美国加州的葡萄生产与科研

对美国加州的葡萄种质资源保存与研究、栽培技术、贮藏保鲜、病虫害防治、脱毒技术以及无核葡萄品种与育种等作了较为详细的论述 ;同时强调指出 ,我国进行葡萄引种时除重视经济性状外 ,还应特别注意病虫检疫。     

Nitrogen mineralization from mature bio‐waste compost in vineyard soils. III Simulation of soil mineral‐nitrogen dynamics

A model for nitrogen (N) dynamics in compost‐amended vineyard soils was tested for its predictive power. A soil–mineral N data set from a 3‐year field study on four different vineyard sites was used for model evaluation. The soils were treated with mature bio‐waste compost (30 and 50 Mg ha^–1 fresh matter, respectively). The model calculated soil mineral‐N contents at all sites with an overall mean bias error of –2.2 kg N ha^–1 for layers of 0.1 m thickness and an overall mean absolute error of 7.4 kg N ha^–1 layer^–1. Modeling efficiencies for the simulations of the respective treatments ranged from –0.05 to 0.41, and Willmott's Index of Agreement showed values of between 0.41 and 0.81. Acceptable model predictions as defined by the observed variability of mineral‐N contents in the respective soils ranged from 40% to 72%. A strong increase in soil mineral‐N concentration following the compost application at all sites could not be reproduced with the model, thereby reducing the prediction accuracy significantly. The model performance confirms that previously derived N‐mineralization parameters are suitable to describe the N release from soil‐applied mature bio‐waste compost under the environmental conditions of vineyards in Germany.     

Delayed harvest of reed canary grass translocates more nutrients in rhizomes

Abstract

Two field experiments, one in large plots and the other in small framed plots, were conducted in Umeå, northern Sweden. The objectives were (1) to examine the seasonal patterns of rhizome growth and nutrient dynamics of the energy crop reed canary grass (Phalaris arundinacea L.) in ley I and II, and (2) to evaluate the roles of soil type (mineral vs. organic), fertilisation level (0, 50, and 100 kg N ha^?1s), and season/harvest time (Oct-96, May-97, and Aug-97) on the rhizome growth and nutrient dynamics by means of a factorially designed experiment. The general pattern of rhizome growth was that biomass was low in June during initiation of shoot growth, but increased steadily during the growing season, reached a peak in late autumn, and remained high until next spring. The N and P accumulation in rhizomes followed a similar pattern. During ley years I and II, reed canary grass rhizome growth was less dependent on soil type, and more dependent on fertilisation and season, with fertilisation being the most important predictor of growth. The season/harvest time, followed by soil type, was the most important factor for both concentrations and therefore total uptake of N, P, and K in rhizomes. Soil type affected N content in rhizomes significantly, and also interacted with season and enhanced the effect on N, P, and K content in rhizomes. The seasonal dynamics of the nutrient content in rhizomes indicate a remobilisation of the nutrients from rhizomes to the regrowth of shoots and roots in spring and relocation/storage from aboveground shoots to rhizomes during late summer and autumn. The results of this study suggest that delaying the harvest to later than October would result in considerably more energy and nutrient resources being translocated from aboveground shoots to rhizomes for growth in the next season.     

Coincidence of maximum severity of powdery mildew on grape leaves and the carbohydrate sink‐to‐source transition

Grapevine leaves infected with powdery mildew are a source of inoculum for fruit infection. Leaves emerging on a single primary shoot of Vitis vinifera cv. Cabernet Sauvignon were exposed to average glasshouse temperatures of 18°C (0·23 leaves emerging/day) or 25°C (0·54 leaves emerging/day). All leaves on 8–10 shoots with approximately 20 leaves each were inoculated with Erysiphe necator conidia to assess disease severity after 14 days in the 25°C glasshouse. Two photosynthetic ‘source’ leaves per shoot on the remaining 8–10 shoots were treated with ¹⁴CO₂ to identify, by autoradiography, the leaf position completing the carbohydrate sink‐to‐source transition. There was a clear association between the mean modal leaf position for maximum severity of powdery mildew (position 3·7 for 18°C; position 4·4 for 25°C) and the mean position of the leaf completing the sink‐to‐source transition (position 3·8 for 18°C; position 4·7 for 25°C). The mean modal leaf position for the maximum percentage of conidia germinating to form secondary hyphae was 4·2 for additional plants grown in the 25°C glasshouse. A higher rate of leaf emergence resulted in a greater proportion of diseased leaves per shoot. A Bayesian model, consisting of component models for disease severity and leaf ontogenic resistance, had parameters representing the rate and magnitude of pathogen colonization that differed for shoots developing in different preinoculation environments. The results support the hypothesis that the population of leaves in a vineyard capable of supporting substantial pathogen colonization will vary according to conditions for shoot development.     

