Responses of sweet pepper (Capsicum annum L.) cultivated in a closed hydroponic system to variable calcium concentrations in the nutrient solution.

Background: The use of water containing calcium bicarbonate (Ca(HCO ) ) at excessively high concentrations in closed hydroponic crops can cause calcium ion (Ca ) accumulation in the recycled nutrient solution (NS) and concomitantly negatively affect yield and product quality. The aim of the study was to determine maximum Ca concentrations that do not harm the crop and to simulate the pattern of Ca accumulation when the Ca concentration in the irrigation water, and concomitantly in the replenishment nutrient solution (RNS), is excessive. In the current study, irrigation water containing 1.

Impact of Cultivar and Grafting on Nutrient and Water Uptake by Sweet Pepper ( L.) Grown Hydroponically Under Mediterranean Climatic Conditions.

In closed-cycle hydroponic systems (CHS), nutrients and water should be delivered to the plants at identical ratios to those they are removed via plant uptake, to avoid their depletion or accumulation in the root zone. For a particular plant species and developmental stage, the nutrient to water uptake ratios, henceforth termed "uptake concentrations" (UC), remain relatively constant over time under similar climatic conditions. Thus, the nutrient to water uptake ratios can be used as nutrient concentrations in the nutrient solution (NS) supplied to CHS to compensate for nutrient and water uptake by plants.

Monitoring particulate matter levels and climate conditions in a Greek sheep and goat livestock building.

Atmospheric pollutants from livestock operations influence air quality inside livestock buildings and the air exhausted from them. The climate that prevails inside the building affects human and animal health and welfare, as well as productivity, while emissions from the building contribute to environmental pollution. The aim of this study was to examine the variation of two climatic parameters (namely temperature and relative humidity) and the levels of particulate matter of different sizes (PM10-PM2.

Temperature, comfort and pollution levels during heat waves and the role of sea breeze.

During the summer of 2007 several Greek regions suffered periods of extreme heat, with midday temperatures of over 40 degrees C on several consecutive days. High temperatures were also recorded on the east coast of central Greece, where a complex sea breeze circulation system frequently develops. The more intense events occurred at the end of June and July.