Influence of Gibberellic Acid and Gibrel on Fruit Set and Yield in Vaccinium macro-carpon cv. Early Black

The influence of gibberellic acid (GA) and Gibrel on the parthenocarpic development of cranberries (Vaccinium macrocarpon cv. Early Black) was investigated. Application of GA or Gibrel at 25 % bloom, 50 % bloom, 100 % bloom and after bloom resulted in a much higher than normal percentage fruit set and large increases in yield. However, treatment of cranberry vines with these compounds also resulted in an abundance of small, commercially undesirable berries. In addition, application of GA caused abnormal elongation of the vines and inthibited terminal bud development. Gibrel caused only slight vine elongation and did not retard terminal bud development. The possible use of Gibrel in the commercial production of cranberries is discussed.     

Growth, Sex Expression and Yield of Squash Melon (Citrullus vulgarisvar. fistulosus) as Influenced by 2(chloroethyl)phosphonic acid, 2,3,5-tri-iodobenzoic acid and (2-chloroethyl) trimethyl-ammonium chloride

Single aqueous sprays of 2(chloroethyl)phosphonic acid (CEPA) 250, 500 and 1000 mg/1; 2,3,5-triiodobenzoic acid (TIBA) 25, 50 and 100 mg/1; and (2-chloroethyl) trimethyl-ammonium chloride (CCC) 250, 500 and 1000 mg/1 were applied to squash melon (Citrullus vulgaris Schrad. var. fistu-losus Stocks.) at the 2–3 leaf stage. Though the final length of the main axis and number of lateral branches were not affected by any treatment, CEPA retarded growth of young plants by reducing the internodal length. It did not change the flowering pattern but delayed flowering and reduced the production of both pistillate and staminate flowers. However, it increased the per cent femaleness as a result of comparatively more suppression of staminate flowers. The TIBA 25 and 50 mg/1 and CCC 500 mg/1 did not affect the staminate flower production but increased the pistillate flowers, which increased the per cent femaleness. The CEPA decreased while both TIBA 25 and 50 mg/1, and CCC 500 mg/1 increased the number of fruits per plant and the yield. The mode of action of the chemicals has been discussed.     

Kinetics and implications of seedling growth responses to 2-chloroethylphosphonic acid

The effects of soaking seed in 2-chloroethylphosphonic acid (CEPA) for 24 or for 48 h on the cumulative 5-day seedling growth ofCucumis sativus L. (cucumber) andPisum sativum L. (peas) were studied. Each cucumber seed absorbed an average of 0.015 ml of CEPA solution, while pea seed absorbed 0.365 ml, over a 24 h period. In cucumber, 240 mg l^?1 CEPA concentration decreased radicle length by 23%, regardless of soaking duration. The same concentration increased radicle weight in a 24 h soaking duration, but decreased radicle weight when soaking was for 48 h. At 48 h, CEPA concentrations of 0.24 and 2.4 mg l^?1 increased plumule growth by 26%. In peas, the 240 mg l^?1 decreased the length and the weight of both the radicle and the plumule in a 48 h soaking duration, but had no significant effect at a 24 h soaking. At the low concentration of 0.24 mg l^?1, seedling growth was stimulated by over 30%. Cucumber was 3 times more efficient than peas in the utilization of CEPA for seedling growth, in terms of total fresh weight of seedling per microgram of CEPA absorbed: 1 127 and 274 mg μg^?1 CEPA in cucumber and peas respectively. Extrapolative calculation, using cucumber responses as standard, suggests from this seedling study that about 12 mg l^?1 CEPA is likely to stimulate growth and/or yield in sprayed pea plants.     

