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41.
A glasshouse experiment was conducted to elucidate the influence of elemental sulfur (S) application rates (0, 0.5, 1.0, and 2.0 g S kg?1 soil) on the release and uptake of S at 0, 20, and 40 days after incubation. Results showed that there was a progressive upward trend in maize leaves, stem, and root S content with application of elemental S. However, maize production followed a nonlinear model. Plants grown in untreated soils suffer from S deficiency and addition of elemental S at a rate of 0.5 g S kg?1 soil alleviated S deficiency. The decrease in maize performance due to the highest S application rate was not related to S toxicity. The greatest leave, stem, and root productions were obtained at S concentrations of 0.41, 0.58, and 0.2%, respectively. Overall, application of elemental S at a rate of 0.5 g S kg?1 soil is recommended for maize performance improvement.  相似文献   
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This study is based on the opinions of selected Iraqi extension workers, regarding the type and amount of training they need, given their experience in the field. The Borich Needs Assessment Model was used for measuring training needs. The data were collected through questionnaires given to 300 respondents (agricultural workers) from January 15, 2016 to March 20, 2016. The results show that crop-planting courses have the greatest benefit. The greatest training need is skill and knowledge of teaching methods, while a moderately needed skill is the use of computer and information and communication technologies (ICT); management skills are the least needed training.  相似文献   
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Phytoremediation using vetiver grass (Vetiveria zizanioides) has been regarded as an effective technique for removing contaminants in polluted water. This study was conducted to assess the removal efficiency of heavy metals (Cu, Fe, Mn, Pb, Zn) using vetiver grass (VG) at different root lengths and densities and to determine metals uptake rate by plant parts (root and shoot) between treatments (low and high concentration). Removal efficiency for heavy metals in water by VG is ranked in the order of Fe>Pb>Cu>Mn>Zn. Results showed that VG was effective in removing all the heavy metals, but removals greatly depend on root length, plant density and metal concentration. Longer root length and higher density showed greater removals of heavy metals due to increased surface area for metal absorption by plant roots. Results also demonstrated significant difference of heavy metals uptake in plant parts at different concentrations indicating that root has high tolerance towards elevated concentration of heavy metals. However, the effects were less significant in plant shoot suggesting that metals uptake were generally higher in root than in shoot. The findings have shown potential of VG in phytoremediation for heavy metals removal in water thus providing significant implication for treatment of metal-contaminated water.  相似文献   
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An automated wood texture recognition system of 48 tropical wood species is presented. For each wood species, 100 macroscopic texture images are captured from different timber logs where 70 images are used for training while 30 images are used for testing. In this work, a fuzzy pre-classifier is used to complement a set of support vector machines (SVM) to manage the large wood database and classify the wood species efficiently. Given a test image, a set of texture pore features is extracted from the image and used as inputs to a fuzzy pre-classifier which assigns it to one of the four broad categories. Then, another set of texture features is extracted from the image and used with the SVM dedicated to the selected category to further classify the test image to a particular wood species. The advantage of dividing the database into four smaller databases is that when a new wood species is added into the system, only the SVM classifier of one of the four databases needs to be retrained instead of those of the entire database. This shortens the training time and emulates the experts’ reasoning when expanding the wood database. The results show that the proposed model is more robust as the size of wood database is increased.  相似文献   
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This study is aimed at assessing the ability of two endophytic bacteria originally isolated from healthy oil palm roots, Pseudomonas sp. (UPMP3) and Burkholderia sp. (UPMB3) to induce resistance in susceptible Berangan banana against Fusarium oxysporum race 4 (FocR4). Increased accumulation of resistance-related enzymes such as peroxidase (PO), phenylalanine ammonia lyase (PAL), lignithioglycolic acid (LTGA), and pathogenesis-related (PR) proteins (ehitinase and β-1,3-glucanase) has been observed in plantlets treated with endophytic bacteria UPMP3 and UPMB3 singly or as mixture under glasshouse conditions. Pre-inoculation of banana plantlets with UPMP3 showed a significant reduction in Fusarium wilt incidence 72 d after challenged inoculation with FocR4. UPMB3 was less effective in suppressing Fusarium wilt compared to UPMP3, whereas, the mixture of both endophytes showed an intermediate effect. Based on these results, it is concluded that UPMP3 could be a promising biological control agent that can trigger resistance against Fusarium wilt in susceptible Berangan banana.  相似文献   
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Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet. Its seeds and pods contain as much as 20–28% protein. Besides, it contains tyrosinase enzyme, which has potential use in the treatment of hypertension. Phosphorus deficiency causes a serious yield and quality constraint of beans at Aligarh, Western Uttar Pradesh, India. To address the problem, a pot experiment was conducted to study the effect of basal phosphorus application on the agricultural performance of this medicinal legume. The plants were grown in pots containing soil supplied with five levels of phosphorus viz. 0, 25, 50, 75 and 100 mg P kg−1 soil as potassium dihydrogen orthophosphate (KH2PO4). The growth and other physiological attributes, leaf nutrient contents, nodule-nitrogen and leghemoglobin content were studied at 60, 90 and 120 days after sowing (DAS), photosynthesis and other related parameters were measured at 90 DAS and yield and quality attributes were recorded at harvest (150 DAS). Nitrate reductase and carbonic anhydrate activities, leaf-N, -P, -K and -Ca contents and nodule-nitrogen and leghemoglobin contents reached the maximum extent at 60 DAS. At 90 and 120 DAS, the values decreased significantly. Chlorophyll content, carotenoids content, and photosynthesis were at maximum level at 90 DAS. At various growth stages, phosphorus application at 75 mg P kg−1 soil resulted in maximum amelioration of most of the parameters studied. It increased the seed-yield by 38.3%, seed-protein content by 14.9% and seed-carbohydrate content by 5.0%, relative to the control. It was concluded that there was a hidden hunger of hyacinth bean for phosphorus owing to soil-phosphorus deficiency that was ameliorated effectively by its basal dressing at 75 mg P kg−1 soil.  相似文献   
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In the present study, the preparation of sorbent from waste-derived siliceous materials has been investigated for the removal of nickel ion (Ni2+) from aqueous solutions. Three types of ashes, i.e., rice husk ash (RHA), palm oil fuel ash (PFA), and coal fly ash (CFA), were used in the preparation of sorbent. Batch studies were carried out to examine the effect of various experimental parameters, i.e., RHA/CFA/PFA ratio in the sorbent preparation, contact time, initial concentration of Ni2+, agitation rate, and pH. Among all the ratios of the prepared sorbent, it was found that sorbent containing RHA and PFA gave the highest Ni2+ removal efficiency. The optimum conditions for Ni2+ removal using RHA/PFA sorbent were obtained at contact time of 30?min, Ni2+ concentration of 100?mg/L, agitation rate of 130?rpm, and pH?4. During the optimum condition, more than 90% of Ni2+ could be removed in all experiment studies. It was also found that the spent RHA/PFA sorbents had a narrow range of particle size distributions as compared to prepared RHA/PFA sorbent. In addition, the surface morphology of the spent RHA/PFA sorbents had more compact structures.  相似文献   
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