bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF DAY AND NIGHT TEMPERATURE AND LIGHT LEVEL ON CATHARANTHUS ROSEUS
Authors: Pietsch Grace M. , Carlson William H.
Published: April 2024

The effects of 5 day temperatures (15-35 C), 5 night temperatures (15-35 C), and 3 light levels (50% shade, ambient, and supplemental light) were determined for Catharanthus roseus cv. `Grape Cooler', Average Daily Temperature (ADT) was calculated for the 25 day/night temperature combinations. As ADT increased, time to flower decreased with the shortest time to flower at an ADT of 32.5 C. Plants grown without supplemental light and with an ADT of 17.5 C or less did not flower at the termination of the experiment (110 days from seeding). Plants grown under higher ADT also had a higher leaf unfolding rate (LUR) than plants grown under the lower ADT. The increase in LUR was linear over the entire temperature range of 15-35 C. Application of supplemental lights increased shoot fresh weight and decreased time to flower.
DAY/NIGHT TEMPERATURE EFFECTS ON NEW GUINEA IMPATIENS MORPHOLOGY AND CARBON PARTITIONING.
Authors: Erwin John E. , Heins R.D.
Published: April 2024

Impatient hawkeri Bull. cv `Mimas' rooted cuttings were planted in 15.2 cm plastic pots and were placed in glasshouses maintained at 15, 20, 25, or 30C. Plants were rotated among glasshouses at 0800 and 1700hr each day (9 hr photoperiod) to yield 16 different day/night temperature (DT/NT) regimes. Data were collected on time of first flower, internode length, stem calibre, flower diameter, leaves per node, individual leaf area, and the dry weight of the leaves, stem, and flowers on a representative shoot from each plant. Morphology data were collected after 80 days. Plants grown at 15C required 27 more days to flower than plants grown at 30C. Internode length increased as the difference (DIF) between DT and NT (DT-NT) increased and as temperatures approached 25C. Stem calibre was unaffected by temperature. Flower diameter had an optimal temperature of 20C. Leaves per node and leaf area had optimal temperatures of 25C. Stem dry weight increased as DIF increased. Flower dry weight was greatest when plants were grown at constant 20C. Shoot and leaf dry weight were greatest in the 25 DT/15C NT regime.
DAY/NIGHT TEMPERATURE EFFECTS ON PELARGONIUM ZONALE L. FLOWER DEVELOPMENT AND LEAF UNFOLDING RATE.
Authors: Erwin John E. , Schwarze Debra J.
Published: April 2024

Rooted cuttings of Pelargonium zonale cv `Fantasy' were planted in 12.7 cm pots and were placed in glasshouses maintained at 12, 18, 24 or 30±2C. Plants were rotated among glasshouses at 0800 and 1700hr each day (9 hr photoperiod) to yield 16 day/night temperature (DT/NT) treatments. Data were collected on primary stem node number after 60 days. Total flower number per inflorescence, flower diameter, peduncle length and inflorescence, peduncle and flower dry weight were collected when all flowers were visible on an inflorescence. Flower number per inflorescence increased exponentially from 23 to 52 flowers/inflorescence as the average daily temperature (ADT) decreased from 30 to 12C. Inflorescence and peduncle dry weight decreased exponentially from 1.05 to 0.28g and 0.34 to 0.05g, respectively, as ADT increased from 12 to 30C. Flower dry weight and diameter were not affected by temperature treatments. Peduncle length increased from 9.2 to 17.1cm as the difference between DT and NT (DT-NT) increased from -12 to +12C. Node unfolding rate increased as temperature increased from 12 to 24 then decreased as temperature increased to 30C.
CONSULTANTS CONTRIBUTION TO HORTICULTURAL PROJECTS IN DEVELOPING COUNTRIES
Authors: Eisa Hamdy M. , Forno Douglas A.
Published: April 2024

In addition to their nutritional benefits, horticultural crops contribute significantly to the development process by providing value added activities, intensive labor use, increasing farmers' income and generation of foreign exchange through exports. In addition to economic benefits, the World Bank's policies emphasize sustainable development and poverty alleviation as primary objectives in the development process. To correctly identify market opportunities and economically viable production practices, development agencies rely heavily on consultants' appraisal of investment opportunities. Successful identification of markets particularly for exports is the primary lever to tap the countries' production potential. Therefore, consultants engaged by development agencies should have a holistic view of the total development picture of horticultural commodities under consideration and up-to-date information of market niches, agreements and prospects for fresh and processed forms. Selection criteria and guidelines for the use of individual consultants and consulting firms have been prepared by the World Bank.
THE FOOD AND AGRICULTURE ORGANIZATION--UN: HORTICULTURAL-RELATED ACTIVITIES AND CONSULTANT RECRUITMENT
Authors: Hodder Alison
Published: April 2024

FAO's function is to assist national governments with agricultural institutional strengthening, food and agricultural development projects, and gathering and dissemination of commodity production and marketing information. Horticultural concerns include activities for genetics resources, production and postharvest handling. Separate divisions administer each of these subject areas. In the past, most of the funding support for these activities has been from the United Nations Development Programme. Currently funding support is more diversified but also more limited. FAO approaches to consultant recruiting and qualifications for horticultural consultants will be discussed.
GENES FROM LYCOPERSICUM CHMIELEWSKII THAT AFFECT TOMATO SOLUBLE SOLIDS, pH, AND YIELD.
Authors: Azanza F. , Juvik J.A. , Tanksley S.D.
Published: April 2024

Two chromosomal segments from the wild tomato L. chmielewskii have been introgressed into the L. esculentum genome. Using molecular markers they have been mapped to the middle and terminal regions of chromosome 7 (7M and 7T, respectively). This study was conducted to further clarify the physiological influence of the introgressed segments on tomato soluble solids, and other fruit and yield parameters. Sixty-four BC2F5 recombinant inbreds were developed from a cross using LA1501 (L. esculentum line that contains both fragments from L. chmielewskii) as the donor parent, and VF145B (processing cultivar) as the recurrent parent. Recombinant inbreds were classified in four groups (++: inbreds without either of the fragments, 7M+: with only the 7M fragment, +7T: with only the 7T fragment and, 7M7T: with both fragments) based on RFLP information, and then compared to each other for all the parameters under study. Inbreds homozygous for the 7M fragment displayed greater soluble solids (26%) and higher pH (0.10) than the control group (++), through a physiological mechanism related to water uptake. The 7L fragment did not influence either soluble solids or pH, but was observed to significantly increase fruit yield by 11%. A gene or genes that increase yield without affecting soluble solids or pH may have potential in the development of commercial cultivars.
NITROGEN FERTILITY, HARVEST FREQUENCY AND WEED DENSITY EFFECT THE PRODUCTIVITY OF A COLLARD : COWPEA INTERCROP.
Authors: Itulya Francis M. , Masiunas John B.
Published: April 2024

A study was conducted at the Irrigated Vegetable Crops Research Farm in Champaign, IL to determine the effects of nitrogen levels, collard harvesting frequency and density of redroot pigweed (Amaranthus retroflexus L.) infestation on the productivity of a collard : cowpea intercrop. The experiment was a split block design with 3 replications. The nitrogen was applied in the form of urea at 0, 80, 160, and 240 kg N ha-1. Redroot pigweed was seeded at 0, 300, and 1200 seeds m2. The more frequently collard was harvested the greater its competitiveness. Intercropping collard and cowpea reduced the growth of redroot pigweed. Nitrogen favored growth of the collard : cowpea intercrop and did not effect redroot pigweed growth.
ADVENTITIOUS MICROPROPAGATION OF RHODODENDRON `P.J.M. HYBRIDS'
Authors: Chytla Marta E. , Preece John E.
Published: April 2024

For genetic transformation studies, it is important that efficient adventitious regeneration systems be developed. In previous studies we had stimulated adventitious shoot formation from rhododendron leaf explants. To further determine which explants would be best to inoculate with Agrobacterium, we compared shoot organogenesis from small (2-4 mm long), medium (>4-8 mm long), and large (>8 mm long) leaves excised from in vitro shoot cultures. Across all reps (up to 66 explants), large leaves produced a mean of 23.4, medium produced 6.1, and small produced 2.2 adventitious shoots after 18 weeks. Adventitious microshoots were rooted in preformed peat plugs in high humidity flats. Prior to placement in the plugs, cut ends were treated with various combinations of IBA and NAA. After 8 weeks, control shoots rooted 60% and microshoots treated with 1.25 or 2.50 mM IBA plus 1.25 mM NAA or with a Wood's (1:20 dilution) solution rooted >95%.
FAST MICROPROPAGATION OF TUNA (Opuntia ficus-indica Mill.) AND PLANT ESTABLISHMENT IN SOIL
Authors: Mohamed-Yasseen Yasseen , Davenport Thomas L.
Published: April 2024

Methods for shoot multiplication, in vitro rooting, and ex vitro rooting of microcuttings are described. Regenerated shoots were formed from explants taken from young joints and flower receptacles when cultured in Murashige and Skoog (MS) medium containing 8.8 μM benzyladenine (BA) and 0.1 μM naphthaleneacetic acid (NAA). They were bisected into equal sections from apex to base and laid horizontally, cut-surface down on MS medium containing 4.4, 8.8, or 17.6 μM BA and 0.1 μM NAA. More than 10 shoots per section were regenerated within four weeks in plants cultured in the 8.8 μM BA medium. Resulting shoots were rooted in vitro in half-strength MS regardless of the presence of auxin or activated charcoal. Ex vitro rooting was accomplished by simply placing excised shoots upright in commercial potting soil. Virtually 100% of the plants were successfully established in soil from both rooting methods.
EFFECTS OF SOIL WATER LEVELS AND SUPPLEMENTARY LIGHTING ON PHYSIOLOGY OF TWO Thymus vulgaris CLONAL SELECTIONS.
Authors: Letchamo W. , Xu H.I. , Gosselin A.
Published: April 2024

Thyme (Thymus vulgaris L) is an important medicinal and aromatic plant used in nutrition, pharmaceutical and cosmetic industries. The main objective of this investigation was to elucidate the influence of different growning conditions on photosynthesis, chlorophyll contnet and leaf water potential in two different thyme clonal selections. Pot experiments were conducted in a greenhouse with three different soil water levels (50, 70 and 90% by weight), under supplementary lighting and natural lighting. Photosynthetic rate was positively related to soil water level and supplementary lighting. Under both light treatments, photosynthesis was found to be highest at 70% soil water level. “Selection 1” showed higher rates of photosynthetsis than “Selection 2”. “Selection 1” had slightly higher leaf water potential than “selection 2” under all growing conditions. Leaf water potential was found to be much higher for both selections grown without supplementary lighting than the variants grown under supplementary light. The mean chlorophyll content of “Selection 1” grown under supplementary lighting was found to be higher than “Selection-2” under all soil water levels (50 % 70% and 90%). There was a clear difference in leaf color between plants grown under the two light levels. This research was partially supported by Matol Botanical International.
OSCILLATORY TRANSPIRATION IN ROSA HYBRIDA `MOONLIGHT'
Authors: Rose Mark A. , Beattie David J. , White John W.
Published: April 2024

Two distinct patterns of whole-plant transpiration were observed in potted roses using an acquisition network that integrated a Dansk Gartneri Teknik climate computer, Dynamax heat-balance sap-flow gauges, Fisher electronic-balance lysimeters, and Everest infrared leaf temperature sensors. One pattern consisted of a steady rate of transpiration in a stable greenhouse environment. The second pattern consisted of large oscillations in transpiration that were unrelated to any known microclimate rhythms. These oscillations had a sine-wave pattern with periods between 60-90 minutes and ranges between 3 and 37 g·hr-1 in natural light and 2 and 69 g·hr-1 in artificial light during the night. Leaf temperatures also oscillated, but were inversely related to the transpiration cycles. Oscillatory transpiration has not been reported in roses.

