Transfer of the fungicide vinclozolin from treated to untreated plants via volatilization

Head lettuce plantlets (Lactuca sativa L. var. capitata) were potted, treated with vinclozolin at the six-leaf stage according to application standards and allowed to dry for 24 h. The potted plantlets were then placed in either growth chambers with controlled temperature (20 and 25 degrees C, respectively) or in a greenhouse (approximately 12 degrees C), together with untreated spinach (Spinacia oleracea L.) and standardized grass cultures (Lolium multiflorum Lam. ssp.) While the treated lettuce pots remained in the respective growing compartments until the end of the experiments, spinach and grass were exposed to the compartment air for 24 h and their shoot material was analyzed for vinclozolin by GC-ECD and GC-high resolution mass spectrometry. Exposure and analysis of untreated spinach and grass were carried out at two- or three-day intervals during the course of the experiments. Also, air samples were taken from the compartments at intervals and analyzed for vinclozolin. Maximum vinclozolin concentration in the growth chamber air was about 330 ng m(-3) while vinclozolin contamination of the untreated plants ranged from 50 to 200 microg kg(-1) FW (fresh weight). In the greenhouse atmospheric vinclozolin concentration reached approximately 15 ngm(-3) and maximum contamination of spinach and grass were 30-40 microg kg(-1) FW. Our data clearly show that unintended contamination of plants growing in the vicinity of vinclozolin-treated plants can occur even if the fungicide layer is completely dry. Implications for safety testing and food plants are discussed.     

Short-term responses of soil chemistry, needle macronutrients and tree growth to clinker dust and fertiliser in a stand of Scots pine

Waste management of clinker dust by spreading it on forest soil was studied in a 25-year-old Scots pine stand on acidic sandy soil. Clinker dust (0.5 kg m?2), fertiliser (N, P, K, Mg, 0.05 kg m?2; N 190 kg ha?1) and untreated soil were applied on 120-m2 plots in four replicates. The fertiliser was included to confirm the nutrient limitation in the stand. Clinker dust increased the soil pH by 1.2 units relative to the pH of 4.6 in the untreated soil by the second year. Soil K and Mg concentrations were larger in the dust and fertiliser treatments. Nutrient diagnostics indicated that needles of untreated trees were deficient in N and K. Fertiliser treatment indicated that the growth of trees was limited by N, since the fertiliser tended to increase needle K, N, N/P, needle dry mass and diameters of stem and shoots. By an auxiliary dataset, no effects of the dust and fertiliser on possible excess of the micronutrient Mn were observed. Clinker dust increased needle K concentration, but due to the N limitation, there was no increase in the growth of stems, branches, shoots and needles. It was concluded that in plots of 120 m2 application of clinker dust at a rate of 0.5 kg m?2 was safe for the 21-year-old Scots pine stand in this trial on an acid nutrient-poor sandy soil during 4 years after the treatment.