bluuebunny/crossref_metadata_2025 huggingface dataset:
Further Investigations on the Genetics of Resistance to Iron Deficiency in Cowpea
Authors: Hale Anna L. , Scheuring Douglas C. , Gerik Thomas J. , Hart Jeffrey D. , Miller J. Creighton
Published: February 2019

Iron Deficiency Chlorosis (FeDC) is a problem in cowpea because it affects the ability of the plant to produce chlorophyll. Earlier studies indicated that FeDC was conditioned by a single gene. Pinkeye Purple Hull (PEPH), a susceptible variety, and Texas Pinkeye Purple Hull (TXPE), a resistant variety, were crossed and allowed to self for one generation. The F1s were backcrossed to the parents. SPAD readings were taken on each population. SPAD measures the transmission of light through the leaves at a wavelength where chlorophyll absorbs and a wavelength where it does not. The SPAD reading is calculated based on a ratio of these two numbers. Thus, the SPAD value is unitless and is an indication of the relative amount of chlorophyll present in the leaf. Chlorophyll was extracted from leaves, and regressed on the SPAD readings from the same leaves. An R2 of .9102 was obtained as well as a regression equation of y = 12.8x + 54.5. Thus, a SPAD value of 1 corresponds with a chlorophyll content of ≈67.3 μg chlorophyll/gfw. The data was analyzed using a bootstrap method, and indicated that FeDC is not controlled by a single gene. A P-value of .0004 showed a highly significant difference between the expected and observed segregation ratios in the F2 plants. Narrow sense heritibility (Mather) was estimated at 0.3.
Ripening and the Climacteric of Pawpaw
Authors: Koslanund R. , Archbold D.D. , Pomper K.W.
Published: February 2019

Pawpaw (Asimina triloba L.), the largest tree fruit native to North America, has become the focus of a significant effort to develop its commercial potential. Due to the very short shelf life of the ripe fruit, a critical component of this effort is the establishment of appropriate harvest and postharvest storage techniques. Although it has been reported that the ripening of the fruit is climacteric, there is no published data to support this. Nor are there any reports on the response of the fruit to cold storage. Fruit were harvested and classified as unripe if no softening was evident or as ripe if softening had commenced. Fruit were held at room temperature or were stored at 4 °C for 28 days, then moved to room temperature. Ripe fruit exhibited respiratory and ethylene climacteric peaks within 3 days of harvest and 5 to 7 days after removal from cold storage. Unripe fruit exhibited climacterics 5 days after harvest and after removal from cold storage. A survey of drops indicated that they were postclimacteric. Thus, pawpaw is a climacteric fruit and cold storage delays the start but not the relative rate of ripening.
New Seedless Table Grape Cultivars for the South
Authors: Clark J.R. , Moore J.N.
Published: February 2019

Two new seedless grape cultivars were released in 1999 from the grape breeding program at the Univ. of Arkansas. `Jupiter' is the fifth release from the program. `Jupiter' is blue-fruited, has large berries, non-slipskin texture, and a mild muscat flavor. Yields of `Jupiter' were very good in replicated trials, and hardiness is also adequate for production in all areas of the South. `Jupiter' ripens 5 days later than `Venus', but earlier than `Mars' or `Reliance'. `Neptune' is the sixth release and first white-fruited cultivar from the program. It has medium-sized berries, large clusters, non-slipskin texture, and a mild, fruity flavor. Yields of `Neptune' were moderate in replicated trials. `Neptune' ripens 17 days later than `Venus' and 3 days earlier than `Mars'. Both cultivars were developed and evaluated with a commercial cultural system including routine fungicide applications, and fungicides will be required to reliably produce these cultivars. Neither of these cultivars has been tested in a Pierce's Disease region of the United States, and it is not anticipated that either will have resistance to this disease.
Matted-row Strawberry Production using Landscape Fabrics and Organic Mulch for Weed Control
Authors: Strang John , Harper Carl , Hadad Dana , Oakley Kay , Slone Darrell , Snyder John
Published: February 2019

Three landscape fabrics, Magic Mat®, a heavy black plastic woven fabric with a fuzzy underside; Weed Mat®, a thin black plastic sheet with small holes; and Typar®, a dark gray spun bonded material, with and without a cover of organic oak bark mulch, were evaluated for weed control and ability of strawberry plant roots to establish through the fabrics over a 4-year period. Landscape fabrics reduced weed numbers for the first 3 years in comparison with the bare ground treatment. With few exceptions. the organic mulch did not improve the weed control capability of landscape fabrics. Fruit yield for the Weed Mat and Magic Mat treatments did not differ from the bare ground treatment, but was lower for the Typar treatment when averaged over organic mulch treatments. Fruit yield was higher where the organic mulch was used when averaged over all landscape fabric treatments. Fruit size was slightly larger for the bare ground and smallest for the Typar treatments during the first harvest season, but there was no difference in fruit size by the third year of harvest. Fruit size for the organic mulched plots was slightly larger than that for the unmulched plots the second year of harvest, but there was no difference for the first or third years. The number of strawberry runner plants that rooted and plant row vigor were greater for the Weed Mat, Magic Mat and plots without the landscape fabric than for the Typar plots, particularly in the second and third season. Rooting of runner plants and plant row vigor was better with organic mulch. Landscape fabric tended to reduce extent of rooting, especially in the first season, but it was improved by the application of organic mulch.
Refrigeration of the Root Zone to Delay Budbreak in Grapes
Authors: Graham J.H. , Montague D.T. , Durham R.E.
Published: February 2019