Oscillatory transpiration is an example of the phenomena that may now be investigated by integrating climate computers and sensors that monitor plant physiological processes. When plant responses to microclimate variables can be predicted and monitored in real time, the `speaking plant approach' can be used, in which plants directly control their greenhouse environment.
MODIFIED-ATMOSPHERE PACKAGING OF SMALL FRUITS: THE INFLUENCE OF CO2 ON O2 UPTAKE AND THE LOWER O2 LIMIT
Authors: Joles Dennis W. , Talasila P. Chowdary , Cameron Arthur C.
Published: April 2024

For raspberry (Rubus idaeus L. `Heritage'), blueberry (Vaccinium corymbosum L. `Jersey') and sweet cherry (Prunus avium L. `Sams') fruit, CaO, as a CO2 scrubber, was combined with modified-atmosphere packaging to generate a range of steady-state O2 levels (≈13 to 1 kPa) over which CO2 accumulated (≈3 to 17 kPa) or was scrubbed (≤ .1 kPa). The steady-state O2 levels in the presence and absence of generated CO2 were similar. Since steady-state O2 levels are a direct function of a fruit's O2 uptake in a modified-atmosphere package, we concluded that the CO2 levels generated had no effect on O2 uptake. The O2 level at which an increase in headspace ethanol was observed also did not differ in packages with and without a CO2 scrubber. For raspberry fruit, supplemental CO2 levels of 10, 20 and 60 kPa were added to sealed packages. The levels of steady-state O2 and CO2 were measured and the rates O2 uptake and CO2 production estimated. It was found that supplemental CO2 levels up to 20 kPa had little effect on fruit O2 uptake.
RIPENING OF TOMATO FRUIT LOCULE GEL TISSUE
Authors: Atta-Aly Mordy A. , Brecht Jeffrey K. , Huber Donald J.
Published: April 2024

Ethylene production by locule gel tissue excised from full-size immature- and mature-green tomato fruit was inhibited by exposure to l00μl·l-1 C2H4, and ACC content was reduced. In contrast, CO2 production, EFE activity, red color development, and tissue liquefaction were stimulated by C2H4, and, in immature gel, the onset of autocatalytic C2H4 production was hastened. The autoinhibition of C2H4 production required continuous exposure to C2H4, as transfer to air and then back to C2H4 resulted in C2H4 production first increasing to control levels, then decreasing again. Locule tissue from pink fruit responded to C2H4 treatment with increased production of both C2H4 and CO2, but ACC levels were unchanged. Inhibition of C2H4 action by pretreatment with STS inhibited both autoinhibition of C2H4 production in immature gel and autocatalytic C2H4 production in mature tissue. These results indicate that there is a transition from a negative to a positive feedback mechanism of C2H4 on C2H4 biosynthesis in locule gel during ripening. Additionally, this feedback mechanism, which involves ACC synthase, is apparently under separate control from the other manifestations of C2H4 action.
GINSENG CULTIVATION AND PHYSIOLOGY
Authors: Proctor John T.A.
Published: April 2024

Ginseng is an herbaceous perennial that is cultivated for its highly valued root. It is used as a cure-all, wonder drug and aphrodisiac, the active principles being saponins (ginsenosides). The essential features of the cultural system are shade, a mulch and the growing of plants on raised beds. The plants are obtained either by direct seeding or by seeding into a nursery bed and transplanting. The established crop requires spraying for diseases, insects and weed control. Although ginseng has been cultivated in North America for over 100 years associated research on mechanisms controlling growth and development of the plant has been minimal. Crop establishment is a highly vulnerable stage in the life cycle of ginseng growing yet we know little about fruit and seed set, seed quality, stratification and germination. The growing environments for ginseng have only recently been precisely defined. However, we need to know more about environmental variables and their inter-relationship particularly in relation to photosynthesis and dry matter partitioning. Disease control is the central problem in world ginseng production and requires an integrated approach.
FARMBOOK: A WHOLE-FARM INFORMATION SYSTEM
Authors: Alessi Sam , Vang Leng , Voorhees Ward
Published: April 2024

Agricultural research has produced many results that can be useful to crop managers. Viewed as a whole, these results are often difficult to apply in concert to a production system. Farmbook is an attempt to integrate research results through a primarily software-driven information management environment. Farmbook first provides an infrastructure for simulation modeling and expert systems by building upon detailed and individualized crop records. This infrastructure must first be easy to use and provide basic information such as production costs, nutrient summaries and yield analysis. Building such a system involves problem analysis and design prior to programming. Data modeling, data flow diagramming, state-transition modeling and object-oriented design have been used to build a Farmbook prototype. Farmbook was tested by farmers on 12 farms in 1992. The flexibility of the system should allow direct application to horticultural crop or greenhouse environments.
MECHANICS OF MODEL BUILDING
Authors: McKinion James M.
Published: April 2024

