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Introduction Heavy metal pollution is one of the most .important stress factors that limit plant growth and survival. Also, these metals accumulate in plant tissues, increase their toxicity and join the food chain. Industrial activities, agricultural chemical and urban wastes are the main sources of heavy metal pollution. Plants have different responses to heavy metals according to its type, concentration and duration of exposure. Wheat is a basic crop mostly grown in a lot of countries.. Material and Methods In the present experiment, the effects of two metal (cadmium and lead) on bread wheat (Triticum aestivum L. cv. Sagittario) was investigated. So, seeds were germinated in Petri dishes in controlled climate room and watered with 0 (as control) -100 and 200 µm lead (as PbNO3) and cadmium (as CdCl2) for four days (each application had four replicates), harvested and growth parameters were evaluated with LSD test. Findings Both cadmium and lead affected negatively growth parameters. Root and shoot lengths, fresh and dry weights decreased by increasing lead and cadmium concentrations. As compared with control groups, the change of lengths and root dry weight were found significant statistically (according to LSD test) in all applications. Results and Discussion It is determined that the most toxic effect was found at the highest dose of lead (200 µm) to Sagittario cv that we used in this study.

Salinity is an important abiotic factor that affects plant life quality. Indole acetic acid is one of the most important hormones that affect growth and development in plants and promotes vegetative growth. Wheat, which is the plant material of this study, is basic crop mostly grown in a lot of countries. The aim of this study was to research the effects of salt (125 mM) and different concentrations (2.5, 5 and 25 ppm) on some growth parameters of bread wheat, which grow under the controlled conditions. For this purpose, wheat seeds imbibed in distilled water (as control) and different indole acetic acid solutions and germinated in Petri dishes. The dishes were watered with 0- 125 mM NaCl solutions and harvested five days later. Growth parameters of seedlings (shoot and root length, fresh and dry weight) were recorded and data were evaluated with LSD test. The salinity had negative effect on wheat’s examined some growth parameters (shoot-root length, dry weights) significantly. In addition to these, 25 ppm indole acetic acid decreased these parameters, too; but these findings not found significant. 5 ppm indole acetic acid, slightly ameliorated salinity’s damaging effect. As a result of this study, 125 mM salt concentration had negative effects on wheat seedlings. Although indole acetic acid is a plant growth regulator, the high concentrations of it may cause negative results. Nevertheless, 5 ppm indole acetic acid concentration, positive effects on wheat seedlings slightly against salinity. In conclusion, plant growth regulators may be used by farmers to protect from salinity stress

Allelopathy is described as the effect of a plant’s chemical secretions on other plants or microorganisms. While plants live in their natural habitat, they can affect another plant’s life cycle in different ways. Weeds are usually found in fields, compete with crops and may have an allelopathic effect. Xanthium strumarium is an important weed species that known being poisonous because of hydroquinone content. Another weed used in this study is Sorghum halepense, one of the most dangerous weed species that threatens biodiversity. In addition to this soybean (Glycine max) used as crop material in this study. It is grown in a lot of countries as an alternative to animal protein but it often exposed to weed invasion in the fields. So it is aimed to research the effects of two weed species on some physiological parameters of soybean. For this purpose. soybean seeds (Glycine max cv. Arısoy) were sown in soil and grown two weeks. There were three area in the field non-contaminated (as control) Xanthium strumarium contaminated and Sorghum halepense contaminated. For each area randomly four orders were chosen and SPAD values of six seedlings were measured in each order. Also, random three seedlings of each area were brought to laboratory for determining relative water content and electrolyte leakage. While Sorghum halepense didn’t affect the pigment content of soybean seedlings, Xanthium strumarium decreased it as it had less SPAD value. Both weed species increased relative water content but Xanthium strumarium had more important effect than other one. Also, both weeds increased electrolyte leakage but Sorghum halepense had bigger effect on this parameter.

Salt stress is an important abiotic factor that limits plant development. The effect of salt stress on the plants varies depending on the salt concentration and plant species. Sunflower and cotton are two different plant species that mostly grown as industrial crop. The aim of this study was to research the effects of different salt concentrations (0 -100 and 200 mM NaCl) on sunflower (Helianthus annus cv Ekllor) and cotton (Gossypium hirsitum cv Lydia) germination and growth. For this purpose, seeds were germinated in petri dishes, watered with salt solutions in controlled conditions during four days. Each application had there replications, and random three seedlings' datas from each petri were recorded at harvest. In sunflower, salinity inhibited seed germination. In addition to this, salinity had negative effect on sunflower’s shoot-root length, fresh and dry weight. Salinity affected cotton germination and growth too. At highest salt concentration, no germination was shown in cotton seeds, so growth parameters couldn’t be determined. As a result of this study, increasing salt doses caused germination and growth impediments in two plant species at different levels. In conclusion, according to our results sunflower seedlings (Ekllor cv.) were found more tolerant to salinity than cotton seedlings (Lydia cv.).