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To investigate the physiological status of plant following the application of a mixture of organic residues, nitrogen-rich meat powder and alfalfa (Medicago sativa L.) powder mixed in different proportions as fertilizers were applied to the soil of a hilly area to cultivate young walnut trees under drought and wet soil conditions, respectively. The results showed that the nitrogen-rich fertilizer treatments could significantly increase the soil water content (SWC), soil organic matter (SOM), soil organic carbon (SOC), and soil organic nitrogen (SON), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available P (AP), available K (AK), a high soil organic carbon/nitrogen ratio under soil drought conditions. Moreover, they also significantly improved the soil nutrients contents of Ca, Mg, Fe, Mn, Cu and Zn, especially Ca and Mg in dry soil. Consequently, this nutrient-rich soil greatly promoted the plant branching and thickening with a high net leaf photosynthesis rate (Pn), water use efficiency (WUE), a low transpiration (Tr) under soil drought conditions. We proposed that high soil carbon/nitrogen ratio improved by applying nitrogen-rich fertilizers might weaken top shoot growth and regulate the plant branching and thickening of young walnut trees under deficit irrigation conditions. [ABSTRACT FROM AUTHOR]

Tropospheric ozone, a phytotoxic air pollutant, has inadvertently increased since industrial era and its effect on agricultural crops has gained urgent scientific attention. The present study aims to evaluate the response of blackgram varieties (Vigna mungo L.) exposed to elevated ozone stress (100 ppb) with antiozonant (Ethylene diurea at 300 ppm). The study was conducted during two seasons and the effectiveness of ethylene diurea (EDU) was explored in terms of plant physiology, biochemistry, antioxidant enzymes, growth, yield and spectral reflectance of blackgram varieties. Ethylene diurea ameliorates the ozone stress by increasing photosynthetic rate by 40.78 and 37.21% in season I and 43.03 and 35.77% in season II for VBN3 and VBN8, respectively, and antioxidant enzyme superoxide dismutase by 24.31 and 19.42% in season I and 22.59 and 18.59% in season II for VBN3 and VBN8, respectively. The growth indices and yield traits were significantly increased with the application of EDU and the effect was more pronounced in sensitive cultivar (VBN3) compared to the tolerant (VBN8) one. Spectral reflectance, a non-destructive study, further validates the effect of tropospheric ozone on blackgram varieties. Newly identified spectral indices [R566, R573], and [R564, R586] demonstrated the greatest potential in detecting ozone sensitivity of blackgram varieties. [ABSTRACT FROM AUTHOR]

The progressive increase in the earth's temperature due to anthropogenic activities is a major concern for humanity. The ensuing heat stress (HS) severely impacts plant growth, endangering ecosystem quality and world food security. Plant growth, physiological processes and final amount of edible products are affected by HS to an extent that reflects the physical damages, physiological commotions and biochemical alterations incurred at various growth stages. Therefore, a better understanding of plant behaviour in response to HS has pragmatic implications for devising counter-measures, alleviation strategies, and for acknowledging the differences between HS and the companion drought stress. Conventional breeding, biotechnological and molecular approaches are used to develop HS tolerant genotypes in plant species bred for food/feed uses. Recent achievements in the omics techniques result in a better knowledge of the molecular mechanisms involved in HS. However, shrewd management of crop practices is still helpful to improve plant resilience to HS. Suitable sowing time, seed priming, bacterial seed treatment, nutrient and water management, exogenous application of osmo-protectants, and conservation of soil moisture are important tools to improve plant behaviour under the critical HS scenarios determined by climate change and global warming. [ABSTRACT FROM AUTHOR]

The present study aims to examine the physiological, biochemical and defence system responses of Calotropis procera to vehicle exhaust pollution. We selected various sample sites along two major roads in the Punjab province of Pakistan, i.e. Faisalabad to Sargodha road (FSR) and Pindi Bhattian to Lillah motorway (M-2). Traffic density at all sites and plant responses (i.e. chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents, transpiration rate, stomatal conductance, photosynthetic rate, substomatal CO2 concentration, water use efficiency, total free amino acids, total soluble proteins and total antioxidant activity) were measured. Levels of carbon (C) and nitrogen (N) and four metals of most possible concern - i.e. lead (Pb), zinc (Zn), cadmium (Cd) and nickel (Ni) - were also examined in all samples. We found their considerable deposition in all the samples along roads. Inhibitory effects of roadside pollutants were noted for photosynthetic pigments, stomatal conductance, transpiration rate, photosynthetic rate and total soluble proteins, whereas stimulatory effects were noted for sub-stomatal CO² concentration, free amino acids and total antioxidant activity. The stimulation of antioxidant enzymes activity revealed stress and mitigation of reactive oxygen species. The present study clearly signifies that C. procera has great potential to endure the stress caused by roadside pollutants. [ABSTRACT FROM AUTHOR]

