Leaf Breakdown/Vine Decline Syndrome
Summary
The incidence and severity of vine decline syndrome is increasing.
You may have seen yellowing leaves in both gold and green in late January
G3 Gold Kiwifruit
Hayward Green Kiwifruit
Many growers assume this to be the result of nutrient deficiency and apply more foliar nutrients and fertilisers.
Unfortunately this only aggravates the problem in both producing vines and in newly grafted orchards.
Read more about fertiliser use on kiwifruit orchards here.
So what should you do?
Check your soil test results.
(scroll down for more detailed soil test info)
If the potassium, copper and sulphur levels are in the high column you have a soil salinity (excess fertilizer) problem and are likely to see the signs of "Vine decline Syndrome".
You Can Manage This
This orchard has been using the Primazest & Agrizest programme for the past 15 years.
No foliar nutrient sprays, copper, Actigard or other antibiotics are applied post bud break.
And in young, grafted orchards:
Primazest programme only.
No other nutrient sprays or applications of fertilizers.
NO copper, Actigard or other antibiotics post bud break.
So, look after plant health &
If your soil fertility is in the mid column range
Don't Apply More Soil or Foliar Fertilisers!
Read the full pdf report and history here
Soil Test Results And Interpretation
Read more about fertiliser use on kiwifruit orchards here.
Growers have been pushing nutrient levels into the “high” range. Some growers wrongly assume, or have been told, that the high range means “high fertility”. This is incorrect and is damaging the vines and crop.
The levels of copper in many orchards is at the toxic level.
Please don't apply, foliar feeds and fertilisers on young vines unless soil and leaf tests show nutrients are deficient (low range).
If nutrients are in the high range this is the toxic range. Don’t add to the problem!
If you need to apply copper or other antibiotics check the data to see if they really benefit the vine/crop and if they are phytotoxic. Check the NPK and other nutrient levels of foliar feeds. In other countries, such as Italy, high nutrient levels are added so that manufacturers can sell the products as agricultural compounds and qualify for tax rebates - many of these products are also sold in New Zealand - check the label and online information carefully.
Many orchards have symptoms of vine decline syndrome. Symptoms may be mild or severe but they have become common and the severity is increasing.
Some examples of soil test results:
