation of msms anthers progressed, sporangium locules collapsed, and the telophase II meiocytes degenerated. Degenerated meiocytes in the collapsed locules gave low density primuline-induced fluorescence. All of these features suggest that the ms gene is expressed at a very early stage of microsporangium development (before meiosis) and results in failure of the tapetum to differentiate. Absence of tapetum results in abortion of meiocytes. Developmental bases for this male-sterility may be attributed to mutation in sporophytic anther tissue.
DEVELOPMENT OF A NUMBER OF PARTHENOCARPIC CUCUMBER HYBRIDS IN IRAQ
Authors: Al-Mukhtar Faisal A.
Published: April 2024

The objective was to develop Fl parthenocarpic cucumber hybrids adapted to greenhouse and plastic house culture. Thirteen gynoecious inbred lines were developed through successive selfing for six generations, followed by strict selection and screening in each cycle. General and specific combining ability tests were conducted using all possible reciprocal crosses. Four Fl hybrids were selected and compared in variety trials in different seasons with the commercially grown `Maram' hybrid. The local hybrid IPA-C2005 ranked the best for various yield components. No significant difference was observed between the yield of IPA-C2005 and `Maram' hybrid. The marketable yield estimates were 2.182 and 2.150 MT/180Mz for both hybrids, respectively.
CHESTNUTS IN NORTH AMERICA
Authors: Miller Gregory
Published: April 2024

Prior to the 20th century, the American chestnut, native to the Appalachian region, was highly valued for its timber and sweet nuts. The introduction of chestnut blight, ca. 1900, has destroyed the species economically, but enough germplasm survives to resurrect the species, if blight can be overcome. Most research in the USA has focused on chestnut blight, neglecting other problems and opportunities, especially commercial production of exotic chestnut species. A large commercial industry does not yet exist in the USA, but does in other parts of the world. Blight-resistant exotic species could be cultivated as a highvalue crop adapted to well-drained, acidic soils. In contrast to other nuts, chestnut kernels are low in fat and high in carbohydrate giving them unique culinary and food processing uses. Current problems are cultivar selection, propagation, insect pests, postharvest quality, and marketing.
DAMAGE-ACTION THRESHOLDS FOR WEEDS IN NEWLY PLANTED APPLE ORCHARDS
Authors: Merwin Ian
Published: April 2024

The development and implementation of economic damage thresholds have helped to reduce insecticide and fungicide usage in fruit production. However, herbicides are still routinely applied by calendar date in orchards, because damage-action thresholds have not been established for weeds. For two years we have evaluated different temporal and spatial combinations of tree-row weed suppression in a newly planted apple orchard. Tree growth, nutrient uptake and groundcover species mixtures have been analyzed yearly. Observations to date indicate that the timing of weed suppression was more critical than the area, in both wet (1992) and dry (1991) summers. Few significant differences were observed comparing tree growth or nutrient uptake in 2.4 or 6m2 weed-free tree-row plots. Early summer weed control appeared to be more beneficial than mid- or late-summer control during both years. Grasses became dominant in early summer treatments, while broadleaf weed cover increased in late summer treatments. These observations indicate that treating a narrow band with post-emergence hebicides may be sufficient to ensure adequate apple tree establishment in some sites.
USE OF COVER CROPS FOR WEED MANAGEMENT IN GRAPE AND TREE FRUITS.
Authors: Elmore C.L. , Smith R.J. , Weber E. , Miller R.
Published: April 2024

Weeds are found throughout the orchard or vineyard floor. They are controlled mostly in a band down the tree or vine row with cultivation, or more frequently with one or more applications of one or more herbicides. Instead of resident vegetation, planted cover crops of choice are being planted to “control” the vegetation. Two aspects of cover crops for weed control have been studied. First, the selective herbicides, sethoxydim, fluazifop, 2,4-D and combinations have been applied to selectively shift plant species within the vineyard to more desirable cover crops. Secondly, cover crops have been planted into prepared soil, grown for biomass, chopped and transferred as a mulch to the tree or vine row. A mixture of cultivated oat, purple and common vetch grown between the rows, chopped and blown into clean soil under trees or vines has effectively controlled annual weeds. The quantity of cover crop biomass produced is critical for adequate weed control.
FREEZE DAMAGE, PRUNING, AND YIELD RECOVERY OF RIO RED GRAPEFRUIT IN TEXAS
Authors: Fucik John E.
Published: April 2024

Following the 1989 Christmas freeze, 4 year-old Rio Red grapefruit trees were rated for freeze damage and given 9 planing treatments, ranging from the non-pruned controls to removing the canopy and most of the trunk. Wound dressing with and without a fungicide was used with some treatments. One set of trees was pruned in March, and a second in May, 1990. Each treatment had 6 single-tree reps. The pruning treatments were evaluated with respect to the fruit harvested, by canopy location, in 1992-93 and the severity of freeze damage.