Adaptive Nutrient Supply and Soil Cultivation Methods in the Upper Zone of Hillside Vineyards

Somló-hill is Hungary's smallest wine district; however, it produces some of the best white wines. Viticulture dates back about 2000 years in the district, and the climate is balanced. Former volcanic activity was an important factor in the development of the brown forest soils (Cambisols). Experiments were conducted in 2006–2008 in vineyards located in the upper zone (above 200 m sea level) of Somló-hill for studying the most adaptive and environmentally friendly soil cultivation and nutrient-supply methods. The following treatments were applied in four replicates: (soil cultivation experiment) SC₁, natural grass cover; SC₂, mechanical soil cultivation; and SC₃, organic mulch (crop residues), and (nutrient supply experiment) NS₁, unfertilized control, NS₂, nitrogen (N) fertilizer (NH₄NO₃) 50 kg ha^?1; and NS₃, farmyard manure (34 tons ha^?1). Main chemical soil characteristics were determined in the 0- to 30-cm and 31- to 60-cm soil layers at blossoming and grape ripening. Yield parameters (kg per m², soluble solids g per 100 g juice, and titratable acidity, g L^?1) were assessed at harvest. The experimental results suggested that covering the soil with crop residues resulted in the greatest yields, explained by the more favorable soil water conditions. Differences in yield parameters were significant in 2 of 3 years. Soil mineral N content also showed significant differences among treatments. Increased N requirement of crop residues and natural crop cover were suggested. Results of the experiments showed that both ammonium nitrate and farmyard manure resulted in increased grape yield compared to the unfertilized control. Maintaining adequate soil moisture levels (containing basalt debris with low humus content and shallow fertile layer with poor water management) and soil organic matter content is of great importance because other nutrients may be ensured by the weathering of basalt.     

啶虫脒/羧甲基壳聚糖缓释微球性能研究

[目的]探索啶虫脒/羧甲基壳聚糖缓释微球的最佳制备条件。[方法]以啶虫脒为囊心药物,以羧甲基壳聚糖-阿拉伯胶-明胶作为载体材料,采用锐孔法制备啶虫脒缓释凝胶微球,以包封率为参考指标,通过正交试验探究啶虫脒缓释微球的最佳制备条件,并探讨壳聚糖缓释微球对啶虫脒的缓释性能。[结果]啶虫脒缓释微球的最佳制备条件为：25 g/L羧甲基壳聚糖、羧甲基壳聚糖-啶虫脒的浓度比为2∶1、1.5%氯化钙、戊二醛浓度为5%。所制备的啶虫脒/羧甲基壳聚糖-阿拉伯胶-明胶缓释凝胶微球的包封率达48.56%,并具有很好的缓释性能,缓释时间达60 h以上。[结论]制得的羧甲基壳聚糖-阿拉伯胶-明胶微球对啶虫脒有控制释放的作用。     

How long can a herbicide remain in the spray tank without losing efficacy?