Grapes grown in West Texas are especially susceptible to freeze damage during spring deacclimation and budbreak. This experiment was undertaken to evaluate whether refrigeration of the root zone would delay budbreak in two grape cultivars, `Chardonnay' and `Cabernet Sauvignon'. The experiment was conducted under greenhouse conditions using 1-year-old grafted plants planted into containers in water bath chillers to cool the root zone. Three root-zone temperatures were maintained: 7.2 °C, 1.7 °C, and a nonchilled control. The experiment followed a randomized split plot, with main plots being temperatures and the sub-plots being genotype, and the experiment was repeated once. Evaluation of budbreak was performed on a daily basis. Other data collected included shoot dry weight and root dry weight with soil, water, and air temperatures recorded using type T thermocouples (copper-constantan) attached to a datalogger. The experiments indicated that budbreak could be delayed in both varieties by the refrigeration of the root zone by an average of 1 to 2 days when comparing the 1.7 °C treatment with the nonchilled control. The refrigerated treatments of `Chardonnay' also tended to show a prolonged budbreak over time. This finding may be significant since `Chardonnay' generally exhibits budbreak relatively early compared to other grape varieties and a prolonged budbreak may allow some buds to escape spring frost injury.
Effect of Plant Growth Regulators on Flowering and Postproduction of Curcuma Alismatifolia `Chiang Mai Pink'
Authors: Sarmiento Mauricio J. , Kuehny Jeff S.
Published: February 2019

Curcuma alismatifolia `Chiang Mai Pink' is a tropical perennial from the Zingiberaceae family with attractive flowers that make it useful as potted plant. Curcuma alismatifolia produces a tall inflorescence resulting in an unmarketable plant due to excessive height. Rhizomes of C. alismatifolia were soaked for 10 minutes in GA at concentrations of 0, 100, 200 or 500 ppm. The same plants were drenched with paclobutrazol at 0, 2, 3 or 4 mg a.i./container when shoots were 10 cm. GA significantly delayed rhizome emergence and flowering and reduced flower height. Paclobutrazol significantly reduced height; however, greater concentrations must be applied to obtain a marketable plant height. Number of flowering stems, postproduction life, and postproduction stretching were not affected by GA or paclobutrazol. Curcuma alismatifolia had an excellent postproduction life (4.64 ± 0.28 weeks) with little postproduction stretching (2.27 ± 0.38 cm).
Effect of Systemic Deer Repellent Tablets and Liquid on Deer Browsing of Containerized Ornamentals
Authors: Wade Gary L. , Jackson Jeff , Henderson Kendra
Published: February 2019

Economic and aesthetic losses from deer browsing of ornamental plants in nurseries and landscapes has increased significantly during recent years. This, according to wildlife specialists, is primarily due to hunting restrictions in urban areas. There are numerous so-called “deer repellents” on the market, but most are foliar applied and can be washed off or diluted with rain or irrigation. This study evaluated the effect of a systemically absorbed deer repellent tablet, Repellex (trademarked product), on deer browsing of containerized ornamental plants. A foliar applied counterpart, Repellex liquid, was also evaluated. The 1.5-gm tablets are a 14–2–2 fertilizer containing denatonium benzoate, lactose, ammonium phosphate, hydrous magnesium, and potassium sulfide. Two to eight tablets, depending on the size of the container, are placed adjacent to the root ball of the plant and 2 inches below the media surface at time of transplant. Gumpo azalea, Indian hawthorne, daylily, and Manhattan Euonymus were used for the study. Plants treated with tablets were held 6 to 8 weeks, according to manufacturer recommendations, under nursery conditions, then transported to deer-holding pens at the Whitehall Forest Research Station at the Univ. of Georgia. The pens, 1/2- to 1 acre in size, contained seven to 12 deer, depending on the study. Growth measurements initially and at weekly intervals were used to assess the degree of deer browsing. Results varied by plant species. Generally, the tablets were ineffective in preventing deer browsing when compared to the control. The foliar applied liquid was effective in reducing deer for up to 6 weeks when compared to the control. Plants treated with a tablet at time of propagation and two additional tablets when transplanted were browsed to the container within 2 days of deer exposure.
SERA-IEG-27: Nursery Crop and Landscape Systems; Plant Evaluation Program
Authors: Dunwell Winston C.
Published: February 2019

SERA-IEG-27, Southern Extension and Research Activities–Information Exchange Group–27, is sponsored by the Southern Association of Agricultural Experiment Station Directors. Thirteen states cooperate with Official Representatives from Extension and Research programs. The objective of the group is to identify, evaluate, select, and disseminate information on superior environmentally sustainable landscape plants for nursery crop production and landscape systems in the Southeast. Plants are distributed to those responding to a request for plant evaluation cooperation. Those that agree to cooperate are expected to grow a liner to landscape size, plant it in an landscape setting and evaluate the plant (numerically, a scale of 1–10 for insect damage, disease damage, cold damage, heat stress, growth rate, flower, fruit, fall color, production potential, landscape potential, invasive potential, and insect disease transmission potential, as well as plant height and width and time/duration of bloom). Following evaluation the group is to collectively and individually disseminate information gained from the plant evaluation system to a wide variety of audiences.
Herbaceous Plant Trial Results—1999
Authors: Owings Allen , Holcomb Gordon , Bates Andrew , Cox Peggy , Crnko Stephen , Witcher Anthony
Published: February 2019

