Model-based evaluation of irrigation needs in Mediterranean vineyards

The irregular rainfall distribution causes interannual variation of water status in Mediterranean vineyards. A frequential analysis of irrigation needs was carried out from continuous simulation of the soil water balance during 39?years in south France. The off-season soil water refilling was often incomplete, with a higher frequency in soils with a high total transpirable soil water (TTSW) and/or susceptible to runoff and high evaporation. On soils with high TTSW (over 250?mm), the irrigation need was nil or small (except in situations of high runoff) and focused on the beginning of the crop cycle. On soils with lower TTSW, the irrigation need increased on average and was spread all along the grapevine cycle due to the limited buffering effect of the soil water reservoir. For 100?mm TTSW, the irrigation need was 40–60?mm for half of the years. The calculated irrigation needs were sensitive to the soil (TTSW, susceptibility to runoff and evaporation) and canopy (crop coefficient) properties. Therefore, soil and canopy management should be considered together with irrigation for an integrated approach of water management.     

Fumonisin B-glucose reaction products are less toxic when fed to swine

The effects of fumonisin B-glucose reaction products in swine diets was examined. Pigs were fed diets containing 528 micromol of total fumonisin B/kg (FB), 528 micromol of total FB-glucose adducts/kg (FB-G, 122 micromol of unreacted FB/kg), or 0 micromol of total FB/kg for 15 days to test the efficacy of the FB-G reaction products in detoxifying FB. Weight gain in FB pigs was lower than in FB-G or controls, which was correlated with feed intake reduction in FB pigs. Serum aspartate aminotransferase, gamma-glutamyltransferase, and total bilirubin in FB pigs were higher than in FB-G or control pigs. Serum sphinganine/shingosine ratios in FB pigs were higher than in FB-G or control pigs. Microscopic examination of tissues from FB pigs showed generalized liver necrosis and apoptosis with marked cellular pleomorphism and disorganized hepatic cords. The liver and kidneys in the FB-G group appeared to be normal. Tissues of controls were free of lesions. Results suggest that dietary FB-G products are less toxic to swine and may provide an detoxification approach in instances of widespread FB grain contamination (p < 0.05).     

Soil fertilization and pH effects on meadowfoam growth and flowering 1

Meadowfoam (Limnanthes alba Hartweg ex. Bentham) is a new oilseed crop. Published information on nutritional requirements and optimum soil pH for growing meadowfoam in controlled environments is currently lacking. This study evaluated the effects of application rates and timing of a modified Hoagland's solution and a range in initial potting medium pH on meadowfoam (L. alba subsp. alba, cv Mermaid) growth and development under controlled environment conditions. Weekly application of 50 mL of nutrient solution at a nitrogen (N) concentration of 840 mg/L (four times higher than the concentration in modified Hoagland's solution) resulted in good Mermaid growth and flower production. Optimum fertilizer application timing is apparently from one week after transplanting (38 days after seeding) until the flowering stems begin to elongate above the rosette leaves. Optimum soil pH seemed to be between 5 and 6, although Mermaid grew relatively well under initial soil pH ranging from 3.8 to 7.3.     

Anthocyanin glycosides from berry fruit are absorbed and excreted unmetabolized by both humans and rats

Anthocyanins, the red/blue pigments found in plants, are polyphenolic compounds consumed by humans and are part of a normal diet. Recent studies have shown that anthocyanins have substantial bioactivity including antioxidant activity and therefore may have beneficial effects on human health. Anthocyanins are a group of over 500 compounds of diverse structures containing different core phenolic aglycons and conjugated with sugars in a variety of glycosylation patterns. In this study, we have investigated the bioabsorption of 15 anthocyanins with structures containing different aglycons and conjugated sugars extracted from blueberry, boysenberry, black raspberry, and blackcurrant in both humans and rats. Intact and unmetabolized anthocyanins were detected in urine of rats and humans following dosing for all molecular structures investigated, thus demonstrating that anthocyanins with diverse molecular structure and from different dietary sources are bioavailable at diet relevant dosage rates. In addition, the relative concentrations of anthocyanins detected in urine following dosing varied, indicating that differences in bioavailability are due to variations in chemical structure. Our results suggest that the nature of the sugar conjugate and the phenolic aglycon are both important determinants of anthocyanin absorption and excretion in rats and humans.     

