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排序方式: 共有62条查询结果,搜索用时 46 毫秒
1.
Lodging in maize leads to yield losses worldwide. In this study, we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics, culm mechanical strength, lignin content,root growth, lodging percentage and production in maize at a high plant density. We compared a traditional nitrogen(N) application rate of 300 kg ha–1(R) and an optimized N application rate of 225 kg ha–1(O) under four N application modes: 50% of N applied a...  相似文献   
2.
The objective of this study was to evaluate the effects of organic and inorganic fertilizers on the yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore, a field trial was carried out in Peshawar, Pakistan, during the winters in 2012–2013. The field experiment was conducted in a randomized complete block design with split plots, having three replications. Fertilizer treatments (control, composted manure Higo Organic Plus at 5 t ha?1, Maxicrop Sea Gold seaweed extract at 5 L ha?1, farm yard manure at 10 t ha?1, inorganic nitrogen–phosphorus (NP) at 90:60 kg ha?1, NP at 120:90 kg ha?1 and NP at 150:120 kg ha?1) were allotted to main plots, while genotypes (Sandrina, Serenada and Kawe Terma) were allotted to the sub-plots. Plots treated with the application of NP at 120:90 kg ha?1 produced the highest beet yield (76.4 t ha?1) and sugar yield (11.1 t ha?1), and had the second highest polarizable sugar content (14.52%) and more economic return (Rs. 553,000 per hectare) as compared to control plots. Sugar beet genotype Serenada had significantly higher beet yield (55.5 t ha?1) and sugar yield (7.9 t ha?1) and a higher economic return (Rs. 380,000 per hectare) than the other genotypes. Sugar beet genotype Serenada supplied with NP at 120:90 kg ha?1is recommended for the general cultivation in the agro-climatic conditions of Peshawar valley.  相似文献   
3.

