bluuebunny/crossref_metadata_2025 huggingface dataset:
1027 EFFECT OF NPK FERTILIZATION ON PRODUCTIVITY AND QUALITY OF CITRUS
Authors: Bravdo Ben Ami
Published: February 2019

Drip fertigation enables control of the root environment in regard to the volume of irrigated soil, the soil matric potential in the immediate vicinity of the roots and the concentration and composition of the minerals. Application of daily NPK fertilization to citrus was found to promote root production with a large surface area and maintenance of controlled NPK concentrations at various stages of growth and development resulted in high productivity due mainly to increased number of fruits produced. Continuous maintenance of appropriate NPK concentrations at the immediate vicinity of the roots during three successive years improved fruit size without apparent reduction in quality. This was attributed mainly to a well balanced crop load and mineral status as expressed in leaf mineral analyses.
1028 COMBINING CONTROLLED RELEASE FERTILIZERS AND DRIP FERTIGATION TO INCREASE EFFICIENCY AND YIELD IN VEGETABLE AND STRAWBERRY PRODUCTION
Authors: Schrader Wayne L.
Published: February 2019

California vegetable and strawberry growers are expecting legislation which will limit their use of fertilizers and water by crop, acreage, and season. An increasing number of growers are adopting drip irrigation, which affords the opportunity for more precise control of water and nitrogen nutrition. Many growers, however, lack the skills and time necessary to manage and monitor water and fertilizer applications effectively in drip irrigation. Consequently, the need for quick, easy, and reliable methods to manage nitrogen fertility with drip irrigation has increased. Two trials were conducted to evaluate the effectiveness of granular controlled release nitrogen fertilizers in fields where excessive water use had been eliminated by using tensiometers and ET data to manage irrigations. A range of management options for maximizing yield and quality in vegetable and strawberry production with reduced nitrogen and water inputs will be discussed.
1030 COMPUTERIZED MULTIFERTILIZER INJECTION SYSTEMS
Authors: Papadopoulos Athanasios P.
Published: February 2019

Horticultural crop management strategists of the past have routinely chosen to remove root-related limitations to productivity by operating at high fertility levels and by excessive irrigation of well-drained soils, without much concern for fertilizer losses to the environment. The relatively low cost of fertilizer as a component of the overall production cost has justified, at least on economic tens. the liberal application of fertilizer on most horticultural crops. However, inefficiencies in fertilizer use can no longer be neglected as society becomes increasingly aware and critical of the valuable energy expended in fertilizer manufacturing and of the damage to the environment from runoff fertilizer. Progress made towards fertilizer use economy will be discussed in relation to the development and use of computer controlled fertilizer injectors which allow the timely application of precise amounts of nutrients according to the changing needs of crops. Seasonal fertigation programs for greenhouse vegetable production in soil and soilless media will be described and corresponding crop performance data will be presented.
1032 EFFICIENCY OF FERTILIZATION METHODS ON ORNAMENTALS
Authors: Broschat Timothy K.
Published: February 2019

Spathiphyllum Schott. 'Mauna Loa Supreme' grown for 6 months in a fine sand soil or a 5 pine bark: 4 sedge peat: 1 sand medium (by volume) were fertilized with 7.6g N, 1.4g P, and 4.5g K/3.5-liter container by 4 different methods. The same raw fertilizer prills (21N-3P-12K) were applied weekly as a liquid, monthly as soluble granules, bimonthly as a lightly resin-coated fertilizer (Osmocote), or every 6 months as a heavily resin-coated fertilizer. All leachates were collected and were measured and analyzed weekly for N O3, PO4, and K. Spathiphyllum grew best in the sand soil with either of the controlled release formula- tions, but fertilization method had no effect on growth in the potting medium. Nitrate and K leaching losses from the potting medium were lowest from the controlled release fertilizers and highest from the soluble granules. Liquid fertilization resulted in the highest amounts of PO4 lost to leaching and controlled release fertilizers the least. In the fine sand soil, NO3 leaching was equivalent from all methods. Soluble granules had the highest levels of leached K and PO4 and the lightly-coated fertilizer lost the least due to leaching.
1034 WASTE WATER IRRIGATION AND MINERAL NUTRIENT STATUS OF FIVE TURFGRASS SPECIES
Authors: Wu L. , Hong L , Harivandi Ali M.
Published: February 2019

The effects of high concentrations of Cl-, K+, Mg2+, and Ca2+ of the simulated waste water on the growth of turfgrass species and partitioning of these mineral element concentrations in the turfgrass-soil system have been studied. This is a two year project and the waste treatment was started in the first week of October 1993. The waste water contains 17.89 mM of K+, 97.5 mM of Ca2+, 78.1 mM of Mg2+, and 389.17 mM of Cl-. Kentucky bluegrass, perennial ryegrass, tall fescue, bermudagrass, and zoysiagrass have been irrigated with 1/5, 1/10, and 1/20 times concentration of the waste water and mowed weekly at 5 cm high. The preliminary results showed that there was no detectable growth inhibition of turfgrass by the three waste water concentrations. Waste water irrigation significantly increased the uptake of the mineral elements by the turfgrass. Significant reduction of the mineral element concentrations in the leach by the turfgrass system only found under the conditions of low concentration waste irrigation. However, the seasonal growth pattern of the turfgrass species may have significant influence on the partitioning of the element concentrations in the turfgrass-soil system and their concentrations in the leach. This prediction will be detected by the future studies.
1037 DESIGNING THE NEW LAND GRANT UNIVERSITY
Authors: Sanders D. C.
Published: February 2019