Predictive relationship between polyphenol and nonfat cocoa solids content of chocolate

Chocolate is often labeled with percent cocoa solids content. It is assumed that higher cocoa solids contents are indicative of higher polyphenol concentrations, which have potential health benefits. However, cocoa solids include polyphenol-free cocoa butter and polyphenol-rich nonfat cocoa solids (NFCS). In this study the strength of the relationship between NFCS content (estimated by theobromine as a proxy) and polyphenol content was tested in chocolate samples with labeled cocoa solids contents in the range of 20-100%, grouped as dark (n = 46), milk (n = 8), and those chocolates containing inclusions such as wafers or nuts (n = 15). The relationship was calculated with regard to both total polyphenol content and individual polyphenols. In dark chocolates, NFCS is linearly related to total polyphenols (r2 = 0.73). Total polyphenol content appears to be systematically slightly higher for milk chocolates than estimated by the dark chocolate model, whereas for chocolates containing other ingredients, the estimates fall close to or slightly below the model results. This shows that extra components such as milk, wafers, or nuts might influence the measurements of both theobromine and polyphenol contents. For each of the six main polyphenols (as well as their sum), the relationship with the estimated NFCS was much lower than for total polyphenols (r2 < 0.40), but these relationships were independent of the nature of the chocolate type, indicating that they might still have some predictive capabilities.     

Possible connection between imidacloprid-induced changes in rice gene transcription profiles and susceptibility to the brown plant hopper Nilaparvatalugens Stål (Hemiptera: Delphacidae)

The chemical pesticide, imidacloprid (IMI) has long-lasting effectiveness against Hemiptera. IMI is commonly used to control the brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae). Some chemical pesticides, however, can induce the susceptibility of rice to BPH, which has indirectly led to the resurgence of BPH. The mechanism of the chemical induction of the susceptibility of rice to BPH was not previously understood. Here, a 44 K Agilent Rice Expression Microarray was used to identify changes in gene expression that accompany IMI-induced rice susceptibility to BPH. The results showed that 225 genes were differentially expressed, of which 117 were upregulated, and 108 were downregulated. Gene ontology annotation and pathway analysis revealed that differentially expressed genes were mainly classified into the eight functional groups: oxidation reduction, regulation of cellular process, response to stress, electron carrier activity, metabolic process, transport, signal transducer, and organismal development. The genes encoding plant lipid transfer protein, lignin peroxidase, and flavonol-3-O-methyltransferenase may be important responses to the IMI-induced susceptibility of rice to BPH. The reliability of the microarray data was verified by performing quantitative real-time PCR and the data provide valuable information for further study of the molecular mechanism of IMI-induced susceptibility of rice.     

Concentrations and environmental risk of chlorothalonil in air near potato fields in Prince Edward Island, Canada

BACKGROUND: Chlorothalonil is used extensively in Prince Edward Island for the control of blight on potatoes, and has been measured throughout summer months in ambient air monitoring studies. This study was designed to characterize near-field drift of chlorothalonil, and to evaluate how exposure to measured air concentrations might impact upon local wildlife species. RESULTS: Air samples were collected using high-volume samplers at three distances downwind of sprayed potato fields, and at four different time intervals. Chlorothalonil was detected in 73% of prespray samples (from < 0.013 to 0.440 µg m⁻³). The mean air concentration 0 m away from the field edge during spray was 5.8 µg m⁻³, which was 7–41 times higher than concentrations measured in similar studies. Air concentrations were found to decline exponentially both with distance and time, although 0 m and 30 m concentrations at 2 h post-spray remained significantly (3 times) higher than prespray (P < 0.05). Wind speed was not found to be significantly correlated with air concentration; however, increases in temperature were found to be significantly correlated with increases in air concentrations at all sample times, at 0 m and 30 m distances. CONCLUSION: Frequent prespray detections and high post-spray concentrations suggest that both chronic and acute exposures to non-target species are occurring; however, risk calculations suggest a relatively low risk of effects to representative species. One measurement showed that a human-health-based short-term guideline had been exceeded, indicating that potential impacts to humans from chlorothalonil under current application conditions cannot be discounted. Copyright © 2011 Crown in the right of Canada. Published by JohnWiley & Sons, Ltd