BACKGROUND AND AIMS The major objective was to identify plant traits functionally important for optimization of shoot growth and nitrogen (N) economy under drought. Although increased leaf N content (area basis) has been observed in dry environments and theory predicts increased leaf N to be an acclimation to drought, experimental evidence for the prediction is rare. METHODS A pedigree of 200...

Despite being treated with preservatives, the service life of transmission poles and fence posts in the Zambian Copperbelt province is close to fifteen years. However, the service life is only two years for untreated timber, mainly due to termite damage. This short service life is exerting more pressure on an already over-burdened timber resource base. This study used an accelerated field test ...

Increasing the durability of crop resistance to plant pathogens is one of the key goals of virulence management. Despite the recognition of the importance of demographic and environmental stochasticity on the dynamics of an epidemic, their effects on the evolution of the pathogen and durability of resistance has not received attention. We formulated a stochastic epidemiological model, based on ...

Coast redwood (Sequoia sempervirens (D. Don) End!.) trees in different canopy strata and crown positions were sampled to develop relationships between sapwood cross-sectional area and projected leaf area. Sampling occurred during the summers of 2000 and 2001 and covered tree heights ranging from 7.7 to 45.2 m and diameters at breast height ranging from 9.4 to 92.7 cm. Foliage morphology varied ...

in order to investigate the effects of plant growth promoting bacteria on growth characteristic of wheat, an experiment was conducted at the research greenhouse, faculty of agriculture, ferdowsi university of mashhad, iran, in year 2009. a completely randomized design based on factorial arrangement (3×6) with three replications was used. the first factor consisted of three cultivars of wheat (c...

This paper aims at investigating the influence of partial replacement of Portland cement with ultrafine fillers compared to limestone powder on the durability and mechanical characteristics of concrete. For this purpose, ultrafine calcium carbonate materials with different specific surface areas of 9.7 and 15.1 m2/g and limestone powder (0.72 m2/g) were used. The results indicate that the ultra...

Leaf area information is required in various horticultural and physiological studies and it will be more useful if done via non-destructive methods. The objective of this study was to establish equations to estimate leaf area (LA) using length (L), width (W), fresh weight (FW), dry weight (DW), length × length (L2), width × width (W2), length × width (L×W), length + width (L+W), fresh weight × ...

bemisia tabaci (homoptera: aleyrodidae) is one of the most important pests of cotton in khorasan which causes crop damage and yield reductions as a result of direct feeding of plant and passing pathogenic viruses. using resistant varieties is an economic and environmental friendly method for controlling this pest. the resistance of seven cotton varieties (green leaf okra, red leaf okra, mehr, v...

Studies of tree seedling physiology and growth under field conditions provide information on the mechanisms underlying inter- and intraspecific differences in growth and survival at a critical period during forest regeneration. I compared photosynthetic physiology, growth and biomass allocation in seedlings of three shade-tolerant tree species, Virola koschynii Warb., Dipteryx panamensis (Pitti...