Severe pruning resulted in smaller fruit than the controls, which was most likely due to the inverse relationship of size to number of per unit of canopy. Fruit size from may-pruned trees was consistently smaller than that from trees pruned in March. The wound dressings and fungicides had no effect on yields or fruit size. Except for the trees which died, the severity of freeze damage was not a good predictor of yield recovery.
THE EFFECT OF GIBBERLLIN AND SOME MICRO NUTRIENTS SPRAYS ON YIELD AND FRUIT QUALITY IN CAVENDISH BANANA (MUSA CAVENDISHII)
Authors: Akl Ahmed M. , Eid Adb El-Fattah M. , Mohamed S.M.
Published: April 2024

The present study was carried out during 1984/85 and 1985/86 to investigate the effect of four gibberellin acid concentrations (0.0, 25, 50, and 75 ppm) and five micronutrients treatments (no micro nutrients, copper, zinc, manganese and the three nutrients together) as well as the combination between them on the yield of Mindy banana plants and fruit physical and chemical properties. Under the conditions of this experiment the results indicated that the treatments contained gibberellin acid at 50 or 75 ppm and mixture of copper, zinc, and manganese significantly increased the yield of Mindy banana plants and improved fruit physical properties; however, fruit chemical constituents were somewhat inferior.
EXPRESSION OF THE β-GLUCURONIDASE GENE IN WATERMELON COTYLEDON EXPLANTS FOLLOWING PARTICLE BOMBARDMENT OR INFECTION WITH AGROBACTERIUM TUMEFACIENS.
Authors: Compton Michael E. , Gray D.J. , Hiebert E. , Lin C.M.
Published: April 2024

Cotyledon explants were established from 5- to 6-day-old `Minilee' seedlings germinated on MS medium with 2% sucrose and 0.7% TC agar, and precultured for 2 days on modified MS as above but with 3% sucrose and 5 μM BA before bombardment. Plasmid DNA [pUC221 and pUC472, which contain the β-glucuronidase (GUS) and NPTII (kanamycin resistance) genes, respectively] was delivered to the explants using a modified particle inflow gun following precipitation on to 1.1 μm tungsten particles. Explants infected with Agrobacterium (strain LBA4404 with the binary vector pBI121, which contains genes for GUS and kanamycin resistance) were not precultured prior to cocultivation for 4 days. GUS expression was measured 1 week after transfer to selection medium. Infection with Agrobacterium was the best method for delivering foreign DNA to watermelon cotyledons. Up to 300 GUS-expressing colonies were observed per explant following infection with Agrobacterium compared to 128 after bombardment.
FLORAL BIOLOGY AND FRUIT SET OF SOME CITRUS SPECIES AND CULTIVARS IN RELATION TO HEAT AND DROUGHT STRESSES
Authors: El-Agamy Samir Z. , Shaheen Mohamed A.
Published: April 2024

Floral biology of 8 citrus species and cultivars including orange (Valencia, Hamlin, Temple and Navel), tangarine (Dancy), lemon (Lisbon) and grapefruit (Marsh and Ruby) was studied on trees grown in extreme high temperature and drought. Measurement: included flowering date, duration and type, pollen viability, diameter and germination (using fluorescent microscope), initial and horticultural fruit set and fruit drop percentage and fluctuation. No significal correlation was found between initial fruit set and pollen viability (except in Marsh grapefruit). Horticultaral fruit set percentages were generally less than 0.5 in all species except in tangaring and lemon.
EFFECTS OF NITROGEN FORM ON NITROGEN UPTAKE AND NITROGEN AND CARBON PARTITIONING IN `CLIMAX' AND `SHARPBLUE' BLUEBERRIES
Authors: Merhaut Donald J. , Darnell Rebecca L.
Published: April 2024

Nitrogen uptake and N and C partitioning were evaluated in `Climax' and `Sharpblue' blueberries fertilized with different N forms. Plants were grown in silica sand and fertilized with a modified Hoagland's solution supplemented with 5 mmoles N as NH4 or NO3. After 12 months of growth, plants were dual labeled with 10% 15N-enriched-N as either NaNO3 or (NH4)2SO4 and 14CO2 and harvested 12 hours after labeling. Total N uptake did not differ between N forms; however, partitioning differed. More N was partitioned to new shoots, leaves, and stems of NH4 vs. NO3 treated plants. N form did not affect current C partitioning in `Sharpblue', but did affect C partitioning of `Climax', with greater C partitioning to roots of NO3 vs. NH4 treated plants. The increased N partitioning to shoots in NH4 vs. NO3 treatments suggests that NO3 reduction and/or translocation to shoots is limited. In `Climax', greater C partitioning to roots and less N partitioning to shoots of NO3 vs. NH4 treatments may partially explain the decreased shoot growth observed in NO3 treatments.
EVALUATION OF VARIOUS GROWING MEDIA AND VARIETIES FOR THE PRODUCTION OF GREENHOUSE TOMATOES IN MISSISSIPPI
Authors: Snyder Richard G.
Published: April 2024

Several growing media were tested with 2 varieties of greenhouse tomatoes to determine which media would be most appropriate for production of this crop in terms of yield and fruit quality, yet still economically feasible for small, family-based growers. Six 7.3 × 29.3 m greenhouses were used at the Truck Crops Branch Experiment Station in Crystal Springs, MS, with a randomized complete block design in each. The media included pine bark fines, rice hulls, rock wool, and coarse sand in five of the greenhouses, with the Dutch hybrid varieties `Caruso' and `Laura'. There were 3 replications of treatments, with 14 plants comprising one plot. In the sixth greenhouse, one variety at a time (`Caruso' or `Laura') was used with 7 additional media, in 4 replications. These included 1) pine bark fines, 2) fines + 15% sand, 3) 90% fines + 10% chicken manure, 4) 90% fines + 10% peat, 5) 67% fines + 33% pine bark mulch + 4.75 kg lime m-3 + 4.75 kg gypsum m-3, 6) mulch, and 7) calcite clay. In most cases, yield of plants grown in pine bark fines or rice hulls was either superior to or not significantly different from those in rock wool. Those in sand and in calcite clay had significantly lower marketable and total yield and more culls than other treatments.
DIFFERENCES IN N PARTITIONING BETWEEN STANDARD AND SPUR-TYPE APPLE TREES
Authors: Righetti Timothy , Khemira H. , Azarenko A.N.
Published: April 2024