Land Grant Universities have undergone tremendous change during the late 1980's and early 1990's. These changes are due to declining resources, changing social needs, the decreasing agricultural components of society, and globalization. Faculty and support positions have been reduced. Research programs have embraced more complex areas of study, leaving adoption of new technologies to extension faculty. The Agricultural Industry has declined in political power as fewer farmers feed more people. All of these conditions lead to many changes in `THE LAND GRANT UNIVERSITY'. These changes have been the subject of extensive and intensive, previous and continuing study, because of Land Grants' dramatic influence on both American and global society. Representatives of various institutions within and on the periphery of these institutions will provide their vision for the future of this great American institution. The objectives of this workshop are as follows: Articulate and illuminate the major changes that face The Land Grant Universities and provide a glimpse of these institutions in the future. How these institutions will and should deal with and respond to these challenges will be discussed in order to provide a picture of the future that will affect all of our membership at the very core. The impact of these changes on various aspects of these universities will be presented as follows: Research and science, by Representative of National Academy of Sciences; Outreach/extension and regional cooperation, Representative of The New England Consortium; Private foundations, Representative of Kellogg Foundation; The greater university view, Chancellor Emeritus UCD. The observations of these speakers should generate important discussions that will affect our society, its members, and American society, as we come face to face with major changes in the paradigm of the Land Grant University.
1040 THE LAND GRANT IN TRANSITION – HOW DO WE GET THERE FROM HERE?
Authors: Foster Richard M.
Published: February 2019

Preparing professionals that will be responsive to the food and agricultural issues of the next century presents a dilemma for current food system education programs. What will be the issues? Who will define the issues? Who are our customers? What will be the role of technology? How will we change? How will we know? While we struggle with these questions and others, the answers reside within both the faculty and the constituencies they serve.
1041 DESIGNING THE NEW LAND GRANT UNIVERSITY
Authors: Meyer James H.
Published: February 2019

Massive changes occurring in the agricultural industries and expanding societal interests in environmental quality, food safety, competition for natural resources, along with population pressure, are making it `evident Land Grant colleges of agriculture (LGCAs) must reorganize to address a broader interface of both agriculture-related issues and issues relevant to society in general. A reduced focus on agriculture as such must be anticipated, with more emphasis directed toward life sciences, food quality, environmental concerns, and rural-urban interfaces.

Since their establishment in 1862, LGCAs have helped U.S. farmers improve production so much that the numbers of people needed in agricultural sector have plummeted, leaving the status and future of these colleges uneasy. Although the original LGCA model was appropriate for its time, the modern environment at scientific and agricultural universities calls for a new model. To achieve renewal, one must change mindset, revise the mission, provide creative, learning leaders and chart the course for evolution of revitalized institutions.
1047 PSEUDOMONADS AND THE ROLE OF-THE ANTIBIOTICS IN THE CONTROL OF GREEN MOLD OF LEMONS.
Authors: Parham J.S. , Smilanick J.L.
Published: February 2019

Pseudomonas cepacia LT412W reduced green mold on lemons caused by Penicillium digitatum. It produces phenylpyrrole antibiotics which cause inhibition zones in co-culture with the pathogen. Their role in control of the disease was investigated. Mutagenesis of P. cepacia (rifampicin resistant) was performed by mating it with E. coli S-17 pSUP1021 (kanamycin resistant), which carries the transposon Tn5. Transconjugate selection and screening for absence of inhibition zones identified a stable mutant. Growth of parent and mutant were comparable. When the mutant was co-cultured with the pathogen on lemon albedo agar, no inhibition zone appeared. Similar co-culture on potato dextrose agar with tryptophan (0.05 g/L), a precursor of phenylpyrroles, did not induce inhibition zones. This suggests the mutation is not in tryptophan biosynthesis. Parent and mutant were assayed for phenylpyrroles. They were cultured in nutrient broth, centrifuged, and the cells extracted with acetone. The extract was dried and dissolved in chloroform. It was spotted on nano-SIL Cl8 TLC plates, run one hour (methanol:acetonitrile:water, 1:1:1), dried, developed with sulfanilic acid, and observed under UV light. The relative mobility of spots from extracts of the parent matched phenylpyrroles, whereas the mutant produced none. Control of decay by the mutant and parent were equal, suggesting no role for phenylpyrroles in suppression of the disease.
1049 COMPUTER RESOURCES AVAILABLE TO HORTICULTURISTS ON INTERNET
Authors: Sistrunk L. A.
Published: February 2019

Internet is one of the main components of the information superhighway. By accessing information on networks, we as professionals can add to the information stream and disseminate research data and academic applications in a timely manner. Users worldwide can use this data to add to their ongoing research efforts. Both binary and ASCII files can be transmitted. One of the main obstacles new users must face is locating the proper area of interest. The use of FTP (File Transfer Protocol) allows users to transfer data between their server and other servers on Internet. For help in finding areas of interest there are two common systems being used. One is called Archie and allows the searching of Archie servers with key words. Substring searches can be used if you do not know the exact name of a resource. Another system is called Gopher and is menu driven. Gopher provides an easier way to search for the information you are looking for, since it allows users to move within modular menu components. LISTSERV, a mail manager system, allows the distribution of information by mailing lists in less time than regular Internet mail programs, further adding to the system efficiency.
1052 AN ASSESSMENT OF THE APPLICATIONS OF PLANT BIOTECHNOLOGY IN HORTICULTURE
Authors: Garton Stephen
Published: February 2019

The applications of plant biotechnology in horticulture have been driven by an assortment of biological, economic and sociological factors such as plant health, vigor and uniformity, product quality, cost of propagule, productivity, cost effectiveness, and ethical and environmental concerns. As the potential of biotechnology to impact horticulture continues to grow, it empowers professional horticultural scientists to become knowledgeable about the development of biotechnology and to critically evaluate the possible impacts of future applications in horticultural crops. Current applications and trends in biotechnology will be reviewed and critically assessed.
1054 GETTING GENETICALLY ENGINEERED PRODUCTS FROM LABORATORY TO MARKETPLACE
Authors: Rawal Kanti M. , Redenbaugh Keith
Published: February 2019

Polygalacturonase (PG) is the principal enzyme responsible for the softening of tomato during ripening. Transformation of tomatoes with antisense PG (asPG) results in significant delay in softening so that fruits with color and flavor can be harvested and shipped from the fields to distant markets. Safety evaluations of the genetically engineered tomato varieties were conducted from two perspectives: a) agricultural, and b) human food. Data were submitted to the appropriate agencies to obtain approvals for commercial production and to seek advisory opinion for the safety of food for human consumption. Calgene Fresh Inc. was created to develop human resources, physical facilities and logistic capabilities for year round supply of high quality branded produce. Vertical integration from seed production to direct consumer marketing is necessary to optimize the business endeavor.
1060 RESPONSES TO TREATMENTS APPLIED TO LIMBS VS. WHOLE TREES
Authors: Barden John A. , Marini Richard P. , Byers Ross E.
Published: February 2019

Researchers often apply treatments to limbs rather than to whole trees. This technique allows the application of large numbers of treatments to a limited number of trees, and also allows adequate replication when a chemical is in very limited supply. The obvious assumption is made that results from limb treatments arc representative of those to be expected using whole trees.

Data from several experiments will be discussed that raise serious doubts about the extrapolation of results from limb treatments to whole-trees. The data are from studies with terbacil applied to apple and peach as well as shade treatments to both apple and peach. Girdling studies will also be discussed in which branches isolated by girdling responded very differently than ungirdled branches.
1061 MODE AND SITE OF CHEMICAL THINNER ACTION
Authors: Greene Duane W.
Published: February 2019

Several chemical thinners are available for use on apples: NAA, NAAm, carbaryll ethephon, benzyladenine and a few potential blossom thinners. Blossom thinners are generally applied at 80% bloom and it is thought that they work by damaging the style and/or pollen tube, thus preventing fertilization of the ovules. Postbloom thinners generally act by creating a localized stress at a time when developing fruit are especially vulnerable. The stress conditions are caused by elevated levels of ethylene, lowered levels of auxin or a temporary reduction in carbohydrate available to developing fruit. The most probable mode of action and site of absorption will be discussed for each thinner.
Harvest Maturity Affects Fruit Yield, Size, and Grade of Fresh-market Tomato Cultivars
Authors: Davis Jeanine M. , Gardner Randolph G.
Published: February 2019

Eight staked, determinate tomato (Lycopersicon esculentum Mill.) cultivars were harvested when green (before breaker stage) or when pink (breaker stage and riper) in two replicated field studies. In general, total yield and average fruit size were reduced when fruit were harvested at the green stage. Harvest maturity had only a small effect on occurrence of most fruit defects, except fruit cracking, which was more severe for pink than for green fruit in the early season experiment. Although total yields for pink harvested fruit were higher than for green harvested fruit in the early season study, the high incidence of fruit crack in pink fruit resulted in similar yields of U.S. combination grade (U.S. no. 1 and U.S. no. 2) fruit for both treatments. Because the largest fruit often bring a premium price, harvesting fruit when pink probably will result in a higher price per kilogram than harvesting fruit when green. Fruit harvested green, however, are generally firmer, more crack resistant, and require fewer harvests than fruit harvested pink.
Split and Tank-mix Preemergence Application of Herbicide for Controlling Weeds in Grapes
Authors: Kaps Martin L. , Odneal Marilyn B.
Published: February 2019

Spring vs. fall plus spring (split) herbicide application times and single vs. tank-mix spring herbicide applications were compared as a means of extending summer annual weed control in vineyards. About 30% of the nontreated control areas were weed-covered by April or May of each of 3 years. Most treatments gave 60 or more days of acceptable annual weed control (≤ 30% cover) beyond the nontreated control. Fall plus spring application of diuron, norflurazon, or simazine at the half-label rate did not increase the days of control over spring application alone at the full-label rate. The tank-mixed herbicides diuron, norflurazon, and oryzalin in combinations of any two at the half-label rate were as effective as the full-label rate of these herbicides used alone. Weed control by oxyflurofen or simazine was extended by tank-mixing with oryzalin (half-label rates). Chemical names used: N -(3,4-dichlorophenyl) -N,N -dimethylurea (diuron); 4-chloro-5-(methylamino)-2-(a,a,a-trifluoro-m-tolyl)-3(2 H) -pyridazinone (norflurazon); 3,5-dinitro-N4,N4-dipropyl-sulfanilamide (oryzalin); 2-chloro-l-(3-ethoxy -4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); and 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine).
Random Amplified Polymorphic DNA in Perennial Ryegrass: A Comparison of Bulk Samples vs. Individuals
Authors: Sweeney Patricia M. , Danneberger T. Karl
Published: February 2019

