Evaluation of two visual birdscarers,the Peaceful Pyramid® and an eye‐spot balloon,in two vineyards

Abstract

The effectiveness of a visual birdscarer, the Peaceful Pyramid®, relative to a much‐cheaper eye‐spot balloon was investigated experimentally in two vineyards in Canterbury, New Zealand. Monitoring of bird damage to natural bunches of Riesling grapes within vineyard blocks showed that the rate of starling (Sturnus vulgaris) damage to the crop was reduced significantly by the balloon relative to pyramid and control plots. Nevertheless, after 24 days of monitoring, birds in the balloon plot had damaged 75% of the grapes, respectively (cf. 84% in the pyramid plot). In a second trial, clusters of table grapes were attached to vineyard wire at a Lincoln vineyard. The balloon and pyramid both reduced bird damage to clusters within 15 m of the device, but had no measurable effect on clusters further away. We conclude that neither device would provide growers with any economically significant reduction in grape damage. This study highlights the importance of undertaking quantitative assessments of the numerous bird‐scaring technologies presently available to growers.     

Multiple forms of Vitis vinifera catechol oxidase

Grape catechol oxidase shows multiple forms upon ion exchange chromatography, acrylamide gel electrophoresis and gel filtration. Conversion of some bands into others, which occurs during isolation and storage, is enhanced by dilution and by treatment with urea or acid pH. Estimation of MWs suggested that the conversions might be due to dissociation of the enzyme into subunits, but attempts to induce reassociation were unsuccessful. The effects of urea and acid pH could be imitated by partial enzymic proteolysis of the enzyme. Analysis of the various bands observed in gel electrophoresis suggested that some of the enzyme forms have the same MWs but differ in charge distribution.     

Degradation of Guanidino Compounds by Silver Carbonate on Celite

A determination was made of fatty acid compositions in twelve commercial red wines made from grapes differing in kind and vintage. Twelve fatty acids were identified, palmitic, myristic, and lauric acids being found predominant. Total acyls (32～81 nmol/100 ml) differed considerably. Changes in fatty acid constituents in must from grape berries and wines according to the process of manufacture were also examined.     

Effects of dietary grape seed extract on growth performance,amino acid digestibility and plasma lipids and mineral content in broiler chicks

Polyphenols are chemically and biologically active compounds. Grape seed extracts (GSEs) have been widely used as a human food supplement for health promotion and disease prevention. However, there is little information regarding its application in animal feeds. An experiment was conducted to investigate the effect of inclusion of GSE at 0.025, 0.25, 2.5 and 5.0 g/kg in a wheat soya bean control diet on growth performance, protein and amino acid (AA) digestibility and plasma lipid and mineral concentrations in broiler chickens at 21 days of age. Performance was not affected by dietary treatment except in the case of birds fed the diet with the highest GSE concentration, which showed a worsening of weight gain and feed conversion. Apparent ileal digestibility (AID) of protein was significantly reduced in the birds fed the highest concentration of GSE, which also had a reduction on the AID of arginine, histidine, phenylalanine, cystine, glutamic acid and proline compared with those fed control diet. The inclusion of graded concentration of GSE in the chicken diets caused a significant linear decrease in the concentrations of plasma copper, iron and zinc. Plasma cholesterol, triglycerides and lipoproteins (high-density lipoprotein, low-density lipoprotein and very-low-density lipoprotein) concentrations were not affected by dietary GSE. In conclusion, this study demonstrated that incorporation of GSE in chicken diets up to 2.5 g/kg had no adverse effect on growth performance or protein and AA digestibility. Feed conversion was reduced and growth rate was retarded, when chickens were fed 5 g/kg of GSE. This study also indicated that grape polyphenols reduce the free plasma minerals.     

Programmed accumulation of LEA-like proteins during desiccation and cold acclimation of overwintering grape buds

Molecular investigation of the process of cold acclimation in woody plants has been limited by the superimposition of dormancy-related events on the process of cold tolerance development. To address this limitation, we have used the grape Vitis labruscana L. ev. Concord to develop a system in which the developmental programme of dormancy can be induced seperately from cold acclimation. Using this system we have characterized differential accumulation of several proteins in grape buds during the normally superimposed endodormancy and cold acclimation programmes, and in buds which have entered only the endodormancy programme. A set of 47 kD proteins accumulated during endodormancy without cold acclimation to a level similar to that found in endodormant and cold-acclimated buds, but without any associated increase in bud cold-acclimation level. However, a 27 kD LEA-like protein accumulated only in cold acclimated buds. We conclude that expression of the 47 kD glycoprotein is endodormancy-related, but is not strictly related to the development of cold acclimation, while the 27 kD protein appears to be more specific to cold acclimation. In addition to strengthening the association of LEA-like proteins with cold acclimation, this system allows more specific assessment of cold acclimation-associated phenomena in overwintering buds.