Even though most people consider the olive tree synonymous with the Mediterranean, the crop has expanded significantly in many parts of the world in recent years. Either if someone wants to improve the way he/she exploits a family farm or start cultivating from scratch, there are some common mistakes he/she needs to avoid.
Most of these mistakes have their “roots” in the lack of knowledge and an organized cultivation plan as well as false traditional beliefs.
The 7 more common mistakes in Olive Farming
- Insufficient research concerning the selection of the cultivated variety. There are two key factors that a grower should consider before deciding which olive variety to plant. The first is the location of the olive grove. Except for the general region, the farmer needs to take into account the local microclimate that can differ significantly from place to place. Usually, a variety can only reach its maximum yield in olive groves with a specific microclimate, even though they are widely used in particular areas. The farmer needs to be sure that the variety he would like to cultivate will not suffer from any local factor (e.g., frequent spring frosts). Secondly, to select the most appropriate variety, the olive grower must decide beforehand what type of product he wants to produce. There are varieties suitable for olive oil, the so-called olive-producing varieties. On the other hand, there are the so-called table varieties used primarily for the production of edible olives. Finally, there are mixed varieties, i.e., varieties for twofold use. In any case, market research must precede to help the farmer make an informative decision, as a possible change of direction afterward often has disastrous results. After personal research and a discussion with the local agronomist, he will be able to finally choose a variety or varieties that will ensure a good production in the coming years.
- Supply of non-certified and possibly infected propagation material. The phytosanitary and the authenticity of the seedlings used is documented by specific certificates that the olive grower must have in his/her possession. All plants must be certified with a label of the Ministry of Agriculture and/or another relevant organization). As much as it is hard to believe, there are a lot of farmers that do not even know the exact variety they cultivate. An acquaintance or friend once gave them 500 young trees without anyone knowing origin and ID. This practice may have been allowed in previous years and was partly safe, but nowadays can jeopardize both our grove and the neighboring ones. In addition to all the other possible problems, the bacterium Xylella fastidiosa is considered the most catastrophic organism that uncertified material can hide. Infected seedlings from a plant nursery can carry the bacterium and transmit it to healthy mature plants in an area really easily. Xylella can destroy trees over 30 years old in a very short time. As a result, it is essential, our seedlings to have all the phytosanitary certifications. The parental plantation should be disease-free, and the substrates used for tree growth should be tested and free from pests and diseases as well. Olive growers need to visit the supplier themselves and ensure that he is approved by the Ministry of Agriculture (or a corresponding organization).
- Wrong planting distances. Every grower wants to make the most out of their grove and obtain the maximum possible yield. Of course, this is understandable. However, putting too many trees in a tiny space will arise only problems. When trees become over ten years old, the foliage will be too dense, overshadowing large parts of neighboring trees’ canopies, reducing the photosynthetic activity of the plants. Furthermore, the lack of proper aeration can create ideal conditions for the rapid transmission of diseases. Therefore, a farmer has to make a choice. If he aims to form a high-density olive orchard, he should select varieties of smaller growth and prune them appropriately. However, suppose his/her priority is to cultivate a specific olive variety not suitable for such cultivation systems. In that case, he should follow the advice of a local agronomist and design a plan with larger planting distances between trees.
- Excessive and reckless fertilization and irrigation of young seedlings. To accelerate maturation, and shorten the time needed for a tree to start having a satisfactory production, some impatient olive growers, start over-watering and over-fertilizing their groves. Although the aboveground part may respond positively, showing impressive growth, the root system does not develop accordingly. This unbalanced growth may cause long-term problems for the whole physiology and performance of the tree.
- It is common to leave the crop entirely to its fate and only visit the olive grove during the harvest. Both the crop and its yield are in danger during autumn, especially when humid and rainy weather. In these conditions, diseases such as olive anthracnose (Colletotrichum gloeosporioides) can spread rapidly and degrade all production even 1-2 weeks before harvest, and while everything looked ideal. Read more about spraying olives with copper here.
- Delay of the harvest. Many amateur farmers wrongly believe that “the later they harvest the olive, the better”. In fact, they think that the longer the olive fruit remains attached to the tree, the more oil it will accumulate over time. However, harvesting later than the ideal maturity stage of the fruit directly and adversely affects the product’s quality, and of course, does not increase the oil content. Furthermore, this delay in harvest directly impacts both the organoleptic characteristics of olive oil and its nutritional value. As the fruits overmature, the concentration of certain substances, which are considered essential quality factors, like aldehydes and polyphenols, drop. However, the problems are not just limited to the current growing season, but they usually extend to the next as well, reinforcing alternate bearing phenomenon and decreasing next year’s yield.
- Performing pruning simultaneously with the harvest. Due to lack of knowledge or just because they want to finish two things at once, some olive farmers cut down any branch with a sizeable olive fruit load to pass it through a separating machine placed in the ground. This technique will very soon prove its catastrophic effect. When the tree is injured or loses a large part of its vegetation, it automatically initiates processes to restore it. Usually, these processes require large amounts of energy. Under such conditions, the tree prioritizes vegetative growth over fruit production. In addition, during years of high yields, the olive tree has transferred all its energy to the fruit and has consumed valuable resources to do so. Once we remove the olives, the tree will use its leaves to regain energy, through photosynthesis and produce more fruit next year. If in our effort to harvest the olives, we remove branches with rich foliage, we reduce its photosynthetic capacity and, therefore, next year’s production.