The usefulness of random amplified polymorphic DNA (RAPD) in characterizing two perennial ryegrass (Lolium perenne L.) synthetic cultivars, `Accolade' and `Caravelle', was tested. Two out of 10 arbitrary primers produced three RAPD markers that distinguished bulk samples of 30 seedlings. Additional fragments were apparent when DNA from individual seedlings was amplified. Amplification products from bulk samples were not simply the sum of amplification products of individual seedlings and did not reflect all the diversity within or between the cultivars. The study illustrates the need to screen individuals to accurately evaluate the genotypic composition of a synthetic cultivar or heterogeneous population.
Photinia and Podocarpus Growth Response to a Hydrophilic Polymer-amended Medium
Authors: Dehgan B. , Yeager T.H. , Almira F.C.
Published: February 2019

Photinia ×fraseri Dress and Podocarpus macrophyllus (Thunb.) D. Don were grown in a Metro-Mix 500 medium amended with 0.0%,0.25%,0.5%,0.75%, or 1.0% (by volume) of a K-based hydrophilic polymer and were irrigated every 3,6,9, or 12 days with a solution that contained either 100, 200, 300, or 400 mg N/liter, respectively: Photinia ×fraseri plants irrigated every 6 days with 200 mg N/liter in irrigation water and grown in 0.75 % polymer-amended medium had higher root and shoot dry weights (6.3 and 28 g, respectively) after 144 days than plants grown in the unamended medium (3.4 and 17 g, respectively). Shoot dry weights of P. macrophyllus grown 192 days in the amended medium were similar to those of plants grown in the unamended medium. Average shoot dry weights increased from 10 to 18 g, respectively, as number of irrigations increased from every 12 days with 400 mg N/liter in irrigation water to every 3 days with 100 mg N/liter in irrigation water. Podocarpus macrophyllus root dry weights were 1.9 and 3.6 g for plants irrigated every 12 and 3 days, respectively, while plants grown in the unamended medium had the highest root dry weight (3.2 g). Data from this study indicated that growth response to a cross-linked, K polyacrylate/polyacrylamide, hydrophilic polymer-amended Metro-Mix 500 medium varied with species and number of irrigation and concomitant fertilizer applications.
Symptoms and Treatment of Manganese Deficiency in Cycas revoluta Thunb.
Authors: Dehgan Bijan , Durando Joseph E. , Yeager Thomas H.
Published: February 2019

Cycas revoluta, an important ornamental palm-like plant of warmer regions of the world, often exhibits a foliar chlorotic/necrotic dieback in landscapes. Despite a weak correlation (r2 ≤ 0.28) of percent symptoms with soil nutrient levels or pH, symptom severity was correlated more notably (r2=0.49) with Mn and had even a higher correlation (r2 = 0.61) with the Fe : Mn ratio. Anatomical examination of chlorotic leaflets indicated an accumulation of tanniniferous cells but did not provide direct evidence of Mn deficiency. Although field surveys indicated a link between low Mn levels and Fe : Mn ratio in the plant and appearance of the disorder, the manifestation of symptoms could not be directly correlated with any edaphic factors. However, identical symptoms were induced in young plants by withholding Mn in a solution culture experiment. Application of chelated Mn on expanding leaves alleviated the disorder, but only for the current growth flush. Irrigation frequency in concert with other cultural practices probably are more responsible for development of symptoms than actual soil Mn inadequacy. In consideration of acute susceptibility of cycads to micronutrient deficiencies, plants should be supplied with a complete micronutrient fertilizer during growth in containers and before field planting.
Improved Growth of Pecan and Ornamental Pear Trees in Containers with Water-holding Reservoirs
Authors: Tilt Ken , Goff William D. , Williams David , Shumack Ronald L. , Olive John W.
Published: February 2019

Pecan [Carya illinoinensis (Wangenh.) C. Koch `Melrose'] and pear (Pyrus calleryana Decne. `Bradford') trees in the nursery grew more in containers designed to hold water in the lower portion. The water-holding reservoir was obtained either by placing 76-liter containers in a frame holding water to a depth of 6 cm or by using containers with drainage holes 6 cm from the bottom. Continuous waterlogging at the bottom of containers resulted in root pruning and root death in the lower portion of the containers, but roots grew well above the constantly wet zone. Fresh weight of plant tops and trunk diameters were greater after two growing seasons in the containers with water reservoirs compared to those grown in similar containers with no water reservoirs. Total root dry weight was unaffected.
Quality of `Fantasia' Nectarines following Forced-air Heat Treatments for Insect Disinfestation
Authors: Lay-Yee Michael , Rose Kellie J.
Published: February 2019

`Fantasia' nectarine fruit [Prunus persica (L.) Batsch var. nectarina (Ait.) Maxim.], held at 0C for ≤ 1 week following harvest, were forced-air heated either immediately after removal from cold storage or after an overnight pretreatment at 20C. Fruit were heated to 41,43, or 46 ± lC for 24,36, or 48 hours. Following treatment, fruit were stored for 3 weeks at 0C, held at 20C for 1 or 5 days, and then assessed for quality. No significant damage, relative to nonheated controls, was observed in pretreated fruit subjected to 41C for 24 hours. Nonpretreated fruit given the same treatment showed only a slight increase in damage relative to controls. Higher temperatures and longer treatment times, however, were associated with an increased incidence of fruit damage (scald, internal browning, or decay). Heat treatment was associated with reduction in ethylene production and titratable acidity of the fruit following storage.
Late Harvest and Delayed Cooling Induce Internal Browning of `Ya Li' and `Seuri' Chinese Pears
Authors: Crisosto Carlos H. , Garner David , Crisosto Gayle M. , Sibbett Steve , Day Kevin R.
Published: February 2019

