Raspberry plants can be grown organically very well, and also the phytosanitary defense with low environmental impact, if well carried out, leads to very positive results. From spring onwards there is a concrete possibility that raspberries will be hit by some adversity, due to diseases or insects. For this you need to keep an eye on them and intervene as soon as possible with products that are not harmful to the environment and are as selective as possible. Don't worry: with due care and a certain constancy, the exquisite fruits of this species will arrive ripe in the summer.
Let's assume that the constant monitoring of plants is an indispensable condition to identify the first signs of the presence of parasites, which, taken in time, will certainly allow easier management, and that even generic treatments, such as attention to balanced and never excessive fertilization, pruning and irrigation play their role in making the plants feel good.
We have already talked about raspberry diseases, let's see now in particular what are the main animal parasites that threaten raspberry and with what precautions and products can we deal with responsible and effective defense, both in productive contexts and in the vegetable garden or backyard.
Anthonomus rubi is a weevil beetle, which lays its eggs on the flower buds of raspberries, and then cuts the flower stalk in order to prevent the bud from opening and allow the larva to eat it undisturbed from the inside.
In case of severe infestations, the decrease in the raspberry harvest reaches 50%, for this reason action must be taken very soon, in the phase of pre-flowering of raspberries, with treatments based on azadirachtin (neem oil). In addition, if there are fern plants nearby, we can use them as mulch between the rows of raspberries, because it seems that this plant has a deterrent effect towards the antonium, you can also try the macerate.
Small fruit fly (Drosophila suzukii)
In recent years, Drosophila suzukii, called small fruit fly, has begun to represent one of the major problems for small fruit. The adult forms of this dipteran lay their eggs inside the ripening fruits, and the larvae feed on the pulp causing superficial depressions in the fruit. The greatest damage occurs in the summer, but after a mild winter the arrival of the insect anticipates, and consequently we must start to worry about it in time by putting food traps to catch the drosophila, such as Red Tap Trap, Red Vaso Trap, or by means of nets exclude fine-meshed insects, which also protect against other pests.
THE red spider mites Tetranycus urticae, very well known and polyphagous, e Neotetranychus rubi, are mites that sting the leaves to feed on their lymph, and initially cause depigmentation in the form of close chlorotic dots, then more extensive discolored areas and in severe cases even desiccation. Their attacks are favored by a hot and dry climate and by the absence of ventilation, conditions that greatly limit the presence of phytoseids, or the natural predators of these mites.
But the most important thing to favor the presence of the antagonists is the give up treatments with broad spectrum insecticides, which kill harmful mites and even good ones, but rather safeguard the biodiversity of the environment and, in the case of extensive raspberry production, spread the phytoseids in the environment by purchasing them from special "bio-factories".
For a modest private production, raspberry plants can be defended by intervening in advance with extracts of nettle and garlic, otherwise, with presence in progress, using a product based on the good mushroom Beauveria bassiana.
Bedbugs are annoying insects of the order of the Heteroptera, e in recent years they have shown particular aggression, especially with the arrival of the Asian bedbug Halyomorpha halys. By pricking the berries of raspberries, they stop their development and make them bad in taste and smell.
To defeat these parasites we can intervene with treatments based on natural pyrethrum or azadirachtin, which present at the moment a certain killing power at least on the juvenile forms, but do not prevent new and rapid recolonizations by these parasites.
Consequently, in order not to have to repeat the treatment very often, it is better to wrap the rows, or individual bushes, in fine-mesh insect-proof nets, after the fruit set. In addition to the Asian bedbug, it has also arrived in recent years the beetle Popilia japonica, which is very polyphagous, attacks many species of fruit trees by eating their leaves, buds, flowers, and fruits, and has a very gregarious behavior such that we can find many specimens all together to do damage. In this case too, insect-free nets are a fundamental means of defense.
Some in spring and summer leafhoppers as the Metcalfa pruinosa cause curling up, leaf distortions and slowdowns in the growth of shoots.
We can also note the presence of white wax as a secretion of these small insects, which fortunately are usually preyed upon by an antagonist. In case of insufficient natural balance and strong attack, azadirachtin works as a product for ecological treatments.
In hot and humid seasons many aphids may appear, also favored by the vegetative luxuriance given by abundant fertilizations. These small insects are parasites of most of the garden and orchard plants, they do not spare raspberries.
For this it is important to fertilize moderately, and always with natural, organic products such as compost, manure, and manure, but also natural minerals such as rock flours. The pruning on the raspberry, which prune the bushes, play an important role, as do the preventive treatments based on macerates of nettle, hot pepper and garlic.
Diluted Marseille soap has a killing effect with ongoing infestations, to be used in the cool hours of the evening.