Many biomechanical and theoretical studies have been based on the pipe-model theory, according to which a tree is regarded as an assemblage of pipes, each having the same amount of leaf area or leaf mass. However, the physiological mechanisms underlying the theory have not been extensively examined, particularly at the branch level. We analyzed how branches and trunks thickened in nine young Ac...

to study the effect of different substrates on growth and yield of gerbera, this experiment was carried out as randomized completely block design with 14 treatments and 3 replications. treatments were as fallowing: fine sand, peat+fine sand (25%+75%), peat+fine sand (50%+50%), perlite+peat (75%+25%), perlite+peat (50%+50%), perlite+peat (25% +75%), perlite+peat+expanded clay (25%+70%+5%), perli...

an experiment was conducted to determine the effect of paclobutrazol (pbz) and different irrigation amount on growth of aerial parts, leaf minerals and root performance in young olive plants cv. ‘manzanillo’ in the department of horticulture, faculty of agriculture, tarbiat modarres university in 2000. a split plot experiment in time was used based on a completely randomized block design with f...

In the floriculture industry, the need for heat tolerant bedding plant cultivars is increasing because of the rising temperature around the world. A pot experiment was carried out to examine the impacts of four heat stress durations (0, 7, 14 and 21 days) on growth and ornamental traits to determine the relative heat tolerance of four cultivars of calendula (Calendula officinalis). Growth and d...

Effects of different concentrations of IAA (0, 0.3, 0.6 mg/l) and 2ip (0, 0.3, 0.6, 0.9, 1.2 mg/l) and their combinations on callus induction and shoot regeneration of hypocotyl and its thin cell layer (TCL) explants in tomato was studied. Explants were prepared from hypocotyls of seedlings in the aseptic condition. Hypocotyl segments were more efficient than TCL explants for callus induction a...

Moso bamboo can rapidly complete its growth in both height and diameter within only 35-40 days after shoot emergence. However, the underlying mechanism for this "explosive growth" remains poorly understood. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. The results showed that Moso bamboos rapidly completed their...

The effects of Meloidogyne incognita race 3 and M. arenaria race 1 on growth of kenaf cv. Everglades 41 was determined under greenhouse conditions. Seedlings of kenaf were inoculated with initial population densities (Pi) of 0, 625, 1,250, 2,500, 5,000, and 10,000 eggs/plant and placed on greenhouse benches in a randomized complete block design. Plant growth and nematode reproduction were asses...

Three studies in the Coastal Plain of Georgia were remeasured 7 or 8 years after planting to determine the effects of planting depth on field performance of open-rooted seedlings [root-collar diameter (RCD) ≥ 5 mm]. Average planting depth (i.e. shoot height before planting minus shoot height above ground after planting) for machine planted P. elliottii was 14 cm while hand-planted P. taeda seed...

the aims of this study were to assess the effects of drought stress on peroxidase (pod), superoxide dismutase (sod) and catalase (cat) activities as well as free proline content and growth parameters of pistacia khinjuk seedlings under drought stress. therefore, the one-year seedlings of pistacia khinjuk subjected to water stress (25%, 50%, 75%, and 100% field capacity) for 8 months in greenhou...

To study the effect of different substrates on growth and yield of gerbera, this experiment was carried out as randomized completely block design with 14 treatments and 3 replications. Treatments were as fallowing: fine sand, peat+fine sand (25%+75%), peat+fine sand (50%+50%), perlite+peat (75%+25%), perlite+peat (50%+50%), perlite+peat (25% +75%), perlite+peat+expanded clay (25%+70%+5%), perli...