Brown discoloration of the core, carpels, and flesh areas of `Ya Li' and `Seuri' Chinese pears [Pyrus bretschmeideri (Rehd.)] depended on harvest date. Fruit harvested no later than 180 days after full bloom (3000 degree days) did not develop the disorder. Browning of the core and flesh tissues increased when cooling was delayed, but was not influenced by subsequent storage temperatures of 0,10, or 20C. In both cultivars, the onset of internal browning was evident after storage in fruit that had been harvested when skin color had changed from green to light green-yellow. Thus, skin color can be used to determine harvest date to avoid internal browninincidence during storage of `Ya Li' and `Seuri' Chinese pears.
Field-screening Prunus for Longevity in the Southeastern United States
Authors: Okie W.R. , Reighard G.L. , Beckman T.G. , Nyczepir A.P. , Reilly C.C. , Zehr E.I. , Newall W.C. , Cain D.W.
Published: February 2019

Long-term field trials of a wide range of peach [Prunus persica (L.) Batsch] germplasm on two peach tree short-life (PTSL) sites revealed marked differences in survival among lines. Generally, cuttings and seedlings of a given line performed similarly, as did ungrafted seedlings and their counterparts grafted to a commercial cultivar. No apparent relationship existed between a line's chilling requirement and survival. B594520-9 survived best in Georgia and South Carolina, providing significantly greater longevity than Lovell, the standard rootstock for use on PTSL sites. B594520-9 is derived from root-knot-nematode-resistant parentage, and progeny of surviving seedlings have demonstrated root-knot resistance similar to Nemaguard seedlings.
Vessel Volume, Gelling Agent, and Basal Salts Affect pH and Gel Strength of Autoclave Tissue Culture Media
Authors: Wetzstein Hazel Y. , Kim Choongsik , Sommer Harry E.
Published: February 2019

Effects of autoclaving volume, gelling agent (Bactoagar, Gel-gro, Phytagar), and basal salts [Murashige and Skoog (MS); Woody Plant Medium (WPM); Gamborg B5 (GB)] on gel strength and pH of tissue culture media were tested. Gel strength was significantly affected by gelling agent and basal medium. MS media were generally softer than comparable WPM or GB media. As the vessel volume during autoclaving decreased, gel strength significantly decreased with Phytagar and Bactoagar gelling agents; Gel-gro had greater gel strength at the intermediate volume of medium autoclave. In all cases, autoclaving resulted in a pH decrease of 0.2 to 0.5 pH units. Lower pH values were associated with softer gels. The type of gelling agent did not greatly affect the postautoclave pH; mean values among gelling agents were within 0.05 pH units. Postautoclave pH of MS medium was lower than that of WPM or GB. This study verifies the need to observe uniform sterilization protocols to maintain consistency in the chemical and physical properties of media.
Explant Origin Affects the Frequency of Tetraploid Plants from Tissue Cultures of Melon
Authors: Adelberg Jeffrey W. , Rhodes Bill B. , Skorupska Halina T. , Bridges William C.
Published: February 2019

Adventitious and axillary shoots of melon (Cucumis melo L.) were cultured from explants on a modified Murashige and Skoog medium containing 10 μm BA. Explants were diversified with regard to genetic source (breeding lines Miniloup, L-14, and B-line), seed parts (apical and cotyledon tissue), seed maturity (10-40 days after pollination; DAP), and cotyledon sections with respect to apical-radicle axis (distal and proximal). Plants were screened for ploidy level by pollen morphometry. Immature cotyledons produced more tetraploid regenerants than mature cotyledons from seed of breeding line Miniloup; the highest frequency of tetraploid regenerant plants was from cotyledons of embryos harvested 18 and 22 DAP. Explants from the apical meristem of the same seeds produced fewer or no tetraploid plants. Proximal sections from immature cotyledons of three genotypes (Miniloup, L-14, B-line) produced higher frequencies of tetraploids than whole mature cotyledons or whole immature cotyledons.
In Vitro Culture of Zygotic Embryos of Taxus Species
Authors: Chee Paula P.
Published: February 2019

An embryo culture method overcomes the lengthy dormancy requirement of Taxus L. spp. (yew) seeds. When zygotic embryos excised from mature T. brevifolia L. seeds were cultured in darkness for 4 weeks on one of three basal salt media (B5, Litvay, and Murashige and Skoog), radicle emergence and seedling development was highest on B5 basal salt medium. After 1 to 2 weeks on B5 basal salt medium, seedling development of T. brevifolia, T. cuspidata L., T. baccata L., and T. baccata stricta L. ranged from 2% to 36%. BA at 2.25 μm had no effect on radicle emergence; 22.5 μm prevented it. Embryos excised from mature or nearly mature seeds had the highest frequency of radicle emergence and seedling development. Cultured embryos developed seedlings in only 8 to 10 weeks. Chemical name used: N6-benzyladenine (BA).
WEED CONTROL IN SWEET POTATOES WITH METOLACHLOR
Authors: Porter Wayne C.
Published: February 2019