In the late 1960's with the advent of wide availability of the digital computer, it became possible through the application of systems theory to build simulation models of biological entities. In production agriculture, scientists have built models of a number of field crops: cotton, corn, wheat, soybean, and alfalfa. In most of the models built to date, crop phenology is addressed directly with detailed aspects of crop physiology and/or soil physics addressed either to a greater or lessor degree. This paper addresses the methodology of the construction of process-level, physiologically-based crop simulation models which possess detailed descriptions of plant physiological and soil physical mechanisms and proposes a minimum set of design features.
LEAKAGE OF SOLUTES FROM IMBIBING SEEDS OF SUPERSWEET CORN CULTIVARS THAT DIFFER IN TOLERANCE TO LOW GERMINATION TEMPERATURES
Authors: Kull Linda , Coons Janice
Published: April 2024

Acceptance of supersweet types of corn is hindered due to reduced field emergence in cold soils. Reduced emergence is related to seed endosperm composition and imbibitional leaching of seed components. Seeds of two supersweet cultivars (Illini Gold and Honey'n'Pearl) with shrunken-2 endosperm were examined for differences in percent germination and days to 25% germination at 10, 15, and 20 C. Seed leachate from seeds imbibed at 10, 15, and 20 C was analyzed for electrical conductivity, sugars, and amino acids. Germination percentages were higher for `Illini Gold' than for `Honey'n'Pearl' at all temperatures, and higher at 20 than 10 C for both cultivars. `Illini Gold' germinated sooner than `Honey'n'Pearl' at all temperatures. Electrical conductivity was higher for `Honey'n'Pearl' than `Illini Gold', and higher at 20 than 10 C for both cultivars. At all temperatures, sugars and amino acids in seed leachate were higher for `Honey'n'Pearl' that for `Illini Gold', but no significant temperature effects were observed. Imbibitional leakage of ions, sugars, and amino acids was more dependent upon cultivar than temperature.
EFFECT OF LIGHT EXCLUSION ON THE PIGMENT DEVELOPMENT, SUGAR, TITRATABLE ACIDITY, AND TOTAL PHENOLICS IN THE CLUSTERS OF 27 GRAPE CULTIVARS.
Authors: Ahmedullah M.
Published: April 2024

The clusters of 27 grape cultivars representing red, blue and black colors were bagged before veraison to exclude light. The unbagged clusters close to the bagged ones served as control. Temperature inside the bag was monitored. The clusters were harvested at commercial maturity and analyzed for quality parameters, anthocyanins, caffeoyl tartarate and total phenolics. The clusters of 15 cultivars showed a visible reduction in color by light exclusion and 12 developed color without light. There were differences in the quality parameters and total phenolics between bagged and unbagged cultivars. The possible relationship of phytochrome in the initiation of pigment development is discussed.
MULCH TYPE EFFECTS IN ANNUAL HILL STRAWBERRY PLASTICULTURE SYSTEMS
Authors: Himelrick David G. , Dozier W.A.
Published: April 2024

Fresh dug `Chandler' and `Selva' strawberry plants were fall planted in 1990, 1991, and 1992 on fumigated, trickle irrigated, raised beds covered with either six or eight different plastic mulches plus a bare ground (BG) treatment. Plastic mulch treatments included clear (CLR), black (BLK), laminated white on black (W/B), laminated black on white (B/W), IRT-76 (IRT), AL-OR brown (ALOR), silver (SIL), and red (RED).

The highest yields for `Chandler' in 1990 were obtained on IRT followed by CLR, ALOR, B/W, BLK, W/B, and BG. The highest yields for `Selva' were on CLR followed by BLK, ALOR, IRT, B/W, W/B, and BG. The highest yields for `Chandler' in 1991 were on W/B followed by BLK, ALOR, IRT, B/W, CLR, and BG. In the case of `Selva' ALOR was the top performing treatment followed by IRT, W/B, BLK, B/W, BG, and CLR. The first two years of data were inconclusive. Data from 1992 planting will be included to clarify yield, earliness, and season length effects.
NUTRIENT CARRIERS FOR DRIP/TRICKLE FERTILIZING PEPPERS
Authors: Paterson James W.
Published: April 2024

The desirability of selected primary plant nutrient carriers (N-P2O5-K2O) for drip/trickle fertilizing bell peppers (Capsicum annuun L.) on a coastal plain sandy loam soil was investigated in 1990 and 1992. Soluble dry and liquid fertilizer carriers selected in both years were urea ammonium nitrate (30-0-0), ammonium sulfate (21-0-0), potassium nitrate (14-0-46), phosphoric acid (0-54-0), ammonium polyphosphate (10-34-0), and muriate of potash (0-0-62). These materials in combinations were compared to a more expensive commercially prepared dry fertilizer (20-20-20) which was formulated from urea, mono and diammonium phosphate and potassium nitrate. Although the commercial fertilizer (20-20-20) produced significantly more early and midseason yields of No. 1 plus No. 2 peppers than one-third of the less expensive formulated grades, all treatments produced the same late and total yields of pepper in 1990. In 1992, the ammonium sulfate, ammonium polyphosphate and muriate of potash treatment produced significantly more total No. 1 plus No. 2 peppers than did the phosphoric acid and muriate of potash with either urea ammonium nitrate or ammonium sulfate; however, no treatment differences were noted in total yields of quality No. 1 peppers.
WATERMELON SEEDLING GROWTH AND ROOT CALCIUM ABSORPTION AS INFLUENCED BY THE FUNGICIDES CAPTAN AND THIRAM
Authors: Liu Aimin , Latimer Joyce G. , Wilkinson Robert E.
Published: April 2024

Unilateral application of Ca2+ and Al3+ induced curvature in roots of `Starbrite' watermelon [Citrullus lanatus (Thumb.) Matsum and Nakai] seedlings from both untreated and commercially pretreated seeds. In untreated seeds, PCMBS inhibited root curvature by decreasing Ca2+ and Al3+ uptake. In pretreated seeds, PCMBS only inhibited Ca2+-induced root curvature. Captan and thiram inhibited Ca2+- or Al3+-induced root curvature. Captan showed the greatest inhibition of Ca2+ uptake at 100 mg/liter, whereas thiram was most effective at 0.01 mg/liter. The effects of captan and thiram were statistically additive. Thiram appeared to show a similar mode of action to PCMBS in affecting Ca2+ uptake. DDT reversed the inhibitory effect of thiram, but not that of captan.

