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991.
ABSTRACT

Three field experiments at three sites in east Zhejiang Province were conducted to determine the influence of applications of boron (B) on growth, yield, and quality of the red bayberry trees (Myrica rubra Sieb. et Zuca) with a manure species of “Buqizhong” in Linhai city. Ground B application or foliar B spraying significantly improved length and incidence rates of spring and summer shoots and increased fruit set rates, which resulted in the increases in fruit yield (13.7–17.5% for ground B application or 13.2–27.3% for foliar B spraying) and in improvement of fruit quality. The optimum yields were recorded with the treatments of ground B application of 40 g tree?1 of borax or foliar B spraying of 2.0 g L?1 of borax. Spring shoot incidents for the treatment of ground application of 50 g borax tree?1 every year during the experiment (4B50) were significantly higher than that for the treatment of ground application of 50 g borax tree?1 only in the first year of the experiment (B50), but the yield difference between them was not significant at P = 0.05. The increased yield effect of ground B application could last for 3 years. Boron application of red bayberry trees can be carried out by foliar-spraying 2.0 g borax L?1 every year or ground application of 50 g borax tree?1 every 3 years. The results of this study showed that application B could significantly improve the growth and increased fruit yield and quality of the red bayberry trees not exhibiting any vegetative symptoms of B deficiency.  相似文献   
992.
ABSTRACT

A pot experiment was conducted in a greenhouse on a calcareous soil (fine, mixed, mesic, Fluventic Haploxerepts) to study the interaction of zinc (Zn) and boron (B) on the growth and nutrient concentration of corn (Zea mays L.). Treatments consisted of a factorial arrangement of seven levels of B (0, 2.5, 5, 10, 20, 40, and 80 mg kg? 1as boric acid), two sources of Zn [zinc sulfate (ZnSO4 · 7H2O) and zinc oxide (ZnO)], and three levels of Zn (0, 5, and 10 mg kg? 1) in a completely randomized design with three replications. Plants were grown for 70 d in 1.6 L plastic containers. Applied Zn significantly increased plant height and dry matter yield (DMY) of corn. Source of Zn did not significantly affect growth or nutrient concentration. High levels of B decreased plant height and DMY. There was a significant B × Zn interaction on plant growth and tissue nutrient concentration which were rate dependent. In general, the effect of B × Zn interaction was antagonistic on nutrient concentration and synergistic on growth. It is recommended that the plants be supplied with adequate Zn when corn is grown in high B soils, especially when availability of Zn is low.  相似文献   
993.
《Journal of plant nutrition》2013,36(10-11):2043-2056
Abstract