Effect of waterlogging yam vines on vegetative growth and tuber yield

The effect of waterlogging the vines of two yam varieties for 24, 48 and 72 hours at two stages of growth, with or without fertiliser application, was studied in the field. Waterlogging caused a progressive degeneration of the leaf starting with the development of fresh lesions on the lower leaf surface, through necrotic spots or portions, to complete leaf necrosis. The degree of leaf damage was greater with Um 680 (Dioscorea alata) than with Obiaoturugo (D. rotundata). Waterlogging also caused the breakdown of the apical buds of the vines. The degree of damage increased with the duration of waterlogging. Younger plants suffered more damage than older plants, and plants treated with fertiliser suffered more than plants without fertiliser. Waterlogging ultimately hastened the final senescence of the yam vine. Waterlogging vines for 24 h had no effect on tuber yield, while waterlogging for 48 and 72 h reduced tuber yield by 32.4% and 43.2% respectively (P< 0.01). Waterlogging vines at the early growth stage produced 47.6% (P <0.01) less yield than waterlogging at a later stage. It is suggested that short-term or long-term waterlogging of the yam vine, or parts thereof, is the main cause of reduced leaf area and low yield in unstaked compared with staked yarn crops. Waterlogging may also be a predisposing factor to disease infection of yam vines by soil-borne micro-organisms.     

Influence of temperature and ethephon concentration on growth and composition of Cabernet Sauvignon grapevines

Potted Cabernet Sauvignon grapevines were acclimated to two different temperature regimes (25°C/15°C and 35°C/25°C day/night temperatures, respectively) until 100% bloom, when the vines were treated with either 0, 250, 500, or 750 ppm ethephon (Ethrel^®). Three days after ethephon application all vines were combined and held at 25°C/15°C in a phytotron room for 15 weeks. Growth was suppressed by a greater range of ethephon concentrations at the cool temperature, but effects were shorter-lived than at the high temperature. Generally, the 500 ppm treatment reduced vigor most effectively. The degree to which ethephon influences vine growth is mediated by temperature. Ethephon and temperature treatments caused significant differences in the concentrations of potassium, calcium, and magnesium in leaves.     

Effects of boron fertilization on `Conference' pear tree vigor, nutrition, and fruit yield and storability

The aim of the study was to examine the response of pear (Pyrus communis L.) trees to soil and foliar applications of boron (B). The experiment was carried out during 2000–2001 in a commercial orchard in Central Poland on mature `Conference' pear trees grafted on Pyrus communis var. caucasica seedlings planted at a spacing of 4 × 2.5 m on a sandy loam soil with a low hot water-extractable B status. Annually, foliar sprays with B were applied. (i) before full bloom (at green and white bud stage, and when 1–5% of flowers was at full bloom), (ii) after flowering (at petal fall, and 7 and 14 days after the end of flowering), or (iii) postharvest in fall (approximately 6 weeks before leaf fall). Spray treatments involved application of B at a rate of 0.2 kg ha^–1 in spring or 0.8 kg ha^–1 in fall. Additionally, other trees were supplied with soil-applied B at the bud break stage at a rate of 2 kg ha^–1. Trees untreated with B served as the control. The results revealed that foliar applications of B before full bloom or after harvest increased fruit set and fruit yield. Tree vigor, mean fruit weight, firmness, soluble solids concentration and titratable acidity of fruits at harvest were not affected by B treatments. Foliar B sprays before full bloom or after harvest increased B concentrations in flowers, and both leaves and fruitlets at 40 days after flowering. Only the foliar treatments after flowering and soil fertilization with B increased the content of this microelement in fruit and leaves at 80 and 120 days after full bloom. Foliar B application before full bloom or after harvest increased calcium (Ca) in fruitlets at 40 days after full bloom, in fruit, and in leaves at 80 and 120 days after full bloom. Nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) in plant tissues were not affected by B fertilization. After storage, and also after the ripening period, fruits from the trees sprayed with B before full bloom or after harvest had higher firmness and titratable acidity than those from the control trees. After the ripening period, fruits from the trees sprayed with B before full bloom or after harvest had lower membrane permeability and were less sensitive to internal browning than the control fruits. These findings indicate that prebloom and postharvest B sprays are successful in increasing pear tree yielding and in improving fruit storability under the conditions of low B availability in the soil.     

