Influence of Vineyard Vegetational Borders on Western Grape Leafhopper (Erythroneura elegantula Osborn), its Egg Parasitoids (Anagrus spp.) and Generalist Insect Predators

Studies have shown that vegetational diversity in or around cropping systems can enhance naturalenemy abundance, although the impact on herbivores is less certain. We studied the influence of vineyardvegetational borders on density of the western grape leafhopper, Erythroneura elegantula, its majorparasitoids, Anagrus spp., and two generalist predators, Orius spp. and Leptothrips mali. Two studyvineyards had planted, perennial flowering hedgerows, one bordered a natural riparian zone, and onehad a sparse border of native trees. From April to September 2007, we counted leafhopper nymphs andadults of Anagrus spp., Orius spp. and L. mali within 10 m of the border, and at additional 20 m intervalsup to 90 m. At two sites with a diverse border, leafhopper density was stable nearest the border; at otherdistances leafhopper density decreased between the first and second generations. This effect was notseen at the sparse border site. Anagrus spp. density was enhanced at one site with a diverse border, butonly late season. There was no border effect on the generalist insect predators, by site or early vs. lateseason. Regression analysis showed a positive relationship between leafhopper and Anagrus spp. density,suggesting that the parasitoids were responding to higher leafhopper density. We conclude that, dependingon the nature of the border vegetation, there can be an effect on leafhopper nymphal density, but in thisstudy there is no evidence that it was due to natural enemies

Assessment of carbon in woody plants and soil across a vineyard-woodland landscape

<p>Abstract</p> <p>Background</p> <p>Quantification of ecosystem services, such as carbon (C) storage, can demonstrate the benefits of managing for both production and habitat conservation in agricultural landscapes. In this study, we evaluated C stocks and woody plant diversity across vineyard blocks and adjoining woodland ecosystems (wildlands) for an organic vineyard in northern California. Carbon was measured in soil from 44 one m deep pits, and in aboveground woody biomass from 93 vegetation plots. These data were combined with physical landscape variables to model C stocks using a geographic information system and multivariate linear regression.</p> <p>Results</p> <p>Field data showed wildlands to be heterogeneous in both C stocks and woody tree diversity, reflecting the mosaic of several different vegetation types, and storing on average 36.8 Mg C/ha in aboveground woody biomass and 89.3 Mg C/ha in soil. Not surprisingly, vineyard blocks showed less variation in above- and belowground C, with an average of 3.0 and 84.1 Mg C/ha, respectively.</p> <p>Conclusions</p> <p>This research demonstrates that vineyards managed with practices that conserve some fraction of adjoining wildlands yield benefits for increasing overall C stocks and species and habitat diversity in integrated agricultural landscapes. For such complex landscapes, high resolution spatial modeling is challenging and requires accurate characterization of the landscape by vegetation type, physical structure, sufficient sampling, and allometric equations that relate tree species to each landscape. Geographic information systems and remote sensing techniques are useful for integrating the above variables into an analysis platform to estimate C stocks in these working landscapes, thereby helping land managers qualify for greenhouse gas mitigation credits. Carbon policy in California, however, shows a lack of focus on C stocks compared to emissions, and on agriculture compared to other sectors. Correcting these policy shortcomings could create incentives for ecosystem service provision, including C storage, as well as encourage better farm stewardship and habitat conservation.</p

Self-reseeding annual legumes evaluated as cover crops for untilled vineyards

Self-reseeding annual cover crops can regenerate in subsequent years without tilling the seedbed and can be part of a strategy to protect vineyard soil from erosion. We compared 22 such cultivars in a 1-year-old ‘Syrah’ wine-grape vineyard located at 1,400 feet in Lake County. We found significant differences between species in the amount of biomass produced in 2004 and 2005. All of the species studied were relatively low statured and fit well in vineyard middles. Pressure bomb readings taken after the cover crops stopped growing showed that with a dry spring (2004), vines with cover crops were modestly more stressed than those under tillage prior to July irrigations, but after irrigation the cover-cropped vines were slightly less stressed. In 2005, which had rainfall in late spring, there were no differences in vine water status throughout the season. We conclude that water use by the cover crop must have been relatively low and did not result in excessive vine water stress

Before-and-after tests on emitters show organic fertilizers can be injected through low-volume irrigation systems

The practice of injecting organic fertilizers into low-volume irrigation systems is not widespread, partly because of concerns that the materials will clog emitters. This study looks at two spray-dried organic fertilizers (fish protein and poultry protein) that were injected through various low-volume irrigation systems, and finds only minimal clogging and even distribution of fertilizer throughout the irrigated area

Feasibility of producing pear wine: Pears produce premium sparkling wine

Pear growers and packers continue to need profitable market channels for fruit that is not packed for fresh market or canned. Off-grade fruit that is designated for the juicing market frequently gives growers and packers poor returns unless there are significant shortages of fruit juice concentrates in the marketplace. Finding a use for these fruit in the creation of a higher priced, value-added premium product could greatly strengthen the performance of this segment of the pear market and at the same time use the off-season production capacity of sparkling wineries. Our experiments demonstrate that an ultrapremium-quality cider can be made from juice grade Bartlett pears. Pear fruit should be ripe for optimum flavors and aromas

Cost analysis: Méthod champenoise sparkling pear wine costs most, but offers highest quality

Commercial production of pear cider could greatly improve the demand for pears that are not packed for fresh market or canned. Bringing pear cider, also called perry, to the marketplace will involve careful planning and market knowledge. The cost of producing pear still wine by custom crush is $275 per ton of pears. The cost of finishing the cider varies with the approach. The classic sparkling wine method champenoise, involving a secondary fermentation in the bottle, was the most expensive, but yielded the highest-quality beverage. Bottling and packaging the value-added product also varied in price. The retail costs would be$3 for a 22-ounce bottle of pear cider and $6 for a 750-milliliter bottle of sparkling pear wine

Self-reseeding annual legumes evaluated as cover crops for untilled vineyards

Self-reseeding annual cover crops can regenerate in subsequent years without tilling the seedbed and can be part of a strategy to protect vineyard soil from erosion. We compared 22 such cultivars in a 1-year-old ‘Syrah’ wine-grape vineyard located at 1,400 feet in Lake County. We found significant differences between species in the amount of biomass produced in 2004 and 2005. All of the species studied were relatively low statured and fit well in vineyard middles. Pressure bomb readings taken after the cover crops stopped growing showed that with a dry spring (2004), vines with cover crops were modestly more stressed than those under tillage prior to July irrigations, but after irrigation the cover-cropped vines were slightly less stressed. In 2005, which had rainfall in late spring, there were no differences in vine water status throughout the season. We conclude that water use by the cover crop must have been relatively low and did not result in excessive vine water stress