In 1999, LSU Agricultural Center landscape trials of herbaceous ornamental plants included zinnias, ornamental sweet potatoes, vinca, and perennial verbenas. Based on growth habit, flowering and disease observations from 1999 and previous years, `Homestead Purple', `Tiger Rose', `Rose King', `Taylortown Red', and `Blue Princess' (`Biloxi Blue') are recommended perennial verbena cultivars for Louisiana landscapes. Zinnias evaluated included Zinnia angustifolia and Z. elegans cultivars. `Crystal White', `Profusion Orange', and `Profusion Cherry' (all Z. angustifolia cultivars) were superior landscape performers. Major incidence of bacterial leaf spot was reported on all Z. elegans cultivars in 1999. Over the last several years, the Pacifica series of vinca had significantly improved visual quality ratings in landscape trials when compared to the Heat Wave and Cooler series. In 1999, Mediterranean Deep Rose had visual quality ratings similar to Pacifica but had increased incidence of disease problems. Ornamental sweet potato cultivars recommended for landscape use in Louisiana based on trials in 1999 are `Blackie', `Black Beauty', `Margarite', and `Pink Frost' (`Tricolor'). `Summer Frost' is not recommended.
Effect of Explant Resource and Growth Regulators on Somatic Embryogenesis and Plant Regeneration in Sweetpotato
Authors: Chen Lianghong , Bhagsari Ajmer S. , Park Soon O. , Dhir Sarwan
Published: February 2019

This study was carried out to optimize conditions for plant regeneration of sweetpotato [Ipomoea batatas (L.) Lam] using shoot tips, petioles, and leaves of Selection 75-96-1 as explants in Murashige and Skoog (MS) with several growth regulators at different levels. Callus initiation and callus proliferation media were 9.0 μm 2,4-dichlorophenoxyacetic acid (2,4-D) and 9.0 μm 2,4-D + 1.1 μm N6-benzyladenine (6-BA) in protocol I; 8.1 μm α-naphthaleneacetic acid (NAA) + 1.2 μm kinetin (KIN) and 5.4 μm NAA + 4.6 μm KIN in protocol II; 0.9 μm 2,4-D, and 0.9 μm 2,4-D + 1.2 μm N-isopenylamino purine (2iP) in protocol III; NAA (8.1 μm) + KIN (1.2 μm) and 2,4-D (0.9 μm) + 2ip (1.2 μm) in protocol IV, respectively. In protocol I and II, shoot tip, petiole, and leaf were used, but only petiole and leaf in protocol III and IV. In the protocol I and II, somatic embryos were obtained only from shoot tip explants; in protocol III and IV, only from petioles. The frequencies of somatic embryo development were 33.3% in protocol I, 42.1% in protocol II, 21.2% in protocol III, and 10.3% in protocol IV, respectively. The leaf explants failed to produce somatic embryos in all the experiments. In protocol I, somatic embryogenesis occurred through the well-known sequence of globular-, heart-shaped-, torpedo-, and cotyledon-type embryos. However, in protocol II, the structures resembling plumule and radicle were observed before the emergence of torpedo/cotyledon type embryo clusters. The somatic embryogenesis in protocol III and IV was similar to that in protocol I. Growth regulators influenced somatic embryo development. Further, this study showed that explant resource and growth regulators affected the frequency of plant regeneration in sweetpotato.
Seed Germination Inhibitors in Cortex Tissue of Sweetpotato
Authors: Peterson Joseph K. , Harrison Howard F. , Snook Maurice E.
Published: February 2019

After removal of the periderm, cortex tissue of the sweetpotato cultivar Regal was collected. Polar extracts of this tissue strongly inhibited germination of proso-millet seed. C18 preparative, step-gradient chromatography (H2O → 100% methanol) gave some 50+ fractions, all of which were assayed for inhibitory properties. Analytical HPLC, using diode array detection and signal processing, showed the presence of chlorogenic, p-coumaric and caffeic acid, scopolin and some unknown phenolic acids. Most fractions were inhibitory to some degree; however, the least polar ones (in 90% and 100% methanol), containing unknown compounds, were most inhibitory. Semi-prep HPLC of these fractions produced eight major peaks (λmax at 210–213 nm, λ2 at 281–284 nm). In our bioassays, the compounds produced 50% inhibition of proso-millet seed germination at ≈60 ppm. It is likely that these compounds contribute significantly to the allelopathic properties of sweetpotato.
Sweetpotato Insect Management in North Carolina
Authors: Sorensen Kenneth A.
Published: February 2019

The 199 sweetpotato growing season was one of extremes: early high temperatures, cool temperatures at planting, drought early and extended, and then hurricane floods. Insect species and population levels were highly variable. Thrips early and armyworms late. Insect control tactics and management strategies were used and include the following. Insect presentations and handouts were made at field days, annual meeting and at several county meetings. A sweetpotato insect field guide was prepared to assist fieldmen with insect scouting. Insect scouting schools were held in several counties to show insects, their damage, and traps to use in detecting their presence and numbers over time. Control studies with insecticide formulations and rates along with timing studies were conducted and prepared for the annual report. Spintor and Admire received registations for worms late and for early season insect control. Aphid vector studies centered on aphid suction traps, yellow sticky traps, and aphid identifications. Foliar and soil insecticides were discussed as to their use and impact. Insecticides of the future were presented and discussed. Cooperative studies and long term plans were discussed.
Evaluation of Selected White-tailed Deer Repellents on Sweetpotato
Authors: Harris Christine , Simonne Eric , Meritt Lani , Codreanu Peggy , Owen John
Published: February 2019