Young bearing spur and standard type apple trees were given either 60 or 120 g actual N as ammonium nitrate depleted in 15N (0.01 atom percentage 15N) in Mar. 1992. The fertilizer was soil applied to 3 single replicate trees for each dose and each tree-type. Spur leaves had similar N contents for both types and both doses. The difference between the two types appeared to be related to differences in the relative number of spur leaves rather in their behavior. The percentage of N from the fertilizer in leaves from spur-type trees was 36% higher than those from standard type trees at low N rates, but 72% higher at high N rates. Doubling the N rate did not increase fruit N concentration in standard trees, but it did increase it in spur-type trees. The latter appeared to be more responsive to N management practices and more susceptible to deleterious effects on fruit quality of high N applications.
IRON HUMATE AS A SOURCE OF IRON FOR CITRUS IN HIGH-pH SOILS
Authors: Alva Ashok K.
Published: April 2024

Availability of iron (Fe) to plants is dependent on the stability of chelate to bind Fe. In soils with pH greater than 7.5, only EDDHA (Ethylenediamine di-o-hydroxyphenyl acetic acid) is the stable chelate to complex Fe. However, Fe EDDHA is an expensive material. Iron humate (IH) is a by-product of drinking water treatment, wherein, Fe is complexed with humic and fulvic fractions of the river water. Field experiments using Hamlin orange and Flame grapefruit on Swingle citrumelo rootstock conducted in two locations with high pH soils (> 7.5) have shown a significant increase in leaf Fe concentrations when IH was applied to the soil. Since the solubility of Fe from IH is lower than that of Fe EDDHA, the long-term effects of IH on growth and mineral nutrition of citrus are under investigation.
GENETICS OF RESISTANCE TO DOWNY MILDEW IN CUCUMBERS.
Authors: Bakr Mohamed A. Abo , El-Hak Seif H. Gad , Yacoup H.M.
Published: April 2024

A study was conducted to determine the inheritance of resistance to downy mildew caused by Pseudoperonospora cubensis in the cucumber genotypes; cv. Beit Alpha, line 1902 M and line THG-1. The common cultivated cultivar in Egypt Beit Alpha was found to be highly susceptible to downy mildew infection. Two crosses were made as follows: 1-“line 1902 M“X”Beit Alpha“ 2-”line TMG-1“ ×“Beit Alpha”. The resulting F1, F2 and backcross generations of the first cross and F1 and F2 populations of the second cross were observed for downy mildew reactions in the field under natural infestiation conditions. Susceptibility of the F1 populations to downy mildew was completely dominant in both crosses. Segregation ratios of the F2 and backcrose populations of the cross “line 1902 M × Beit Alpha” indicated that two pairs of recessive genes controlled the tolerance reaction of Line 1902 to the fungus. Segregation ratio for reaction to downy mildew in the F2 population of cross “line TMG-1 × Beit Alpha” indicated that three pairs of recessive genes were controlled the resistance reaction to the fungus. The following tentative genotypes for downy mildew reactions are proposed: Cv. Beit Alpha: Dm1Dm1Dm2Dm2Dm3Dm3 (Suscceptible), Line 1902 M: dm1dm1dm2dm2Dm3Dm3 (Tolerant) and Line TMG-1 dm1dm1dm2dm2dm3dm3 (Resistant).
SECONDARY SOMATIC EMBRYOGENESIS AND PLANTLET CONVERSION OF WHITE ASH
Authors: Bates Sharon A. , Preece John E. , Yopp John H.
Published: April 2024

Secondary embryos formed on somatic embryos that were placed on medium containing no PGRs (MS, 64.7% and DKW, 76.5%). Secondary embryogenesis was also observed when somatic embryos were in liquid MS (1μM NAA and 1 μM BA) on a shaker. Somatic embryos were placed on agar-solidified MS or DKW medium containing 1 μM TDZ or no PGRs. After 12 weeks, cotyledon expansion was observed on 41.2% (DKW, no PGRs) to 100% (DKW, 1 μM TDZ) of the embryos. Although cotyledons expanded, radicles and epicotyls elongated on very few somatic embryos. Epicotyl elongation primarily occurred on somatic embryos placed on agar-solidified MS with 1 μM IBA, 1 μM BA, and 3 μM TDZ and refrigerated (4°C) for 2 weeks or when somatic embryos were placed on liquid MS with 1 μM IBA, 1 μM BA, and 1 μM TDZ. Plantlets from somatic embryos survived in the greenhouse if epicotyls were excised and rooted ex vitro under mist or in high humidity trays.
In vitro Propagation of Kurrat (Allium ampeloprasum, var. Kurrat) and Leek (Allium ampeloprasiun var. Porrum).
Authors: Mohamed-Yasseen Yasseen , Davenport Thomas L. , Splittstoesser Walter E. , Skirvin Robert M.
Published: April 2024

Kurrat and leek are popular Middle-eastern and European vegetables in the family Liliaceae. Explants were obtained by longitudinally slicing, 3 to 4 times, seedling stem bases of leek and kurrat or by making multiple longitudinal slices across the central axis of mature kurrat stem bases which were previously cross cut 1 cm above the bases. Some explants were cultured directly for shoot-induction in Murashige and Skoog (MS) medium containing 4.4 μM benzyladenine. Others were allowed to form callus in MS medium containing 1.4 μM 2,4-D and 1.4 μM kinetin before transfer to the shoot-induction medium. The number of regenerated shoots from callus was consistently higher than those placed directly in shoot-induction medium. Shoots formed roots in MS medium containing 1 g/l activated charcoal. All rooted plants established easily in soil.
Micropropagation of Endangered Succulent Plants: Aloe juvenna, Aloe volkensii, and Stapelia semota.
Authors: Mohamed-Yasseen Yasseen , Davenport Thomas L.
Published: April 2024

