Disease risk from yesterday

A wetness event recorded yesterday was infection event for Botrytis and Downy mildew.  Refer to yesterday's post on spray choices.  Please make sure to alternate mode of actions to reduce the risk of fungicide resistance development.

Comments

Post a Comment

Popular posts from this blog

Late season fungicide options (= materials with short PHI)

Image
At Winchester, the night time relative humidity has been still very high, close to 100%, in nearly every nights in the past three weeks. In addition, we have been observing rapid development of thunderstorms, pretty much every day in the past few days. I know I sound like a broken record, but these conditions favor downy mildew development because downy mildew pathogen prefers to produce spores under dark, humid conditions. Then spores will be spread via rain. At this point, you do not need to worry about downy mildew infection on clusters; however, they can still infect leaves. Often time, you will initially see infection on the top of the canopy because younger leaves are more susceptible than older ones. Losing the top leaves and laterals are not a big deal; however, once the infection gets severe, it can defoliate many leaves rather quickly (as in the picture above), and that can affect maturing process. Knowing how wet this year has been, it is probably wise to be proactive on dow...
Read more

A new part-time position in my lab

Image
We are looking for an agricultural technician position in my lab, which is located in Winchester, VA. The main duty is assisting various vineyard and experimental operations in our vineyards and other field plots, such as canopy management, weed management, and treatment applications. It is a part-time position, but the position will be held year around. During the winter months, duties will be mostly inside, assisting vine propagations, pruning, etc. We are looking for someone who enjoys working in vineyards and with good communication skills. The other requirements are: valid driver license, basic computer (Word, Excel, etc.) skills, and willingness to learn new things. If you know someone who is interested in, please let them know to apply for this position through the link below. The posting will close on 4/1. https://listings.jobs.vt.edu/postings/74676
Read more

Late season disease management considerations

Image
Some of our early cultivars such as Alandale is changing it color.  It is just a matter of time to see other cultivar to enter phase of veraison.  Hopefully, we will keep seeing dry weather with little bit of rain here and there.... There are several diseases to be considered at this stage.  One of them is Botrytis.  The spray timing for Botrytis is at bloom, bunch closure, and veraison.  The pathogen seems to be active throughout the season, but Botrytis likes berries when they get mature and accumulate more sugar.   As usual, canopy management is the first line of defense against grape disease management and this is particularly true for Botrytis since it tends to develop after a long period (15-17 hours) of high humidity condition. Please keep in your mind that Botrytis is very well known for its capability to overcome fungicides.  Thus, a rotation of mode of action groups is very important aspect for Botrytis management.  The mode of acti...
Read more