With an estimated white-tailed deer population of >25 million in the United States and 1.7 million in Alabama, deer feeding damage has become a serious problem for vegetable growers. Typically, deer feed on foliage during plant growth or dig roots near harvest time. Because there is currently no method available to control deer feeding damage to sweetpotatoes, studies were conducted with both confined and free-ranging white-tailed deer to determine the effectiveness of several commercial deer-repellent products on `Beauregard' sweetpotato. In 1998, testing was conducted at the Alabama Agricultural Piedmont Substation in Camp Hill, Ala., with free-ranging deer. Treatments included Deer Away (egg-based spray and powder), Tree Guard, Garlic Barrier, Thiram (a commercial fungicide), as well as a nontreated control. Damage was rated on a 0 to 4 scale (0 = no damage; 4 = 100% damage). In 1999, testing was continued with confined deer at the Auburn Univ. Deer Research Facility in Auburn, Ala. Havahart egg-based spray, Hinder, Grant's, XP-20 (Thiram), and Ro-Pel were applied to potted `Beauregard' plants. Nontreated plants were also included. Pots were placed in 2 one-acre pens, each containing six adult deer. Damage was rated on a 0 to 3 scale (0 = no damage; 3 = plant eaten to pot line or uprooted). Significant (P < 0.05) differences were found among products. The most effective products in 1998 were Deer Away powder, Garlic Barrier at 3× the manufacturer's recommended rate, and Deer Away spray. In 1999, Havahart egg spray provided the highest level of protection, followed by XP-20. Although no product provided complete protection to sweetpotato, egg- and Thiram-based products were most effective in 2 years of testing. None of these products are labeled for use on food crops at this time.
Web-based Resource for Accessing Vegetable Variety Trial Information
Authors: Simonne Eric H. , Harris Christine E. , Vinson Edgar , Dane Karen Y.
Published: February 2019

Vegetable variety trials are of interest to the entire vegetable industry from breeders, seed companies, growers, consultants, researchers, to Extension personnel. The Auburn Univ. vegetable variety trial results have been made more accessible and user-friendly by becoming available online at http://www.ag.auburn.edu/dept/hf/faculty/esimonne. Users can point and click through a completely searchable database by selecting one of the following categories: 1) explanation of rating system and database, 2) list of vegetable crops, 3) description of variety types of crops, 4) contacting seed companies and web sites, 5) vegetable variety trial team members. For additional information about vegetable variety production, a link to horticulture extension publications has been included. The database gives each vegetable crop tested by Auburn Univ. a rating and allows a search for varieties. For each crop, the five options available to search the database are “rating,” “variety name,” “variety type,” “seed company,” and “type.” The Web page is primarily intended to be a quick, practical reference guide to growers and horticulture professionals in Alabama. Variety performances presented are based on small-scale research plots and test results may vary by location. It is always recommended to perform an on-farm trial of several varieties before making a large planting of a single variety.
Photoperiod Affects Growth and Flowering of Lysimachia clethroides Duby
Authors: Lewis Pamela M. , Armitage Allan M. , Garner James M.
Published: February 2019

Gooseneck loosestrife (Lysimachia clethroides Duby) rhizomes were cooled for 10 weeks at 4 ± 1 °C prior to greenhouse forcing in continuous long days (LD); continuous short days (SD); 4, 6, 8, or 10 weeks of SD followed by LD until anthesis; and 4, 6, 8, or 10 weeks of LD followed by SD. None of the plants grown in continuous SD flowered, and fewer than 30% of plants flowered when grown in 4, 6, or 8 weeks of LD followed by SD for 21 to 25 weeks. At least 10 weeks of LD prior to SD were required to obtain 70% flowering. Plants receiving continuous LD or 4, 6, or 8 weeks of SD followed by LD flowered in the highest percentages (85% to 90%), but only 10% of plants receiving 10 weeks of SD followed by LD flowered. The number of greenhouse days required for visible bud formation and anthesis increased linearly as initial SD exposure increased, but the number of racemes produced by flowering plants was not affected. Plant height was greatest in continuous LD, and decreased linearly as initial SD exposure prior to LD increased from 0 to 10 weeks. Plants grown in continuous SD remained vegetative rosettes throughout the experiment, and their height increased linearly as initial LD prior to SD increased from 0 (continuous SD) to 10 weeks. These results demonstrate that supplemental LD lighting can promote growth and flowering in this species and that lighting can be discontinued 3 weeks before harvest of cut flower crops.
Blackheart in a Tender Apple Cultivar is Not Influenced by Using a Hardy Frame
Authors: Embree C.G. , Estabrooks E.N. , Ju H.-Y.
Published: February 2019

To determine the effects of rootstock and frameworking on hardiness, `Gravenstein' apple, which is not winter hardy, was grafted on trees frameworked with the hardy genotypes `Budagovsky 9' (B. 9), `Lobo', Kentville Stock Clone (KSC 28), or `Dudley', all of which were propagated on either `Beautiful Arcade' (BA) seedlings or on `Alnarp 2' (A. 2) rootstocks. For comparison, `Dudley' was grafted on `Dudley' frames propagated on both rootstocks. Growth after 8 years was greatest at Kentville; `Gravenstein' was larger than `Dudley', although when grafted, it was 40% smaller on the dwarf B. 9 than on the `Lobo' frame. On one night in Feb. 1993, all sites recorded temperatures below –30 °C. Blackheart was therefore measured in the rootstock trunk, framebuilder, and scion to document the resistance to this sublethal winter injury. Trees at the two colder sites, Truro and Centreville, had more blackheart than did those at the milder site. The percentage of blackheart in the trunk and frame was greatest for B. 9 and least for KSC 28. The tender scion, `Gravenstein', exhibited extensive blackheart regardless of site, rootstock, or the hardiness of the frame. The hardy scion, `Dudley', had some blackheart in the colder locations but none at Kentville. Blackheart levels in `Gravenstein' were very high on the framebuilder B. 9, and while generally less with the other hardy framebuilders, they were still high. While the hardy frames may have helped improve the survival of this cultivar, they did not change its hardiness status relative to `Dudley', even when `Dudley' was one of the hardy framebuilders.
Applying Soybean Oil to Dormant Peach Trees Thins Flower Buds
Authors: Deyton Dennis E. , Moran Renae E. , Sams Carl E. , Cummins John C.
Published: February 2019