Many succulent plants are becoming endangered because of extensive collection and declining habitat. Shoot tips and stem nodes from mature plants of A. juvenna and A. volkensii were cultured in Murashige and Skoog (MS) medium containing 9.8 or 19.6 μM indolebutyric acid (IBA). Explants cultured in liquid medium produced two fold the number of shoots as those in agar medium. All regenerated shoots from Aloe explants produced roots directly to form microplants. Stem nodes of mature plants and of aseptically germinated seedlings of Stapelia semota were cultured in MS medium containing 1.1, 2.2, 4.4, or 8.8 μM benzyladenine and 0.1 μM naphthaleneacetic acid. Proliferation of subsequent shoots was achieved in the same media. Shoots rooted in MS medium containing 4.9 μM IBA. Microplants from both Aloe and Stapelia were successfully established in commercial potting soil.
WATER USE EFFICIENCY AND GROWTH OF POINSETTIAS GROWN UNDER FOUR IRRIGATIONS SYSTEMS AND TWO FERTILIZER LEVELS
Authors: Dole John M. , von Broembsen Sharon L.
Published: April 2024

`Gutbier V-14 Glory' poinsettias grown with capillary mats (MAT) used the greatest amount of water and produced the most runoff, while plants grown with recirculatory subirrigation (RSI) used the least amount of water and produced the least runoff compared with microtube (MIC) and hand watering (HAN) systems. MIC and MAT systems required a greater number of irrigations to produce a crop than HAN and RSI systems. For the two overhead irrigation systems, MIC and HAN, plants grown with 250 mg liter-1 had greater leaf, stem and root dry weights than those grown with 175 mg liter-1. The two subirrigations systems, RSI and CAP, produced plants with greater leaf, stem and root dry weights when grown with 175 mg liter-1 than with 250 mg liter-1. Plants grown using CAP and HAN systems had higher leaf N concentrations than those grown with RSI and MIC systems. Overall, MIC plants grown with 250 mg liter-1 were larger and of higher quality than the other treatments.
HOT WATER TREATMENT IMPROVES TOMATO SHELF LIFE
Authors: McCollum T.G. , McDonald R.E.
Published: April 2024

Mature, green tomatoes were immersed in heated water (42, 44, 46, or 48C) for up to 90 min, and then either not cooled or cooled in water or a solution of 2% CaCl2 prior to storage at 2.5C. Following 2, 3, or 4 weeks of storage, the fruit were transferred to 21C for ripening. During ripening, the fruit were evaluated for color development, defects, and decay. Following storage, fruit required ca. 3 weeks at 21C to ripen regardless of storage duration. The number of fruit that developed acceptable market quality decreased as time at 2.5C increased; however, treated fruit tended to retain better condition than did nontreated fruit. Hydrocooling the fruit either in water or CaCl2 did not appear to be beneficial. The major cause of fruit loss was decay. All hot water treatments inhibited decay and resulted in a greater number of fruit with acceptable quality compared with nontreated fruit. Hot water treatment appears to be a beneficial treatment for maintaining tomato fruit quality.
PRODUCTION OF TRANSGENIC CITRUS PLANTS EXPRESSING THE CITRUS TRISTEZA VIRUS COAT PROTEIN GENE
Authors: Moore Gloria A. , Gutiérrez-E Alejandra , Jacono Colette , McCaffery Michael , Cline Kenneth
Published: April 2024

Citrus tristeza virus (CTV) is the most devastating citrus virus world-wide. Studies in a number of laboratories have shown that protection against a virus may be achieved by the introduction of the cloned viral coat protein (CP) into transgenic plants. The CTV CP has been isolated and sequenced [Sekiya et al., J. Gen. Virol. (1991) 72:1013-1020] and cloned into a custom engineered plant expression vector [Slightom JL, Gene (1991) 100:251-255]. We have also developed a protocol for the Agrobacterium-mediated transformation of internodal stem sections of Citrus seedlings [Moore et al., Plant Cell Rep. (1992) 11:238-242]. Transgenic plants of Carrizo citrange [C. sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] and sour orange (C. aurantium L.) expressing the CTV CP gene have been identified based on β-glucuronidase expression, PCR and Southern analyses, and immunoblot analysis with antibody to the CP. Transgenic sour orange plants are being propagated to generate sufficient material to test whether the plants are resistant to challenge by CTV.
DRIP IRRIGATION OF VEGETABLE CROPS IN THE SOUTHEASTERN U.S.
Authors: Hochmuth George
Published: April 2024

Microirrigation (drip or trickle) is part of intensive vegetable production employed in the humid southeastern part of the U.S. Drip irrigation is increasing in importance for vegetable irrigation because growers can achieve irrigation water savings of about 50% for many vegetables and growers can more efficiently apply fertilizers and labeled agricultural chemicals with drip irrigation. In Florida, more than 10,000 ha of vegetables including tomatoes, peppers, watermelons, eggplants, cucumbers, and squash are irrigated with drip irrigation and this acreage increases every year. With the increasing pressure from urbanization and concern for environmental issues, water quantity and quality are prime considerations in vegetable farming. Drip irrigation will continue to be an important tool for managing water quantity and quality on the vegetable farm. This workshop paper will present the current status of drip irrigation practices used on commercial vegetable crops in the southeastern U.S.
STATUS OF AUTOMATION IN RELATION TO PLANT MICROPROPAGATION
Authors: Liptay Albert
Published: April 2024

