in order reaching to occurate water regime under minimum tillage system and its effect on the physiological indices of 3 rice cultivars an experiment  was conducted as a split-plot design based on  randomized complete block with three replication in the year of 2006-2007 at research field of shavour station. treatment contains three water regimes with one day or check, two (i2) and three days (...

We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit...

introduction lentil with about 28 percent protein occupies the second after soybean. it is one of the major crops in developing countries as a complement to cereals and is an excellent source of protein and amino acids in the diet. results of studies shown that for most crops, including lentil, the occurrence of drought stress in some phenology stages cause irreparable damages to yield. therefo...

Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the rela...

1 We examined amongand within-species effects of seed mass for seedling establishment from seed to 5 years of age in a field experiment at Paracou, French Guiana. 2 Six seeds of each of eight species were weighed and planted into each of 120 plots (1 m 2 ) throughout closed-canopy forest along 12 100-m transects in 1998. 3 We described the microhabitat of each planting site using principal comp...

We studied a guild of desert winter annual plants that differ in long-term variation in per capita reproductive success (lb, the product of per capita survival from germination to reproduction, l, times per capita reproduction of survivors, b) to relate individual function to population and community dynamics. We hypothesized that variation in lb should be related to species' positions along a ...

Eutrophication is one of the major threats to shallow lake ecosystems, because it causes large-scale degradation submerged plants. N:P ratio an important indicator estimate nutrient supply water bodies and guide restoration The massive input N P changes structure aquatic communities ecological processes. However, mechanism underlying influence in content a body on growth plants still unclear. I...

The impact of elevated CO2 (1000μmol/mol) was assessed on the common weed, Arabidopsis thaliana (Landsberg erecta), which is used as a model plant system. Elevated CO2 stimulated relative growth rate (RGR) and leaf area gain of Arabidopsis beginning from the cotyledon stage and continuing through the juvenile stage. This early advantage in growth enabled the plants grown in elevated CO2 to gain...

Earlier studies in the horticultural production area around Buenos Aires (Argentina) indicated that field grown leaf lettuce fertilised with 150 kg N ha accumulated NO3-N in the leaves up to concentrations well above the reference limits adopted by European countries. Previous studies also showed that the planning of sowing dates and a sound management may help overcome nutritional quality prob...

1. We hypothesize that flowering phenology correlates with plant height growth pattern and that the pattern is associated with functional traits including maximum plant height (Hmax), RGR, stem tissue mass density (SD), hollow ratio (proportion of central hollow of stem cross-sectional area) and leafmass per area (LMA) in grassland herbaceous species. 2. We investigated plant height growth traj...