Applications of soybean oil to dormant peach [Prunus persica (L.) Batsch] trees were tested for prebloom thinning of flower buds in five separate experiments. Data were combined from experiments in which 2.5% to 20% emulsified soybean oil was sprayed on `Belle of Georgia' or `Redhaven' trees. The number of dead flower buds was concentration-dependent with maximum bud kill of 53% occurring with application of 12% soybean oil. The amount of thinning was fairly consistent from year to year, ranging from 34% to 51% when 10% soybean oil was applied, but was less consistent when 5% was applied, ranging from 6% to 40%. Overthinning by midwinter applications of soybean oil occurred in one experiment when bud mortality on nontreated trees was 40% due to natural causes. Mild to moderate spring freezes occurred in three experiments, but did not reduce yield more in soybean oil–thinned than in nontreated trees. Flower bud survival was improved when trees were sprayed with 10% or 12% soybean oil prior to a –4 °C spring frost. Applications of soybean oil to dormant trees thinned flower buds, reduced the amount of hand thinning required, and hastened fruit maturity.
Suaeda salsa, A Desalinating Companion Plant for Greenhouse Tomato
Authors: Albaho Mohammed S. , Green James L.
Published: February 2019

To determine its effect on salinity of the growth medium and on tomato (Lycopersicon esculentum Mill.) growth and yield, the halophyte Suaeda salsa (L.) Pallas, or seepweed, was planted as a companion plant in the closed insulated pallet system (CIPS). In this production system, water moves from a bottom reservoir through capillary wicks to the medium in the root pouch in response to plant uptake. Fertilizers are placed at the top surface of the root matrix, so nutrient ions move downward to the roots by chemical ion diffusion to establish relatively stable chemical gradients within the matrix. Plants were subjected to capillary subirrigation water containing 0 or 4 g·L–1 NaCl. Sodium (Na+) concentration of the root medium at termination was 50% lower when S. salsa was grown in the same pouch with tomato. Sodium concentration was also significantly less in the tomato foliage, but S. salsa did not prevent suppression of growth of tomato plants by NaCl. Suaeda salsa plants reduced blossom end rot of tomato fruit but did not significantly affect fruit weight, number or yield.
Tolerance of Cucurbits to the Herbicides Clomazone, Ethalfluralin and Pendimethalin. II. Watermelon
Authors: Grey Timothy L. , Bridges David C. , NeSmith D. Scott
Published: February 2019

Field studies were conducted in 1993, 1994, and 1995 to determine tolerance of seeded and transplanted watermelon [Citrullus lanatus (Thunb.) Matsum and Nak.] to clomazone, ethalfluralin, and pendimethalin using method of stand establishment (directseeded vs. transplanted) and time of herbicide application [preplant soil incorporated (PPI), preplant to the surface (PP), or postplant to the surface (POP)] as variables. Yield and average fruit weight in plots with clomazone were equal to or greater than those in control plots for the 3-year study regardless of method of application. Bleaching and stunting were evident with clomazone in early-season ratings, but injury was transient and did not affect quality or yield. Of the three herbicides, ethalfluralin PPI resulted in the greatest injury, stand reduction, and yield reduction of the three herbicides. Pendimethalin (PPI, PP, or POP) reduced yield of direct-seeded but not of transplanted watermelon. Chemical names used: 2-[(-2-chlorophenyl)methyl]-4, 4-dimethyl-3-isoxazolidinone (clomazone); N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine (ethalfluralin); N-(1-ethylopropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin).
Soil Fumigation and Runner Plant Production: A Synthesis of Four Years of Strawberry Nursery Field Trials
Authors: Larson Kirk D. , Shaw Douglas V.
Published: February 2019

Strawberry (Fragaria ×ananassa L.) runner plant production during a 4-year period was compared on nursery soils treated with methyl bromide (MB) and chloropicrin (CP) mixtures (MB:CP) and three alternative soil treatments: CP, mixtures of 1,3-dichloropropene (Telone®) and CP (DP:CP), and no fumigation (NF). The effect of soil treatment on runner plant production for a single nursery propagation cycle was determined in all 4 years. In 2 years, runner production in a final propagation cycle was also determined as a function of soil treatment in previous cycles. A single propagation cycle in NF soil decreased runner production relative to all other treatments. Treatments with CP at rates of 140 to 191 kg·ha–1 generally decreased runner production significantly (P ≤ 0.05) in comparison with treatment with MB:CP; use of CP at rates ≥303 kg·ha–1 resulted in statistically equivalent runner production. In one trial, use of two DP:CP formulations (516 kg·ha–1 of a 7:3 DP:CP mixture, and 448 kg·ha–1 of a 3:7 DP:CP mixture) significantly reduced and did not affect runner production, respectively, relative to the use of MB:CP. Use of MB:CP in the previous propagation cycle also increased runner productivity in comparison with NF. Runner productivity of planting stock produced with 314 kg·ha–1 of CP did not differ statistically from that of stock produced with MB:CP, but productivity of planting stock on soil treated with 157 kg·ha–1 of CP was intermediate between that on NF and MB:CP-treated soil. Planting stock grown on nontreated soil in two previous propagation cycles produced 25% fewer runner plants than did similar stock grown on MB:CP-treated soil. Productivity of planting stock produced with CP at rates of 280 to 314 kg·ha–1 in two previous propagation cycles did not differ statistically from that of stock produced with MB:CP. Results of meta-analyses indicated that fumigation with MB:CP was more effective in increasing runner production than was CP or NF, regardless of the propagation cycle or rate of application. For mixtures of 1,3-dichloropropene and CP, nursery productivity was maximized by using at least 280 kg·ha–1 of CP.
The Value of Presidedress Soil Nitrate Testing as a Nitrogen Management Tool in Irrigated Vegetable Production
Authors: Hartz T.K. , Bendixen W.E. , Wierdsma L.
Published: February 2019