Micropropagation (MP) via tissue culture may include propagation from a bud on the mother plant, organogenesis, i.e., plantlet formation from a piece of tissue from the mother plant, or somatic embryogenesis, i.e., formation of a new embryo from a cell or group of cells. While MP may involve species-dependent problems, automation of MP exhibits problems depending on which manner of propagation is selected. Currently, most commercial MP is done via organogenesis. However, because of the potential for very large numbers of new plantlets derived through somatic embryogenesis at reasonable costs, there are numerous efforts attempting automation of MP of somatic embryogenesis. A number of species exhibit somatic mutation during the process of somatic embryogenesis and species-specific techniques have to be found to reduce or eliminate these and other problems. Automation of MP through meristem isolation of organogenesis is one way of overcoming the somatic mutation problems associated with somatic embryogenesis. This paper outlines the physiological and technical problems associated with automation of MP.
STATUS OF INTELLECTUAL PROPERTY RIGHTS PROTECTION
Authors: Jondle Robert J.
Published: April 2024

The various forms of intellectual property rights are discussed and compared including utility patents, Plant Variety Protection Certificates, Breeder's Rights, and Plant Patents. Recent developments in Plant Variety Protection and Breeder's Rights are reviewed, including the recent court decision in Asgrow v. Winterboer. How an “essentially derived” variety will be defined in the new 1991 UPOV convention, and in member countries, including several examples will be discussed. Recent examples of issued utility patents will also be presented.
THERMOINHIBITION IN SPINACH SEEDS
Authors: Leskovar Daniel I. , Santos Jose R. , Belefant-Miller Helen
Published: April 2024

Spinach (Spinacia oleracea) seed germination inhibition was examined at various temperature regimes. Inhibition occurred at higher than optimum (22C) constant temperature. At 30C, germination ranged from 10 to 40%, and was totally suppressed at 35C. Thermoinhibition at constant 30C was overcome by alternating 30/15C (12/12 h), resulting in higher percentage germination than 35/15C, 35/20C and 35/25C. Germination of whole, slit-pericarp, and pericarpless seeds incubated at 30C indicated that the pericarp imposed physical restriction and chemical inhibition on embryo growth. The ABA content of the pericarp was highest for cv `Cascade'; however, excised `Cascade' embryos imbibed with exogenous ABA, at a similar level as the endogenous pericarp concentration, had normal germination at 30C. Genotypes exhibited differential sensitivity to supraoptimal temperatures with `Ark 88-354' < `Fall Green' < `ACX 5044' < `Cascade'.
PLANT SPACING EFFECTS ON YIELD AND FRUIT SIZE OF HIGHBUSH BLUEBERRIES
Authors: Moore James N. , Brown Maurus V. , Bordelon Bruce P.
Published: April 2024

The influence of in-row plant spacing on highbush blueberry yield and fruit size was studied on two cvs., `Blueray' (erect growing) and `Bluecrop' (spreading). Plants of both cvs. spaced at 0.6lm in-row significantly outyielded plants at wider spacings (0.92, 1.22m) in each of the five harvest years when based on per hectare yields. On a per plant basis, however, plants spaced at 1.22m outyielded closer spaced plants in the last two harvest years of the experiment, indicating that interplant competition was reducing per plant yields on close spaced plants as plants grew larger. Over the 5-year harvest period, plots with 0.61m plant spacing produced a cumulative total yield increase of 17239 kg/ha more than plots with the conventional spacing of 1.22m. There were no effects of plant spacing on fruit size in the experiment.
DEVELOPING A SMALL-SCALE, LOW-INPUT CULTURAL SYSTEM FOR ELEPHANT GARLIC, A SPECIALTY CROP
Authors: Davis Jeanine M.
Published: April 2024

Elephant garlic (Allium ampeloprasum L.), which is not a true garlic, produces large bulbs with mild-flavored cloves. It is a high-priced specialty vegetable which is sold as individual bulbs or in multi-bulb decorative braids. The crop is of interest to small-scale growers because it is planted in the fall and harvested in mid-June, making it suitable for use in a multi-crop production system. Since 1989 studies have been conducted to develop a small-scale, low-input cultural system for elephant garlic. Organic versus synthetic fertilization, planting stock clove size, planting date, nitrogen rate, mulches, and multi-row plantings have been examined. Cloves have not been planted in the same field twice to avoid any soil-borne pest problems. There have been no diseases or insects and weeds have been managed with shallow cultivation. High yields of large, high-quality bulbs have been obtained by planting stock cloves greater than 20 g in mid-October and spacing them 20 cm apart in the row. A total of 140 kg N per hectare has been applied in three split-applications. Yields have averaged over 50 kg per 100 linear meters of row. Bulbs are cured by air-drying for six weeks.
WITLOOF CHICORY EVALUATIONS IN TENNESSEE
Authors: MacDermott Jomo , Coffey D. L. , Mullins C. A. , Straw R. A.
Published: April 2024

