The olive tree or Olea Europea, species to which belong all the varieties, is an evergreen medium-sized arboreal, but can reach heights of 15 meters.
Characterized by opposite leaves, ovate, leathery, dark green color on the upper side and whitish on the lower, is the only one of the six hundred species belonging to the family of Oleaceae to have an edible fruit directly in the form of table olives or processed into oil.
Typically Mediterranean culture, seems to be present in different regions of the peninsula for over a million years with numerous cultivar on the basis of which presents different crop production and management influenced also by climatic conditions.
The foliage globular or rounded, dense, over the years tends to assume a hemispherical profile and, depending on its branches, classifies cultivars in plants with erect posture, as the Moraiolo, Morchiaio, Carolea and others, at pendulous posture, including Frantoio, Maurino, Pendolino and others, or at open posture as Leccino, Ascolana tender, Giarraffa and other.
In any case, the density of the foliage, which we will take into account during treatment, varies according to environmental variables, cultivar and cultivation techniques.
Long-lived plant, adapts to extreme conditions such as drought and high temperatures, it is also resistant to low temperatures, up to a maximum of eight degrees below zero, and is suitable for many types of terrain while preferring those ventilated.
An educational-scientific classification divides the areas of olive cultivation in the Italian territory in hot, medium and cold. Of course, depending on the area of belonging, we will have different problems: in the cold zone that includes areas in the north to the inland areas of the Apennine ridge, you will face the frost; in warm and media one which includes the coastal areas of Liguria and most of the southern and island regions, will be faced the problem of water management interventions with irrigation.
Depending on the geographical area in which we operate, then, will be different characteristics of the fruit and the management of the plant.
Treatments: weeding and fertilizing
At shrubby development plant in the origin, in which the renewal of the foliage takes on the issue of shoots from adventitious buds at the base of the plant, it is today, due to changes in the natural habitus, as a single trunk tree that develops a strong correlation between the growth of the foliage and the roots: reducing the size and therefore the functionality of the former, they also reduce the root system.
Managed in rows, it is currently experiencing a trend of environmental-ecological drift that leads to reduced operations of chemical weed control on the rows of the grass, especially in areas that are not flat.
It is true that the managing between the rows can compete with the plants in terms of minerals and water, but, in turn, ensures the enrichment of carbon in the soil, improving the physical characteristics of the terrain and the stimulation of microbial activity resulting in increased availability elements for the roots.
Concerning the fertilization, whose purpose is to reintegrate the nutrients removed from the plant with the operations of harvesting and pruning, it is possible to estimate the removal of mineral elements for plant multiplying their content in various organs, expressed as a percentage of dry matter for the total amount of fruits, branches and leaves removed.
As a general rule for an irrigated olive trees in production, without excessive thrust in alternating productive typical of this plant and management of the foliage oriented to minimal pruning, can be considered average annual biomass removal of 20 kilos of olives, 10 of wood and 2 of leaves. Using these data and placing the relationship between the dry matter and cool in the order of 52-58 per cent, it is estimated that the average annual removal of 200 kilos of azote, 160 of phosphorus and 190 of potassium. At this data must then be made the appropriate adjustments.
The fertilization that takes place at various times of growth of the plant can be ground or foliar. In the fertilizer to the soil, if you use a bacpack mist blower or, however, a system equipped with nozzles, we should pay attention to the choice of compost and water quality since some fertilizers are not completely soluble and could cause problems during delivery.
The foliar fertilization, that can be combined with pesticide treatments, allows the use of a knapsack mist blower with fan which ensures a good and homogeneous distribution, provides to the plants a rapid supply of nutrients and, therefore, is useful for rapid correction of nutritional imbalances. In addition, this type of fertilization is recommended in dry olive groves where water scarcity reduces the effectiveness of fertilizer to the soil.