The utility of presidedress soil nitrate testing (PSNT) in irrigated lettuce (Lactuca sativa L.) and celery (Apium graveolens L.) production was evaluated in 15 commercial fields in California from 1996 to 1997. Fields were selected in which soil NO3-N (5- to 30-cm depth) was >20 mg·kg–1 at the time the cooperating grower made the first sidedress N application. The grower's N regime was compared with reduced N treatments established by reducing or eliminating one or more sidedress applications. All fields were sprinkler and/or furrow irrigated, with minimal in-season precipitation. Reductions in seasonal N application averaging 143 and 209 kg·ha–1 N in lettuce and celery trials, respectively, had no effect on marketable yield in any field. Crop biomass N at harvest in the lowest N treatment in each field averaged 94% (lettuce) and 88% (celery) of that in plots receiving the full grower N program. Based on controlled-environment aerobic incubation of soil from 30 fields in long-term vegetable rotations, in-season N mineralization averaged 1% to 2% of soil organic N. A soil NO3-N “quick test” procedure utilizing a volumetric extraction of field-moist soil and measurement by nitrate-sensitive colorimetric test strips was evaluated and proved to be a practical on-farm method to estimate soil NO3-N concentration. Lettuce midrib NO3-N concentration at cupping stage was poorly correlated with current soil NO3-N level. We conclude that PSNT can reliably identify fields in which sidedress N application can be delayed or eliminated without affecting crop performance.
Growth Regulators Reduce Leaf Yellowing in Easter Lily Caused by Close Spacing and Root Rot
Authors: Han Susan S.
Published: February 2019

The development of greenhouse leaf yellowing in Easter lilies (Lilium longiflorum Thunb.) was significantly reduced by the application of growth regulator solutions containing gibberellins 4 and 7 (GA4+7) or benzyladenine (BA). Solutions containing BA alone significantly reduced leaf yellowing on plants caused by close spacing but were less effective than GA4+7. Application of BA alone, however, was not effective against root rot-induced leaf yellowing. When plants were treated with GA4+7 or BA + GA4+7 around the visible bud stage, nearly all of the leaves remained green until the end of the growing season. These growth regulators, however, increased the final height of the plants by 8–10 cm. The developmental rate and size of the flower buds, as well as the length of the pedicels were not affected by the growth regulator treatments. Thus application of these growth regulators greatly improved the quality of the leaves without compromising the quality and timing of the flowers. Chemical name used: N-(phenylmethyl)-1H-purine-6-amine (benzyladenine, BA).
Evaluation of Turfgrasses for Resistance to Mole Crickets (Orthoptera: Gryllotalpidae)
Authors: Braman S.K. , Duncan R.R. , Hanna W.W. , Hudson W.G.
Published: February 2019

Bermudagrass (Cynodon sp.) and paspalum (Paspalum vaginatum) genotypes were evaluated in laboratory, greenhouse, and field experiments for potential resistance to the common turfgrass pests, tawny mole cricket (Scapteriscus vicinus Scudder) and southern mole cricket (Scapteriscus borellii Giglio-tos). Potential resistance among 21 seashore paspalums to both insects in an environmental chamber at 27 °C, 85% relative humidity, and 15 hours light/9 hours dark) revealed that Glenn Oaks `Adalayd' was least tolerant of cricket injury, while 561-79, HI-1, and `Excalibur' were most tolerant. Nymphal survival was not influenced by turfgrass type. Plant selections that maintained the highest percentage of their normal growth after 4 weeks of feeding by tawny mole crickets over three separate greenhouse trials were 561-79, HI-1, HI-2, PI-509018, `Excalibur', SIPV-1 paspalums, and `Tifeagle' and `Tifsport' bermudagrasses. Although none of the tested genotypes was highly resistant to tawny mole cricket injury, `TifSport' bermudagrass and 561-79 (Argentine) seashore paspalum were most tolerant.
Cold Storage Duration Influences Ethylene Biosynthesis and Ripening of `Bartlett' Pears
Authors: Agar I. Tayfun , Biasi William V. , Mitcham Elizabeth J.
Published: February 2019

Ripening behavior of `Bartlett' pears (Pyrus communis L.), with or without ethylene (C2H4) treatment, was assessed at harvest, and after 2, 4, 6 and 12 weeks of cold storage at –1 °C. Fruit exhibited increasing rates of C2H4 production and consequently faster ripening rates with increased length of cold storage. Ripening characteristics were influenced by storage duration, but to different degrees. The data indicate that the threshold C2H4 concentration for softening may be lower than that for color change from green to yellow. Ethylene treatment for 24 h at harvest resulted in a rate of ripening equivalent to that following cold storage for 2 to 4 weeks, depending on the orchard location. Storage for 12 weeks significantly increased C2H4 production upon transfer to ambient temperature, indicating that fruit were reaching the end of their storage life. `Bartlett' pears may ripen to a firmness of 14 N (ready to eat) at 20 °C within 2.5 to 7 days depending upon the duration of prior cold storage.
Screening the Cucumber Germplasm Collection for Fruit Storage Ability
Authors: Wehner Todd C. , Shetty Nischit V. , Wilson L. George
Published: February 2019

