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Table grape is a fruit well suited for consumption as fresh-cut product. Selenium (Se) is an essential mineral nutrient for human growth, and Se-deficiency is a worldwide nutrition problem. Meanwhile, with Se-enriched fruits is becoming more and more popularity, improving Se content and fruit quality in grape is especially important for human health. Se content of grape berries was increased by Se fertilizer application, the maximum Se content and raise ratio of European and American species was 34.96 ug kg −1 FW and 36.88% respectively, higher than those of Eurasian species 19.46 ug kg −1 FW and 21.40%. In addition, Se fertilizer increased nutrition quality, including soluble sugar, Vc, soluble protein, soluble solid, reduced organic acid, while it had no effect on polyphenol antioxidants of Eurasian species. K and Ca content of grape berries was significantly increased, and reduced accumulation of heavy metals Pb, Cr, Cd, As, Ni. Se in fruits was positively related to fruit quality, and negatively correlation of heavy metals. In conclusion, Se fertilizer can be used to increase Se content of grape, especially for European and American species, with significant effect of increasing grape nutrition quality and an effective means of lowering heavy metals. [ABSTRACT FROM AUTHOR]

Water availability is a major factor that limits grain yield in the Loess Plateau of China. As competition for water intensifies between the agricultural and industrial sectors, it is essential to improve the agricultural water use efficiency (WUE) in the region. This requires the development of alternative irrigation schedules that maximize WUE. A field experiment was conducted for winter wheat (Triticum aestivum L.) during the period 1995–1998 to calibrate and test a biophysically based model WAVES in terms of grain yield and WUE predictions. Different irrigation treatments were carried out and the data collected included water and energy balance components, biomass, and grain yield. The model was run for 3 years with the measured meteorological data and grain yield was modeled using two different formulations. Comparisons between the measurements and the model predictions were made with 3 years of independently measured data. The results showed that the simulated grain yield and WUE based on biomass and harvest index are in better agreement with the measurements than those based on transpiration and harvest index. The model is sensitive to different irrigation treatments, and in reasonable agreement with field measured data. Results from both the field experiments and model simulation showed that evapotranspiration was greatest in the highest irrigation treatment, but the grain yield was not the highest and WUE was relatively low. Appropriately limited irrigation could improve the grain yield and WUE. Therefore, the WAVES model can be used to simulate grain yield and WUE of winter wheat in the Loess Plateau. A better irrigation scheme should aim for maximum WUE and any attempts to solely increase grain yield in the region would not be sustainable. [Copyright &y& Elsevier]

On the Loess Plateau of China crop yields are mainly limited by available water. A field experiment was conducted for winter wheat (Triticum aestivum L.) during the period 1995–1998 to evaluate the effects of limited irrigation on yield and water use efficiency. A controlled soil water deficit, either mild or severe, was applied at different stages of crop growth. Photosynthesis rate, soil water content, and root and shoot dry mass accumulation were measured. Final grain yields and total water consumption were recorded, and the water use efficiency and harvest index were calculated.The results showed that, in different growing periods, evapotranspiration, grain yield, biomass, water use efficiency (WUE), and harvest index depended on the controlled ranges of soil water content. Grain yield response to irrigation varied considerably due to differences in soil moisture contents and irrigation scheduling between seasons. Evapotranspiration was largest in the high soil moisture treatment, and so was the biomass, but this treatment did not produce the highest grain yield and WUE was relatively low. WUE increased linearly with harvest index (HI) and improvement in the latter gave better WUE under limited irrigation conditions. Appropriately controlled soil water contents can improve the grain yield, WUE, and harvest index. Consistently high values of grain yield, WUE, and harvest index were produced under conditions of mild water deficit at the seedling and start of regrowth to stem-elongation stages, in addition to a further soil water depletion at the physiological maturity to harvest stage. We therefore suggest that periods of mild soil water depletion in the early vegetative growth period together with severe soil water depletion in the maturity stage of winter wheat is an optimum for limited irrigation regime in this region. [Copyright &y& Elsevier]