2-Methoxy-3-isobutylpyrazine (MIBP) contributes a bell pepper aroma to many grape cultivars and has a reported aroma threshold of ∼2 ng L(-1) in water. The purpose of this study was twofold: (1) develop a procedure using headspace solid phase micro-extraction combined with GC-MS in the selected ion monitoring mode (HS-SPME-GC-MS-SIM) for analysis of MIBP in grape berries, and (2) determine the ...

We only have a limited understanding of the nutrient uptake physiology of individual roots as they age. Despite this shortcoming, the importance of nutrient uptake processes to our understanding of plant nutrition and nutrient cycling cannot be underestimated. In this study, we used a N depletion method that allowed for the measurement of nitrate-N uptake rates on intact, individual, fine roots...

To determine how irrigation influences variegated grape leafhopper biology and pest status, field studies were conducted in an experimental vineyard at the Kearney Agricultural Center. Results showed that increases in the amount of applied water were correlated to increases in leafhopper nymph density and size. Similarly, adult leafhoppers dispersed in greater numbers and had a higher reproduct...

Grapevine leafroll disease (GLD) is an economically important virus disease affecting wine grapes (Vitis vinifera L.), but little is known about its effect on wine chemistry and sensory composition of wines. In this study, impacts of GLD on fruit yield, berry quality and wine chemistry and sensory features were investigated in a red wine grape cultivar planted in a commercial vineyard. Own-root...

Agrobacterium vitis, the causal agent of grape crown gall, can have severe economic effects on grape production. The bacterium survives systemically in vines and, therefore, is disseminated in propagation material. We developed an assay for use in indexing programs that is efficient and sensitive for detecting A. vitis in grape tissue. Initially, real-time polymerase chain reaction (PCR) primer...

BACKGROUND Melolonthinae beetles, comprising different white grub species, are a globally-distributed pest group. Their larvae feed on roots of several crop and forestry species, and adults can cause severe defoliation. In New Zealand, the endemic scarab pest Costelytra zealandica (White) causes severe defoliation on different horticultural crops, including grape vines (Vitis vinifera). Underst...

Problem statement: In warm-winter regions, the need for intervention of chemical means to break bud rest becomes a dominant factor for maintaining economic production of table grapes. However, the problem is more acute when farmers want to grow organic table grapes in the absence of environmentally-friendly budbreak promoters. Approach: This study aimed to evaluate the effect of a mix of natura...

Grape glycosides are, in part, important aroma and flavor precursors. Their quantification may offer a means of determining the impact viticultural practices, such as leaf removal, on potential wine quality. Fruit zone removal Riesling Chardonnay grapevines grown at two sites for seasons was evaluated its influence total phenol-free grape harvest. Vines were trained to low bilateral cordon syst...