All available cucumber (Cucumis sativus L.) cultigens were tested for combining ability for fruit storage ability by crossing them with the gynoecious inbred Gy 14. Fruit weight and firmness were measured before and after storage, and fruits were rated for water loss after storage. The cultigens with the lowest percentage of fruit weight loss during storage were PI 172839, PI 344067, PI 264667, PI 171612, PI 339245, PI 220171, PI 279469, and PI 368550; those with the lowest percentage of loss in fruit firmness were PI 379284, PI 339241, PI 414159, PI 422177, `Regal', PI 109483, `Addis', PI 285603, PI 257486, and `Calypso'. The cultigens demonstrating the least fruit shriveling were `Dasher II', `Sprint 440', `Texas Long', PI 390255, PI 432870, `Pacer', PI 419078, PI 390247, PI 321011, and PI 414158. The 10 best cultigens from the initial screening study, along with the four worst cultigens and six checks, were retested directly (not as F1 progeny) for fruit keeping ability in two storage conditions and at two harvest dates. No significant differences were detected between the two harvest dates and storage conditions.
Randomly Amplified Polymorphic DNA Markers Linked to Fusarium Wilt Resistance in Diverse Melons
Authors: Zheng X.Y. , Wolff David W.
Published: February 2019

Three randomly amplified polymorphic DNA (RAPD) markers (E07, G17, and 596) linked to the Fom-2 gene, which confers resistance to race 0 and 1 of Fusarium oxysporum f. sp. melonis, were evaluated by RAPD-polymerase chain reaction for their linkage to Fusarium wilt resistance/susceptibility in diverse melon cultigens (48 resistant, 41 susceptible). Primer 596 was identified in the multiple disease-resistant breeding line MR-1, whereas E07 and G17 were identified in the susceptible `Vedrantais'. The RAPD markers E07 (1.25 kb) and G17 (1.05 kb) correctly matched phenotypes in 88% and 81% of the cultigens. The validity of the RAPD scores was verified by Southern hybridization analysis for sequence homology and bulked segregant analysis of a selected cross population for the linkage. These results will facilitate the introgression of resistance genes into susceptible lines from multiple sources in marker-assisted selection.
Yellowing of Broccoli in Storage Is Reduced by 1-Methylcyclopropene
Authors: Fan Xuetong , Mattheis James P.
Published: February 2019

Broccoli (Brassica oleracea L. var. italica Plen) was held for 12 days at 10 °C in air or in ethylene (1 μL·L–1), with or without prior exposure to MCP (1 μL·L–1) for 12 hours. In a second experiment, the effects of concentration of MCP, prior to exposure to ethylene, were evaluated. Treatment with MCP reduced whereas exposure to ethylene stimulated respiration and yellowing. Treatment with MCP before continuous exposure to ethylene negated the effects of ethylene. The inhibitory effect of MCP on respiration of broccoli exposed to 1 μL·L–1 ethylene was concentration-dependent, while the effect on yellowing was not. The results indicate that the yellowing of broccoli is mediated by ethylene action, and that MCP treatment inhibits yellowing and reduces respiration, even when broccoli is exposed to ethylene. Chemical name used: 1-methylcyclopropene (MCP).
Germination and Emergence of Parsley in Response to Osmotic or Matric Seed Priming and Treatment with Gibberellin
Authors: Pill Wallace G. , Kilian Elizabeth A.
Published: February 2019

`Moss Curled' seeds of parsley (Petroselinum crispum L.) were primed osmotically in polyethylene glycol or matrically in fine, exfoliated vermiculite at –0.5 MPa for 4 or 7 days at 20 or 30 °C with 0 or 1 mm GA3. All priming treatments stimulated and hastened germination. Matric priming resulted in greater germination (89%) than osmotic priming (83%) when seeds were primed for 7 days at 30 °C, but priming agent had no effect on germination percentage following priming at 20 °C or for 4 days. In seeds primed for 4 days at 20 or 30 °C, matric priming hastened germination more than did osmotic priming. Germination was generally less synchronous with matric than with osmotic priming. Increasing priming time from 4 to 7 days increased the rate of germination, but increased germination synchrony only when seeds were primed at 20 °C. Inclusion of 1 mm GA3 during priming had little or no effect on germination. All matric priming treatments (other than 4-day priming) were repeated to assess seedling emergence in a greenhouse (25°C day/22 °C night). Priming increased the percentage, rate and synchrony of emergence, and increased hypocotyl length at 3 weeks after planting. Priming at 30 °C with 1 mm GA3 resulted in the greatest emergence percentage, hypocotyl length, and shoot dry weight. We conclude that matric priming is a satisfactory alternative to osmotic priming of parsley seeds. Chemical name used: gibberellic acid (GA3).
Persistence and Horticultural Value of Inflorescence Dichotomy in Plantain
Authors: Tenkouano A.
Published: February 2019