Phenological resistance of grapes to the green June beetle,an obligate fruit-eating scarab

Changes in fruit characteristics associated with ripening increase the vulnerability of crops to insect depredation, making it difficult for growers to protect cultivated fruits from pest injury close to harvest. This study evaluated phenological resistance, the use of cultivars that ripen before or after peak pest activity, for reducing injury to grapes (Vitis spp.) by the green June beetle (GJB) (Cotinis nitida), an obligate feeder on soft, ripe fruits. Accumulation of sugars, softening of berry skins and recruitment of GJB feeding aggregations were monitored on replicated vines of early-, mid- and late-season ripening cultivars that require from 85 to 125 growing days from bloom to harvest. GJB flight peaked in late July and early August coinciding with later stages of veraison of early-season ripening cultivars which recruited numerous GJB feeding aggregations resulting in >95% crop loss. Small (1–2 weeks) phenological differences between mid-season ripening cultivars and peak GJB flight translated to marked differences in injury, whereas cultivars that ripened in mid-August or later, after GJB flight had waned, sustained little or no damage. Trapping experiments confirmed that the tougher berries and low sugar content of less-ripe fruit clusters inhibited beetle feeding and induction of yeast-mediated volatiles responsible for GJB host-location. Implications of these findings for sustainable or organic management of GJB and other near-harvest fruit pests are discussed.     

Magnesium deficiency of kiwifruit (Actinidia deliciosa)

Magnesium deficiency was associated with large yield reductions in a five-year-old commercial kiwifruit (Actinidia deliciosa) orchard. The effect on yield resulted primarily from a reduction in fruit numbers, there being no difference in mean fruit weight between fruit harvested from affected and unaffected vines. Magnesium deficiency had no deleterious effect on postharvest storage characteristics of fruit stored at 0.5–1°C for 18 weeks; fruit from deficient vines were firmer but had slightly lower soluble solids than fruit from control vines. Although deficiency symptoms were first observed on the basal leaves of the non-fruiting shoots mid season, indications of the impending deficiency could be established very early in the season using foliar analysis. Magnesium concentrations in youngest fully expanded leaves (YFEL) on the affected vines were less than 2.0 g kg⁻¹ DM four weeks after budbreak and remained below this value for the rest of the season; concentrations in YFEL on unaffected vines did not decrease below this value and gradually increased after fruitset to 4.5 g kg⁻¹ DM at harvest. To avert potential production losses, it is suggested that soluble magnesium fertilizers (containing at least 200 kg ha⁻¹ Mg) should be broadcast early in the season if foliar magnesium concentrations less than 2.0 gkg⁻¹ DM are measured four–six weeks after budbreak.     

Brassinosteroids Modify Yield,Quality, and Antioxidant Components in Grapes (Vitis vinifera cv. Alphonse Lavallée)

Brassinosteroids (BRs) are a class of polyhydroxysteroids that have been recognized as a “sixth class of plant hormones.” Exogenous application of BRs affects a broad spectrum of physiological responses, secondary metabolite accumulation, and resistance against stress factors in plants. In this study, the effects of pre-harvest 24-epibrassinolide (24-eBL) applications on the accumulation of antioxidant compound, yield, and quality properties of Alphonse Lavallée grape cultivar were examined. 24-eBL was applied to vines with 13 combinations including different application times and concentrations of 24-eBL (0.2, 0.4, 0.6, and 0.8 mg L⁻¹) and control. It was found that 24-eBL increased yield, quality, and antioxidant compounds in grapes when it was applied at appropriate concentration and application time. The concentration 0.2 mg L⁻¹ of 24-eBL applied to vines at three times (7 days after berry set + veraison + 30 days after veraison) was the most suitable application providing the highest yield and some quality properties such as cluster weight, berry weight, and specific gravity. Concentrations 0.6 and 0.8 mg L⁻¹ of 24-eBL applied at veraison to vines can be suggested for total phenolics, β-carotene, ascorbic acid, and trans-resveratrol accumulation for Alphonse Lavallée as a practical application, while the application consists of 0.6 mg L⁻¹ of 24-eBL and 7 days after berry set + veraison + 30 days after veraison seems to be the best treatment for anthocyanin content.

     

Influence of some metal ions on the lipid content and arachidonic acid production byMortierella sp.

The influence of Ca²⁺, Mg²⁺, Mn²⁺, and Fe²⁺ ions on lipid accumulation, fatty acid composition and arachidonic acid (ARA) production byMortierella sp. S-17 was investigated. A beneficial effect of Mn²⁺ in the concentration range of 2–500 mg/L on lipogenesis was observed. The other elements at about 1 g/L repressed lipid accumulation and ARA yield. The highest yield of ARA (723 mg per liter or 148 mg per gram of dry mycelium) after incubation of the fungus in a glucose medium in the presence of 2 mg Mn²⁺ per liter was obtained. A strong inhibitory effect of Fe²⁺ (above 40 mg/L) on ARA formation was observed.     

