How to defend fruit plants in autumn: common diseases and pests

With the arrival ofautumn, temperatures drop and for the plants, the maturation of wood and new buds for the following year’s production begins. Therefore, during the months of October and November, it is essential to know how to care for and defend fruit trees to prepare them for the winter season and the upcoming state of dormancy.

In this article we will explore the main autumn threats to orchards and the treatments to take.

Why is it important to take action?

Taking action to defend crops in the fall is crucial if you want lush, fruit-rich plants in the following season. At this time of year fruit trees are at the end of their cycle, that is, in the post-harvest stage, so the period of rest, called dormancy, is about to begin. During this period trees are particularly vulnerable to pests, fungi and bacteria, which, pose a great threat as they hide in protected places such as bark or fallen leaves.

Major autumn diseases

Some of the main diseases that can affect fruit trees at this time are:

• Scab: a disease caused by two species of fungi(Diplocarpono Marssonina and Venturia), can affect apple, pear and loquat trees and causes dark brownish-purple spots on the upper leaf page and spreads to stems and fruit. Early attacks cause malformation and fruit drop, while late attacks cause it to wrinkle and split.
• Fire blight: caused by the bacterium Erwinia amylovora, can occur in plants such as apple, pear, quince and loquat. Symptoms can appear on all aerial parts; leaves shrivel and dry up, turning a reddish-brown color. In addition, it can also affect woody tissues, causing them to dry out, eventually causing the plant to die.
• Peach blister: caused by a fungus, it causes leaves to fall, limiting bud formation.

How to prevent: plantvoice

Fall marks a particularly sensitive time for fruit plants, which are heading into winter rest and require targeted attention to best cope with the coming season. Before listing the main techniques to defend fruit plants during autumn, it is good to specify that the most effective weapon is prevention, through monitoring. Today this is made easier thanks to innovative technologies such as the one developed by Plantvoice: a biocompatible device, about the size of a toothpick, capable of detecting the health status of plants in real time. Here are some of Plantvoice’s features:

• Through the concept of “sentinel plant” is installed on a representative plant of a homogeneous plot.
• Thanks to the API interface , it integrates with other agricultural management platforms.
• Detects anomalies in real time and automated, thanks to an application.
• It predicts the quality of crops.
• It saves water, fertilizer and pesticides.

How to defend plants in autumn: a practical guide

Before carrying out any kind of treatment, it is important to clean and remove all dead parts of the plant, such as branches, dry leaves, fruit deposited on the ground, or weeds. This step is critical because, as mentioned earlier, fungal pathogens can survive even in areas close to the tree.

Here are the main techniques for autumn treatment of fruit trees:

Crown thinning – Pruning

November is the best time to prune fruit trees, removing dry, diseased and damaged branches. Specifically, thinning pruning involves the selective removal of certain branches from the tree, and it brings many benefits to the plant:

• It improves air circulation.
• It increases light penetration.
• It makes the plant canopy healthy and productive.
• Reduces the risk of fungal diseases.
• Facilitates fruit picking.

Here are some tips for carrying out hair thinning treatment:

• Before acting carefully inspect the plant to understand the branches to be pruned.
• Remove dead or diseased branches to prevent any diseases from spreading.
• Remove branches growing inward.
• Thinning excessively dense branches.
• Carry out pruning with clean cuts and sharp tools.
• Sterilize instruments before and after use.
• Observe the plant’s reaction in the months following pruning.

Irrigation and fertilization

To give the plant the right nutrients to face the winter and prepare for flowering, the plant needs water and fertilizer. In the early fall months, it is, therefore, important to fertilize fruit trees to strengthen the plant’s reserves. Generally, a fertilizer rich in potassium and phosphorus, such as guano or wood ash, is recommended; however, if the soil is particularly dry, it is useful to perform some irrigation to protect the roots.

Root protection

During the colder months, tree roots are vulnerable to winter frosts, which are dangerous to plant health. To protect them, they can be covered with a layer of organic mulch.

Pesticide treatments and products to use

Another treatment to be carried out in November is a pesticide treatment, of the preventive type against pests and fungal diseases. The recommended types of treatments are those based on copper, or sulfur against some species of fungi (powdery mildew, monilia and rust). In addition, natural or mineral oil-based insecticides, which is allowed in organic farming, are recommended. These products are functional for controlling aphid ovulation and various mealybugs. In addition to this, to combat fungal diseases typical of the autumn period, it is recommended to use a copper-based product: bordolese mush. The latter is very effective during this period, as it adheres better to the plant and is less susceptible to runoff.

Knowing how to defend fruit trees duringautumn is very important to enable fruit trees to better cope with winter and provide abundant and quality production. Remember that each orchard is its own ecosystem, so it is essential to adapt care practices to the specific needs of the plants, taking into account local climatic conditions and soil characteristics.