Mummy berry pseudosclerotia survive for several years

Organic blueberry production in the PNW has many challenges, including diseases like mummy berry caused by the fungus Monilinia vaccinii-corymbosi (Reade) Honey. Management recommendations focus on reducing overwintering pseudosclerotia, however, it is unknown how long they survive. Based on qualitative observations pseudosclerotia are hypothesized to survive multiple years after contact with the soil surface. The development of apothecia from M. vaccinii-corymbosi pseudosclerotia was evaluated over multiple years at a location without a history of blueberry production. A total of 1,000 pseudosclerotia were placed on field soil plots in 2018 and replicated eight times. Another 100 pseudosclerotia were placed in wire corrals on field soil and replicated fifteen times. Plots and corrals were regularly examined each spring for the emergence of apothecia. The pseudosclerotia were able to survive, germinate, and produce apothecia for up to five years after their placement. Very few pseudosclerotia produced apothecia in any year, varying from 0 to 18 at any observed time. Pieces of partial or whole pseudosclerotia were observed for up to three years after placement. Our study shows that a pseudosclerotial “seed bank” exists under blueberry bushes, necessitating a long-term implementation of mummy berry cultural management tactics

Evaluation of Grape Powdery Mildew Forecasting Programs Grape (Vitis vinifera 'Chardonnay') Powdery Mildew (Uncinula necator)

Three forecasting programs for scheduling fungicide applications were selected for comparison with the standard Oregon phenology based program. The California (Gubler-Thomas, UC-Davis) program used leaf wetness and temperature early in the year to predict ascospore infection periods and only temperature during the summer to predict conidial infection periods. The New York (Gadoury) program was based on rainfall and temperature. The German (Oi Diag) program incorporated relative humidity along with temperature and rainfall. Treatments were arranged in a randomized complete block design in a block of 'Chardonnay' planted in 1985 on a 7 x 10 ft spacing. Vines were trained to a bilateral cordon with spur pruning. Shoot thinning occurred 12-13 May to provide uniform cane density. Each treatment was replicated on 3 sets of 5 vines. Treatments were applied using a handgun sprayer at 300 psi at a rate of 200 gal water/A for applications between 1 May (budbreak) and 13 May (6" growth). Treatments were applied using a hooded boom sprayer at 300 psi at a rate of 200 gal water/A for all applications after 13 May. Approximately 3.5 gal of spray suspension was applied per 15 vines (150 gal water/A) between 1 May and 13 May, 4.5 gal between 21 May and 28 Jul, and 5 gal (200 gal water/A) for the rest of the applications. Treatments were applied as required by the guidelines for each program. However, additional conditions for stopping programs at or just after verasion were incorporated as requested by Oregon growers. The standard program and the water control were applied on 13 May (6" shoots), 21 May (12" shoots), 2 Jun (prebloom, EL growth stage 17), 16 Jun (90% bloom), 1 Jul, 15 Jul (bunch closure), 22 Jul, 5 Aug, and 12 Aug (verasion). No Botrytis control measures, including leaf removal, were applied to test vines. All programs used one of two fimgicides, Thiolux DF at 3 lb/100 gal water or Rally at 2 oz/100 gal water for each application. Trap plants of 'Cabernet Sauvignon' were placed next to nontreated vines for 24 hour periods within the same block of grapes from 8 May to 3 Jul. After 24 hours of exposure, plants were transferred to a greenhouse several miles away for incubation under conditions favorable for powdery mildew development

2017 pest management guide for wine grapes in Oregon

Second revision March 24, 2017. 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/catalogThis pest management guide is developed for use by vineyard managers in Oregon. It provides recommendations for chemicals, formulations, and usage rates of products that are intended to prevent, manage, and control vineyard diseases, insects, mites, weeds, and vertebrate pests. When considering a pesticide, evaluate its efficacy and its impact on beneficial arthropods, honey bees, and the environment. Not all registered pesticides are listed in this guide. These recommendations are based on research, label directions, and vineyard-use experience for Oregon

Phomopsis Cane & Leaf Spot

NYS IPM Type: Fruits IPM Fact SheetPhomopsis cane and leaf spot, once known as “dead arm,” is a common disease in most regions of the world where viticulture is practiced. Severely infected leaves are misshapen, yellow, and fall from the vine prematurely. Infected rachises are brittle so that portions of the cluster may fall off before harvest. Infected fruit are discolored and can drop to the ground before maturity. When incidence of the disease is high, crop losses of 10 to 40 percent can occur

Structurational analysis of cross-cultural development of an academic registry information system in Mozambique

Contains fulltext : 92381.pdf (preprint version ) (Open Access