Antifungal Potential of Chenopodium album L. against Chickpea Blight

Chenopodium album L. （bathu） leaves and roots were selected to evaluate their antifungal potential against the Ascochyta rabiei responsible for chickpea blight that causes destructive yield losses. Methanolic extract of C. album leaves and roots was prepared and their various applied concentrations, viz., 1%, 2%, 3%, 4% and 5% were tested against A. rabiei. Leaf extracts were found more effective and showed significant antifungal activity over the root extracts. C. album leaf was found effective in screening bioassays, so this was subjected for fractional guided bioassays. Different various organic fractions of leaf extract were isolated, viz., n-hexane, chloroform, ethyl acetate and n-butanol. These isolated fractions were serially diluted to check their minimum inhibitory concentration （MIC） along with a synthetic fungicide （72% WP, Puslan）. The MIC of various concentrations from 500 mg/mL to 1.95 mg/mL was recorded after 24 h and 48 h intervals. Ethyl acetate and synthetic fungicides were found most effectual in retarding conidial germination with MIC of 1.95 mg/mL after 48 h incubation periods. Chloroform fraction also inhibited the fungal growth whereas n-hexane and n-butanol fraction were found to be ineffective.     

Mechanical properties of composites made from locally manufactured carbon fabrics and the composites produced from air-textured glass yarns

Composite materials have a wide range of applications in structural components because of their high strength-to-weight and stiffness-to-weight ratios. However, the most crucial and common life-restricting crack growth mode in laminated composites i.e. delamination is of great concern. Air jet texturing was selected to provide a small amount of bulk to the glass yarn. The purpose was to provide more surface contact between the fibres and resin and also to increase the adhesion between the neighbouring layers. These were expected to enhance the resistance to delamination in the woven glass composites. The development and characterisation of core-and-effect textured glass yarns was presented in the previous paper. This paper describes the comparison of the mechanical properties of composites produced from air-textured glass yarns and the composites made from locally manufactured carbon fabrics. The tensile, flexure and inter-laminar shear strength (ILSS) were compared and it was observed that although glass fibres are inferior to carbon fibres in terms of mechanical properties however, the flexure strength and ILSS of glass based composites increases after texturing and were found closer to the properties of carbon based composites.     

Recent progress in omics and biotechnological approaches for improved mango cultivars in Pakistan

Genetic Resources and Crop Evolution - Mango (Mangifera indica L.) is an important fruit crop throughout the world. Consequently, due to its excellent nutritional value and delicious taste, it is...     

Agronomic evaluation of controlled release of micro urea encapsulated in rosin maleic anhydride adduct

Abstract

Plant derived bio-based materials are environmental-friendly and provide a cheap and an attractive source for synthesis of controlled release urea fertilizers which have positive impact on plants’ health. In this work, application of rosin-maleic anhydride adduct encapsulated controlled release micro urea fertilizer (RA-mCRUF) was investigated for the optimization of its controlled urea release properties and evaluation of growth promoting effect on maize (Zea mays) plant under three different soil texture classes. Through response surface methodology, the independent response variables, were optimized for controlled release response of urea. Study found optimized coating repeats, 5.00 cycles; drying time, 11.71?h; and particle size, 41.82?µm; at urea release response of 331.62?mg L^?1 in distilled water. Optical microscopy images further demonstrated a more compact and homogeneous surface of RA-mCRUF without any coating defects. Besides, RA-mCRUF predicted a better growth performance of maize plant in clay loam soil. Moreover, RA-mCRUF treated maize plant showed 9.0–24.5?mg g^?1 increase in chlorophyll contents and 7.44–12.75?g rise in plant dry biomass. This work successfully produced a new type of RA-mCRUF which has applied role in soil nutrients conservation and addressing effectively food security through crops protection.     

Isolation and structure analysis of a glucomannan from the seeds of Libyan dates

Polysaccharides extracted from seeds of Libyan dates with hot ethanol 80% (FI) and 0.1 M phosphate solution (FII) were fractionated and purified by ion-exchange and gel-filtration chromatography. According to methylation and hydrolysis analysis, the main chains of FI and FII consisted of (1-->4)-linked glucomannan; only traces of branched sugar residues were detected. This is the first report on the isolation of glucomannan from date seeds.     

The economics of precision land leveling: A case study from Pakistan

This paper identifies the economic and physical benefits attributable to precision land leveling. While the work is specific to Pakistan the implications are relevant for other arid areas of the world where irrigation is practiced.Two sets of fields were selected, one set that had been precision leveled and another set that had been leveled using traditional techniques. These fields were resurveyed and then the farmers were interviewed every month during the winter crop season. Cutting samples were taken on all the fields during harvest. The average yield of the precision leveled fields was 2274.7 kg/ha and the yield for traditional leveled was 1681.1 kg/ha. This difference is significant at the 0.001 level. In addition the mean time to irrigate a hectare field was 2.79 h for precision leveled and 5.24 h for traditional leveled. Again this is significantly different at the 0.001 level. The change yield attributable solely to precision land leveling was calculated by regression analysis at 246.1 kg/ha per 3 cm change in max—min range. The remaining difference in yields was attributable to increased use of nitrogen and phosphorus fertilizers on the precision leveled fields over the traditional leveled fields.The economic analysis of precision and leveling, assuming a life of 10 years, is positive but not above the two or three to one return that is usually required to persuade subsistent farmers to invest in a new technology. However, the precision land leveling acts as a catalyst and increases the efficiency of the other associated inputs and hence is a more valuable investment than is indicated by simple economic analysis.     