Acid soil (pH 4.6) reduced number of leaves, leaf, stem, shoot and whole plant dry weight, and stem length. Pretreated seeds produced greater root dry weight and root:shoot ratio in acid soil than did untreated seeds. Fungicides may have reduced Al3+ toxicity by inhibiting Al3+ uptake in acid soil.
LIPID CHANGES IN BELL PEPPER FRUIT DURING CHILLING AND REWARMING
Authors: Whitaker Bruce D.
Published: April 2024

Lipid composition and pigment content in bell pepper fruit that were freshly harvested, chilled 2 weeks at 2C (CH), or chilled then rewarmed to 20C for 4 days (RW), were determined. There was slight to moderate loss of glycerolipids during chilling, with much greater losses after rewarming. Loss of galactolipid (GL) exceeded that of phospholipid (PL). The ratio of the GL, MGDG:DGDG, did not change in CH and RW fruit, and there was no loss of chlorophyll or change in the Chl a:b ratio, but neutral carotenes declined ca 30 % after rewarming. Only small changes in total membrane sterols (TMS) were noted in CH and RW fruit, but major changes in sterol glycosylation and esterificatian occurred. The stigmasterol:sitosterol ratio increased during chilling and after rewarming. Due to PL loss, the ratios of TMS and cerebrosides to PL increased sharply in RW fruit. The ratio of 18:2 to 18:3 declined with chilling and with rewarming in all acyl lipids, but total unsaturation increased only in GL. These results indicate that most membrane damage occurs after rewarming and that the chloroplasts are especially chilling sensitive.
SUSCEPTIBILITY OF BELL PEPPER MICROSOMES TO PEROXIDATIVE CHALLENGE AT DIFFERENT TEMPERATURES
Authors: Cowart Darlene M. , Erickson Marilyn C. , Shewfelt Robert L.
Published: April 2024

Temperature stress resulting in membrane-associated disorders has been linked to lipid peroxidation through free radicals, but the susceptibility of membrane lipids in microsomal fractions to chilling stress has not been clearly delineated. Microsomal membranes isolated from bell peppers were subjected to five oxidative conditions (iron-ascorbate, xanthine oxidase, cumene hydroperoxide, and lipoxygenase (LOX) with and without PLA2) at three temperatures (6, 21, and 37C) and measured at 30 min. intervals during a 2 hour incubation to determine the effect of temperature on peroxidation as measured by TBA-RS. During the first 30 min., the rate of peroxidation was greater at 6C than at 21C or 37C in four of the five systems tested. Preincubation with PLA2 followed by addition of LOX produced the highest amount of peroxidative products when compared with all other systems demonstrating the importance of free fatty acids in lipoxygenase-catalyzed peroxidation. The results demonstrate an increased susceptibility of microsomal membranes isolated from a chilling-susceptible fruit to peroxidative challenge at chilling temperatures than at higher temperatures.
CHARACTERIZATION OF CHILLING-REGULATED PROTEINS IN FLORAL BUDS OF BLUEBERRY
Authors: Muthalif Mubarack M. , Rowland Lisa J.
Published: April 2024

Attempts have been made to identify changes in gene expression in dormant buds of woody plants in response to chilling unit accumulation. In our earlier analyses of total proteins from blueberry floral buds, we found that the concentration of at least three polypeptides varied in response to chilling. More recently, soluble proteins have been extracted from floral buds of the high-chilling variety `Bluecrop' and the low-chilling variety `Tifblue'. This extraction procedure was found to enrich for the chilling-regulated proteins, which include three major polypeptides of 72, 65, and 17 kilodaltons and several minor polypeptides. Furthermore, the chilling-induced polypeptides were found to be extremely thermal stable, resisting denaturation even after boiling for more than 15 minutes. Cold hardiness levels were assessed for dormant buds of `Bluecrop' and `Tifblue ' after 0, 300, 600, 900, and 1200 chilling units. A positive correlation was observed between the level of cold hardiness and the levels of chilling-induced proteins suggesting a role for these proteins in the development of cold hardiness.
A FORCING PROGRAM FOR ISRAELI-GROWN LEUCOJUM AESTIVUM AS POTTED PLANTS
Authors: De Hertogh A.A.
Published: April 2024

Over 3 years, greenhouse and phytotron trials were conducted using Israeli-grown Leucojum aestivum. The objective was to evaluate the potential of this bulb as a potted plant for North American forcing. It was found that bulb sizes of 12/14, 14/16, and 16/up cm (in circumference) produced quality plants. Bulbs of 10/12 cm had reduced number of florets per floral stalk. The optimal cold requirement was 15-19 weeks. The major physiological disorder associated with forcing was flower abortion. Phytotron studies showed that this occurred readily at 30/26 C (Day/Night temperatures) and was minimal at 18/14 C. When > 12 cm bulbs were properly programmed and forced in the greenhouse, they produced plants that were 25-35 cm tall at flowering, with 1-2 floral stalks and 4-6 florets per stalk. No plant growth retardants are required for forcing this bulb as a 15 cm diameter potted plant.
CHARACTERIZATION OF THREE SOLUBLE INVERTASES FROM LILIUM LONGIFLORUM FLOWER BUDS
Authors: Miller William B. , Ranwala Anil P.
Published: April 2024

