Grapes | University of Maryland Extension

Updated: October 23, 2024

Round Two: Multi-Colored Asian Ladybeetle (MALB) Management For Grape Growers

The previous “Timely Viticulture” addressed some basic information on MALB and this message will concentrate on management tactics. Some sections of this message were intentionally repeated, but there is new information throughout.

Timely Viticulture Timeline: Pre-Harvest

Updated: October 23, 2024

Brown Marmorated Stink Bug (BMSB) Part 2–Management in the Vineyard

The brown marmorated stink bug (BMSB) has become a state-wide problem in Maryland vineyards, and its range and damage is increasing. The full impact on vineyards and wine quality potential of this newly introduced pest is unclear. TimelyVit — Part 1 — was created to give growers background on the pest and this TimelyVit will address some management options. Regretfully, it must be stressed that this is a new “introduced” pest and very little is currently known of its management, thresholds for management.

Timely Viticulture Timeline: Mid Season, Pre-Harvest, and Harvest

Updated: October 23, 2024

Brown Marmorated Stink Bug (BMSB) Part 1

The brown marmorated stink bug (BMSB) has been a localized problem in Maryland thus far but that may be expected to change in the future. The full impact on vineyards and wine quality potential of this newly introduced pest is unclear. This Timely Viticulture was created to give growers some background on the pest. The next TimelyVit will address some potential management options. Regretfully, it must be stressed from the beginning that this is a new “introduced” pest and very little is currently known of its biology, but it is evident that it has the potential to be a very significant pest.

Updated: October 23, 2024

Brown Marmorated Stink Bug (BMSB) Part 3 - Fruit Damage and Juice/Wine Taint

The brown marmorated stink bug (BMSB) has become a state-wide problem in Maryland and Mid-Atlantic vineyards, and its range and damage is increasing. The full impact on vineyards and wine quality potential of this newly introduced pest is unclear. TimelyVit BMSB Part 1 gives background on the pest and TimelyVit BMSB Part 2 addresses management options. This TimelyVit BMSB Part 3 discusses fruit damage and the latest research on juice and wine taint during harvest, processing, and fermentation. Again it must be emphasized that this is a new “introduced” pest and very little is currently known of its management, thresholds for management.

Updated: October 23, 2024

Timely Viticulture

Timely Viticulture is an electronic newsletter designed to remind grape producers of seasonal vineyard needs and considerations throughout the year.

Updated: October 23, 2024

Spotted Lanternfly (SLF) II - Scouting and Management

The Spotted Lanternfly (SLF) is now confirmed in Cecil and Harford Counties in Maryland, and has the potential to be a very significant pest in vineyards. For background information, please see the TimelyVit Spotted Lanternfly (SLF) I—Background, for basic information. This Timely Viticulture was created to give growers information of how to scout for the pest and some management options and strategies.

Updated: October 22, 2024

Using Difenoconazole Fungicides for Effective Disease Management

Difenoconazole is a sterol-inhibiting (SI) fungicide recently registered for use on grapes and other fruit. It belongs to FRAC Group 3, along with myclobutanil (Rally), tebuconazole (Elite, Tebuzol, Orius), and fenarimol (Vintage, formerly Rubigan). Difenoconazole protects vines and fruit from powdery mildew (PM), black rot (BR), and Phomopsis cane and leaf spot.

Updated: October 22, 2024

Pre-Harvest Disease Management and Late Season Bunch Rots

Many vineyards are approaching or already within 30 days of the anticipated harvest date for early wine grape varieties. During this window, grape berries are becoming very susceptible to a variety of late-season rots, such as ripe rot, sour rot, Botrytis bunch rot, and other “secondary-fungi” associated with bunch rots.

Updated: October 22, 2024

Pre-Bloom To Post-Bloom Disease Management

The growth period from 2 weeks pre-bloom until 3 to 4 weeks post-bloom is the most critical for protecting foliage, and especially flowers and newly set fruit from black rot (BR), Phomopsis (Ph), powdery mildew (PM), Downy mildew (DM), and Botrytis bunch rot infections.

Timely Viticulture Timeline: Pre-Bloom, Bloom, and Post Bloom

Updated: October 22, 2024

Guidelines for Developing an Effective Fungicide Spray Program for Wine Grapes in Maryland (FS-848)

The purpose of this fact sheet is to help wine grape growers in Maryland develop effective fungicide spray programs to manage a complex of five major fungal diseases affecting vines and fruit: powdery mildew, downy mildew, black rot, Botrytis bunch rot, and Phomopsis cane and leaf spot. The spray schedules below suggest several options for each spray but do not include all fungicides registered in Maryland for control of these diseases. Three supplemental tables are provided to further assist growers in choosing fungicides. Table 1 rates the effectiveness of all fungicides mentioned in the fact sheet against these diseases. Information on effectiveness is intended as general guidance only. Results in a given vineyard will depend on the weather, disease pressure (level of inoculum present), canopy management, age of vines, fungicide formulation and rate, and spray intervals and coverage. Table 2 lists resistance-prone fungicides by chemical class (mode of action) to help growers choose rotational partners with different modes of action fungicides mentioned in this guide. Author: Anne DeMarsay, Ph.D., The Fruit DoctorTM; Title: The New Guidelines for Developing an Effective Fungicide Spray Program for Wine Grapes in Maryland, 2012 (FS-848)