58 research outputs found
Chemigation with Micronized Sulfur Rapidly Reduces Soil pH in a New Planting of Northern Highbush Blueberry
Northern highbush blueberry (Vaccinium corymbosum L.) is adapted to acidic soil conditions and often grows poorly when soil pH is greater than 5.5. When soil pH is high, growers will usually mix prilled elemental sulfur (So) into the soil before planting (converted to sulfuric acid by soil bacteria) and, if needed, inject acid into the irrigation water after planting. These practices are effective but often expensive, time consuming, and, in the case of acid, potentially hazardous. Here, we examined the potential of applying micronized So by chemigation through a drip system as an alternative to reduce soil pH in a new planting of ‘Duke’ blueberry. The planting was located in western Oregon and established on raised beds mulched with sawdust in Oct. 2010. The So product was mixed with water and injected weekly for a period of ≈2 months before planting and again for period of ≈2 months in late summer of the second year after planting (to assess its value for reducing soil pH once the field was established), at a total rate of 0, 50, 100, and 150 kg·ha−1 So on both occasions. Each treatment was compared with the conventional practice of incorporating prilled So into the soil before planting (two applications of 750 kg·ha−1 So each in July and Oct. 2010). Within a month of the first application of So, chemigation reduced soil pH (0–10 cm depth) from an average of 6.6 with no So to 6.1 with 50 kg·ha−1 So and 5.8 with 100 or 150 kg·ha−1 So. However, the reductions in pH were short term, and by May of the following year (2011), soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of So chemigation, respectively. Soil pH in the conventional treatment, in comparison, averaged 6.6 a month after the first application and 6.3 by the following May. In July 2012, soil pH ranged from an average of 6.4 with no So to 6.2 with 150 kg·ha−1 So and 5.5 with prilled So. Soil pH declined to as low as 5.9 following postplanting So chemigation and, at lower depths (10–30 cm), was similar between the treatment chemigated with 150 kg·ha−1 So and the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, or total dry weight of the plants in year 2. Concentration of P, K, Ca, Mg, S, and Mn in the leaves, on the other hand, was lower with So chemigation than with prilled So during the first year after planting, whereas concentration of N, P, and S in the leaves were lower with So chemigation during the second year. The findings indicate that So chemigation can be used to quickly reduce soil pH after planting and therefore may be a useful practice to correct high pH problems in established northern highbush blueberry fields; however, it was less effective and more time consuming than applying prilled So before plantin
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Field Grafting Grapevines in Oregon
There are basically two types of grafting, bench grafting and field grafting. Worldwide the main reasons for bench grafting vines are: a) to obtain vines of the desired fruiting variety on roots resistant to phylloxera or nematodes, or b) to obtain vines on roots tolerant to certain soil conditions such as drought or high lime. The main reasons for field grafting are: a) to correct mixed varieties in an established vineyard, or b) to change the variety of an established vineyard. In Oregon, the current main objectives of grafting are to correct mixed varieties within a block and to change one variety to another, because the existing variety is unsuitable for the site or the winery. Phylloxera is not yet a problem in Oregon so grafting vinifera onto resistant rootstocks may not be required. There has been an increase in interest in field grafting grapevines in Oregon. Field grafting in Oregon as well as other cool climate areas has had very limited success. Previous studies indicate that percent graft success in Oregon can range from about 30% to 95% depending on, among other factors, the weather in the Spring. Results this Spring indicate that percent take can be as low as 1%
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Pruning and Training Systems Impact Yield and Cold Hardiness of "Marion' Trailing Blackberry
The floricane-fruiting, trailing blackberry (Rubus L. subgenus Rubus, Watson) cultivar Marion was evaluated in two plantings for the impact of floricane pruning date. This included leaving the dead canes unpruned and training new primocanes over the dead wood (new-over-old), primocane topping and suppression date in alternate year (AY) and every year (EY) production systems at various planting densities. The presence of primocanes during fruit development did not affect yield of the floricane in the current season but suppressing primocanes to June 30 in Oregon, USA, led to insufficient time for primocane growth, reducing yield of the floricane the following year by 36% relative to no primocane suppression. Pruning out senescing floricanes immediately after fruit harvest or laterthus allowing more time for remobilization of nutrients or reserveshad no impact on yield. However, yield in the new-over-old system was higher, likely due to less training damage to primocanes in this treatment. All of the AY treatments studied led to lower berry weight compared to EY production but this has not been an issue in the processed fruit market to date. Plants in AY production produced more canes per plant than in EY but at the industry standard spacing of 1.5 m, AY plants yielded only 60% to 66% more than EY plants in these studies, despite evidence of plants in AY production having greater cold hardiness. There was no significant effect of planting at higher density (0.6 and 0.9 m) on cumulative yield over 4 years. However, planting at 0.6 m and topping the primocanes to the top trellis wire (1.8 m) increased yield significantly compared to other AY treatments. This alternative production system may offer economic advantages to the 1.5 m EY or AY production systems through reducing management costs and allowing for mechanical pruning and training