Studies were conducted to evaluate metolachlor for weed control and crop tolerance in sweet potatoes. Metolachlor was applied posttransplant at rates of 0.5, 1.0, or 2.0 lb/A. Tank-mix combinations of metolachlor + clomazone were also evaluated. Clomazone was the standard herbicide used for comparison. Metolachlor alone or in combination with clomazone did not cause any serious reduction in sweet potato plant vigor when applied posttransplant. Metolachlor provided excellent control of Brachiaria platyphylla, Cyperus iria, Cyperus esculentus, and Amaranthus hybridus. Tank-mixes with clomazone did not improve the weed control of metolachlor alone. Yields of No. 1 and marketable roots from metolachlor treated plots were equal to or greater than yields from plots treated with clomazone.
RESISTANCE IN SWEETPOTATO TO ROOT-KNOT NEMATODE: ITS VALUE AND OTHER BENEFITS
Authors: Dukes P. D. , Bohac J. R. , Mueller J. D.
Published: February 2019

A root-knot nematode (Meloldogyne incognita) project was initiated in a field of infested sandy loam (EREC) in 1991 and continued. There were ten sweetpotato entries consisting of six cultivars (Beauregard. Excel, Georgia Jet, Jewel, Red Jewel, and Sumor), three advanced lines (W-270, W-274, and W-279) and PI 399161 which were selected for their diversity in disease reactions and other traits. Each entry was planted in the same plots each year to monitor effects of continuous cropping, disease reactions, yield and population shifts of the pathogen. Marketable yields were reduced each year for Georgia Jet and Red Jewel, but not for Beauregard. Internal necrosis in the storage roots was most severe for Beauregard. Several of the highly resistant entries, especially Sumor and W-279, performed well each year, including high yields, good quality. and little or no nematode reproduction. This study demonstrates the considerable economic benefits of a high level of durable resistance to root knot in sweetpotato.
GENETIC CORRELATION BETWEEN RESISTANCE TO SWEETPOTATO WEEVIL AND OTHER INSECTS
Authors: Thompson Paul G. , Schneider J. C. , Graves Boyett , Kim B. K.
Published: February 2019

Twenty-four half-sib sweetpotato families were field tested for freedom from injury by sweetpotato weevil and other soil inhabiting, injurious insects (WDS). Three pairs of adult male and female weevils were applied to the crown of each plant at the beginning of storage root enlargement. Naturally occurring numbers of WDS were high enough for considerable injury from those insects. WDS injury free roots ranged from 19% in Centennial, the suceptible control, to 57% in Regal, the resistant control. The highest family mean for percent non-injured by WDS was 55%. Weevil injury free roots ranged from 67% in Centennial to 90% in Regal with 3 families producing mean weevil non-injured roots of 89%. The genetic correlation between weevil injury free and WDS injury free roots was 0.69 ± 0.28. That estimate is preliminary and based on data from one environment. Evaluations will be repeated in 1994 for estimates of GXE to derive genetic correlation estimates with less environmental interactions.
VIRUS-FREE MICROPROPAGATED PLANTS AND CLONE EFFECTS ON SWEETPOTATO YIELD, 1993
Authors: Schultheis Jonathan R.
Published: February 2019

Commercially grown sweetpotato contain virus. Hill selection is practiced to maintain quality and trueness to type of a variety. Three field plantings of Beauregard and Jewel were made in 1993 to compare the yield of virus-free planting stock obtained from micropropagared plants (VFM); virus-infected planting stock obtained from micropropagated plants (VIM); foundation, registered, grower seed stock; and a selected California Jewel clone in which the virus was removed, then micropropagated (CVFM). For Beauregard, VFM had significantly more yield of marketable and number 1 roots at the 0.06 level of significance than plants not micropropagated. The yield of number 1 roots was also greater with VFM compared with VIM. Marketable yields of Beauregard were superior when registered versus grower seed (nor in certification program) were compared. For Jewel, marketable yields were increased from VFM versus plants not micropropagated. VFM and the VIM yielded similarly as did registered and grower seed stock. The VFM Jewel clone from North Carolina outyielded CVFM. Yield was at least as good when obtained from VFM compared with the other planting stocks. A yield increase of 10 to 20% was common when using VFM, hill selected sweetpotatoes.
RUSSET CRACK-LIKE SYMPTOMS IN BEAUREGARD SWEETPOTATO REDUCED BY VIRUS INDEXING AND MICROPROPAGATION
Authors: Jester W. R.(Bill) , Averre Charles W. , Schultheis Jonathan R.
Published: February 2019

Russet crack-like symptoms have been observed with increasing frequency on Beauregard storage roots in North Carolina and resulted in some crop failures in neighboring states. The objective of this experiment was to determine if this cracking disorder was soil-borne, seed transmissible or transmissible via grafting. Beauregard plants were obtained from cuttings from commercially available virus-indexed micropropagated plants (M), and selected symptomatic roots (culls) originating from 1992 Foundation stocks (R). In a third treatment plants from each source were alternated in a row, then M and R plants were cleft grafted. The planting was made June 30, 1993 and replicated five times (12 plants per rep). Yield was determined and roots from each hill were washed and examined for russet crack-like symptom(s), and interior color on the proximal end. M roots had 82% good color; while R roots had 19%. M plants contained 0.3% symptomatic roots; R plants 65.5%. Similarly, only 1.6% of the M plants contained a symptomatic root, while 95.0% of the R plants had symptomatic roots. One-third of the grafted M plants contained one or more roots with cracking symptoms. M outyielded R. The russet crack-like disorder was determined to not be soil-borne, but was transmissible through the seed or grafting.
SEED-BORNE VIRUSES IN U.S. COWPEA CROPS: A STATUS REPORT AND STRATEGY FOR VIRAL DISEASE CONTROL
Authors: Hampton Richard O.
Published: February 2019