Production of witloof chicory (Cichorium intybus) roots for chicons or for inulin is typically a northern U. S. or European enterprise. Although chicons (Belgian endive) command a high market price, nearly all are imported from Europe. If appropriate cultivars and optimum summer growing conditions can be identified, Tennessee's mild winters may permit relatively low cost forcing techniques. Studies with these objectives were initiated in 1992 at two locations using six cultivars, two planting dates and two within row plant densities. Root yields varied from 13 to 40 Mg·ha-1 between locations and among cultivars. Incidence of bolting was greater than 50% for the earliest maturing cultivar, `Daliva', but less than 5% for the late maturing cultivar, `Rinof', at the warmer experimental site (Knoxville, elev. 251m). No bolting of any cultivar occurred at the cooler experimental site (Crossville, elev. 549m). Data on yield and quality of forced chicons and nitrate content of edible leaf tissue will be presented.
ACCLIMATIZATION OF CHRYSALIDOCARPUS LUTESCENS WENDL.
Authors: Reyes Trinidad , Nell Terril A. , Barret James E.
Published: April 2024

A 3×3 factorial experiment in a split-plot design was conducted to evaluate interior performance of Chrysalidocarpus lutescens. Treatments included three irradiance levels (481, 820 and 1241 μmol m–2 s–1) and three fertilizer rates (440, 880 and 1660 mg/23-cm pot, weekly). Plants were grown for 8 months under greenhouse conditions. Afterwards, plants were placed indoors (20μmol m–2 s–1 for 12 hr daily, 21 ±1 C and relative humidity of 50 ±5%) for 3 months. At the end of the production phase, light compensation point (LCP) varied from 243 μmol m–2 s–1 at the high irradiance level to 140 at the low irradiance level. Dry weight and nonstructural carbohydrates were lower and chlorophyll content was higher as irradiance levels were reduced. Increasing fertilizer to the highest rate decreased dry weight and nonstructural carbohydrates. After 3 months indoors, LCP declined to 1 26 μmol m–2 s–1. Number of fronds increased in all treatments at the expense of reserved carbohydrates. However, the drastic carbohydrate depletion observed after the interior holding period (97% in stem starch and 62% in root starch) indicates that C. lutescens is not a species for extended use under very low interior conditions
ACTIVITY OF ADH AND ETHANOL PRODUCTION IN CARNATION FLOWERS TRANSFERRED TO N2 FROM AIR AND LOW O2
Authors: Chen Xiuhua , Solomos Theophanes
Published: April 2024

Freshly harvested carnation flowers (Dianthus caryophyllus L. cv. White's Sim) were kept for 4 days either in air or low O2 before they were transferred to N2. Low O2 in the range of 1.2–2.7% resulted, depending on the concentration, in a decrease in respiration and 3–5 fold increase in alcohol dehydrogenase (ADH) activity, without a concomitant increase in ethanol production. Anoxia initially, within 4 hours, depressed by about 40% the rate of CO2 evolution in air, but had no effect on low O2-treated flowers. Anoxia induced in all treatments an increase in the activity of ADH, but the levels of ADH were 1.5 fold higher in the low O2-treated flowers than those kept in air. This difference increased to 10-fold after 6 days because by then, the air treated flowers were almost dead. Prior exposure to hypoxia enhanced the anoxic life of flowers by 3–4 days. Anoxia also induced an increase in ethanol production in both air and low O2-treated flowers. The peak value of ethanol evolution was about 1.5-fold higher in the low O2 than in air-treated flowers. The data are discussed in terms of the effect of hypoxia on carnation flower metabolism and longevity.
SAFE HANDLING OF PESTICIDES TRAINING IN COLORADO GREENHOUSES
Authors: Panter Karen L.
Published: April 2024

In late 1992, a grant was received from the National Institute of Occupational Safety and Health (NIOSH) to conduct training programs on Safe Handling of Pesticides for employees at ten Denver-area greenhouses. The training program met Occupational Safety and Health Administration (OSHA) requirements for employee right-to-know and Hazard Communication Standards. Sessions in Spanish and English were held, involving two video presentations, discussions of Material Safety Data Sheets, and procedures in each greenhouse for employees' health and safety. Before and after quizzes were given to the English-speaking participants and indicated an average increase of 5.2 points (out of 27 possible) after program participation. Evaluations indicated that, on a scale of 1 to 5 (5 high), participants thought the training would be “helpful when I handle hazardous materials” - 4.4; “presentation was clear and understandable”- 4.6; and “understand Hazard Communication Standard”- 4.5. Due to illiteracy among many in the Spanish-speaking sessions, evaluation was extremely difficult
GROWER SELF-EVALUATION AS AN EXTENSION TOOL
Authors: Kelly John F. , Zandstra Bernard H. , Myers Norman L.
Published: April 2024

A self-administered response to production-related questions, based on the most recent recommendations for the production of asparagus, was used to identify strengths and weaknesses of growers on an individual or group basis. Points were assigned to the various responses, and growers were evaluated relative to the group of respondents. Individual grower evaluation summaries were returned to the county horticultural agent for use in individual grower consultations. This report discusses the specific issues related to asparagus production and presents factors to be considered in preparing and evaluating such a tool.
TRANSPLANT TECHNIQUES & TIMING INFLUENCE SURVIVAL OF YUCCA GLAUCA TRANSPLANTS.
Authors: Brott Jody J. , Read Paul E.
Published: April 2024

Juvenile Yucca glauca plants, with a fibrous, woody rhizomatous root still connected to the mother plant and well developed basal fibrous roots that were present when they were transplanted prior to tap root development, exhibited faster recovery from transplant stress and earlier bloom as compared with juvenile plants transplanted with fully developed immature taproots. All juvenile transplants exhibited >90% survival as compared with mature transplants with fully developed taproots, none of which survived. Juvenile transplants with no taproot development prior to transplanting recovered and produced flower stalks with full bloom within 2 years of transplanting. Juvenile transplants with taproot development took 3 years from transplant to recover and produced flower stalks with full bloom.
AN INTRODUCTION TO MARINE HORTICULTURE
Authors: Bird Kimon T.
Published: April 2024

