Knowledge of salt tolerance in vegetable plants is necessary to increase productivity and profitability of crops irrigated with saline wastewaters. Eggplant (Solanum melongena) is moderately sensitive to salinity but more attention to salinity is required in the agricultural production of eggplant and its varieties. The objective of the present work was to investigate the response of some eggplant varieties to increasing salinity during the germination and seedling stages. Germination, length, and dry and fresh weight of radicle and hypocotyl, length and dry and fresh weight of root and shoot, number and area of leaves and sodium (Na + ) and potassium (K + ) ions in seedling leaves, were the assayed parameters. Increasing salt stress (0, 50, 100, and 150 mM NaCl) negatively affected growth and development of eggplant (S. melongena 'Kemer', 'Pala', and 'Aydin Siyahi') at the germination (percentage and period; length and fresh and dry weight of of radicle and hypcotyl) and seedling stages (length and fresh and dry weight of root, shoot, and whole plant; leaf number and area). When salt concentration increased, leaf Na + content increased but K + content and K + /Na + ratio decreased. The response of varieties to salt was different depending on the growth stage, and salinity tolerance of cultivars increased at the later growth stages.

To examine lead (Pb) accumulation and distribution, and its effects on growth and nutrient content, Solanum melongena seedlings were grown in pot culture conditions in a glasshouse. The experiment was arranged in a randomised block design with 75, 150, and 300 mg litre-1 Pb applications, and replicated 3 times. The highest Pb applications represent severely contaminated land, the lowest representing above average pollution levels in industrial situations. Growth parameters such as root elongation and plant height; fresh and dry biomass of root, shoot, and leaf; leaf area; mineral elements (Ca, Mg, K, P, Fe, Zn, Cu, and Mn); chlorophyll content; and stomatal parameters were measured in roots, shoots, and leaves. The control treatment provided typical values for this plant as a reference, grown in alkaline soils. Growth parameters such as root elongation and plant height; fresh and dry biomass of root, shoot, and leaf; and leaf area were negatively affected by increasing Pb concentrations. Growth toxicity index increased as the concentration of Pb increased. Exposure to excess Pb caused accumulation of Pb in roots, shoots, and leaves of eggplant seedlings. At the higher Pb concentrations, roots accumulated 6-fold more Pb than shoots and 4-fold more than leaves. The highest level of Pb generally inhibited the uptake of all mineral elements compared with the low-level Pb treatment. The results of this experiment show the phytotoxicity of increasing Pb, which is apparent from the reduction of chlorophyll concentration in eggplant. In addition, a negative effect was determined by Pb concentration on stomatal parameters of stomata density, stomata length-width, and stomatal index in this study.

Direct seeded red pepper is a cash crop in Kahramanmaraş province of Turkey as well as some other nearby provinces. Weeds are a major constraint in red pepper production. Field studies were conducted to determine critical period for weed control (CPWC) in direct seeded spice pepper in Kahramanmaraş, in 2008 and2009.The CPWC in red pepper based on a 2.5%, 5% and 10% acceptable yield loss (AYL) was calculated by fitting logistic and Gompertz equations to relative yield data. The CPWC in red pepper was determined from 0 to 1087 growing degree days (GDD) in 2008 and from 109 to 796 GDD in 2009 for 10% AYL after crop emergence in red pepper. For 2.5-5% AYL, the CPWC starts with germination and lasts until harvest. Direct seeded red pepper is very vulnerable to weed competition and weed control programs for direct seeded spice pepper in Turkey should include pre-emergence and residual herbicides.Keywords: acceptable yield loss (AYL), critical period of weed control (CPWC), direct seeded pepper, red pepper (Capsicum annum L.), spice pepper, weeds.

No abstract

No abstract