Blackeye cowpea mosaic potyvirus is the most easily observable seed-borne virus in cowpeas, but is typically seed-transmitted at lower rates (i.e., 0.1 to 2%) than the less conspicuous cowpea severe mosaic comovirus or cucumber mosaic cucumovirus. All three viruses are readily vector transmissible after seed-borne inoculum reaches the field, perpetuating and spreading the viruses. Individually and particularly in mixtures, these viruses are capable of decreasing both seed quality and yield. Disease-tolerant cultivars are available, but fail to control viral diseases. Development of superior new cowpea cultivars with multiple viral-disease resistance is clearly within reach and has become essential to long-term, sustainable, profitable cowpea production. This breeding objective requires public-research supported efforts by the combined cowpea seed and processing industries. Southern bean mosaic sobemovirus is also recognized as an important cowpea pathogen, but was encountered at a much lower frequency than the above three viruses in both plant and seed samples, in 1992 and 1993.
PROTOPLAST ISOLATION AND CULTURE OF KENAF (HIBISCUS CANNABINUS L.)
Authors: Liu Donglong , Reichert Nancy A.
Published: February 2019

Protoplast isolation and culture protocols were developed for leaf tissue from 6 kenaf cultivars [Everglades 41 (E41), E71, Guatemala 4 (G4), G45, G51, and Tainung 1]. For protoplast isolation, the best combination of hydrolytic enzymes was cellulysin (1% w/v; Calbiochem) plus macerase (0.5% w/v; Calbiochem), with a 24 hour digestion at 30°C in the dark. Yields reached 7.2 (10)6 protoplasts/g leaf tissue. Protoplast viabilities ranged from 65% to 96%. Minor cultivar differences were observed related to protoplast yield, but all viability estimates were in an acceptable range. Greatest cell division frequencies and plating efficiencies were obtained when protoplasts were initially cultured in liquid medium at a density of 1.0 (10)5 protoplasts/ml. Electrofusion protocols were developed for kenaf protoplasts testing the range from 1200 to 3000 V/cm. A fusion voltage of 2000 V/cm yielded the highest fusion frequency and retained viability above 80%.
VEGETATIVE GROWTH AND NITROGEN FIXATION OF PIGEONPEA AND COWPEA AT THREE TEMPERATURES
Authors: Baptiste Raymond , Marsh Lurline , Marsh Dyremple , Trinklein David
Published: February 2019

Low temperatures adversely affect legume- Rhizobium symbiosis in the temperate regions. Plant growth and N-fixation of two pigeonpea and two cowpea genotypes were examined at three temperature regimes (20/10 C, 30120 C and 38/25 C day/night). Sterilized seeds were inoculated with broth culture containing approximately 1 × 109 cells ml-1 of Bradyrhizobium USDA 3278, 3458 and 3472. Nitrogen fixation by pigeonpea was inhibited at 20/10 C. Cowpea IT82E-16 inoculated with USDA 3458 at 20/10 C produced the greatest amount of nodules. Inoculation had no effect on Nitrogenase activity in pigeonpea. Pinkeye Purple Hull inoculated with USDA 3472 at 20110 C had the highest Nitrogenase activity. These results indicate a wide degree of variability among genotypes and Bradyrhizobium in their response to temperature.
INHIBITION OF TAP ROOT ELONGATION IN CONTAINERS BY SIX DIFFERENT MATERIALS COATED WITH SPIN OUT™
Authors: Krieg Randon J. , Witte Willard T.
Published: February 2019

Tap roots of two coarse rooted species, Nyssa sylvatica and Quercus acutissima, were subjected to six treatment materials which were cut to fit or placed on the bottom of a 7.61 container. Each treatment material (paint only, Styrofoam plug tray, 3M floor buffer mat, peat fiber sheet, stone and weed barrier fabric) was either painted with Spin Out™ of impregnated with Spin Out™ WP. Treatments that allowed the tap root to penetrate the material, i.e. weed barrier fabric, stone and 3M floor buffing mat, were more effective in controlling tap root elongation. The weed barrier fabric significantly reduced tap root length of Quercus acutissima and Nyssa sylvatica by 80% and 67% respectively compared to controls and by 65% and 53% respectively compared to the paint only treatment. In some cases the 3M and stone treatments were more effective than the weed barrier fabric but were impractical because of weight or expense.
COMPARISON OF THE PHYSICAL AND CHEMICAL PROPERTIES BETWEEN CONTAINER-GROWN WOODY ORNAMENTALS
Authors: Edwards April D. , Newman Steven E. , Laiche Adolph J.
Published: February 2019

Kenaf (Hibiscus cannabinus) is an alternative fiber crop being grown in Mississippi that maybe used as a tree-less fiber substitute for making paper. A by-product in this process is the pithy light-weight fiber core. The objective of this study was to examine the chemical and physical properties of kenaf fiber core as a medium component in growing woody ornamentals and compare to pine bark. Comparisons of media in which Ilex crenata `Cherokee' and Rhodoendron eirocarpum `Wakabuisi' were grown were made. The physical and chemical properties including bulk density, total pore space, water retention, pH and soluble salt concentrations were determined. Aged kenaf had lower pH values than fresh and both aged and fresh kenaf had higher pH values than pine bark. The total pore space of kenaf was lower than the pore space of pine bark. At the termination of the study, the kenaf media had considerable shrinkage, which was considered unsuitable for a long-term crop.
CONTINUOUS USE OF PLANT NUTRIENT SOLUTION FOR HYDROPONIC CULTURE OF SWEETPOTATO:IMPLICATIONS AND EFFECTS
Authors: Trotman A.A. , David P.P. , Mortley D.G. , Carver G.W.
Published: February 2019

