Struggling new vines

[mfolsom]

Hi everybody! I'm new to the vineyard business. I recently built a small vineyard and planted new vines back in late march. They've been growing really well until this last few weeks, a good portion of them are struggling, while others appear to be thriving. I'm clearly not doing something right and I figure I'm either over-watering, under-watering or they have a disease. I could really use some guidance from people with experience. For reference, I'm in Southern California, in the city of Escondido. Here's what's going on:

I have half gallon per hour drips on each vine and I've verified they're all dripping at the base of the plant. I was originally watering them 2 gallons of water of a four hour duration once a week. This was fine, but in the last two - three weeks there's been some heat waves, with temperatures in the 90's, sometimes low 100's. During these heat waves, I often would have the drips water the vines twice during the week, same amount of water each time. Some vines appear to be thriving just fine, but others are struggling. The symptom is always the same, yellowing of the leaves starting at the bottom of the vine and then they shrivel up brown and dead. The tops still have green on it, but many have slowed or stop growing. I'm afraid if I don't make changes, they'll simply die off.

Most of the information I can find about watering vines are for mature vines, but I'm not clear how much water a new, establishing vine would need.

Any advice you have for me would be appreciated! I've attached photos of some of the vines.

 

[VinesnBines]

I’m hoping some more experienced growers will chime in. I don’t know much about growing in California. You can over water but again I don’t know how much is too much in your area.
Are you spraying? It sort of looks like powdery mildew. Again I hope some of the more experienced folks will chime in.

 

[mfolsom]

I have not sprayed anything yet...this sort of just cropped up. I had looked up videos of powdery wildew, and it didn't look like the textbook example. When I zoon in on a couple of these images, I can see a white powder, which wasn't apparent when just looking at them with the naked eye. In the past, I've used Neem oil for other plants. Do you see any problem using that?

 

[VinesnBines]

What varieties do you have? If vinifera or white hybrids, you can/should use sulfur for powdery mildew. We spray in the East as preventative because disease does hit all of a sudden.

 

[mfolsom]

I have Sauvignon blanc. I have neem oil readily available and a copper spray as well. I don't have a sulfur. Maybe I can find some locally.

 

[Snafflebit]

I agree the spotty leaves make me think powdery mildew. But, do not mix neem oil and sulfur until weeks have passed between dosing. Check the directions on the sulfur. Have you checked if the roots are moist? I would dig up one plant to see if there are roots established. This looks like the plant is dry. Those grow tubes may be cooking the plant in this heatwave. Also the vines will stop growing when the temperature gets into the 90's

 

[mfolsom]

Should I remove the shelters now? I was originally told they should stay on the first year.

I'll check the roots of one. How much should I be watering them?

 

[Snafflebit]

Any plant will struggle after transplant. I would increase watering frequency. Grow tubes, people love them or hate them. If it looks like they are causing problems I would remove them. The vines are growing to the catch wire. It appears the grow tubes did their job

 

[Neb Farmer]

I agree with increasing your watering. Young plants do not have the root system yet , so they might need a little more water until their roots can find the moisture deep in the ground. You have to baby the babies.


Also, you WILL need to spray for powdery mildew since these are vinifera. However, I am pretty certain you won't want to spray sulphur , or probably anything else , until your weather dips under 85 degrees F . Spraying in hot weather can 'burn' the plants.

 

[Joe B.]

The canes on the young vines are already hardening off that tells me not enough water I'm in California to and the heat has been unreal and is going to stay for a while. Remember you want to water the root zone to encourage growth not just the vine. As stated above you will have to baby them the first year. Powdery mildew has been in the past for me since July with the hot dry weather and past watering practices is your issue. Don't over do it and don't expect to see a bunch of new growth just because they start getting able water.