Fertilizer

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Handy Andy

Senior Member
Joined
May 23, 2020
Messages
191
Reaction score
71
Location
Sao Jorge
I have some issues with my grape vines, other than mildews.

In addition to spraying against downy and powdery mildew, I am spraying with a leaf nutrient to try and alleviate problems with NPK and Magnesium deficiency.

Is using leaf nutrients my best option in the long term for vine health? Is there a better solution? Would it be better to spread fertilizer on the ground, and thus fertilize the roots and overall vine?

I have lost about 6 vines since last year due to what appear to be cankers in the branches. Could deficiencies in my vines make them vulnerable to cankers, and possibly prevent bud break?

Edit > It has rained a lot this year, could an excess of water be causing some of my leaves to appear magnesium deficient and lighter in colour than other leaves?
 
Last edited:
usually fertilizer formula of 10-10-10 or other balanced mix is added in spring at bud break and just after harvest. about one cup per plant is sufficient. timing at bud break allows the nutrient the reach the rest of plant once grapes form also in the fall as 40% of root growth is in fall. as far as magnesium I used Epsom salt in tank mix every time I sprayed. I can't remember dosage but a cup for 30 gallons comes to mind. I am not sure about the cankers. lots of rain could wash out nutrients if small amounts available giving the lighter color in leaves. grapes usually don't like wet feet insure you have good drainage of vineyard could also cause problems. visit the WineMagazine web site I believe they offer a primer on backyard vineyards that could provide additional information
 
If you really want to know what elements are deficient in your vines I suggest sending off samples for a petiole analysis.
I spent two years diagnosing vine deficiencies by looking at leaves on a vineyard. First the disease looked like zinc deficiency, then boron deficency.
The test showed the problem was nitrogen deficency which I never would have suspected. And, it was a simple fix with ammonium sulfate.

I use A & L Western Laboratories you could probably find a closer lab
 
I have stony volcanic soils, with good drainage on a gentle slope. I notice at the bottom of the slopes the soil is much richer than on the top, so I guess the rain over the years has washed topsoil down the slope.

Finding a laboratory in the Azores Hum maybe they have one. Eu vou perguntar ao serviço de assessoria agrícola se eles estão abertos caso exista um laboratório.

Edit @salcoco are you using cups of granular fertilizer, or liquid.
 
I have lost about 6 vines since last year due to what appear to be cankers in the branches. Could deficiencies in my vines make them vulnerable to cankers, and possibly prevent bud break?

Cankers are usually caused by a fungus. Improving pruning methods should help the most.

http://cecentralsierra.ucanr.edu/Ag...ape_Pests_Diseases/Grape_vine_canker_disease/
....could an excess of water be causing some of my leaves to appear magnesium deficient and lighter in colour than other leaves?

I have some calcareous soils, and wet springs can cause iron deficiencies early in the year. So it is possible wet years can cause some problems. But I do not know if similar issues can cause magnesium issues or not.

But also be aware that some diseases and mineral deficiencies look similar on the plant, but are from different causes. So you may think you have a nutrient deficiency, but actually have a pathogen, or vise versa. It is complicated.

For example, see disease and other disorders:

http://www.omafra.gov.on.ca/IPM/english/grapes/diseases-and-disorders/index.html
versus nutrition issues:

http://www.omafra.gov.on.ca/IPM/english/grapes/plant-nutrition/index.html
 
Last edited:
There should be a word for imaging diseases on vines, like Hypochondriac for humans, perhaps Vinochondriac, whereby every blemish could be the next imaginary vine ailment.

My Vines did not get treated for fungus until too late last year. It is possible that the fungus caused the cankers in a few vines which I am seeing this year.

Is it best just to pull sick vines out, or might they recover ?????

I spent some time in my vineyards with a magnifying glass looking for problems. I noted one train of ants going into a hole on one sick vine and not coming out, all the other insects appeared to be behaving normally. The only other problems appear to be nutrient based and a very small amount of powdery and downy mildew.

The Possible Nutrient problems I hope to fix next year with granular fertilizers.
 

Latest posts

Back
Top