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Oleracea L. (oleracea + l)
Kinds of Oleracea L. Selected AbstractsImpact of avian and arthropod predation on lepidopteran caterpillar densities and plant productivity in an ephemeral agroecosystemECOLOGICAL ENTOMOLOGY, Issue 5 2003Cerruti R. R. Hooks Abstract., 1.,Most studies evaluating the combined impact of spiders and other predators on herbivore densities in agroecosystems have focused primarily on their trophic connections with invertebrate predators (e.g. carabids, chrysopids); however linkages among spiders and vertebrate predators may also help structure the population dynamics of insect herbivores. A field experiment was conducted to examine the impact of avian and spider predation on lepidopteran caterpillar densities and plant productivity within a Brassica agroecosystem. 2.,Arthropod abundance, leaf-chewing damage, and final plant productivity associated with broccoli, Brassica oleracea L. (var. italica), were recorded for four treatments: (1) bird present but spiders removed; (2) both birds and spiders present; (3) birds excluded, spiders present; and (4) birds and spiders both excluded. 3.,Densities of Artogeia rapae L. (Lepidoptera: Pieridae) and Trichoplusia ni Hübner (Lepidoptera: Noctuidae) large caterpillars and post feeding stages were reduced significantly by bird predation. The abundance of large caterpillars was also reduced on spider-inhabited plants during early plant growth; however the assemblage of birds and spiders did not suppress caterpillar densities more significantly than either predator alone. 4.,Plants protected by birds, spiders, and birds plus spiders sustained less folivory attributable to leaf chewing caterpillars than check plants. Plant productivity was also greater for predator-protected plants than check plants. 5.,Although spiders and parasitoids were responsible for some of the mortality inflicted upon lepidopteran caterpillars, it was concluded that in this study system, birds are the most important natural enemies of folivores. [source] Effects of shade nettings, sowing time and storage on baby spinach flavonoidsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2007Sara ÅM Bergquist Abstract Flavonoids are important in plant interactions with the environment and may have positive effects on human health. Effects of light quality and quantity on flavonoid concentration were studied in baby spinach (Spinacia oleracea L.) cultivated under three types of shade netting differing in transmittance of UV-B and PAR, at two times during the season. Leaves harvested at two growth stages for each sowing were subjected to different post-harvest storage conditions. Shade nettings had a relatively small effect on flavonoid concentration in baby spinach. The largest effect was found when radiation was most intense. The nettings then decreased total flavonoid concentration by 15,24% at the normal commercial growth stage at harvest. Radiation and plant growth both affected flavonoid concentration, in opposite or similar directions depending on time of season. This variation was reflected in the statistical analysis, showing significant interactions among the factors. There were large differences (up to 100%) in flavonoid concentration between the different times of the season, in shaded as well as unshaded spinach. Flavonoid concentration and composition changed during storage, but no consistent difference was found between the shaded and unshaded leaves. In most cases, total flavonoid concentration increased significantly during the first 6 days of storage. In conclusion, the use of shade netting is acceptable for production of baby spinach as regards flavonoid concentration and composition. Copyright © 2007 Society of Chemical Industry [source] Influence of growth stage and postharvest storage on ascorbic acid and carotenoid content and visual quality of baby spinach (Spinacia oleracea L.)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2007Sara ÅM Bergquist No abstract is available for this article. [source] Influence of growth stage and postharvest storage on ascorbic acid and carotenoid content and visual quality of baby spinach (Spinacia oleracea L.)