Premising that in the fight against adversity of plants "prevention is the best cure" and that "good nutrition is the best resource of resistance to diseases", we will examine in this second part the diseases that affect the group of drupaceae.
The agrarian group of drupaceae includes plants that produce fruits properly defined as "drupes": the peach (nectarine-percoche), the plum, the apricot, the sweet and sour cherry (black cherry) and the almond.
They are fruit trees that, from a limited initial diffusion, then quickly expanded thanks to the introduction of new selections such as dwarf nectarine peaches, early cherries or super-sized Sino-Japanese plums.
These reasons have favored their cultivation interest, sometimes extending their cultivation outside their ideal acclimatization zone, with particular reference to the needs of cold (too much or too little) and the difficulties (congenital or environmental) of their fertilization.
The success of the cultivation of stone fruit therefore results from a mix of ideal conditions including the setting, the correct management of fertilization and defense, and, as for other crops, it is important to constantly check their status, in order to be able to intervene adequately, in contain the spread of pathologies and promote proper development.
For this reason it is important to be able to recognize the pathogens or the causes of the vegetative block that affect the various crops from the very first symptoms; to facilitate the identification of the adversities affecting the drupaceae, we group the adverse causes in table-cards with the symptoms and the damage caused by the pathogens.
1) Non-parasitic diseases: nutritional or environmental
To exemplify the various diseases that damage drupaceae, the different causes can be grouped into: environmental, parasitic, fungal diseases, damage from insects and animals.
In order to be able to vegetate, flower and produce regularly, all stone fruit need neutral or sub-acid soil, rich in fertilizing elements, organic substance and suitable humidity.
The lack of soil suitable for cultivation and lacking in nutrients causes a general deterioration of the plant, with manifestations of poor flowering, and therefore poor production, and leaf yellowing associated with various presence of pathogens.
Food shortages have a negative impact on the whole physiology of the plant, first of all reducing their resistance to fighting diseases, and, in the specific fruit sector, the damage is reflected in the economy due to lack of production, poor quality of the fruits and poor shelf life. of the same.
The drupaceae, like all plants, can show specific manifestations such as yellowing or leaf drying, poor flowering and fruiting or small insipid and misshapen fruits.
Depending on the type of nutrient the plant is lacking in, the main causes are explained in the following table: