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...

Both leaf production and leaf expansion are tightly linked to cell expansion and cell division, but the functional relationships between all these variables are not clearly established. To get insight into these relationships, a quantitative genetic analysis was performed in 118 recombinant inbred lines derived from a cross between the Landsberg erecta and Antwerp accessions and was combined wi...

Beech seedlings (Fagus sylvatica L.) were grown in various combinations of three photosynthetic photon flux densities (PPFD, 0.7, 7.3 or 14.5 mol m(-2) day(-1)) for two years in a controlled environmental chamber. Dry mass of leaves, stem and roots, leaf area and number of leaves, and unit leaf rate were affected by both previous-year and current-year PPFD. Number of shoots and length of the ma...

Dry matter (DM) partitioning is function of the solar radiation intercepted by the crop canopy and their plant’s leaf area exposed within the canopy. Row orientation (RO) and Row-spacing (RS) within canopy influenced the leaf size and might be the light use efficiency. We, therefore, studied cob bearing leaf area and leaf-area-profile (LAP) of maize planted at different RO, RS and N-rates (0, 1...

The trial with 11 genotypes of winter oilseed rape (Brassica napus subsp. napus) with different provenance was based on experimental station Borovce near SCAR – RICP Piešťany (Slovak Republic) in autumn 2008 (the Trnavská pahorkatina locality, altitude 167 m, maize growing region). Approximately in weekly intervals, since beginning of April to middle of June 2009, for the purpose of growth anal...