Maize–sorghum intercropping systems for purple nutsedge management

Intercropping is a viable option for weed management. Six maize–sorghum intercropping systems were compared in a two-year field study for the management of purple nutsedge. The intercropping systems included maize planting in 70-cm spaced rows intercropped with one row of dwarf or tall sorghum and maize in 105-cm spaced double-row strips intercropped with one or two rows of dwarf or tall sorghum; sole maize planted in 70-cm spaced single rows was used as a control. Two intercropping systems as maize in 70-cm spaced rows + one row of tall sorghum and maize in 105-cm spaced double-row strips + two rows of tall sorghum controlled purple nutsedge by 48 and 52% compared with the sole crop of maize, respectively. However, all the maize–sorghum intercropping systems decreased the maize grain yield compared with control. Maize planted in 105-cm spaced double-row strips + one row of dwarf sorghum was the best option because it reduced the maize yield by only 6%. However, the decrease in maize yield was compensated for by sorghum yield. Intercropping maize in 105-cm spaced double-row strips + one row of dwarf sorghum may be used for management of purple nutsedge in maize.     

Physiological responses of saplings of rainforest timber species differing in successional group to light regimes and nitrogen

Saplings of 19 valuable rain forest timber species representative of three successional status groups (early secondary, late secondary and climax) were grown in a polyhouse to examine their responses to three light intensity/quality treatments and nitrogen supply. Solar radiation was modified using painted polyethylene sheet to mimic natural light environments across a rain forest vertical column as follows: 1. Transparent plastic, 80% of full sunlight, R:FR = 0.95, 2. Blue shade, 14% of full sunlight, R:FR = 0.69; 3. Green shade, 7% of full sunlight, R:FR = 0.50. Transparent plastic conditions promoted an increase in stem height and diameter (i.e., growth), leaf thickness and gas exchange per unit leaf area. Additional nitrogen availability enhanced growth and specific leaf area (i.e., leaves were thinner), particularly in the full sun environment and on early secondary and late secondary successional species, but did not influence photosynthetic rate. Successional status of the species did not affect photosynthetic rate although early secondary successional species grew faster and had fewer branches than species of the other successional groups. We recommend that for a successful mixed stand the high-light requiring species should be planted first, with increased nitrogen supply, and the shade tolerant species should be introduced later with no extra nitrogen supply required.     

Consequences of high temperature under changing climate optima for rice pollen characteristics-concepts and perspectives

The enhancement in both frequency and intensity of high temperature, besides its large variability will result in up to 40% yield reduction in rice by the end of 21^st century. Vegetative growth in rice continues with day time temperature up to 40°C but development of florets is extremely sensitive to temperature higher than 35°C. The effect of night time temperature stress is even more adverse than day. Heat stress results in deprived anther dehiscence, impaired pollination and abnormal pollen germination that cause floret sterility. The decrease in pollen viability is presumably caused by imbalance in proteins expression, abandoned biosynthesis, partitioning and translocation of soluble sugars, imbalance in phytohormones release, and loss of pollen water content. Rice responds to heat stress by adjusting various physiochemical mechanisms viz., growth inhibition, leaf senescence and alteration in basic physiological processes. Antioxidant enzymes, calcium and iron also play an important role in managing heat stress. Response of rice to heat stress varies with plant ecotype, growth stage, heat intensity and time of stress application. High temperature stress can be managed by developing heat-tolerant genotypes. Rice breeding and screening may be based on anther dehiscence, pollen tube development and pollen germination on stigma.     

Improving drought tolerance in maize by foliar application of boron: water status,antioxidative defense and photosynthetic capacity

Boron (B) plays a vital role in cell division and elongation in apical meristem. Drought stress (DS) severely reduced the B-uptake and thus growth and crop-productivity of plants. The aims of this study were to evaluate whether foliar application of B corrects physiological-disorders under DS in two contrasting maize genotypes i.e. Dekalb-6525 (drought-tolerant) and Yousafwala-hybrid (drought-sensitive). Initially, foliar rate of B (0, 2, 4 and 6 mg L^?1) was optimized in terms of improved plant growth under drought-stress. Then, optimized rate of B (4 mg L^?1) was applied to assess the physiological and biochemical basis of B-induced improved growth of maize under deficit-moisture supply. Drought-stress reduced the growth of plants by lowering in water-status (leaf water-relations), photosynthetic capacity (gas-exchange aspects, photosynthetic-pigments), membrane permeability, imbalance in redox potential (oxidative-stress, antioxidant-defense system) and tissue-B concentration. Application of B considerably improved maize growth by improving water-status, photosynthetic capacity, tissue-B concentration as well as up-regulation of antioxidative defense-system. Moreover, ameliorative effects of B on maize was also evident from stress relieving indicators such as slight decrease in accumulation of proline, total free amino-acids, total soluble-sugars and MDA content under water-deficit conditions. In addition, cultivar Dekalb-6525 showed considerable improving response to B application over Yousafwala-hybrid.