Iron chelators are the most effective Fe fertilizers known to date. However, due to their negative charge they are easily leached out of the root zone. Besides the risk of groundwater contamination with organic compounds and metals, repeated applications of expensive Fe chelates are often required. With the aim to reduce leaching, desferrioxamine B (DFOB) and ethylenediaminedihydroxyphenylacetic acid (EDDHA) were immobilized on Sepharose and tested as Fe sources to plants. Two cultivars of cucumber (Dlila and Kfir) grown in hydroponic cultures at pH 7.3, efficiently utilized Fe from immobilized FeDFOB, and immobilized FeEDDHA. In general, plant response to the immobilized fertilizers became comparable to that of soluble chelates within a period of 17 to 26 days. The kinetics of alleviating Fe induced chlorosis in plants treated with the immobilized chelates was slower than that obtained with soluble chelates. Moreover, the Fe3+ reduction rates obtained for immobilized FeDFOB were slower than those measured for soluble FeDFOB. Our observations suggest that immobilized FeDFOB can serve as a slow release Fe fertilizer. The slow kinetics of reduction and uptake from the immobilized as compared to the soluble chelates can be attributed to the lower accessibility to the plant's roots.  相似文献   
994.
A field experiment was conducted during the summer season of 2009 and 2010 at Vivekananda Parvatiya Krishi Anusandhan Sansthan, Hawalbagh, Almora, Uttarakhand, under the mid-hills of north-western Himalaya, to study the effect of farmyard manure and fertilizers on fruit yield, economics, energetics of pepper (Capsicum annuum L.) and on soil chemical properties. The highest level of farmyard manure (20 t ha?1) along with 125% of recommended NPK (125, 27.5, and 52.1 kg N, P and K ha?1) resulted in significantly higher fruit yield (33.9 t ha?1) over other combinations. Both farmyard manure and inorganic fertilizers significantly increased fruits/plant, average fruit weight, plant height, fruit length, and fruit diameter. The maximum net returns (4520 $ ha?1) was achieved at 20 t of FYM along with 125% of recommended NPK. Energy ratio of 1.29 and 1.13 was the highest under 20 t FYM ha?1 and 125% of recommended NPK, respectively. Available nutrients (N, P, and K) improved the status of the soil significantly due to 20 t ha?1 of FYM and 125% of recommended NPK over other treatments.  相似文献   
995.
Investigation of the Red Sea sponge Negombata magnifica gave two novel alkaloids, magnificines A and B (1 and 2) and a new β-ionone derivative, (±)-negombaionone (3), together with the known latrunculin B (4) and 16-epi-latrunculin B (5). The analysis of the NMR and HRESIMS spectra supported the planar structures and the relative configurations of the compounds. The absolute configurations of magnificines A and B were determined by the analysis of the predicted and experimental ECD spectra. Magnificines A and B possess a previously unreported tetrahydrooxazolo[3,2-a]azepine-2,5(3H,6H)-dione backbone and represent the first natural compounds in this class. (±)-Negombaionone is the first β-ionone of a sponge origin. Compounds 1-3 displayed selective activity against Escherichia coli in a disk diffusion assay with inhibition zones up to 22 mm at a concentration of 50 µg/disc and with MIC values down to 8.0 µM. Latrunculin B and 16-epi-latrunculin B inhibited the growth of HeLa cells with IC50 values down to 1.4 µM.  相似文献   
996.
The accumulation of phenolic acids in soil is one of the main problems associated with continuous cropping of peanut. Although laccases secreted by fungi can efficiently transform phenolic acids, there are few reports on the use of these enzymes to bioremediate continuous cropping soil. Food waste and wheat straw are waste products; however, they could be used productively as resources for laccase production by the endophytic fungus Phomopsis liquidambari B3. We cultured Phomopsis liquidambari B3 in medium containing food waste as the main nitrogen source and wheat straw as the main carbon source. In order to study the effects of fermentation liquid on phenolic acid degradation, rhizosphere soil microbial communities and peanut seedling growth, the fermentation product, which had high laccase activity, was added to continuously cropped soil of peanut. The concentration of 4-hydroxybenzoic acid, vanillic acid, and coumaric acid in soil had decreased by 57.4, 52.5, and 49.4%, respectively, compared with no-treatment control during 28 days. Analysis of denaturing gradient gel electrophoresis profiles showed that the bacterial and fungal community structures in rhizosphere soil were affected by changes in the phenolic acids concentration. The biomass of peanut plants and the number of root nodules were increased 68.3% and 5.9-fold, respectively. These results showed that the laccase product reduced the accumulation of phenolic acids in soil, the decrease in phenolic acids concentration and the increase in certain dominant microorganisms promoted peanut seedling growth and nodulation. This technology provides a new strategy for bioremediation of continuous cropping soil, while simultaneously reducing waste and protecting the environment.  相似文献   
997.
土壤有机营养对“红富士”苹果果实产量和品质的影响   总被引:3,自引:1,他引:2  
通过野外调查与室内分析相结合,运用相关分析和通径分析等统计方法,研究苹果园土壤有机酸、 单糖、 B族维生素的含量与苹果果实品质和产量的关系。结果表明,土壤阿拉伯糖、 烟酰胺、 柠檬酸与果实有机酸含量呈极显著正相关,相关系数分别为0.621、 0.648、 0.587; 阿拉伯糖、 柠檬酸和维生素B2与果实可溶性糖含量通径系数大,为1.123、 0.668、 0.757,是影响可溶性糖含量的主要正因子,土壤草酸含量与其通径系数为负值(-0.558); 核糖和鼠李糖与果实花色苷的通径系数最大,为0.706、 0.644,而乙酸和草酸对花色苷形成有负影响,通径系数为-0.765、 -0.664; 三类土壤有机营养与果实维生素C含量的正相关性都极为显著;果实可溶性固形物与酒石酸、 维生素B6含量呈极显著正相关,相关系数为0.682、 0.613;土壤糖类与果实硬度大小呈负相关,与果实的大小呈显著正相关; 阿拉伯糖、 核糖、 维生素B2和乳酸与果树产量的通径系数及相关系数明显,是影响果树产量的主要因素。  相似文献   
998.
A common garden crop grown in the coastal plain region of North and South Carolina (United States) is the non-heading, leafy green type of Brassica oleracea L. known as collard (B. oleracea L. subsp. oleracea convar. acephala (DC.) Alef. var. viridis L.). Predominantly a fall and winter vegetable in this region, collard is often the only green planting to be found in the yard or garden of a rural home during these cool seasons. Historically, the traditional collard patch and even commercial fields were planted with unique varieties perpetuated by individual seed savers, and collectively, the regional diversity for this crop was probably very significant for well over a century. Genetic erosion of this collard germplasm pool has been severe in recent decades as commercial hybrids have been adopted by both large-scale producers and home gardeners. Although a significant number of collard landraces are being perpetuated to this day, existing diversity among landraces still grown in the region is now in the hands of an aging population of seed savers who maintain germplasm through on-farm preservation. From 2003 to 2006, we explored the coastal plain region of North and South Carolina in search of collard gardens containing traditional landraces. Exploration trips were conducted mid-winter to early spring. About 90 samples of collard were obtained from seed savers during the course of this exploration. Observations of morphological differences of these landraces indicate that significant diversity exists in this group. Obtained landraces are being deposited into the U.S. plant introduction collection and will be available for future use. This preserved collection could prove to be an important new source of genes for B. oleracea improvement.  相似文献   
999.
For the countries struggling with climate change, sustainable forestry is one of the greatest challenges and is difficult to define, implement, and to measure. According to the scientific community’s consensus on climate change, forests are one of the major sinks and sustainable forest management (SFM) is needed to prevent deforestation and its negative effects on natural ecosystems. Despite being a party to many international treaties/agreements related to land use policies (LUP) that are promoting SFM to protect and develop forest resources, the 2/B application in Turkish forest legislation has been causing deforestation in Turkey since the 1970s.

In this study, 2/B applications–political and legal process–causing deforestation by land use change (LUC) are investigated by carrying out a legal analysis. About 500.000 ha of forests have been lost due to the 2/B application and as a LUP directly affects SFM, carbon sequestration capacities (CSC), and therefore, climate change. To exemplify this pre and post-LUC change and effect, the amount of carbon that was prevented from being absorbed as 176,7 tonnes/ha on average in a given forest area for the year 2016. There is a vital need to address the negative effects of ill-defined forest legislation to achieve SFM.  相似文献   

1000.
一株土著B[a]P降解菌的筛选及降解特性研究   总被引:2,自引:2,他引:0  
通过在液体培养基中添加苯并[a]芘(B[a]P)作为唯一碳源反复驯化培养,从长期受石油烃和多环芳烃(PAHs)污染的土壤中分离出8株能够降解B[a]P的细菌,其中一株细菌(命名为BB-1)具有最大降解效果。采用16s RNA基因测序结果表明,BB-1与巨大芽孢杆菌(Bacillus megaterium)同源性为100%。为了研究BB-1的降解特性,在pH7.0、30℃条件下培养8 d,菌株B[a]P的降解率高达66.36%。为了考察培养基初始pH和外加蔗糖浓度对BB-1降解B[a]P的影响,30℃下振荡培养8 d,当设置培养基初始pH为4.0、6.0、8.0和10.0时,BB-1对B[a]P的降解率分别为12.14%、39.61%、55.21%和30.03%,可见pH为8.0时其降解效果最优;当添加0.1%蔗糖和0.5%蔗糖为外加碳源时,菌株BB-1对B[a]P的降解率分别为70.56%和74.89%,表明0.5%蔗糖的降解效果最优。  相似文献   
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