As the fertilizer to the soil, foliar fertilization should be carried out even in various times of the year depending on the stages of development: the first intervention, with nitrogen fertilizer, is made in the budding stage, the second pre-flowering and the last during fruit set.
In order that the results are optimal distribution of the product should be carried out in the early hours of the morning and in the absence of wind.
Treatments and most widespread diseases
Health and environmental protection have become essential characters of each other in all crops and, even more in the olive, where this trend combined with the characteristics of the crop, has led many to embrace organic method.
To preventive measures of choice of healthy and certified plants, to maintaining biological balances, the choice of suitable cultivars, irrigation systems suitable and favorable for consociations, are associated treatments necessary to combat the over three hundred species of parasites who live with the olive. Among these, only one hundred of fungi and bacteria are harmful, a dozen virus and other organism but are only a few really significant exponents for which you implement specific struggles.
Among the bacteria, the Rogna – Pseudomonas savastanoi pv savastanoi, attacks the plant causing tumors on twigs and vegetative organs. The era of greater presence is autumn-winter, spring and after harvesting during which, especially if mechanical, produces lesions or wounds that leave space for the penetration of beat.
Among the phytoiatric actions, you should disinfect after pruning, cold and hail, with copper compounds bacteriostatic.
These operations, that can be performed with knapsack mist blower, require typical precautions of interventions with copper compounds being products of coverage by contact. In order to have a homogeneous distribution on the whole surface of the leaves, you will have to perform a good calibration of the mist blower with the right pressure and flow. The treatments must be carried out in the absence of wind and precipitation, and the distribution must be homogeneous and uniform.
Among the fungi, we cite the Eye of peacock or Spilocaea oleaginous, among the most widespread fungal diseases, presents forms more or less severe.
It is a disease affecting the leaves and drupes – on fruit causes circular spots more or less extensive. Spring is the season of greatest risk of contamination followed by an incubation period of considerable length.
As for treatments, even in this case we will distribute with the knapsack mist blower a copper based product before vegetative recovery if there is high possibility of disease, for example in the presence of soil and climatic conditions favoring the onset, to facilitate the fall of leaves infected by the action of phytotoxic copper. A second treatment must be done in pre-flowering.
The episodes that may occur in September, can be diagnosed in the summer with the early diagnosis made in the laboratory and in the case of positive feedback, we will schedule a third intervention at the appearance of the first spots.
We mention one of the main fungal agents, the Plumbing or Mycocentrospora cladosporiodes, leprosy or Colletotrichum goleosporioides, the Verticillium or Verticillium dahliae and the sooty mold. Among the animal parasites, the olives Moscow or Bactrocera oleae, the olive Tignola or Prays oleae and the black Cochineal or Saissetia oleae.
The treatments in the olive grove with knapsack mist blower
The main field of application for the knapsack mist blower, is of course the pest.
We can not say there are real technical criteria or optimized technologies as it can be said for other types of crops. This, mainly because for the olive come into play, assuming strong weight and importance, variables factors, in addition to natural and environmental components, the architecture of the plants and their arrangement on the plot.
Considered the foliage development, its irregularity and low leaf density due to the shape and texture of the leaves, a localized wetting process appears to be the best solution.
In this, the characteristics of a knapsack mist blower, which could be the model M1200 Cifarelli, characterized by the generation of a population of uniform droplets with an average diameter of 100 microns, provides good results in terms of coverage, penetration of the droplets in the vegetation and, compared to an optimal use of the machine meets the requirements of environmental protection by reducing the drift and the dispersion of the product. The maximum vertical range of 16 meters, more than enough for treatment of an arboreal plant, and on olive grove as in this case.
Finally, it is recommended to locate the distribution of the plant protection product on branches than on the foliage especially in the first of the three treatments made on average in a year that typically occurs during the spring, when the humidity still favor the development of fungi.
This is advisable also for the characteristics of the foliage and because a plenty wetting of the wood allows to treat the wounds caused by pruning possibly preventing the entry of pathogens.