We can think of marine horticulture as the production of specialty crops just as in conventional horticulture. Certain marine algae provide foods and have been cultivated for centuries. Ornamental marine plants find their way into the recreational and display aquarium market. Some are now used for landscaping. There is a large market in the U.S. for marine plants needed for environmental technologies. Marine botanists use a number of horticultural and biotechnological methods to provide steady supplies of these plants. Marine plant germplasm may also find future use in U.S. agronomy and horticulture. This paper will review these current uses and possible future applications of marine plants in horticulture.
ALUMINUM-INDUCED CHANGES IN CARBOHYDRATE CONCENTRATIONS OF PEACH ROOTSTOCKS
Authors: Graham Charles J. , Reighard Gregory L.
Published: April 2024

A greenhouse experiment was conducted to assess the effects of increasing aluminum concentrations on carbohydrate levels of peach. Nemaguard and Lovell peach seedlings were grown in sand culture and irrigated daily with one-fifth strength Hoaglands solution containing A1 rates of 0, 25, 50, and 100 ppm. Beginning at week 6, plants were harvested at two-week intervals over an 8-week treatment period, and tissues (root, stem, and leaf) were analyzed for soluble sugars and starch. Lovell had significantly greater concentrations of root sucrose, glucose, fructose, and sorbitol; stem glucose and fructose; and leaf sucrose, glucose, and fructose. Nemaguard contained significantly greater concentrations of root, stem, and leaf starch and total carbohydrates compared to Lovell. Increasing aluminum concentration resulted in a significant linear increase of starch in the root and stem tissue, but a quadratic response in the leaf tissue of both cultivars. Increasing rates of A1 produced a decreasing curvilinear response in the concentration of glucose and fructose in roots, stems, and leaves. Analysis across harvest dates revealed that glucose and fructose declined curvilinearly in all tissues as the treatment duration increased. Starch concentrations increased curvilinearly in the roots and stems but decreased curvilinearly in the leaves when analyzed across harvest dates.
INTERACTIVE EFFECTS OF ROOTING MEDIA AND PHOSPHORUS FERTILIZER ON ROOT ARCHITECTURE OF COLORADO MESQUITE
Authors: Martin Chris A. , Stutz Jean C.
Published: April 2024

The effects of two rooting media [5 pine bark : 1 soil (v/v) and 5 Tufflite (a volcanic pumice) : 1 soil (v/v)] and (+ or -) phosphorus fertilizer [Ca(H2PO4)2H2O @ 6.58 g P per pot] on root architecture of Colorado mesquite (Prosopis alba Grieb. 'Colorado') were studied. Rooted cuttings were transplanted into 10-liter containers, topdressed with 45 g of 20N-0P-16.5K (IBDU slow release formulation) and 3 g Micromax micronutrient fertilizer, grown outdoors on black polyproplyene fabric, and irrigated daily to container capacity for three months. With or without P, specific root length was less for mesquite roots in Tufflite than for those in pine bark. Without P fertilizer, extended path length and root altitude were higher for roots grown in Tufflite than for those in pine bark. Adding P fertilizer decreased specific root length regardless of media type. In the pine bark medium, root altitude and extended path length were highest for trees fertilized with P; however, P fertilizer did not affect root altitude and lowered the extended path length when trees were grown in the Tufflite medium. These results indicate that roots were thicker and more branched in the Tufflite medium compared to pine bark and that P fertilizer caused a more herringbone branching pattern for mesquite roots when grown in pine bark, but resulted in a slightly more dichomatous branching pattern for roots when grown in Tufflite.
PRIMING TEMPERATURE AND SALT CONCENTRATION EFFECTS GERMINATION OF PEPPER SEED AT LOW TEMPERATURES
Authors: Carter Anne K.
Published: April 2024

Capscicum annuum L. var Vera Cruz seeds were primed at 15°C or 23°C for 5 days in 0, 200, 400, 600mM NaCl. The seeds dried for 3 days. Treatments plus an unprimed control were germinated in an incubator at 15° or 23°C. Germination was recorded daily and maximum % germination, (MaxG), mean daily germination (MDG) and T50 were calculated. Treatments were as follows: 23°C prime, 23°C germination (23P23G), 23P15G, and 15P15G. The 0mM NaCl priming treatment had over 50% germination during the priming process, thus germination was not recorded. P23G23 - MaxG was the same for all treatments. The T50 and MDG were improved by approximately 2 days for the 200mM and 400mM treatments. P15G15 - None of the seeds germinated in any of the treatments after 10 days. P23G15 - The 200, 400, and 600mM priming treatments improved MaxG, MDG, and T50 over the unprimed control, but were not different from each other. However, the MaxG was between 50-60% as compared to 90-95% in the P23G23 treatment. While priming at 23°C does allow seeds to germinate at cold temperatures, other treatments are necessary to improve MaxG.
LEAKAGE AND MOBILIZATION OF STORAGE RESERVES DURING IMBIBITION OF SWEET CORN.
Authors: McClure G.B. , Lang N.S.
Published: April 2024

