The future of conventional agriculture is to effectively combine auxiliary and less harmful phytosanitary insects . This would be a preliminary step towards organic farming with the maximum reduction of active ingredients. Let’s see what we can do to opt for a suitable integrated fight in cucumber cultivation.
As an initial reflection, to say that at the moment there is no total awareness of organic farming in many areas, and the use of the basic principles on which organic farming is based is not yet strongly seen: caring for the soil (habitual incorporation organic matter) and a total control of the cultivation work, temperature and humidity (in the case of a greenhouse).
For this reason, there is an intermediate step which is integrated pest control . This is, instead of using 100% the insecticides and fungicides of the market, manage them in the most efficient way possible together with auxiliary insects.
In this article, we dedicate it exclusively to the cultivation of cucumber , as it is a crop that is quite susceptible to pests and diseases, and because the great effectiveness of numerous insects that feed on others that cause real headaches to growers has been demonstrated for years cucumber.
TWO KEY INSECTS IN CUCUMBER INTEGRATED CONTROL: WHITEFLY AND THRIPS
Any cucumber farmer has nightmares when he dreams of these two insects, as they are a real pest installed in this crop.
Although they appear in different stages of development, the first case, the whitefly, is very persistent and it is very difficult to eliminate it with the current phytosanitary products, which in turn greatly wear down the cuticle of the leaf and make it susceptible to being penetrated by a multitude of fungi .
One of the best steps and initial investments that a cucumber product can make is to make your greenhouse as tight as possible . That is, put nets around that reduce or limit the entry of both pests.
Double doors with physical traps are a good tool to limit entry, taking into account that the reproduction of both insects is very dizzying.
WHITEFLY CONTROL WITH A. SWIRSKII
In the first stages of cultivation, close to transplantation, it is necessary to carry out control with the whitefly, since its installation is very fast.
The whitefly in cucumber cultivation is easily located on the opposite side of the leaf, on the underside, and identification is very simple.
In this sense, A. swirskii has proven to be a good hunter against whitefly in cucumber cultivation, together with chromotropic traps in the early stages of development.
However, we are in a critical phase and in many cases it is recommended to do a whitefly cleanup before the introduction of A. swirskii.
For this, since in the introduction of this auxiliary insect, it would be in an initial phase (larval), the use of adulticide insecticides is appropriate so as not to hinder its growth and reduce the possible whitefly population.
CALENDAR OF INTEGRATED FIGHT AGAINST WHITE MOSAIC IN CUCUMBER CULTIVATION
Before the introduction of A. swirskii: contact insecticides (foliar) and neonicotinoids (irrigation) such as acetamiprid, thiacloprid, thiamethoxan, imidacloprid.
After incorporating A. swirskii to the culture: soaps (potassium and phosphoric), spiromesifene (ovicide), pymetrozine (food blocker), etc.
In any case, all these insecticides have been shown to be compatible with the development of A. swirskii in the initial stages of development of the cucumber crop.
CONTROL OF THRIPS WITH A. SWIRSKII
Now it is the turn of F. occidentalis , which makes an appearance when the cucumber crop bears fruit, which may affect its growth and lose production.
Damage caused by thrips in cucumber crops occurs from the time the fruit is in formation, located in the flowers, through the suction of cells in the fruits, which in the future, in the fattening and ripening phase, create deformations and makes the fruits non-commercial.
The integrated control of thrips in cucumber cultivation is not as simple as in the case of the whitefly, since insecticides that are capable of controlling F. occidentalis fairly well punish the development of auxiliary fauna such as A. swirskii.
[alert style = »yellow»] Pyrethrins (deltamethrin and acrinathrin), which have amply demonstrated their efficacy against thrips in cucumber, affect the development of auxiliary fauna, so they should not be used under any circumstances, unless they are not have entered yet. [/ alert]
In this type of control, the massive placement of chromatic traps, in this case blue, with a high density (400-500 traps / ha) has a lot to say.
Let’s see how to do a type of integrated control in cucumber cultivation combined with A. swirskii.
CALENDAR OF INTEGRATED CONTROL AGAINST THRIPS IN CUCUMBER CULTIVATION
Before the introduction of A. swirskii: Spinosad ( Spintor 480 ), currently functional but with serious loss of efficacy due to repeated use. It is recommended not to give the maximum number of passes as it can have a persistent effect after the introduction of A. swirskii and we would throw the integrated fight to the ruin.
During the introduction of A. swirskii: Lufenuron (effect against larvae, not adults) + Azadiractin (repellent effect).
The introduction of a fungus that affects the development of thrips ( F. occidentalis) in cucumber crops also stands out within the integrated fight . We are talking about Beauveria bassiana, to which we are obliged to dedicate a future article due to the possibilities it offers in modern agriculture.
However, it has the great problem that it is affected by the fungicides currently used in cucumber.
INTEGRATED CONTROL OF MILDEW ( PSEUDOPERONOSPORA CUBENSIS)
With the auxiliary insects discussed and the insecticides that can be combined, being in itself a rather complicated puzzle, now we have to mix everything with fungicides and the dreaded cucumber mildew .
And it is that, if everything was already very complicated, the current fungicides used against mildew in cucumber crops are fatally toxic for the populations of A. swirskii. In this case, we are talking about fungicides such as mancoceb, which affects this precious auxiliary insect in category 3 (75% mortality).
Speaking of a combined and sustainable strategy, we must give importance to the use of copper , which has been used for decades and forms of resistance have not yet been described, since it affects the fungus by various effects.
However, the strategies of using copper against mildew are preventive and it will not make sense to use them when there are already visible symptoms of the disease.
To combat cucumber mildew ( Pseudoperonospora cubensis ) we can look for highly efficient fungicides applied in irrigation, and that have high systemicity.
CALENDAR OF INTEGRATED CONTROL AGAINST MILDEW IN CUCUMBER CULTIVATION
Preventive effect against mildew: use of coppers, fluopicolide, cyazofamide. All of these are effective against the development of the first mycelia, but not the internal mycelia.
Curative effect against mildew: fosetyl-Al and propamocarb, cymoxaline, metalaxyl, azoxystrobin. As both are products with great systemism, their effect is curative since they affect the internal mycelia of the fungus.