Black Spanish/Le Noir San Antonio Problem

[itslonestar]

Five-year old, 8 Black Spanish/Le Noir vines and 2 Champanel vines near San Antonio. Second year growth (2014) produced 75 pounds grapes, now bottled. Third year (2015) spring was wet and believe may have been impacted by either Pierce’s Disease (PD) or simply leaf rot due to wet, humid conditions. Clusters flowered, but then hit by heavy rains. However, large number or fruit-bearing clusters started during growing season, but all fruit subsequently fell off leaving dead, dry raceme. Leaves, vines, stems later developed “indications” of PD – but could have been the result of wilt/rot due to very heavy spring rains followed by multiple months of very hot and humid days. Grape decline had already begun before I noticed a lot of sharpshooters…of which I had not seen the year prior. I have lots of pictures…just trying to determine whether to stick it out and see how the 2016 season goes, or pull them up and start over again.

 

[ibglowin]

Black Spanish is PD resistant. You need a heavy spray program in TX and you didn't mention any spraying at all in your post.

http://aggie-horticulture.tamu.edu/fruit-nut/files/2010/10/pd-grapes.pdf

 

[itslonestar]

Thanks for responding, Mike. Yes; used Malathion after leaves were developed and prior to insect period as recommended by our ag agent. Fungicide used after initially concerned with leaf wilt and fungus identified under leaves. another application of Malathion when shartpshooters first appeared.

 

[ibglowin]

Sounds like you may need to beef things up this year with a better spray program.

http://www.txwines.org/wp-content/uploads/2014/08/Jim-Kamas-Grapevine-Fungal-Diseases-and-Pests.pdf

 

[itslonestar]

Thank you...very helpful.