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2006Sara ÅM Bergquist Abstract To investigate the variations in quality with growth stage and postharvest storage, spinach was sown on three occasions. For each occasion, the spinach was harvested at three growth stages at 6-day intervals. The second stage corresponded to a growth period used for baby spinach by commercial growers. After harvest, the leaves were stored in polypropylene bags at 2 °C or 10 °C. The highest ascorbic acid content in fresh material was found at stage I. During storage, the ascorbic acid content decreased considerably and the dehydroascorbic acid/vitamin C ratio increased. Storage at 2 °C gave a smaller reduction in ascorbic acid content than storage at 10 °C. Total carotenoid content increased or remained stable during storage. Lutein was the major carotenoid, making up about 39% of the total carotenoid content, followed by violaxanthin, ,-carotene and neoxanthin. Visual quality decreased during storage in most cases, and was correlated to initial ascorbic acid and dry matter contents. The initial AA content might therefore be used as a parameter for predicting the shelf-life of baby spinach. The results also indicate that by harvesting baby spinach a few days earlier than the current commercial stage of harvest the postharvest visual quality and nutritional quality may be improved. Copyright © 2005 Society of Chemical Industry [source] Application timing and efficacy of alternatives for the insecticidal control of Tipula paludosa Meigen (Diptera: Tipulidae), a new invasive pest of turf in the northeastern United StatesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2008Daniel C Peck Abstract BACKGROUND: Two invasive crane flies, Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae), were detected in New York State for the first time in 2004. Both are damaging pests of turfgrass and other horticultural systems in North America where establishment has already been documented. To develop management recommendations for the Northeast and define opportunities for preventive (autumn) and curative (spring) control, four insecticide trials targeting T. paludosa larvae were conducted over a 2 year period. RESULTS: The most efficacious (,70% control in both trials) products against early instars in autumn were bifenthrin, carbaryl, chlorantraniliprole, clothianidin and trichlorfon. Results varied for azadirachtin, Beauveria bassiana, cyfluthrin, dinotefuran, imidacloprid, imidacloprid + bifenthrin and indoxacarb. Clothianidin and dinotefuran were most efficacious against fourth instars in spring; results varied for imidacloprid, indoxacarb and trichlorfon. CONCLUSION: Several insecticides offer alternatives for preventive and curative control of T. paludosa, but, because there is little overlap with application windows for scarab larvae pests, management may entail an entirely new insecticide treatment window, implying new economic and environmental burdens to the turfgrass industry. Moreover, curtailing the impact and spread of these invasives may be severely hampered because the best performing alternatives (clothianidin, dinotefuran) are not registered in New York. Copyright © 2008 Society of Chemical Industry [source] Interaction between metabolism of atmospheric H2S in the shoot and sulfate uptake by the roots of curly kale (Brassica oleracea)PHYSIOLOGIA PLANTARUM, Issue 4 2000Sue Westerman Exposure of curly kale (Brassica oleracea L.) to gaseous H2S resulted in a decreased sulfate uptake by the roots. At 0.2 ,l l,1 H2S, a level sufficient to meet the sulfur need of plants for growth, the sulfate uptake was maximally decreased by 50% after 3 or 4 days of exposure. Higher levels up to 0.8 ,l l,1 H2S did not further affect the sulfate uptake. The nitrate uptake was not affected upon exposure to 0.2,0.8 ,l l,1 H2S. H2S exposure did not affect the sulfate content of the plants, but it resulted in an increased content of thiols and cysteine in the shoots, whereas that in the roots was hardly affected. Plants grown under sulfate-deprived conditions had a decreased biomass production, very low content of sulfate and decreased content of thiols in both shoot and roots. Sulfate-deprived plants had a two-fold higher sulfate uptake after transfer to a sulfate-containing solution, while nitrate uptake was decreased by 50%. When sulfate-deprived plants were exposed to 0.25 ,l l,1 H2S, plant biomass production and nitrate uptake were restored but the sulfate uptake after transfer to a sulfate-containing solution remained high. Also here, H2S exposure resulted in an increase in the thiol and cysteine content of both shoot and roots, whereas the content of sulfate remained low. The presented results clearly demonstrate a direct interaction between the regulation of sulfate uptake by the roots and the metabolism of gaseous H2S by the shoot. Curly kale is able to use both sulfate and H2S as a sulfur source