With shorter days and cooler temperatures, fall has officially arrived. It’s the perfect time to go outside and do a seasonal orchard maintenance, as well as enjoy the abundance of delicious fruits. However, right after the harvest, only empty and exhausted trees are left. Their winter survey and next season fruiting depend primarily on the farmer’s knowledge, effort, and overall tree dormancy management. A few simple practices will help the trees through the winter dormant period and ensure their vitality for spring flowering and fruiting:
1. Orchard Sanitation
If there were any disease or insect pest signs during the vegetation, all infected fruit should be removed from the trees. This is because they can be a source of inoculum the next spring. The best practice is to remove infected fruit during the harvest. When leaves start falling from the tree, they should be mowed in order to speed their decomposition and to spread leaf compost in order to boost the populations of microbes, which also decompose leaves and help to reduce overwintering inoculum. This mass of dead leaves actually contains a high concentration of nutrients that can be very beneficial to plants. This can harness the nutrients held in the leaves by converting them to mulch.
When 50-70 % of the leaves have fallen, farmers can spray the trees with copper based fungicides to reduce overwintering inoculum and to prevent disease occurrence during the next season. The spraying is repeated at the end of the winter period, usually before vegetative bud break. These fungicides can also be applied in an integrated and organic farm system as well.
2. Winter Preparation
The most important orchard chore to prepare for winter is protecting the tender trunk bark on trees from hungry meadow voles. Voles can seriously damage or girdle and kill young trees by eating the bark and cambium layer at the base of the tree. Once the tree is girdled, water and nutrients can no longer move up and down the trunk, and the tree will die. To avoid losing a young tree, farmers can place vole guards around the trunks. This will prevent the voles from eating the bark. Care should be taken to remove this spiral plastic guard wrap in spring since they can harbor insects and diseases. If the farmer uses a plastic or metal mesh guard, they can stay on year-round as long as the farmer can enlarge them as the tree grows. A useful trick is to compact the snow around trees with snowshoes so that it freezes into a hard ice pack. Voles will not be able to tunnel through this to get to the trees.
A fall application of fertilizers can be beneficial for several reasons. Proper nutrients at this time allow the plants to recover from the fruit load that was removed from the tree and to get prepared for the winter period. At post-harvest time, it is recommended to apply fertilizers with a lower ratio of nitrogen and a higher ratio of potassium and phosphorus. Newly planted and young trees shouldn’t be fertilized. This will avoid their abundant growth before winter begins. Fertilizers for fall application can be a combination of micronutrients (zinc, boron, magnesium). The plants need them to start the process of acclimation, which provides the ability to withstand cold temperatures and other physiological processes that occur in winter.
4. Planting of New Trees
Cool temperatures during the fall are ideal for tree replanting and the raising of the new orchard. If they are planted in the fall, young trees have enough time to create roots and harden before winter. Due to better rooting and faster tree growth, fall planting and/or replanting is recommended. Immediatelly after planting, young trees shouldn’t be pruned. If it is necessary, only minor pruning is allowed before winter. Otherwise, pruning may encourage the tree to continue its growth. As a result, it won’t harden before cool tempertures come and cause winter injuries. Major pruning, therefore, can be performed in the early spring, after cool winter temperatures and before tree vegetation starts ie. plant sap starts to flow. Fall is the best time to prepare your orchard for the next season and to ensure a high quality yield. You can track all of the necessary activities for your farm and orchard using AGRIVI farm management software. This includes the work hours of workers and machinery, the usage of fertilizers and pesticides for each field, money for buying farm materials and the selling of delicious fruit, cost-benefit analysis of whole farm production and weather forecasts to plan orchard activities.
Text sources: Fertilizer Magazine || MOFGA
Image sources: J. Nikon || Lankava || NC Alternative Crops and Organics