Effects of 2-Chloroethyl Trimethylammonium Chloride (CCC) and 2-Chloroethylphosphonic Acid (CEPA) on Dry Matter Distribution in the Cowpea (Vigna Unguiculata L.)

Effects of foliar applications of CCC and CEPA on dry matterdistribution in two cowpea cultivars which exhibit differentdegrees of premature abscission of fruits were investigated.At the concentration of 0-1 mg1^–1, CCC increased stemweight in the cultivar Adzuki, but had no effect on the cv.Mala (which exhibits a relatively high degree of premature abscission).While CCC did not significantly influence root weight in Adzuki,the concentrations of 1 and 10 mg 1^–1 increased root weightin Mala. In both cultivars, the 1000 mg1^–1 treatment decreasedseed weight, with a greater decrease in Adzuki. All concentrations of CEPA, up to 1000 mg 1^–1, decreasedstem and root weights in Mala, and leaf weight in Adzuki. The10 mg1^–1 concentration increased seed weight in Mala by100 percent, and leaf weight by 28 percent, without any significanteffect on pod weight, or on the weight of the whole plant. Therewas also no increase in pod number. Overall, Mala was more responsive than Adzuki to the growthregulators, particularly CEPA. In the low concentration responses,CEPA increased seed weight not by increasing gross plant weight,but mainly by causing a change in distribution of dry matter.     

Phytoplankton primary production,chlorophyll and species composition,organic carbon and turbidity in the Marsdiep in 1990, compared with foregoing years

Annual primary production in 1990 in the Marsdiep amounted to about 250 g C.m^–2, which is lower than during the mid 1980s, but still higher than the about 150 g C.m^–2a^–1 measured during the 1960s and early 1970s. The annual curve shows a clear spring peak and a broad but lower summer peak. Chloropyll-a showed a similar annual curve, the maximum of 35 mg.m^–3 during the spring peak, as well as the annual average of 6 mg.m^–3 were lower than during the late 1970s and the 1980s. Organic carbon values for 1990 were similar to those observed in 1978 to 1984. Turbidity (at high tide) at our sampling station did not change over the period 1973 to 1990. The high winter temperature of 1989/90 did not influence the timing of the phytoplankton spring bloom. The diatom spring peak is better related to light. With more light in spring and clearer water, the peak occurs earlier. The trend of an increase of the period of occurrence ofPhaeocystis continued.Phaeocystis colonies and single cells were present almost the year round, however, the maximum cell numbers ofPhaeocystis (80,000 ml^–1) was relatively low. Newly formed colonies on spines of diatoms (Chaetoceros sp.,Bacteriastrum hyalinum) were observed in autumn. Its life-cycle remains enigmatic.Rhizosolenia indica, a warm water species, was observed for the first time in net-plankton samples, it occurred from September to December 1990.     

Climate change and the phytoplankton spring bloom: warming and overwintering zooplankton have similar effects on phytoplankton

Indoor mesocosms were used to study the combined effect of warming and of different densities of overwintering mesozooplankton (mainly copepods) on the spring development of phytoplankton in shallow, coastal waters. Similar to previous studies, warming accelerated the spring phytoplankton peak by ca. 1 day °C^?1 whereas zooplankton did not significantly influence timing. Phytoplankton biomass during the experimental period decreased with warming and with higher densities of overwintering zooplankton. Similarly, average cell size and average effective particle size (here: colony size) decreased both with zooplankton density and warming. A decrease in phytoplankton particle size is generally considered at typical footprint of copepod grazing. We conclude that warming induced changes in the magnitude and structure of the phytoplankton spring bloom cannot be understood without considering grazing by overwintering zooplankton.     