Three soluble invertases (EC 3.2.1.26) previously identified in developing flower buds of Lilium longiflorum Thunb (HortSci. 25:1076, 1990) have been further investigated. These enzymes are fully separable on DEAE-Sephacel and differ substantially in enzymological properties. Each enzyme was further purified by consecutive use of Sephacryl S-200 gel filtration, Con A Sepharose affinity chromatography and Phenyl-Agarose hydrophobic interaction chromatography. This produced 135, 189 and 202 fold purification of invertase I, II and III, respectively. Each was an acid invertase showing pH optima between 4.0 and 5.0. The molecular weight of each invertase was estimated to be 75,000 Da by gel filtration. Invertase I, II and III showed temperature optimum at 40, 50 and 45°C, respectively. A temperature stability study revealed that Invertase III was the most stable followed by II and I. Invertase I, II and III had Km values of 1.0, 6.4 and 6.6 mM for sucrose, respectively. Invertase II and III had lower affinity to raffinose and stachyose than Invertase I. All three invertases were completely inhibited by Hg2+ and Ag+ ions at 1.7 mM concentration. At this concentration Cu2+ inhibited 45% of activity of Invertase I, but only 30% of activity of Invertase II and III.
VARIATION IN RESPONSES OF FOUR JAPANESE RADISH (RAPHANUS SATIVUS L.) VARIETIES TO VERNALIZATION TREATMENT.
Authors: Engelen-Eigles Gerard , Erwin John E.
Published: April 2024

Low temperature promotion of flower induction was studied on 4 Japanese radish cultivars: “Early 40 days', `Chinese Radish Jumbo Scarlet', “Everest' and `Minowase Early Long White'. Germinated radish seed were vernalized in a petri dish at 6C (inductive) or 18C (non-inductive). Photoperiod was maintained at 16hr using a mixture of fluorescent and incandescent lamps (75:25% total wattage). Japanese radish is classified as a cold promoted long day plant. Cultivars were vernalized for 5, 10, 15, 20, 25 or 30 days. Data were collected on node number and days to anthesis. Node number and days to anthesis decreased on all cultivars after a 20 day vernalization treatment. Node number and days to anthesis decreased on “Early 40 days' and “Everest” when they were vernalized for only 5 days. `Chinese Radish Jumbo Scarlet' did not flower under non-inducing temperatures and long days even after 30 days which suggested that this cultivar was a cold obligate (requiring) variety. “Early 40 days', “Everest', and `Minowase Early Long White' flowered under non-inductive temperatures and long days implying that these cultivars exhibit a facultative rather than obligate vernalization response.
PESTICIDE USE AND SAFETY PRACTICES OF INDIANA MASTER GARDENERS
Authors: Dana Michael N. , Lerner B. Rosie , Gann Ralph , Gibb Timothy , Shaner Greg , Whitford Fred , Kemery Ricky
Published: April 2024

Indiana Master Gardeners were surveyed to determine their attitudes and practices related to pesticide use in the home garden and landscape. The data are of interest for the purpose of preparing educational programs for Master Gardeners and the public. Of the 1054 surveys mailed, 53.8% were returned with usable responses. When questioned about protective clothing worn during spray application of pesticides, most respondents indicated that long sleeves were not worn (57%), that long pants were worn (71%), that protective shoes were worn (76%) and that breathing protection was not used (80%). A median response of 0% of pesticides were reported to be stored in a locked cabinet. However, of those pesticides that were not in a locked cabinet, 74% were stored at least 4 feet off the floor. Master Gardeners with children reported locked storage of pesticides more often than those without children. Responses concerning disposal of containers indicate an area for future education. Only 54% of Master Gardeners reported rinsing their pesticide containers prior to disposing of them, while 73% indicated that the containers were included in the regular trash collection. Responses often varied with age, gender, and other demographic characteristics of the respondents.
Effects of IBA and Branch Position on Rooting Softwood Cuttings of `Yoshino' Cryptomeria
Authors: Jull Laura G. , Warren Stuart L. , Blazich Frank A.
Published: April 2024

Softwood stem cuttings of Cryptomeria japonica (L.f.) D. Don `Yoshino' consisting of (1) tips (terminal 20 cm) of first order-laterals (secondary axes), (2) the distal half (terminal 10 cm) of tips of first-order laterals, (3) the proximal half (basal 10 cm) of tips of first-order laterals or (4) tips (terminal 10 cm) of second-order laterals (tertiary axes) were treated with 0, 3000, 6000 or 9000 ppm 1H-indole-3-butyric acid (IBA) and placed under intermittent mist for 12 weeks. IBA treatments did not effect percent rooting, root number, root length, or root dry weight Tips of first-order laterals and the proximal half of first-order laterals yielded the highest rooting percentages (75% and 78%, respectively), whereas the distal half of the first-order laterals and tips of second order laterals rooted in lower percentages (50% and 34%, respectively). Tips of first-order laterals and the proximal half of first-order laterals both produced 4.5 roots per cutting. Root length, root area and root dry weight were also highest with these two branch positions.
AUXIN INFLUENCES ROOT INITIATION AND DEVELOPMENT FOR CHIONANTHUS RETUSUS STEM CUTTINGS
Authors: Eakes D. Joseph , Gilliam Charles H. , Keever Gary J.
Published: April 2024

