Improvement of Vineyard Management of Vitis vinifera L. cv. Grk in the Lumbarda Vineyard Region (Croatia)

The vine-growing region of Lumbarda, located in the southeastern part of the island of Korcula, Croatia, has deep sandy soils (paleodunes) associated with the Mediterranean climate and provides optimal conditions for cultivating the autochthonous vine variety Vitis vinifera L. cv. Grk. Unfortunately, recently growers have noted declining yield and quality of grapes resulting from inadequate vineyard management (particularly unsustainable management of soil organic matter) and the occurrence of viral diseases. To revitalize and maintain the vineyards in the Lumbarda region, a detailed study was carried out involving intensive soil survey, analysis of grapevine nutrient status, positive clonal selection, and establishment of new vineyards with virus-free plant material. Preliminary soil survey results provided insight into the extent of variability in major physical and chemical soil characteristics. Based on these results, eight markedly different vineyards were selected for detailed analysis of grapevine nutrients [boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), and zinc (Zn)] at key development stages to detect potential imbalances that may hamper vine growth and affect its production. Leaf blades and petioles were sampled at midflowering and midveraison stages during the 2007–8 growing season from each of the selected vineyards. The greatest variability in nutrient content between the study sites was recorded for Cu, and considerable variability was also determined for B, Mn, Mg, and P. Differences in fertilization practices are the most common reasons for this variability. The results point to B deficiency in some of the vineyards and suggest potentially toxic levels of Cu in others.     

Sampling saproxylic beetles: lessons from a 10-year monitoring study

We sampled saproxylic beetles using trunk window traps in two birch-dominated forests in Finland during 1990-1999. The sampling scheme, 10 traps attached to living fruiting bodies of Fomes fomentarius growing on dead birches, remained unchanged in both forests throughout the study period. Beetles belonging to 32 selected families were identified every year, whereas all species were identified during the last 4 years. Total number of identified individuals was 40,294 and number of species 583, of which 258 were saproxylic (dependent on dead wood). Species richness of rare and threatened saproxylic beetles in the samples varied a lot between the years and did not fluctuate synchronously between the forests. Variation between years was smaller when all saproxylic species were pooled together and some abundant species fluctuated synchronously in the two forests. Similarity indices and DCA-ordination did not generally suggest decreasing similarity between samples with increasing temporal isolation. Incidence-based similarities of common saproxylic species within and between forests and years were high (means 0.7-0.8), whereas those of rare saproxylics were roughly 50% smaller and much more variable. More than 75% of the common saproxylic species found during the entire 10-year period were detected already after 3 years of sampling but accumulation of rare and threatened species was much slower. Our results suggest that: (1) occurrence of rare and threatened species in samples is much less predictable than that of common species and, e.g. reserve selection based on rarities should be made cautiously; (2) estimation of total number of threatened species in a forest is very difficult, because such species accumulate slowly in the samples; (3) samples from different years can be comparable in certain cases.     

Deficit Irrigation of Soya Bean [Glycine max (L.) Merr.] in a Sub-humid Climate

An experiment was conducted to investigate the influence of different levels of water deficit on yield and crop water requirement of soya beans in a sub‐humid environment (Southern Marmara region, Bursa, Turkey) in 2005 and 2006. One full‐irrigated treatment (T₁), one non‐irrigated treatment (T₅) and three different deficit irrigation (T₂ = 25 % water deficit, T₃ = 50 % water deficit, T₄ = 75 % water deficit) treatments were applied to ‘Nova’ soya bean planted on a clay soil. Non‐irrigated and all deficit irrigation treatments significantly reduced biomass and seed yield and yield components. The full‐irrigated (T₁) treatment had the highest yield (3760 kg ha^?1), while the non‐irrigated (T₅) treatment had the lowest yield (2069 kg ha^?1), a 45.0 % seed yield reduction. T₂, T₃ and T₄ deficit irrigation treatments produced 11.7–27.4 % less seed yield than the T₁ treatment. Harvest index showed less and irregular variation among irrigation treatments. Both leaf area per plant and leaf area index were significantly reduced at all growth stages as amount of irrigation water was decreased. Evapotranspiration increased with increased amounts of irrigation water supplied. Our results indicate that higher amounts of irrigation resulted in higher seed yield, whereas water use efficiency and irrigation water use efficiency values decreased when irrigation amount increased.     

Validation of an ELISA method for the serological diagnosis of canine brucellosis due to Brucella canis

In the present study, the validation of an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of canine brucellosis is described. Two different antigenic extracts, obtained by heat or ultrasonic homogenization of microbial antigens from a wild isolate of Brucella canis bacteria, were compared by ELISA and Western blot (WB). A total of 145 canine sera were used to define sensitivity, specificity and accuracy of the ELISA as follows: (1) sera from 34 animals with natural B. canis infection, confirmed by blood culture and PCR, as well as 51 sera samples from healthy dogs with negative results by the agar–gel immunodiffusion (AGID) test for canine brucellosis, were used as the control panel for B. canis infection; and (2) to scrutinize the possibility of cross reactions with other common dog infections in the same geographical area in Brazil, 60 sera samples from dogs harboring known infections by Leptospira sp., Ehrlichia canis, canine distemper virus (CDV), Neospora caninum, Babesia canis and Leishmania chagasi (10 in each group) were included in the study. The ELISA using heat soluble bacterial extract (HE-antigen) as antigen showed the best values of sensitivity (91.18%), specificity (100%) and accuracy (96.47%). In the WB analyses, the HE-antigen showed no cross-reactivity with sera from dogs with different infections, while the B. canis sonicate had various protein bands identified by those sera. The performance of the ELISA standardized with the heat soluble B. canis antigen indicates that this assay can be used as a reliable and practical method to confirm infection by this microorganism, as well as a tool for seroepidemiological studies.