Communications in agricultural and applied biological sciences最新文献

Intensive use of pesticides, especially insecticides, in agriculture during the past several decades has already led to contamination of surface and underground waters and sediments in some regions, thus presents a serious problem for the environment. Lindane was one of frequently applied insecticides for soil treatment. In Serbia, it has been in use since 1944, but in the period 2001-2007 its use was restricted only to timber treatments. In 2009 an international ban on the use of lindane in agriculture was implemented under the Stockholm Convention on Persistent Organic Pollutants. However, due to a long-term use and persistence, its residues can be present in underground water and sediment, thus present a potential risk for incorporation in food chains. According to Directive 2008/105/EC it is listed as one of the priority water pollutants, whose presence is mainly detected by chemical methods. However, biological tests are gaining in importance in the last few years and since some plant species are highly sensitive to certain pollutants. This work aimed to assess potential of white mustard (Sinapis alba L.), cucumber (Cucumis sativus L.) and barley (Hordeum vulgare L.) as phyto-indicators of water contamination with lindane. The effect of lindane (rates 0.1 μg a.i./L--maximal allowable concentration (MAC) in water; 0.2; 0.5; 1 and 2 μg a.i./L) was assessed on physiological (germination energy and germination- %) and morphological parameters (root and shoot lengths, fresh and dry weights) of tested species. Assay was carried out using slightly modified filter paper method recommended by ISTA Regulations book (2011). The experiment was set in four replicates. Data were processed using Duncan's multiple range test for determining the differences between treatments for confidence interval 95%. Results of bioassay indicate that germination energy (70.75%) and germination (79.00%) of white mustard were significantly inhibited by lindane applied at MAC rate compared to the control (79.75, 82.00%, respectively). Physiological parameters of other test species were not affected by this insecticide. Lindane inhibited root elongation of barley seedlings at 2 μg a.i./L (20-fold MAC) and of cucumber at 0.5 μg a.i./L (5-fold MAC). Only fresh root weight of barley was inhibited by lindane at MAC quantities. Based on presented results, valid and reliable indicators of lindane presence in water can be considered germination energy and germination of white mustard and fresh root weight of barley seedlings.

The single and simultaneous phytotoxic effect of copper sulphate and Pyrinex 48 EC insecticide were investigated on chicken embryos. The eggs were injected by 0.1 ml of copper sulphate solution (0.05%) and/or by 0.1 ml of Pyrinex 48 EC (chlorpyriphos, 480 g/l; 1%). The treatments were performed on day 0 of incubation, and the embryos were examined on day 3 and 19 of it. Germinal disc was prepared to study the early stage of development. Number of embryonic death, developmental abnormalities and body weight of embryos were recorded on day 19. Liver samples were taken for histology and the skeleton was stained by Dawson method. The embryo mortality was not influenced by single treatment of copper sulphate, however, Pyrinex 48 EC and the combination of the test items significantly increased it on day 3. Same tendency was observed in the case of developmental aberration. Single administration of both test items and their combination significantly increased the embryo mortality on day 19. Frequency of abnormalities was not influenced by copper sulphate but single and simultaneous application of insecticide increased it significantly. Pyrinex 48 EC alone and in combination with copper sulphate significantly reduced the body weight, however, the copper sulphate alone did not influence it. Developmental abnormalities were observed sporadically in all cases. There were no findings of drug-induced hepatopathy, however, the ratio of the mitotic cells were markedly reduced. Based on the results, addition and synergistic toxic interaction may be between the copper sulphate and Pyrinex 48 EC that can highly reduce the viability of the embryos.

Neem plants (Rutales: Meliaceae) are well known for their multitude of human benefits in various fields. Specifically well investigated are the Indian neem tree Azadirachta indica A. Juss., the Thai neem A. siamensis Val., the originally Malaysian/Philippinean neem A. excelsa (Jack) and, as a close relative, the Persian lilac, Melia azedarach. The major and most active natural products are azadirachtin, salannin, nimbin and marrangin from Azadirachta species, and azadirachtin analogues like meliantriol from Melia species. Neem fruits, leaves, bark, and roots have specific virtues. They have been traditionally exploited for a considerable part of human history and are documented in Sanskrit texts. Due to human activity in trade and travel both at land and sea, the plant species has been distributed around the globe and is cultivated in many tropical, and subtropical regions. A multitude of natural products of neem have been isolated, chemically characterized or identified, and investigated for their properties in the management of insects, Acarina, Crustacea, nematodes, bacteria, fungi, viruses and soil fertility (for reviews see Kraus, 2002; Schmutterer, 2002A; Rembold, 2002; Koul, 2004; Schmutterer and Huber, 2005; Kleeberg and Strang, 2009; Hummel et al., 2008, 2011, 2012). Neem products are virtually nontoxic, compatible with beneficial insects, pollinators and bees. They are environmentally benign, sustainable, renewable, and of a price affordable for developed countries. In conclusion, neem is a prime example of a natural resource with many beneficial applications in agriculture, human and veterinary medicine. So far, its use is practically free of resistance problems which are frustratingly prevalent in many areas of synthetic insecticide and drug development. Investigating more neem applications will increase future human welfare and health while being of general ecological benefit to the planet.

The broad mite Polyphagotarsonemus latus (Banks) is considered a major pest in potted azalea, Flanders' flagship ornamental crop of Rhododendron simsii hybrids. In addition to severe economic damage, the broad mite is dreaded for its increasing resistance to acaricides. Due to restrictions in the use of broad spectrum acaricides, Belgian azalea growers are left with only three compounds, belonging to two mode of action groups and restricted in their number of applications, for broad mite control: abamectin, milbemectin and pyrethrin. Although P. latus can be controlled with predatory mites, the high cost of this system makes it (not yet) feasible for integration into standard azalea pest management systems. Hence, a maximum efficacy of treatments with available compounds is essential. Because abamectin, milbemectin and pyrethrin are contact acaricides with limited trans laminar flow, only broad mites located on shoot tips of azalea plants will be controlled after spraying. Consequently, the efficacy of chemical treatments is influenced by the location and spread of P. latus on the plant. Unfortunately, little is known on broad mites' within-plant spread or how it is affected by climatic conditions like temperature and relative humidity. Therefore, experiments were set up to verify whether climate conditions have an effect on the location and migration of broad mites on azalea. Broad mite infected azalea plants were placed in standard growth chambers under different temperature (T:2.5-25°C) and relative humidity (RH:55-80%) treatments. Within-plant spread was determined by counting mites on the shoot tips and inner leaves of azalea plants. Results indicate that temperature and relative humidity have no significant effect on the within-plant spread of P. latus. To formulate recommendations for optimal spray conditions to maximize the efficacy of broad mite control with acaricides, further experiments on the effect of light intensity and rain are scheduled.