In a greenhouse study, continuous use of the same plant nutrient solution for hydroponic culture of sweetpotato was investigated to determine the effect on storage root yield, plant growth and nutrient solution composition. Plants were grown for 120 days under continuous flow from a 30.4-liter reservoir. Plant growth was compared when nutrient solution was changed at 14-day intervals and when nutrient solution was not changed but nutrients replenished through addition of a Modified half-Hoagland's (N:K=1:2.4) plant nutrient solution when volume in reservoir was -10 liters. Storage root yield was significantly decreased (181 vs 310.3 g/plant) and foliar biomass was significantly increased (372.4 vs 2% g/plant) when nutrient solution was not changed Nitrate and phosphate concentrations decreased in the plant nutrient over the duration of the experiment while sulfate and chloride concentrations increased. Salinity and electrical conductivity were monitored at 2-day intervals and increased with duration of the crop. Increased foliage production may have been the result of nitrogen replenishment going largely for foliage rather than storage root production. It may be that continuous use of the same plant nutrient solution as practiced in this study, resulted in lowered phosphate and nitrate concentrations that limited uptake of these ions by sweetpotato plants, thus reducing yield
NEITHER GREEN NOR WHITE ASPARAGUS SPEARS ARE AFFECTED BY SUPPLEMENTAL NITROGEN
Authors: Makus D. J.
Published: February 2019

`Jersey Giant' asparagus (Asparagus officinalis L.), grown in an Enders silt loam mineral soil near Booneville, Ark., was given an application of 80 kg/ha of Supplemental nitrogen (N, as NH4N O3) either prior to or after the Cutting season in 1993. Neither N treatment affected spear objective Color, Pigments, soluble solids concentration (SSC), or yield. Supplemental N decreased spear Ca and K levels. Green asparagus had higher levels of total-N, K, S, P, Ca, Mg, Fe, Zn, Al, Mn, and Cu, but lower levels of NO3 than did white asparagus. As the Cutting season progressed, spear SSC, S, Ca, NO3 (NO3 in White spears only), Zn, Mn, and Cu (Cu in white spears Only) levels decreased, While spear K and Al (Al in white spears only) increased on a dry weight basis. Fall residual soil NO3 levels were not affected by N application, but organic matter was lower in soil which received early supplemental N.
PLANT SPACING, COLD TREATMENT, AND FLOWER VIBRATION INFLUENCE ON GREENHOUSE TOMATO PRODUCTION
Authors: Mullinix Benjamin G. , Phatak Sharad C. , Cooper Janet
Published: February 2019

Six tomato cultivars [Hotset, Petra, Stella, Big-O, Tropic, & Monte Carlo (fresh market)] were grown in a greenhouse in 1979 from July through November in 3 experiments. Exp. 1: The first two cultivars were used in a 15 cm, 30 cm, or 45 cm in-row spacing with rows spaced 60 cm apart. Cumulative fruit number and weight per unit area declined with increasing in-row spacing. Exp. 2: The first four cultivars were subjected to either cold or no cold treatment during germination before transplanting. No differences were found between the two treatments for mean fruit weight or total fruit number. Exp. 3: The last two cultivars were subjected to both the cold treatment and flower vibration. Cumulative fruit weight was greater for vibrated flowers. Greater mean fruit weight occurred earlier with cold treatment and declined significantly later in season, and was more pronounced in Tropic than Monte Carlo.
BULK PLANTING SYSTEM FOR LOW-COST SEEDING OF CABBAGE
Authors: Porter Wayne C. , Parish Richard L.
Published: February 2019

The initial investment of a precision seeder is cost prohibitive to many small vegetable growers. This study was initiated to evaluate the use of a relatively inexpensive bulk seeder to plant cabbage (Brassica oleracea L. Capitata). Cabbage was direct-seeded with a precision seeder or a relatively inexpensive bulk seeder. Treatments with the bulk seeder consisted of blending viable hybrid seed with nonviable, nonhybrid seed at several ratios to reduce hybrid seed cost and optimize plant spacing. Seed ratios represented 10, 20, 30, 40, 50, and 100% viable seed. Pre-thin plant stands of 30 and 40% hybrid seed treatments were similar to precision-seeded plant stands. Average head size was greatest with 10, 20, and 30% hybrid seed ratios. Marketable yields were similar for all hybrid seed ratios except the 10% ratio. Production costs per acre for the precision seeder were between that of the 40 and 50% ratios. Net income for 40% hybrid seed was similar to that of the precision seeder.
THE TENNESSEE SNAP BEAN INDUSTRY
Authors: Mullins Charles A. , Straw Richard A.
Published: February 2019

Snap beans comprise the largest acreage of any vegetable crop grown in Tennessee with an annual production of about 6,000 hectares. Approximately two-thirds of the production is for five fresh market packers and the rest is primarily for two large processors located within the state. Most production is machine harvested with over 50 harvesters owned by Tennessee producers. Primary fresh market cultivars grown are `Strike', `Hialeah', and `Greencrop'. Fresh market snap beans are mechanically and hand graded to remove small pods, broken pods, and trash. Hydrocooling has become a standard practice in fresh market packing operations. Packed beans are sold throughout most of the Eastern United States. Primary processing cultivars are `Roma II', `Trueblue', `Hystyle'. `Peak', `Benton', and `Labrador'. Snap beans are grown on the Cumberland Plateau and in West Tennessee for nearby processing plants. At present, only a small portion of snap beans grown for processing are shipped out of state.