Integrated Weed Management Through Tillage and Herbicides for Wheat Production in Rice-Wheat Cropping System in Northwestern Pakistan

Conservational tillage (CT) in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds,reducing cost of cultivation,and enhancing wheat yield.Field experimen...     

新疆大学农场资源土壤动物调查初报

对新疆大学农场资源土壤动物现状进行了首次调查研究,共获标本2050只,隶属于6门,17纲,26目和56种。根据其经济用途分为食用土壤动物、药用土壤动物、饲料土壤动物、天敌土壤动物、环境指示土壤动物和观赏土壤动物6大类,并论述了资源土壤动物的开发利用和保护措施。     

Use of urea coated with natural products to inhibit urea hydrolysis and nitrification in soil

Laboratory incubation experiments were conducted with uncoated urea or urea coated with dementholized oil (DMO), pitch (the mint oil discard), terpenes (the products of menthol mint oil), or dicyandiamide (DCD) to study the retardation of urea hydrolysis and nitrification in soil. Two levels (0.5 and 1 %) of coating were tested. Urea was applied at a rate of 200 mg kg⁻¹ of dry weight of soil. The urea hydrolysis and nitrification processes were inhibited by all three natural products. All the three natural products viz., DMO, terpenes, and pitch significantly retarded urease activity of soil.     

Associations of <Emphasis Type="Italic">NAM</Emphasis>-<Emphasis Type="Italic">A1</Emphasis> alleles with the onset of senescence and nitrogen use efficiency under Western Australian conditions

Wheat grain yield and protein content are significantly influenced by the onset of senescence and the duration of the grain filling phase. The onset of senescence also affects Nitrogen use efficiency (NUE) through interacting pathways involving N accumulation and translocation of N into the grains. The objective of this study was to relate variation in NUE and its components with two groups of the NAM-A1 gene alleles; (i) early onset of senescence in cultivars carrying the NAM-A1a allele, (ii) delayed onset of senescence in cultivars carrying the Non-NAM-A1a allele (b, c, d) in wheat cultivars grown under Western Australia conditions. A field trial was carried out over two seasons examining 19 cultivars under different N rates and time of N application. The Normalized Difference Vegetation Index was utilized to determine the onset of senescence after anthesis. The early onset of senescence results in high grain yield, harvest index, and NUE due to improvements in the N utilization ability. Accelerating the onset of senescence results in a short grain filling period leading to grain maturity before the onset of unfavourable summer conditions. The function of alleles of NAM-A1 gene in controlling senescence hence the NUE is highly regulated by environmental conditions. This study concluded that the function of NAM-A1a allele induces the onset of senescence with a positive effect on the NUE and its components under Western Australian conditions.     

Changes in Availability of Plant Nutrients during Composting of Cow Manure with Poplar Leaf Litter

Safe management of animal and plant waste is one of the world's most important environmental challenges. Composting has been proposed as a useful technique for beneficially recycling wastes. This study showed that significant temporal changes in the nutrient availability occurred during the composting of cow manure with poplar leaf litter within 120 days. In particular, total C in the final compost was directly related to the addition of tree litter and inversely related to the time of composting, whereas extractable P and NO₃ increased with increasing amounts of tree litter and ammonium showed the opposite trend. During the later stages of the composting process higher concentrations of water soluble K, Ca, Mg, and Na were observed. The major benefit observed was that heavy metal concentrations initially present in the manure were significantly reduced during composting. Heavy metals in the final compost decreased in the order: Fe > Mn > Zn > Cu > Ni > Cd. The increased availability of plant nutrients following composting coupled with the lower extractability of heavy metals indicates that composting may be a sustainable option for agricultural waste recycling and increased productivity.     

Influence of Poly(lactic acid) Layer on the Physical and Antibacterial Properties of Dry Bacterial Cellulose Sheet for Potential Acute Wound Healing Materials

Dry bacterial cellulose nanofiber (BC) sheet coated with poly(lactic acid) (PLA) was developed and characterized towards acute wound healing applications. This new approach of PLA coating on BC revealed enhanced physical and antibacterial properties. Commercial BC sheets originated from the manufacturing of nata de coco jelly were dried and coated with the PLA at various concentrations of 2, 4, 6, 8, 10 and 12 % w/v for the purpose of improving the mechanical properties and followed by loading of antiseptic such as benzalkonium chloride (BAC). PLA has been proposed for the use of coating materials at a concentration of 8 %, the biocomposite sheet started exhibiting a low moisture uptake, prolonged swelling in simulated wound fluid solution and high tear (9.17 Nm²/kg) and burst indices (32.5 kPa·m²/g). The 8 % PLA coating revealed porous fiber-like morphology as observed under scanning electron microscope. Therapeutic loading capacity of the BC/8 PLA was substantially higher than the pristine BC. Furthermore strong antimicrobial activities against Staphylococcus aureaus and Escherichia coli were observed for the BC/8PLA biocomposite film. These reports were clearly suggestive of the fact that synthetic biodegradable polymers, such as PLA, may be exploited for the synergistic combination with BC for antimicrobial and acute wound management. This new and modified fiber source material could reduce the dependency on plant based cellulose for more demanding biomedical applications such as wound healing materials, vascular graft, cartilage replacement, drug delivery and tissue engineering.     