Interconversion and transport of seed storage reserves during imbibition may influence subsequent germination. Sweet corn (Zea mays L. cv. Florida Staysweet) seeds were imbibed in aerated distilled water for either 0, 3, 6,9,12, or 24 h intervals. Seed leachate electrical conductivity, leachate soluble carbohydrate concentrations, and seed moisture were quantified at each interval. Lipid, non-structural carbohydrate, and protein concentrations of embryo and endosperm tissue were quantified for each imbibition interval. After imbibition treatments, seed germination performance was evaluated at 10 and 25C. Leachate conductivity and seed moisture increased with duration of imbibition. Glucose and fructose were the major soluble carbohydrates found in the seed leachate. Embryo lipid and sucrose concentrations significantly increased within 6 h of imbibition, while endosperm lipid decreased. Endosperm sucrose concentration remained constant throughout the duration of imbibition. Germination percentage was not significantly improved at 10 or 25C during the course of imbibition. Conversely, time to germination decreased significantly at 10C within 3 h. Storage reserve mobilization during imbibition may be responsible for the decreased time to germination observed at 10C.
ANATOMICAL INVESTIGATION OF ESSENTIAL OIL GLANDS AND THIER DISTRIBUTION IN OCIMUM BASILICUM VARIETIES
Authors: Flinn C.L. , Murray R. , Simon J E.
Published: April 2024

Methyl cinnamate and citral, compounds used in large quantities by perfume and flavoring industries, are the major constituents of essential oils found in certain basil varieties. The composition and quantity of oil, sequestered in as many as 16 different types of glandular structures, however, has been shown to change over time with plant development. In this study, we used scanning electron microscopy to characterize glands associated with leaves and flower parts of 3 lines of Ocimum basilicum, 2 with a high percentage of metyl cinnamate and one with high citral (as rel. percent of total oil). Density and distribution of oil producing glands were visualized with a tissue printing method on adaxial and abaxial leaf surfaces of young, mature, and post-mature leaves. Scanning electron micrographs revealed the morphology of six types of glandular structures. Density of oil-producing glands decreased with leaf expansion. The tissue printing method allowed for rapid visualization of oil-containing glands. The density of resulting prints will be easily quantified with computer image analysis.
SuperSorb-C AS A GROWTH MATRIX FOR Ca2+ NUTRITION STUDIES OF DARK-GROWN SEEDLINGS
Authors: Myers Patricia N. , Cutler James W. , Mitchell Cary A.
Published: April 2024

SuperSorb-C (Aquatrols, Inc., Cherry Hill, NJ) has been used as a soil amendment in the horticultural industry for its tremendous water-holding capacity. However, the addition of nutrients to the medium, especially bivalent cations, greatly diminishes the ability of the copolymer acrylamide acrylate to absorb water. This study investigated the use of SuperSorb-C as the sole growth matrix for physiological investigations of hypocotyl elongation. Soybean seedlings were grown in a darkroom at varied levels of Ca2+. Increased Ca(NO3)2 in the absorbing solution of the SuperSorb-C from 1 to 10 mM decreased the water-holding capacity of the copolymer from % ml g-1 to 46 ml g-1. The water potential of the medium was high for all Ca2+ concentrations, ranging from -0.02 to -0.12 MPa. The average elongation rate of dark-grown soybean seedlings over a 54 h period increased from 0,9 to 1.1 to 1.4 mm hr-1 with 1.0,2.5, or 5.0 mM Ca2+, respectively, then declined slightly with further increases in Ca2+. The increased elongation rate was correlated with increased root development. SuperSorb has potential as a significant tool in the physiological studies of nutrient effects on plant growth and stress responses. This project was supported in part by NASA grant NAG10-0093.
EFFECT OF NITROGEN FERTILIZER ON NITROGEN ACCUMULATION BY COMMON BEAN (Phaseolus vulgaris)
Authors: Mera M. , Nienhuis J. , Kmiecik K.A.
Published: April 2024

Legume plants capable of fixing N2 in the presence of abundant N in the soil are desirable to better integrate legumes into crop rotations including high N-demanding cereals. It has been suggested that the exotic bean line 'Puebla 152' may be insensitive to nitrate levels that normally inhibit bean nodulation and/or rate of fixation. Four levels (0, 30, 60, 120 Kg N/ha) of N as 15N-depleted ammonium nitrate were partialized into five weekly applications and imposed on Puebla 152, snap bean `Eagle', and non-nodulating soybean `Clay', in field experiments conducted in 1991 and 1992 on a very low N soil. CIAT's non-nod bean line Nod 125 was included in 1992. Each increment of added N increased the total N accumulated by the plants, in all genotypes. No significant genotype × N fertilizer interactions were detected. In average, Puebla 152 accumulated 25 and 46% more N than Eagle and Clay, respectively, in 1991, and 53, 119 and 119% more N than Eagle, Clay and Nod 125, respectively, in 1992. The analysis of 15N to estimate the proportion of N derived from the atmosphere is underway and will be presented at the meeting.
IRON BIOAVAILABILITY FROM AMARANTHUS SPECIES
Authors: Rangarajan Anusuya , Kelly John F.
Published: April 2024

Genetic variability in iron bioavailability was examined in different species of Amaranthus, in order to attempt to improve the iron nutritional quality of this vegetable. 35 lines of Amaranthus, surveying 12 species, were selected from the collection at the plant introduction station at Ames, Iowa. These lines were direct seeded at the MSU Horticulture Research Center. 18 lines were harvested on days 28, 35, and 42 after planting, and the other lines were harvested only on day 35. Lyophilized leaf material was analyzed for total iron using atomic absorption spectroscopy. Bioavailable iron was estimated using an invitro assay simulating gastrointestinal digestion. Statistically significant differences in both total and available iron were detected among species and between harvest dates. Total iron concentrations increased from day 28 to 35 and then were decreased on day 42 for all species except A. tricolor. This species accumulated the highest concentration of iron in the leaves of all species examined, increasing to day 42. The bioavailable iron measured was also highest in A. tricolor, yet as a percent of the total iron, this species had the smallest fraction of iron available.