The Canary Islands grape harvest has given many headaches to wineries and grape growers across the board this season. The north and center zone of Tenerife has suffered many irregularities, such as Lanzarote and El Hierro islands.
The Canary Islands begin to harvest in mid-July and usually expand to late October, more than anywhere in the world where in little over a month it settled. It is due to the characteristic terroir that is recorded in each area. The islands complete altitudes, microclimates and varieties of soil very differents.
This year, the campaign has begun almost three weeks later than usual and has been much more complicated than in previous years when the crops were quite positive, particularly in Lanzarote. It’s estimated a decrease between 20% and 50% of grape production compared to 2015.
What is this about? One of the drawbacks has been the so-called "bleed flower", consisting of poor fertilization of some flowers and grape berries not formed. Part of the bunch would have only flower without berries. This happens due to the sudden changes in temperature, such as heat suffered in January and February and the cold March and April.
In addition; in the Canary Islands a meteorological phenomenon appeared, they call it "donkey's belly" this consists in the accumulation of low clouds that cause an increase in humidity, causing fungi to proliferate. By this, the plague of Powdery Mildew started to develop, which has surprised and attacked the vineyards strongly. This hotbed fungi has impoverished the development of its native grape, the volcanic Malvasia.
What is the powdery mildew and how it affects the vineyard? The Powdery Mildew is a disease caused by a fungus (Erysiphe Necator) that infects the cluster, cracking the fruit and slowing the growth. The infection can be found in the fruit, leaves, buds and stem. It is presented as discolorations in a web shape reddish or brown. It is curious that the infection begins to develop in the bloom, usually is not detected until veraison.
When the disease is already widespread, the fungus can be found on both sides of the leaves. In optimal conditions, powdery mildew takes a week to complete a reproductive cycle. The infection will spread quickly and develop on the surface of the grape with a characteristic appearance of mold.
Powdery mildew doesn’t bring anything good. The crop losses can be huge when it affects the cluster as it leaves the fruit unusable. But you can always prevent. The greatest risk of infection occurs in the early stages of the vegetative cycle. Therefore, it is important to detect it when it’s still in dormant period in order to take effective and quick controlling measures. You need to prevent the development of powdery mildew in your vineyards. Analyzes if it’s present in your soil with WineSeq and don’t let powdery mildew surprise you!