Salinity Stress Promote Drought Tolerance of Chenopodium Quinoa Willd

A greenhouse experiment was conducted to investigate the impact of water and salt stress in Quinoa plants (Chenopodium quinoa Willd.). Irrigation treatments using saline solutions of 0 (control), 50(T₁), 200(T₂), 400(T₃), 600(T₄), and 800(T₅) mM sodium chloride (NaCl) were adopted. The results indicated that quinoa plants can tolerate water stress (50%FC) when irrigated with moderately saline water (T₁ and T₂, respectively). Salinity stress increases quinoa drought tolerance in terms of biomass production. Neither osmotic stress nor ions deficiency/toxicity seems to be determinant under T₁ and 100%FC. Salinity induced a significant increase of sodium (Na⁺) and chloride (Cl^?), while reduced magnesium (Mg²⁺) and calcium (Ca²⁺) in stems, leaves, seed’s coating, and seeds. The potassium (K⁺)/Na⁺ ratio never fell below 1 with T₁; yet, fell to 0.78 and 0.89 with T₂ for 100% and 50%FC, respectively. The seed coat limited the passage of possibly toxic concentrations of Na⁺ and Cl^? to seed interior, as high Na⁺ and Cl^? was found in the seed coat.     

博斯腾湖湿地边缘带农田土壤重金属的污染风险评价

对新疆博斯腾湖湿地边缘带农田土壤中8种重金属元素(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)地球化学特征进行分析。采用污染负荷指数(PLI)、潜在生态风险指数(RI)和生态风险预警指数(IER)对农田土壤重金属污染与环境风险进行评价。结果表明:(1)湿地边缘带农田土壤Pb和Zn呈现重度污染,As、Cd、Cr和Ni轻度污染,Cu轻微污染,Mn无污染。土壤As、Cd、Cr、Cu、Ni、Pb和Zn平均含量处于轻微风险水平。Cd是污染程度与生态风险等级最高的重金属元素;(2)湿地边缘带农田土壤PLI平均值为1.43,呈现轻度污染,RI平均值为20.62,呈现轻微生态风险状态,IER的平均值为–4.53,呈现无警态势。湿地边缘带PLI、RI与IER空间分布格局基本一致;(3)湿地边缘带农田土壤Pb与Zn来源主要受到人类活动的影响,Cr、Cu、Mn与Ni来源主要受到土壤地球化学作用的控制,As与Cd受自然因素和人为因素共同影响。     

新疆天山西部岩面生地衣群落最小面积的初步研究

我们采用Sφrensen和Kulcinsky平均相似性系数，研究了分布在天山西部山脉的岩面生地衣群落的最小面积。结果表明，岩面生地衣群落的定性和定量最小面积分别为30－60cm^2和40－70cm^2，同时证明了整体取样技术适合岩面生地衣的植物群落学研究。     

Protective effect of rutin on paracetamol- and CCl4-induced hepatotoxicity in rodents

Rutin, a well-known flavonoid was investigated for its possible protective effect against paracetamol- and CCl(4)-induced hepatic damage. Paracetamol produced 100% mortality at the dose of 1 g/kg in mice while pre-treatment of animals with rutin (20 mg/kg) reduced the death rate to 40%. Oral administration of a sub-lethal dose of paracetamol (640 mg/kg) produced liver damage in rats as manifested by the rise in serum level of transaminases (AST and ALT). Pre-treatment of rats with rutin (20 mg/kg) prevented the paracetamol-induced rise in serum enzymes. The hepatotoxic dose of CCl(4) (1.5 ml/kg; orally) also raised the serum AST and ALT levels. The same dose of rutin (20 mg/kg) was able to prevent the CCl(4)-induced rise in serum enzymes. Rutin also prevented the CCl(4)-induced prolongation in pentobarbital sleeping time confirming its hepatoprotectivity. These results indicate that rutin possesses hepatoprotective activity and the presence of this compound in Artemisia scoparia may explain the folkloric use of the plant in liver damage.