Five field trials were conducted over a three-year period (2006–2008) at two locations in southwestern Ontario to determine the length of time herbicides can remain in the spray tank prior to application in the field without impacting efficacy. Four pre-emergence and five post-emergence herbicides were mixed at their labelled rates and then applied in maize. Herbicides were either applied immediately after mixing in water, or after being held in solution for 1, 3 or 7 days. The most common weed species in the trials were Abutilon theophrasti, Amaranthus retroflexus, Ambrosia artemisiifolia, and Chenopodium album. Holding the herbicides in spray solution for up to 7 days did not affect the efficacy of the post-emergence herbicides in this study. Similarly, control of A. retroflexus and C. album with the pre-emergence herbicides was not affected holding the herbicides in spray solution for up to 7 days. However, control of A. theophrasti was decreased when isoxaflutole plus atrazine, dimethenamid plus dicamba/atrazine, or rimsulfuron plus S-metolachlor plus dicamba was in spray solution for more than 1 day. Nonetheless, there were no decreases in yield for any of the treatments evaluated. These data provide valuable information which growers can use to make informed decisions on whether to apply herbicides in non-ideal weather or to postpone application. The results of this study suggest that for the herbicides and weed species tested it is better to postpone application rather than make applications under non-ideal conditions.     

Delayed permanent water rice production systems do not improve the recovery of 15N-urea compared to continuously flooded systems

Crop recovery of nitrogen (N) fertiliser in flooded rice systems is low relative to fertiliser N recoveries in aerobic crops, and the N losses have environmental consequences. Recent water shortages across the globe have seen a move towards alternative water management strategies such as delayed permanent water (DPW, also known as delayed flood). To investigate whether N fertiliser regimes used in DPW systems result in greater recovery of N fertiliser than traditional continuously flooded (CF) rice systems, we conducted a multi-N rate field trial using ¹⁵N-labelled urea. Around 27% of the ¹⁵N-labelled fertiliser was recovered in aboveground biomass at maturity, regardless of water regime or N fertiliser rate, and approximately 20% recovered in the soil to 300 mm depth. Plants in the CF system accumulated more total N at each rate of applied N fertiliser than plants in the DPW system due to greater exploitation of native soil N reserves, presumably because the earlier application of N fertiliser in the CF systems led to greater early growth and higher crop N demand. The greater crop biomass production as a result of higher N uptake in the CF system did not increase grain yields above those observed in the DPW system, likely due to cold weather damage. In the following season at the same site, a single N rate (150 kg N ha⁻¹) trial found no significant differences in crop N uptake, biomass yields, grain yields or ¹⁵N-labelled urea recovery in DPW, CF and drill sown-CF (DS-CF) treatments. However, owing to higher ¹⁵N fertiliser recovery in the 0–100 mm soil horizon, total plant + soil recovery of ¹⁵N was significantly higher in the CF treatment (63%) than the DS-CF and DPW treatments (around 50% recoveries). The loss of 40–50% of the applied N (presumably as NH₃ or N₂) in both seasons regardless of watering regime suggests that new fertiliser N management strategies beyond optimising the rate and timing of urea application are needed, particularly in light of increasing N fertiliser prices.     

A wireless sensor network for precision viticulture: The NAV system

In the last decade, wireless technologies have been increasingly applied in precision agriculture. Wireless monitoring systems in particular have been used in precision viticulture in order to understand vineyard variability, and therefore suggest appropriate management practices for improving the quality of the wines.The NAV (Network Avanzato per il Vigneto – Advanced Vineyard Network) system is a wireless sensor network designed and developed with the aim of remote real-time monitoring and collecting of micro-meteorological parameters in a vineyard. The system includes a base agrometeorological station (Master Unit) and a series of peripheral wireless nodes (Slave Units) located in the vineyard. The Master Unit is a typical single point monitoring station placed outside the vineyard in a representative site to collect agrometeorological data. It utilizes a wireless technology for data communication and transmission with the Slave Units and remote central server. The Slave Units are multiple stations placed in the vineyard and equipped with agrometeorological sensors for site-specific environmental monitoring, which store and transmit data to the Master Unit. Software was developed for setup and configuration functionality. A graphical user interface operating on the remote central server was implemented to collect and process data and provide real-time control. The devices were tested in a three-step process: hardware functionality and data acquisition, energy consumption and communication. The NAV system is a complete monitoring system that gave flexibility for planning and installation, which fully responded to the objectives of the work in terms of energy efficiency and performance.