This study aimed to assess the persistence and horticultural value of bunch dichotomy in plantain. Meristematic tissue was collected from a plant of the cultivar UNN showing a double-bunch phenotype and cultured in vitro. Ninety-five seedlings were acclimatized for 6 to 8 weeks in a greenhouse, prior to transfer to the field. Field evaluation was carried out at three experimental farms (Abuja, Ibadan, and Onne) of the International Institute of Tropical Agriculture, in Nigeria. Micropropagated plants of two plantain accessions, `Agbagba' and `Obino l'ewai', that produce single bunches were included as controls. Reversal of the double-bunch phenotype to a single-bunch phenotype was observed. Few plants underwent an additional dichotomization event to produce three bunches. This suggests that branching may be due to random genetic events instead of a stable mutation. Furthermore, field performance data were not significantly different for phenological or yield traits between clones producing one, two, or three bunches. Thus, selection for increased number of bunches may not be warranted in this Musa population.
Comparative Rooting of Shoot Tips of Four Japanese Persimmon Cultivars vs. Shoots Regenerated from Roots Cultured In Vitro
Authors: Tetsumura Takuya , Yukinaga Hisajiro
Published: February 2019

When cultured in vitro, roots of four Japanese persimmon (Diospyros kaki L.) cultivars formed adventitious shoots on MS medium with 10 μm zeatin and 0.01 μm indole-3-acetic acid, although their organogenetic capacities varied. Histological study revealed that the origin of the adventitious shoots was the pericycle. The regenerated shoots grew well on the shoot proliferation medium (MS with 5 μm zeatin). Final rooting percentages of shoots regenerated from roots of three of the four cultivars were greater than those of shoots that originated from shoot tips and that had been subcultured >50 times. Shoots regenerated from `Jiro' roots rooted 10 days earlier, had more roots than those from shoot tips, and maintained higher rooting ability over ten subcultures. Rooted `Hiratanenashi' shoots regenerated from roots survived better after acclimatization than those from shoot tips. No obvious variants were observed either in vitro or in the field. The trees regenerated from roots flowered within 4 years. These findings suggest that partial rather than true rejuvenation was responsible for both the early flowering and the juvenile characteristics, i.e., the enhanced rooting ability, observed in the regenerated plants. Chemical name used: 6-(4-hydroxy-3-methylbut-2-enylamino) purine (zeatin).
A Highly Efficient In Vitro Cranberry Regeneration System Using Leaf Explants
Authors: Qu Luping , Polashock James , Vorsa Nicholi
Published: February 2019

A very efficient adventitious regeneration (shoot organogenesis) system for cranberry (Vaccinium macrocarpon Ait.) leaves was developed. A basal medium consisting of Anderson's rhododendron salts and Murashige and Skoog's (MS) organics, supplemented with 10.0 μm thidiazuron (TDZ) and 5.0 μm 2ip, was effective for adventitious regeneration from leaves for the five cranberry cultivars tested: `Early Black', `Pilgrim', `Stevens', `Ben Lear', and `No. 35'. Parameters examined included: 1) varying combinations of three plant growth regulators (TDZ, 2ip, and NAA); 2) explant orientation (adaxial vs. abaxial side in contact with the medium); and 3) leaf position relative to the apical meristem from the source plant. Cultivars varied in regeneration frequency, but cultivar × growth regulator interaction was nonsignificant. With optimal treatment conditions, regeneration occurred on more than 95% of the explants, with `Early Black' and `Pilgrim' producing as many as 100 shoot meristems per explant. At all concentrations tested, NAA (as low as 0.1 μm) increased callus formation and significantly reduced regeneration. Emerging adventitious shoots were always observed on the adaxial side of the leaves regardless of explant orientation on the medium. Regeneration was much greater when the abaxial side was in contact with the medium, and was not related to leaf position on the source plants. Elongation of adventitious shoots began ≈2 weeks after transfer to the basal medium without growth regulators. Cuttings of elongated shoots rooted 100% both in vitro in the basal medium and ex vitro in shredded sphagnum moss. The high regeneration efficiency achieved by using this system will be very useful in the application of techniques, such as Agrobacterium- and particle bombardment-mediated transformation. Chemical names used: 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea (thidiazuron, TDZ); N6-(γ-γ-dimethyallylamino) purine (2ip); α-naphthaleneacetic acid (NAA).
Differential Tolerance of Fresh Market Sweet Corn Cultivars to the Herbicides Nicosulfuron and Primisulfuron
Authors: Grey Timothy L. , Bridges David C. , Raymer Paul , Day Don , NeSmith D. Scott
Published: February 2019

Field studies were conducted to determine the tolerance of 11 sweet corn (Zea mays L.) cultivars to the herbicides nicosulfuron and primisulfuron. The su cultivar `Merit' was intolerant of nicosulfuron and primisulfuron, as indicated by significant differences from the untreated check for all measured variables. Most other su cultivars exhibited stunting, but injury was ≤19% (0% = no injury; 100% = dead) with nicosulfuron and primisulfuron in 1992. The se cultivars Alpine and Harris Moran Silverado exhibited variable stunting to nicosulfuron (25% and 23% injury, respectively) and primisulfuron (43% and 50%, respectively) in 1992. The sh2 cultivar Supersweet Jubilee was injured less by nicosulfuron (16%) than by primisulfuron (33%) in 1992. All cultivars except Merit recovered from early-season herbicide injury in 1992 and 1993. Significant differences among the se, su, and sh2 cultivars were recorded for the remaining variables (stalk height, marketable ear number and yield, ear length and diameter), but no patterns with respect to a specific sugary genetic background developed in 1992 or 1993. Nicosulfuron and primisulfuron were safely applied to the cultivars Alpine, Harris Moran Silverado, Royal Gold, Seneca Chief, Calumet, Jubilee, and Supersweet Jubilee without reductions in fresh ear yield. Chemical names used: {2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino] carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide} (nicosulfuron); {methyl 2[[[[[4,6-bis(difluoromethoxy)-2-pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzonate} (primisulfuron).