IMPACT OF IRRIGATION REGIME AND APPLICATION OF KAOLIN ON THE STOMATAL CONDUCTANCE AND LEAF WATER POTENTIAL OF PEPPER AND TOMATO

The effect of different irrigation regimes and the application of kaolin on stomatal conductance and leaf water potential of pepper (Capsicum annuum L.) and tomato (Lycopersicon esculentum Mill.), is discussed in the paper.The experiment was set up by a completely randomized block system with three replications. The peppers were observed in three, and tomatoes in two treatments of irrigation regimes. The kaolin treatments of both crops were: a) control without kaolin (C) and 5% kaolin suspension (K).The results of these studies show that the application of deficit irrigation treatments and kaolin treatment have no statistically significant effect on stomatal conductance and leaf water potential of pepper and tomato plants

Application of s/s method in the treatment of contaminated soil from non-sanitary landfills in the republic of Serbia

Stabilization/solidification (S/S) methods are applied in processes of the treatment of waste before to secure landfill disposal and the treatment of contaminated soil. In Serbia understanding of this method is limited. Republic of Serbia has 375 sites where land contamination is confirmed in laboratoty analysis. The most of identified sites are present in non-sanitary municipal landfills and uncontrolled dumps which require remediation. This paper analyzes possibilities of application of S/S methods in remediation of soil contaminated with copper (Cu). Cement based S/S method is applied to samples of contaminated materials. In some samples, additive, based on natural and synthetic zeolites, is added to cement. The level of Cu leached is indicator of the efficiency of S/S methods. The results show the conditions under which the S/S methods could be used for the most efficient immobilization of Cu in contaminated soil

Challenges of the Republic of Serbia in the treatment of waste sludge contaminated with heavy metals

The interactions of heavy metals and cement phases in the solidification/stabilization (S/S) process have been examined. The S/S method was applied to the waste sludge contaminated with heavy metals to determine the conditions under which the treated materials can be safely disposed of at landfills for inert, non-hazardous, or hazardous waste. Sludge samples were mixed with soil and sand to simulate improper sludge disposal directly into the soil. S/S technology was selected using different cement fractions to treat these contaminated samples. The use of Portland cement or mixtures of different types of cement for the treatment of sludge containing heavy metals is widespread. Samples of leached content were analyzed for the presence of the following metals: arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn). The study results lead to the conclusion that the sludge contaminated with heavy metals after the application of S/S with the addition of different cement fractions is transformed into non-hazardous, monolithic material

The effects of drought on the expression of TAO1, NCED and EIL1 genes and ABA content in tomato wild-type and flacca mutant

The effects of drought (partial root-zone drying-PRD and regulated deficit irrigation-RDI) and full irrigation (FI) on the expression of ABA biosynthetic genes (TAO1 and NCED), EIL1 gene and ABA content in the leaves of tomato wild-type (WT) and flacca mutant were investigated. Results confirmed differences in the expression of the investigated genes under the investigated treatments, during treatment duration as well as between investigated WT and flacca plants. The most significant differences between WT and flacca were found under PRD treatment. The similar expression pattern of all genes in the WT plants could indicate synergistic signaling pathways for ABA and ethylene. In flacca, reduced NCED and significant EIL1 expression might reflect the increase in ethylene production, which could influence the ABA signaling and production that occurred under PRD. Drought also induced an increase in ABA content that is most expressed in flacca under RDI

Comparison of Photoacoustic Signals in Photosynthetic and Nonphotosynthetic Leaf Tissues of Variegated Pelargonium zonale

Green-white variegated leaves of Pelargonium zonale were studied using the photoacoustic method. Our aim was to characterize photosynthetically active green tissue and nonphotosynthetically active white tissue by the photoacoustic amplitude signals. We observed lower stomatal conductance and higher leaf temperature in white tissue than in green tissue. Besides these thermal differences, significantly higher absorbance in green tissue was based on chlorophyll and carotenoids which were absent in white tissue. However, optical properties of epidermal layers of both tissues were equal. The photoacoustic amplitude of white tissue was over four times higher compared to green tissue, which was correlated with lower stomatal conductance. In addition, at frequencies >700 Hz, the significant differences between the photoacoustic signals of green and white tissue were obtained. We identified the photoacoustic signal deriving from photosynthetic oxygen evolution in green tissue, using high intensity of red light modulated at 10 Hz. Moreover, the photoacoustic amplitude of green tissue increased progressively with time which corresponded to the period of induction of photosynthetic oxygen evolution. For the first time, very high frequencies (1 kHz to 5 kHz) were applied on leaf material

Cavitation Wear of Basalt-Based Glass Ceramic

This paper examines the possibility of using basalt-based glass ceramics for construction of structural parts of equipment in metallurgy and mining. An ultrasonic vibration method with a stationary sample pursuant to the ASTM G32 standard was used to evaluate the possibility of the glass ceramic samples application in such operating conditions. As the starting material for synthesis of samples, olivine–pyroxene basalt from the locality Vrelo–Kopaonik Mountain (Serbia) was used. In order to obtain pre-determined structure and properties of basalt-based glass ceramics, raw material preparation methods through the sample crushing, grinding, and mechanical activation processes have been examined together with sample synthesis by means of melting, casting, and thermal treatment applied for the samples concerned. The mass loss of samples in function of the cavitation time was monitored. Sample surface degradation level was quantified using the image analysis. During the test, changes in sample morphology were monitored by means of the scanning electronic microscopy method. The results showed that basalt-based glass ceramics are highly resistant to cavitation wear and can be used in similar exploitation conditions as a substitute for other metal materials