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Phylloxera in Oregon Grape Vines: Biology and Treatment of Planting Stock With Hot Water Dips
In 1994-95, the Oregon Wine Advisory Board supported a cooperative study entitled "Crown gall and phylloxera in Oregon grape vines: Biology and treatment of planting stock with hot water dips" with Bernadine Strik and Marilyn Canfield (Larry Moore) as co-principal investigators. We will report our findings on hot water dips for phylloxera eradication here. Marilyn Canfield has submitted a separate report on Crown Gall. We will also report on our preliminary findings on rootstock performance in phylloxerated and non-phylloxerated sites (funded by the Center for Applied Agricultural Research). A more complete report on this study will be provided in up-coming industry newsletters. Ho
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Viticulture Extension and Research Support Funds
Develop and publish literature to provide up-to-date information on specific topics zDevelop grape grower and County Extension Agent training sessions and short courses zResearch phyiloxera biology in Orego
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Grape Phylloxera Biology and Management in Oregon
Grape phylloxera (Daktulosphaira vitifoliae), a root-feeding aphid-like insect, is the most important pest of European winegrape vineyards worldwide. They cannot be controlled on infested vines which eventually die. There are currently no satisfactory chemical or biological control methods for this pest; its management throughout the world has been by planting resistant rootstocks and through techniques that seek to limit the rate of spread. Although it has been in California since the mid- I 800s, phylloxera was discovered for the first time in a commercial vineyard in Oregon in 1990 and in Washington in the late 1980s. Seven vineyards are now known to be infested. With over 95 percent of Oregon's 6,000 acres of grapes being own-rooted, susceptible vines, the potential for serious economic loss to the industry is great. Infested vineyards will have to be replanted on grafted vines (resistant rootstock) at a cost of over $1 1,000 per acre for re-planting and years out of production. Rate of spread of this insect within a vineyard is estimated to be 2 times to 4 times in Oregon -- thus at the very least, a 1/8 acre infestation will be I acre in size in 3 years. Phylloxera can be spread from one vineyard to another on infested soil or plant material. The life cycle of this insect varies with location. Our findings indicate the presence of sexual, winged forms in the Pacific Northwest. The relevance of this discovery to viticulture here is unknown but may be important to insect population variability and movement (greatly increase rate of spread). Because distribution of phylloxera in the Pacific Northwest is currently limited, characteristics of its current distribution and movement are necessary to limit movement in the future. Although replanting vineyards on phylloxera resistant rootstock is the long term, preferred and inevitable mechanism for control of the pest, there is a large number of resistant rootstocks to choose from, but none of which have yet been characterized as suitable for production systems in Oregon. Existing phylloxera infestations must be managed to decrease the rate of spread, within and among vineyards. Delaying the need for the industry to replant on resistant rootstock is essential, as growers will have to make educated decisions on what stocks are best for Oregon. Our industry does not want to be faced with having to replant 80 percent of existing vineyards because of inappropriate initial rootstock recommendations, a situation now in effect in California's Napa and Sonoma counties. Research on phylloxera biology, rate of spread, and its association with other pests in Oregon is needed to better manage this insect. We need sufficient time to conduct concurrent research on rootstocks resistant to variations of phylloxera, resistance to other pests such as nematodes and fungal pathogens, and suitability for our viticultural region. Studies on other traits of rootstocks, to provide consistent productivity and quality perfection for Oregon conditions has the potential to make Oregon's change to rootstocks a positive development and an enhancement of long-term competitiveness. Additional information on phylloxera biology, rate of spread, methods to decrease the rate of spread, and rootstocks for Oregon vineyards is available in the Oregon Winegrape Growers' Guide (1992). The objectives of our research were to determine when phylloxera hibernants (over-wintering populations) become active in the spring and how populations change throughout the season. This would not only determine the number of generations a year, but also when spread can begin in the spring. Also, it's important to be able to estimate the rate of spread as accurately as possible so that growers may predict replanting date and the industry can forecast spread within the Oregon. We also wanted to determine whether we have a winged form of phylloxera in Oregon, because this could greatly affect the rate of spread of this pest. Determining the low temperature tolerance of phylloxera found in Oregon is necessary to better estimate number of generations per year and the potential amount of population die- back in cold winters. Finally, we planned to determine the resistance of rootstocks to biotype(s) of phylloxera found in Oregon
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Nutrient Requirements, Leaf Tissue Standards, and New Options for Fertigation of Northern Highbush Blueberry