Although the salt resistance mechanisms in plants have received much consideration for many years, varieties' differences affecting salt resistance are still unsettled. Within the Ocimum genus there occur about 200 species in different varieties and forms. A pot experiment was performed to better understand salt stress responses in crop plants; we compared the impacts of salinity stress on growth and physio-biochemical characteristics in three varieties of basil (Ocimum basilicum) var. odoratus, O. b. var. alba and O. b. var. purpurascens) grown under four levels of salinity stress (0, 50, 100, and 150 mM NaCl) with mycorrhiza (Glomus clarum Nicol. & Schenck) or without. Results showed significant differences within salinity treatments in all cultivars studied. In this study, the biomass production and physio-biochemical parameters of all cultivars reduced with raised salinity levels except concentration of reducing sugars, sodium, and proline at 150 mM of NaCl, only the variety 'purpurascens' didn't show reduction and observed resistant against severe salinity. The colonization of arbuscular mycorrhiza fungi enhanced the biomass production and accumulation of nutrients, reducing sugars, total soluble carbohydrates, photosynthetic pigments, proline, and protein by reducing Na. This study should help understand the function of AMF fungi in basil cultivars' tolerance to salinity stress. [ABSTRACT FROM AUTHOR]

A greenhouse experiment with green gram on boron (B) deficient calcareous soils was conducted for two years at Ludhiana (Punjab), India to study soil B fractions and response of green gram to B application. Three soils with calcium carbonate (CaCO3) content 0.8 (Soil I), 2.1 (Soil II) and 4.6 (Soil III) percent were collected from different sites of Ludhiana and Bhatinda districts, Punjab, India. The treatments comprised of five levels of soil applied B (0, 0.5, 0.75, 1.0, and 1.5 mg B kg−1). The experiment was laid out in completely randomized design (CRD) factorial design with three replications. Readily soluble B comprised 0.39 to 0.76 percent in Soil I, 0.32 to 0.54 percent in Soil II, and 0.21 to 0.34 percent in Soil III of the total B, taking into account of all the levels of B applied at both stages of crop growth. Readily soluble B increased with increasing application rates of B and decreased from grand growth stage (40 days after sowing) to maturity of the crop. Specifically adsorbed, oxide bound, residual, and total B was higher in Soil III as compared to Soil II or Soil I. At maturity, specifically adsorbed B converted into other fractions to maintain equilibrium in soil solution. Organically bound B was greater than oxide bound B. Among all fractions, the residual fraction accounted for the major fraction of the total B. Soil application of lowest level of B was adequate to cause significant increase in dry matter yield and seed yield of green gram regardless of type of soil. [ABSTRACT FROM AUTHOR]

In order to maximize food intake per harvesting effort and minimize energy expenditures required to move between feeding patches in nature, herbivores such as moose (Alces alces L.) generally select large plant shoots when browsing in winter. To determine moose preferences for shoots of different morphologies, an experiment was conducted in northern British Columbia in which shoots from birches cut at different times of the growing season were fed in 2 consecutive years to eight human-habituated moose in cafeteria-style feeding trials. The results indicate that moose preferred smaller winter shoots of birches regardless of when the parent plant was cut and also appeared to reject larger shoots containing sylleptic branches. It is argued that the preferences for smaller shoots by moose detected in these trials should be observable under natural conditions, but are generally only supported by literature from some parts of Scandinavia. The findings underscore the importance that factors such as mouth filling per harvesting effort, snow depth and consistency, predators and browse patch distribution must have on foraging decisions made by moose while browsing in the wild. Implications of the findings include the significance of cutting time on the size of shoots produced by birch after cutting, how this affects moose browsing birch and, subsequently, how managers can theoretically use cutting time as a tool in forest cleaning operations to direct the foraging efforts of moose towards or away from forest plantations. [ABSTRACT FROM AUTHOR]

Aphids are economically important insect pests of agriculture and forest crops. They feed on phloem sap by extremely efficient mouthparts modified into long and flexible stylets. Adaptation to phytophagy is completed by an extremely ductile reproduction system that can alternate biparental and parthenogenetic generations. In order to reach plant phloem, aphids must overcome plant defences, either physically and/or chemically. However, plants respond to aphid attack by activating defence genes that lead to the production of physical barriers and/or chemical toxic compounds (direct resistance). In addition, attacked plants can attract the natural enemies of aphids by releasing specific volatile compounds (indirect resistance). We can take advantage of these different types of resistance in order to enhance the sustainable control of these phytophagous insects. In this review we summarize the main aspects of plant-aphid interactions, focusing on those issues that can have an economic application. [ABSTRACT FROM AUTHOR]

Increasing rates (5, 10, 25 and 40% v/v) of 6 sources of organic wastes were substituted for peat to assess changes in the physical properties of peat-perlite substrates and investigate the relationship between plant response and these properties. Wastes were either fresh or composted bio-filter sludge (FBF and CBF), sewage sludge (FSS and CSS), and de-inked paper sludge (FDP and CDP). Geranium plants (Pelagornium × hortorum 'Orbit Hot Pink') were grown in the substrates. Growing substrates' saturated hydraulic conductivity (Ks), airfilled porosity (ƒa), pore tortuosity ( ), and relative gas diffusivity (Ds/Do) all increased linearly (p = 0.0001) as the rate of organic wastes increased. Geranium plant height (PHT), shoot dry mass (SDM) and root dry mass (RDM) were either linearly or quadratically decreased (p = 0.0001) as the amount of waste increased in the substrates. During both growing seasons, Geranium SDM and RDM were either linearly or quadratically correlated with Ds/Do and . Organic waste types and their rate of application strongly affected the aeration status of the substrates. Ds/Do and better expressed the relationship between plant growth and the physical conditions of the root zone. [ABSTRACT FROM PUBLISHER]