Paraoxonase responses to exercise and niacin therapy in men with metabolic syndrome

Abstract

Our purpose was to characterize changes in paraoxonase 1 (PON1) activity and concentration after single aerobic exercise sessions conducted before and after 6 weeks of niacin therapy in men with metabolic syndrome (MetS). Twelve men with MetS expended 500 kcal by walking at 65% of VO_2max before and after a 6-week regimen of niacin. Niacin doses were titrated by 500 mg/week from 500 to 1500 mg/day and maintained at 1500 mg/day for the last 4 weeks. Fasting blood samples were collected before and 24 hours after each exercise session and analyzed for PON1 activity, PON1 concentration, myeloperoxidase (MPO), apolipoprotein A1, oxidized low-density lipoprotein (oLDL), lipoprotein particle sizes and concentrations. PON1 activity, PON1 concentration, MPO, and oLDL were unaltered following the independent effects of exercise and niacin (P > 0.05 for all). High-density lipoprotein particle size decreased by 3% (P = 0.040) and concentrations of small very low-density lipoprotein increased (P = 0.016) following exercise. PON1 activity increased 6.1% (P = 0.037) and PON1 concentrations increased 11.3% (P = 0.015) with the combination of exercise and niacin. Exercise and niacin works synergistically to increase PON1 activity and concentration with little or no changes in lipoproteins or markers of lipid oxidation.     

Daily egg production ofTemora longicornis (Copepoda,Calanoida) during winter and early spring in the Marsdiep (Southern North Sea)

Mature females of the copepodTemora longicornis from the Marsdiep tidal inlet were incubated at ambient water temperature during the winter of 1989/1990 to estimate their egg production during 24 hours. Throughout winter this production remained at a level of 0 to 10 eggs per female. In March a steep rise to 60 to 80 eggs coincided with an equally steep rise in chlorophyll-a from 4 to 20 g.l^–1. Excess food given during incubation tended to increase the observed production rate only in October at relatively high temperature. Additive effects of rising food level and temperature on daily egg production were found in spring. In March and April 1988 and 1990 the observed maximum daily egg production per female increased from about 20 at 5°C and 5 g.l^–1 chlorophyll to 70 at almost 10°C and 20 g.l^–1. The egg production in winter gives a prebloom potential to maintain a stock of premature stages ready to utilize the algal spring bloom. Early spawning before April can also contribute to the development of the abundance peak of adults in May–June. Due to growth rates increasing with temperature in the months March and April, most of the adults at their peak density may have hatched from eggs before the period of maximum egg production rate at the end of April. The exceptionally high production rate observed at the end of March may be related to a developingPhaeocystis bloom.     

An unusual bloom of the dinoflagellate Akashiwo sanguinea off the central Oregon, USA, coast in autumn 2009

An algal bloom caused by the dinoflagellate Akashiwo sanguinea was observed in October–November 2009 along the central Oregon coast (44.6°N), off Newport, Oregon, U.S.A. In this paper, the conditions are described which led to the development and demise of this bloom. The bloom was observed for 1 month from 5-October until 4-November with the peak of abundance on 19-October (347,615 cells L⁻¹). The A. sanguinea bloom followed September blooms of the diatoms Pseudo-nitzschia spp, Chaetoceros debilis, and the dinoflagellate Prorocentrum gracile. The bloom occurred when nitrate and silicate concentrations were <2 μM and <8 μM, respectively, and when the water column was stratified. This A. sanguinea dinoflagellate bloom event was closely related to the anomalous upwelling conditions in 2009: upwelling ceased early, at the end of August, whereas a normal upwelling continues into early October. This relaxation extended to near the end of September as a prolonged downwelling event, but then active upwelling reappeared in October and November. The explanation for the occurrence of the A. sanguinea bloom in October may be related to a combination of a prior diatom bloom, a stratified water column with low nutrient concentration in September, and an active upwelling event in October. As for the ultimate source of the cells, the hypothesis is that the seed stock for the A sanguinea bloom off Oregon was southward transport of cells from the Washington coast where a massive bloom of A. sanguinea was first observed in September 2009.     