for growth, and matching the supply of sulfur in the form of pedospheric or atmospheric sulfur to the sulfur needed for growth appears to be regulated nicely. However, the significance of thiols as signal in the shoot/root coordination of sulfate uptake appears to be limited. From the data it is evident that there is no direct mutual regulation between the uptake of sulfate and nitrate by the roots. [source] Molecular characterization of novel resynthesized rapeseed (Brassica napus) lines and analysis of their genetic diversity in comparison with spring rapeseed cultivars,PLANT BREEDING, Issue 6 2003F. Seyis Abstract Resynthesized (RS) rapeseed generated from interspecific hybridization between suitable forms of Brassica rapa L. (syn. campestris; genome AA, 2n = 20) and B. oleracea L. (CC, 2n = 18) represents a potentially important resource to expand genetic diversity in the narrow gene pool of oilseed rape (B. napus L., AACC, 2n = 38). In this study 165 RS rapeseed lines originating from crosses between an Indian Yellow Sarson (B. rapa ssp. trilocularis) and five different cauliflower (B. oleracea convar. botrytis) cultivars were studied using amplified fragment length polymorphism (AFLP) markers and their genetic diversity was compared in relationship to an assortment of 40 diverse spring oilseed and fodder rape varieties. Using three AFLP primer combinations, a total of 467 polymorphic bands were scored. Cluster analysis allowed differentiation among the different RS lines, which, as expected, were genetically highly divergent from the cultivars. The genetic diversity of the material is discussed in relation to its morphological variability with a view to the implementation of RS lines in oilseed rape breeding. [source] Seed germination ecology of Portulaca oleracea L.: an important weed of rice and upland cropsANNALS OF APPLIED BIOLOGY, Issue 1 2009B.S. Chauhan Abstract Portulaca oleracea, a C4 species, is reported to be a serious weed in 45 crops in 81 countries. Experiments were conducted in the laboratory, the screenhouse and the field to determine the influence of environmental factors on seed germination and seedling emergence of P. oleracea. In the laboratory, germination in the dark was low and was not influenced by the tested temperatures (35/25°C, 30/20°C and 25/15°C alternating day/night temperatures). In the light/dark regime, however, germination was lower at 25/15°C and 35/25°C than at 30/20°C (70%, 75% and 81% germination, respectively). In conditions of 106 mM sodium chloride or ,0.34 MPa osmotic potential, seeds germinated to only 50% of maximum germination of the control. Germination was not influenced by buffered pH solutions ranging from 5 to 9. In the screenhouse, germination was greatest for seeds placed on the soil surface, but emergence declined with increasing seed burial depth in soil; no seedlings emerged from the depth of 2 cm. Seedling emergence and seedling dry matter were markedly reduced by the addition of rice residue to the soil surface at rates equivalent to 4 to 6 t ha,1. In the field, seedling emergence of P. oleracea was greater under zero till (ZT) (17,20%) than under minimum tillage (6,10%), a likely reflection of low seed burial and exposure of seeds to light with a ZT system. This study identifies some of the factors enabling P. oleracea to be a widespread weed in the humid tropics, and the information could contribute to improved control strategies. [source] Phytoecdysteroid C2-hydroxylase is microsomal in spinach, Spinacia oleracea L.,ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009Ahmed Bakrim Abstract An enzyme involved in the biosynthesis of phytoecdysteroids, the C2-hydroxylase, has been investigated in spinach, Spinacia oleracea. This enzyme is microsomal and its Km has been determined using 2-deoxy-20-hydroxyecdysone as substrate (Km=3.72,µM). It is much more efficient with 2-deoxy-20-hydroxyecdysone than with 2-deoxyecdysone and, conversely, the C20-hydroxylase is more active on 2-deoxyecdysone than on ecdysone. These data support the conclusion that C20-hydroxylation precedes C2-hydroxylation. The C2-hydroxylase is inhibited by high concentrations of 20E. Substrate specificity and subcellular localization of C2-hydroxylase differ between plants and insects, and these data, as well as those previously reported on other biosynthetic steps, show the great difference between plant and insect ecdysteroid biosynthetic pathways and suggest an independent origin for the pathways in both kingdoms. © 2009 Wiley Periodicals, Inc. [source] | |||||||||||||