Terminal stem cuttings, 15.24 cm in length, of Chionanthus retusus Lindl. & Paxt. (Chinese Fringetree) were taken on 24 Sept. 1992. All cuttings were made from hardened off current years spring growth. The basal end of the cuttings were cut at an angle and treated with one of eight treatments before being stuck in a 100% vermiculite medium and placed under intermittent mist with a polyethylene covering. Treatments were: 3,000, 8,000 and 16,000 ppm IBA as K-IBA liquid quick dips and as commercial talc preparations (Hormex Nos. 3, 8 and 16), 10,000 ppm NAA as a quick dip, and an untreated control. Cuttings were harvested and evaluated on 10 Dec. 1992. All auxin treatments increased rooting %, average root length, total root fresh weight, and root rating when compared to the untreated control. Cuttings treated with 10,000 ppm NAA had the greatest rooting %, longest average root length, greatest root number, and highest root rating compared to the other auxin treatments, with the exception of the 16,000 ppm K-IBA quick dip treatment which was similar.
GROWTH RESPONSES OF YOUNG APPLE TREES ON 3 ROOTSTOCKS TO DROUGHT STRESS
Authors: Fernandez R.T. , Perry R.L. , Flore J.A.
Published: April 2024

`Imperial Gala' apple trees on M.9 EMLA, MM.lll and Mark rootstocks were subjected to two drought and recovery periods in a rainshelter. The objectives were to determine rootstocks adaptation and parameter sensitivity to drought stress. Leaf growth rate, area, emergence; shoot length, trunk cross sectional area and gas exchange were measured for each stress and recovery period. Leaf growth rate was most consistently reduced by drought and returned to control levels when irrigated. Length of less vigorous shoots was consistently reduced by stress but did not recover upon irrigation. Leaf emergence and trunk cross sectional area were inconsistent in response to stress. Growth of trees on Mark rootstock was reduced to the greatest extent by drought followed by MM.lll and M.9 EMLA. At termination plants were separated into roots, 1-year and 2-year shoot growth and rootstock to determine dry weights. Dry weights confirmed the growth measurements with a 34%, 27% and 16% reduction in total plant dry weight for drought stressed trees on Mark, MM.lll and M.9 EMLA, respectively. The greatest differences in estimated whole plant photosynthesis were for trees on Mark rootstock followed by MM.lll with the least differences for M.9 EMLA which reinforced the growth measurements. It was concluded that Mark was most sensitive followed by MM.lll with M.9 EMLA being most tolerant to drought.
DIVERSITY AMONG SEEDLINGS OF MAACKIA AMURENSlS
Authors: Graves William R. , Giridhar J. , Pai B.
Published: April 2024

Commercial production of Maackia amurensis Rupr. & Maxim. (Amur maackia) is very limited despite the ornamental and nitrogen (N2)-fixing potential of this tree species. The goal of this on-going project is foster production efforts by selecting genotypes based on growth rate, morphology, stress resistance, and efficiency of N2 fixation. To establish a collection of plants with diverse genetic backgrounds, we requested half-sib lots of seed from arboreta, public gardens, and zoos in 1991. Mean seed mass of the 38 lots that were obtained ranged from 35 to 99 mg. Germination ranged from 67 to 100% and was 78% for the oldest lot, which was harvested at least 66 years ago. Over 2500 seedlings representing the 38 lots were grown in a greenhouse during the 1992 season. The mean epicotyl length and number of compound leaves varied among seedlings in the different lots. Results to date indicate that selecting genotypes based on growth rate and morphological features will be possible.
TRANSITION TO FLOWERING IN LETTUCE: EFFECT OF PHOTOPERIOD
Authors: Waycott William
Published: April 2024

A series of controlled environment experiments were undertaken to study the effect of daylength on the transition to flowering in lettuce (Lactuca sativa L.), a quantitative long-day plant. A wide range of domesticated and wild lettuces were grown at five different photoperiods (8, 10, 13, 16, and 20 hr day-1) and measured for the number of days to 5, 10, and 30 cm. The results showed that the transition to flowering in lettuce is controlled by at least three different genetic systems: 1) a modified long-day system, typified by the American crisphead group, 2) a long-day system to which many of the European butterhead lettuces belong, and 3) the early flowering system. The first group was typified by a perceived non-linear response to daylengths between 10 hr and 13 hr, the response taking roughly the same number of days to flower under both of these daylengths. The second group showed a linear respond to incremental changes in daylength, while the crispheads were linear between 8 hr and 10 hr, and between 13 hr and 20 hr. This second group is known to have the long day gene tag, which induces rapid bolting in cultivars during long days. Our results indicate the effect of tag was no more than this linear response, and support the use of crispheads as a source of resistance to premature flowering, or bolting, for some time. The third system, early flowering, was nearly a day-neutral system. The plants flowered with a minimal response to increasing daylengths. Efforts of establish the exact physiological point of transition to flowering will be presented.
EFFECT OF HIGH-CO2, ATMOSPHERE ON PHENOLIC METABOLISM IN ROMAIN LETTUCE
Authors: Hamza Fatoumata , Lambert Hélène , Castaigne Francois , Makhlouf Joseph
Published: April 2024

The study aimed at establishing the role of phenolic metabolism in the development of “brown stain” (BS) of romaine lettuce (Lactuca sativa L.) stored under high CO2. The lettuce were stored for 7 days at 4°C under a continuous stream of air or CO2 (15%) in air, then transferred to air at 20°C for two days. Results indicate that the development of BS under CO2 at low temperature was not related to activation of phenylalanine ammonia-lyase (PAL). After aeration of the produce the increase in BS symptoms coincided with the increase in phenol content of the tissue.