Effects of 2-Chloroethylphosphonic Acid on Growth, Plastid Pigments, and Sucrose Translocation in Radish

2-Chloroethylphosphonic acid (CEPA) caused a significant declinein chlorophyll content of radish plant within 5 d of treatment.Such effects were greater when plants were treated at the two-than at the four-leaf stage. In early treated plants, concentrationof CEPA increasing from 20 mg/1 progressively increased leafweight, while decreasing root (radish) weight. A concentrationof 10 mg/1, applied at the three-leaf stage, increased leafand root weights by 27 and 30 per cent respectively in the cultivar‘Cavalier’. Similar responses were obtained withthe cultivar ‘Cherry Belle’. While Cavalier showeda discrete 10 mg/1 optimum, ‘Cherry Belle’ exhibiteda range of concentrations (10-40 mg/1) optimal for growth. At relatively high concentrations, early application of CEPAcaused inverse changes in sucrose-¹⁴C in the leaves and theroot, so that decreased retention by leaves was accompaniedby increased transport to roots. Low concentrations of CEPAappear promising for growth stimulation in root-crop plants.     

Temporal variations in phytoplankton, particulates, and colored dissolved organic material based on optical properties during a Long Island brown tide compared to an adjacent embayment

Since 1985, the coastal embayments of Long Island, New York, have been plagued with recurrent blooms, aptly called brown tides, of the pelagophyte Aureococcus anophagefferens. The distinct ocean color observed during these blooms suggests that optical methods can be used as a tool to study, detect, and track brown tides. Thus, the goal of our project was to compare the optical properties and pigment composition during bloom and non-bloom conditions and assess temporal variations in the phytoplankton and other constituents in the seawater associated with bloom development. From 17 May to 8 June 2000, we measured a time series of particle size distributions and concentrations as well as size-fractioned algal pigments and optical properties in two Long Island embayments where brown tides are known to occur. During our study, A. anophagefferens represented an insignificant contribution to the algal community in West Neck Bay (WNB), whereas a bloom developed in Quantuck Bay (QB). Initially, temperature and salinity were similar at the two locations; however, bulk optical properties, chlorophyll, and particle concentrations were nearly a factor of 2 greater at QB. Bulk optical properties remained constant at WNB, yet increased exponentially at QB as the bloom developed. The composition of particulates, including phytoplankton, varied little at QB, and the optical properties suggested the dominance of A. anophagefferens (confirmed by microscopy). The largest temporal variations were observed in the colored dissolved organic material (CDOM); the colloidal (0.2–0.7 μm) fraction, exhibiting a strong protein-like signal, increased dramatically at the height of the bloom. At WNB particle sizes and algal composition varied despite the invariant bulk optical properties; CDOM variations were minimal. Overall, the optical properties in the two bays demonstrated that at QB temporal variations were dominated by biomass and colloidal protein changes, whereas shifts in the algal community occurred at WNB. This study demonstrates the utility of in situ optical observations to resolve temporal changes in the ecological conditions associated with algal bloom development.     

喷施硅对蒙古黄芪抗氧化酶活性以及产量和品质的影响北大核心CSCD

以蒙古黄芪为试验材料,设置大田随机区组试验,研究苗期、开花期和根茎伸长期叶面喷施不同浓度硅(500、1000、2000和4000 mg/L)对蒙古黄芪生长发育、抗氧化酶活性、药材产量和品质的影响,并检测施硅对黄芪白粉病、根腐病的防治效果,以揭示硅对增强黄芪抗病性、提升品质和产量的影响机理,为生产中蒙古黄芪的高效栽培提供理论依据。结果表明:(1)在不同生育时期,喷施不同浓度硅能增加蒙古黄芪株高、茎粗、株幅和叶绿素含量,促进蒙古黄芪生长,并以2000 mg/L硅处理效果较佳。(2)不同生育时期喷施硅能提高蒙古黄芪叶片SOD、CAT、POD和APX等抗氧化酶活性,降低MDA含量,以开花期、根茎伸长期2000 mg/L硅处理较佳。(3)施硅能有效降低蒙古黄芪白粉病、根腐病的病情指数,当施硅浓度为2000 mg/L时防效均达到最高,并分别达到47.05%和39.08%。(4)施硅处理能有效提高蒙古黄芪单株干、鲜生物量、产量以及可溶性浸出物和黄芪甲苷含量等品质指标,并在2000 mg/L硅浓度处理下均达到最佳水平,此时可溶性浸出物和黄芪甲苷含量分别比对照显著提高了16.48%和31.96%。研究发现,叶面喷施适宜浓度硅可显著增强蒙古黄芪对白粉病、根腐病的抗性,促进植株生长,进而显著提高药材产量,改善药材品质,并以硅浓度为2000 mg/L时效果最佳。