Northern highbush blueberry (Vaccinium corymbosum) is well adapted to acidic soils with low nutrient availability, but often requires regular applications of nitrogen (N) and other nutrients for profitable production. Typically, nutrients accumulate in the plant tissues following the same pattern as dry matter and are lost or removed by leaf senescence, pruning, fruit harvest, and root turnover. Leaf tissue testing is a useful tool for monitoring nutrient requirements in northern highbush blueberry, and standards for analysis have been updated for Oregon. Until recently, most commercial plantings of blueberry (Vaccinium sp.) were fertilized using granular fertilizers. However, many new fields are irrigated by drip and fertigated using liquid fertilizers. Suitable sources of liquid N fertilizer for blueberry include ammonium sulfate, ammonium thiosulfate, ammonium phosphate, urea, and urea sulfuric acid. Several growers are also applying humic acids to help improve root growth and are injecting sulfuric acid to reduce carbonates and bicarbonates in the irrigation water. Although only a single line of drip tubing is needed for adequate irrigation of northern highbush blueberry, two lines are often used to encourage a larger root system. The lines are often installed near the base of the plants initially and then repositioned 6–12 inches away once the root system develops. For better efficiency, N should be applied frequently by fertigation (e.g., weekly), beginning at budbreak, but discontinued at least 2 months before the end of the growing season. Applying N in late summer reduces flower bud development in northern highbush blueberry and may lead to late flushes of shoot growth vulnerable to freeze damage. The recommended N rates are higher for fertigation than for granular fertilizers during the first 2 years after planting but are similar to granular rates in the following years. More work is needed to develop fertigation programs for other nutrients and soil supplements in northern highbush blueberry.Keywords: fertilizer, humic acids, ammonium-nitrogen, soil pH, organic, Vaccinium corymbosu
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Raspberry cultivars for Oregon
Published June 1989. A more recent revision exists. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo
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Uptake and Partitioning of Nutrients in Blackberry and Raspberry and Evaluating Plant Nutrient Status for Accurate Assessment of Fertilizer Requirements
Raspberry and blackberry (Rubus sp.) plantings have a relatively low nutrient requirement compared with many other perennial fruit crops. Knowledge of annual accumulation of nutrients and periods of rapid uptake allows for better management of fertilization programs. Annual total nitrogen (N) accumulation in the aboveground plant ranged from 62 to 110 and 33 to 39 lb/acre in field-grown red raspberry (Rubus idaeus) and blackberry (Rubus ssp. rubus), respectively. Research on the fate of applied ¹⁵N (a naturally occurring istope of N) has shown that primocanes rely primarily on fertilizer N for growth, whereas floricane growth is highly dependent on stored N in the over-wintering primocanes, crown, and roots; from 30% to 40% of stored N was allocated to new growth. Plants receiving higher rates of N fertilizer took up more N, often leading to higher N concentrations in the tissues, including the fruit. Reallocation of N from senescing floricanes and primocane leaves to canes, crown, and roots has been documented. Accumulation of other macro- and micronutrients in plant parts usually preceded growth. Primocanes generally contained the highest concentration of most nutrients during the growing season, except calcium (Ca), copper (Cu), and zinc (Zn), which often were more concentrated in roots. Roots typically contained the highest concentration of all nutrients during winter dormancy. Nutrient partitioning varied considerably among elements due to different nutrient concentrations and requirements in each raspberry and blackberry plant part. This difference not only affected the proportion of each nutrient allocated to plant parts, but also the relative amount of each nutrient lost or removed during harvest, leaf senescence, and pruning. Macro- and micronutrient concentrations are similar for raspberry and blackberry fruit, resulting in a similar quantity of nutrient removed with each ton of fruit at harvest; however, yield may differ among cultivars and production systems. Nutrient removal in harvested red raspberry and blackberry fruit ranged from 11 to 18 lb/acre N, 10 to 19 lb/acre potassium (K), 2 to 4 lb/acre phosphorus (P), 1 to 2 lb/acre Ca, and 1 to 4 lb/acre magnesium (Mg). Pruning senescing floricanes in August led to greater plant nutrient losses than pruning in autumn. Primocane leaf nutrient status is often used in nutrient management programs. Leaf nutrient concentrations differ with primocane leaf sampling time and cultivar. In Oregon, the present recommended sampling time of late July to early August is acceptable for floricane-fruiting raspberry and blackberry types, and primocane-fruiting raspberry, but not for primocane-fruiting blackberry, where sampling leaves on primocane branches during the green fruit stage is recommended. Presently published leaf tissue standards appear to be too high for K in primocane-fruiting raspberry and blackberry, which is not surprising since the primocanes are producing fruit at the time of sampling and fruit contain a substantial amount of K.This is the publisher’s final pdf. The published article is copyrighted by the American Society for Horticultural Science and can be found at: http://horttech.ashspublications.org/Keywords: leaf tissue analysis, nutrient removal, organic, Rubus, fertilization, nitroge
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Growing grapes in your home garden
Growing grapes in your home garden can be a wonderful hobby and
a challenging experience. You can grow many cultivars (varieties)
of grapes; the fruit of each cultivar has an aroma, flavor, and other
qualities that make it unique.Published June 1989. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo
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