Background  

The ultimate goal of proteomic analysis of a cell compartment should be the exhaustive identification of resident proteins; excluding proteins from other cell compartments. Reaching such a goal closely depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific difficulties: (i) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure, (ii) polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins. Several reported procedures to isolate cell walls for proteomic analyses led to the isolation of a high proportion (more than 50%) of predicted intracellular proteins. Since isolated cell walls should hold secreted proteins, one can imagine alternative procedures to prepare cell walls containing a lower proportion of contaminant proteins.  相似文献   
4.
A field experiment was conducted on silty clay loam soil in the years 2011–2012. Two sesame (Sesamum indicum L.) cultivars (Local Black and Local White) were evaluated using various 3 different sowing dates (20th June, 10th and 30th July) and four agrotechnical level (0, 40, 80 and 120 kg N ha–1) at New Developmental Farm The University of Agriculture, Peshawar, Pakistan. The objective of this study was to evaluate the effects of sowing dates on growth, yield and oil fatty acid composition of two sesame cultivars grown under different nitrogen fertilization. Results showed that cv. Local Black was characterized by significantly higher content of oil (47%), seed yield (696 kg ha–1) and oil yield (335 kg ha–1) while cv. Local White had higher palmitic acid (8%) and linoleic acid (38.7%). Yield and its main components were positively affected by the earlier sowing date. With regard to fatty acid composition, a decrease in oleic and stearic acid and an increase in linoleic and palmitic acid were observed. At early sowing, oleic and palmitic acid decreased whereas linoleic and stearic acid increased. The decrease in the oleic/linoleic acid ratio observed at early sowing, suggests a possible role of temperature on the activity of oleate desaturase in the developing seeds. Intensive technology of cultivation (120 kg N ha–1), compared to the economical technology (40 kg N ha–1), significantly increased the seed yield of both sesame cultivars. This was due to higher number of branches, Capsules m–2, capsules plant–1, seeds capsule–1 and 1000 seed weight (g). The intensive technology of cultivation had a beneficial effect on the content of palmitic acid, linolenic acid and oleic acid in sesame seed.  相似文献   
5.
Transboundary animal diseases (TADs) are highly contagious and have the potential to spread very rapidly irrespective of the national borders, causing serious economic losses. These diseases cause high morbidity and mortality in susceptible animal populations. Furthermore, the extent of their consequences may significantly affect the food security and national economics. In Pakistan, the main TADs include rinderpest, peste des petits ruminants, foot and mouth disease and avian influenza. In the present paper the status of these diseases in Pakistan is discussed.  相似文献   
6.
Tropical Animal Health and Production - Newcastle disease (ND) is a devastating disease and cause high t mortality and morbidity in poultry and nonpoultry avian species worldwide. An intensive...  相似文献   
7.
为了更好地了解合肥市饮用水源地水生态环境状况,于2020年夏季、秋季、冬季及2021年春季对大房郢水库的水质、浮游植物和浮游动物进行监测,对比浮游生物群落现存量与历史变化,并使用冗余分析(RDA)以及蒙特卡洛置换检验探究环境因子对浮游生物群落的影响。结果表明,研究区域浮游植物以蓝藻门为主要优势种属,密度及生物量较2005年分别增加37.7%和7.0%,浮游动物以桡足类为主要优势种,密度较2005年大幅度下降了77.5%,生物量多样性增加了47.8%,影响浮游生物群落结构的主要环境因子为NH3-N、T(温度)、pH和TN。此外,研究也揭示了季节变化对水库浮游生物的物种组成影响小,但对浮游生物的丰度及多样性影响显著。  相似文献   
8.
Peach fruit is enriched with natural antioxidants but oxidation caused by biotic and abiotic stresses, reduce these antioxidants and consequently effect the quality and yield of the fruit. Therefore, an experiment was conducted to investigate the role of ascorbic acid to sustain the natural antioxidant activity, improve the fruit quality and yield of peach cultivars (Early Grand and Florida King). The peach cultivars, Early Grand and Florida King were tested against four levels of ascorbic acid (200, 400, 600 and 800?ppm) and compared with control as water spray. The foliar application of ascorbic acid significantly influenced anti-oxidant activity and physico-chemical attributes of peach cultivars. However, the foliar application of ascorbic acid @ 800?ppm significantly increased the fruit weight, fruit yield, fruit firmness, total soluble solids, titratable acidity, antioxidant activity of fruit peel, with least percent infected fruits and fruit juice pH as compared to the rest of the treatments. Similarly, significant variation was recorded for peach cultivars regarding anti-oxidant activity and various physico-chemical attributes. The maximum fruit weight, fruit yield, fruit firmness, total soluble solids, titratable acidity and TSS/TA ratio were noted in fruit of cultivar Florida King. On other side the foliar treated fruit of peach cultivar Early Grand had the highest percent infected fruits, fruit juice pH and antioxidant activity of fruit peel. It is concluded from the significant findings of present research that the peach cultivar Florida King performed better in terms of maximum fruit yield, whereas the cultivar Early Grand produced better quality fruits with high anti-oxidant activity when treated with 800?ppm of ascorbic acid as foliar spray.  相似文献   
9.
Low phosphorus (LP) limits crop growth and productivity in the majority of arable lands worldwide. Here, we investigated the changes in physiological and biochemical traits of Tibetan wild barleys (Hordeum vulgare L. ssp. spontaneum) XZ99 (LP tolerant), XZ100 (LP sensitive), and cultivated barley ZD9 (moderately LP tolerant) under two phosphorus (P) levels during vegetative stage. These genotypes showed considerable differences in the change of biomass accumulation, root/shoot dry weight ratio, root morphology, organic acid secretion, carbohydrate metabolism, ATPase (Adenosine triphosphatase) activity, P concentration and accumulation under LP in comparison with CK (control) condition. The higher LP tolerance of XZ99 is associated with more developed roots, enhanced sucrose biosynthesis and hydrolysis of carbohydrate metabolism pathway, higher APase (Acid phosphatase) and ATPase activity, and more secretion of citrate and succinate in roots when plants are exposed to LP stress. The results prove the potential of Tibetan wild barley in developing barley cultivars with high tolerance to LP stress and understanding the mechanisms of LP tolerance in plants.  相似文献   
10.
ABSTRACT

Soil salinity is a major abiotic factor limiting crop production but an amendment with synthetic zeolite may mitigate effects of salinity stress on plants. The objective of the study was to determine the effects of zeolite on soil properties and growth of barley irrigated with diluted seawater. Barley was raised on a sand dune soil treated with calcium type zeolite at the rate of 1 and 5% and irrigated every alternate day with seawater diluted to electrical conductivity (EC) levels of 3 and 16 dS m?1. Irrigation with 16 dS m?1 saline water significantly suppressed plant height by 25%, leaf area by 44% and dry weight by 60%. However, a substantial increase in plant biomass of salt stressed barley was observed in zeolite-amended treatments. The application of zeolite also enhanced water and salt holding capacity of soil. Post-harvest soil analysis showed high concentrations of calcium (Ca2 +), magnesium (Mg2 +), sodium (Na+), and potassium (K+) due to saline water especially in the upper soil layer but concentrations were lower in soils treated with zeolite. Zeolite application at 5% increased Ca2 + concentration in salt stressed plants; concentrations of trace elements were also increased by 19% for iron (Fe2 +) and 10% for manganese (Mn2 +). The overall results indicated that soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil.  相似文献   
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