The data suggest that stimulation of phenol synthesis involved regulation of enzymes other than PAL, later in the phenyl propanoid pathway.
YIELD CHARACTERISTICS OF A RICE CULTIVAR GROWN IN HYDROPONICS USING OPTIMIZED NUTRITIONAL REGIMES
Authors: Volk Gayle M. , Mitchell Cary A.
Published: April 2024

High yields and harvest indices in greenhouse studies indicated that japonica rice cultivar Ai-nan-tsao should be considered for inclusion in NASA's Controlled Ecological Life-Support Systems program. Ai-nantsao achieved a yield rate of 12.87 g m-2 d-1 when grown in continuously recirculating hydroponic systems under 12-h photoperiods in a growth chamber. Hydroponic systems have been improved such that contained plants have enhanced root development and a decreased edge effect. The total harvest index was 27% while shoot harvest index was 29%. A planting density of 775 plants m-2 resulted in an average of 5 tillers (and therefore 5 panicles) per plant. Average panicle weight was 1.5 g. Currently, various levels of nitrogen in the nutrient solution are being evaluated to attempt to shorten the life cycle and increase the harvest index. Nutritional analyses of the grain and inedible portions of the plants will identify changes in grain composition with respect to nutritional treatments relative to greenhouse soil culture. This project was supported in part by NASA grant NAGW2329.
EFFECT OF pH ON ROOT GROWTH OF SIX CULTIVARS OF WATERMELON
Authors: Liu Aimin , Latimer Joyce G. , Wilkinson Robert E.
Published: April 2024

Watermelon [Citrullus lanatus (Thumb) Matsum and Nakai] cultivars Charleston Gray(CG), Crimson Sweet(CS), Dixielee(DL), Jubilee(JL), Mirage(MG) and Starbrite(SB) were grown in white quartz flintshot sand and watered daily with 0.01M sodium acetate buffer at pH 4.0, 4.5, 5.0, 5.5, 6.0, or 6.5. After two weeks, stem length, leaf area, leaf and root dry weight, and root number were measured. Nnumber of root decreased with decreasing pH below pH 5.0 in all cultivars except CG, which had an increase trend. Root number of MG and SB had negative linear and quadratic correlations respectively, with decreasing pH. In all cultivars, root dry weight increased with decreasing pH below pH 5.5. Under pH≤4.5, all cultivars except CG, had short or no tap root and thickened lateral roots. CG had a decrease in stem length, leaf dry weight and leaf area with increasing pH, and was sensitive to high pH. However, MG and SB had reduction in leaf area and stem length with decreasing pH, which suggests that MG and SB are sensitive to low pH. Although there were no differences in shoot parameters of 2wk-old plants of CS, DL and JL, observations made at 7 days after seeding indicated a possible pH effect on early growth of seedling.
CILAHTRO AND DILL RESPONSE TO NITROGEN FERTILIZER RATES
Authors: Rangappa Muddappa , Bhardwaj Harbans L. , Mohamed Ali I. , Hamama Anwar A.
Published: April 2024

Two separate experiments were conducted during 1992 to determine optimum rate of nitrogen fertilizer for cilantro (Coriandrun sativum L.) and dill (Antheum graveolens L.) production in Virginia. Three varieties of cilantro and two varieties of dill were used. The experiments were planted on July 28 and August 26 with three nitrogen rates (100, 200, and 300 kg/ha) and fresh weights (30 cm row length from each plot) were recorded periodically during the vegetative growth. Generally, the nitrogen did not affect the yield indicating that soil nitrogen plus 100 Kg of applied nitrogen per hectare was adequate for optimum growth of both cilantro and dill. At 45 days after planting (DAP), C1410 had the highest fresh yield of 1.8 kg/m whereas at 66 DAP the highest yielding variety was 18135 in both plantings (7.1 and 3.1 kg/m, respectively for first and second plantings). The differences between dill varieties were non-significant except with the second planting where Bouquet significantly outyielded Dukat at 70 DAP. The analyses to determine effects of varieties, nitrogen rates, and plant age on chemical properties of cilantro and dill is continuing and will be presented.
DROUGHT RESISTANCE STRATEGIES OF FOUR NATIVE ORNAMENTAL PERENNIALS
Authors: Chapman Douglas S. , Augé Robert M.
Published: April 2024

We characterized the drought resistance of four native ornamental perennials: purple coneflower (Echinacea purpurea), orange coneflower (Rudbeckia fidgida var. Sullivantii), beebalm (Monarda didyma) and swamp sunflower (Helianthus angustifolius). We measured (a) stomatal conductance as leaves dried, (b) lethal water status values and (c) leaf osmotic adjustment during the lethal drying period. Maintenance of stomatal opening as leaves dry, low lethal water status values and ability to osmotically adjust indicate relative drought tolerance, with the reverse indicating drought avoidance. E. purpurea had low leaf water potential (ΨL) and relative content (RWC) at stomatal closure, and low lethal ΨL and RWC. R. fulgida var. Sullivantii had a similar low ΨL at stomatal closure, low lethal ΨL and displayed relatively large osmotic adjustment. M. didyma had the highest ΨL and RWC at stomatal closure and an intermediate lethal ΨL, yet displayed a relatively large osmotic adjustment. H. angustifolius became desiccated more rapidly than the other species despite having a high ΨL at stomatal closure; it had a high lethal ΨL and displayed very little osmotic adjustment. Despite differences in stomatal sensitivity, dehydration tolerance and osmotic adjustment, all four perennials fall predominantly into the drought avoidance category.