Tag Archives: vineyard

Mosquito verde en viña

Green leafhopper in vineyard: how to deal with this pest

Mosquito verde en viña

The detection of green leafhopper pests in vineyard has put wine growers on alert at a key moment of the grape season, just a few weeks after harvesting time begins. Several official bodies have warned of the substantial increase of mobile forms of green leafhopper in vineyard, as high population scenarios have appeared in which it is foreseeable to exceed the treatment thresholds.

In Spain, the Department of Plant Protection of the Generalitat Valenciana (Valencia) has issued warnings to producers in the central area of the province. The same occurs with the Network of Alert and Phytosanitary Information of the Junta de Andalucía  as several spots have been detected in the province of Malaga. In Toledo, ASAJA  has also confirmed the presence of this pest in vineyards in the district of Méntrida and La Torre de Esteban Hambrán. In these areas, caution is even greater after the devastating plague that farmers suffered last crop.

Green leafhopper in vineyard results in an insect between 2 and 3 mm in length. It is placed on the underside of leaves and is used to fly at the slightest movement. Green leafhopper attacks the nerves of leaves, as it feeds on the plant sap. Its effect is extremely detrimental because it stops the vegetative development and, consequently, the fruit ripening. Visually, the most evident consequence is the marginal desiccation of leaves, which turn yellow.

The most intense presence of green leafhopper in vineyard usually occurs during summer because of high temperatures, warm and dry weather conditions. Economic losses for growers can be significant because the effects can be extended in the post-attack season, with a possible decrease in sprout vigor and crop yield.

Treatments for green leafhopper in vineyard

The scenario caused by the proliferation of green leafhopper in vineyard (Empoasca vitis Goethe) in Spain has also occurred in Europe, as a substantial increase in the population of cicadellidae has been observed in recent years. Seipasa has produced Pirecris®, a natural biopesticide showing an excellent performance in the control of several species of cicadellidae in vineyard.

The active ingredient of Pirecris® guarantees its efficacy and knock-down effect. In addition, the formulation of a high technology product has allowed Seipasa to obtain the product, guaranteeing a ‘green’ profile based on a plant matrix that enhances the action.

Pirecris® efficacy against the green leafhopper has been tested through more than 18 field trials conducted in several countries. One of them is the one carried out in the south of France during the summer of 2014. For this trial, a complete randomized block with 4 repetitions and 5 treatments was unfolded: an untreated control, Pirecris at 3 different doses (1; 1.5 and 2l / ha) and a reference chemical pyrethroid (0.125 l / ha). Two applications (A and B) were performed: the first one, on July 2014 and the second 7 days later. The number of larvae in 50 inner leaves was evaluated at 3 and 7 days after each application.

As shown in figure 1, the first application of Pirecris® significantly reduced E.vitis populations. These populations were lower than the ones in the control treatment for all doses tested.

Mosquito verde en viña

Figure 1.- Evolution of the number of E.vitis larvae found in 50 leaves. A: first application; B: second application. Samples made at 0, 3 and 7 days after each application.

Green leafhopper populations remained low in all treatments with Pirecris during subsequent samplings, especially after the second application. The results are similar to those obtained by the reference treatment. The efficacies obtained in this trial were high (about 90%), especially with the medium and high doses (1.5 and 2 l / ha), surpassing those obtained by the reference pyrethroid (see figure 2).

Mosquito verde en viña

Figure 2.- Evaluation of the Abbott efficacy of Pirecris and the reference pyrethroids against E.vitis in vineyard corresponding to samples taken at 0, 3 and 7 days after each application.

The results prove that Pirecris® is a solid and efficient alternative for the treatment of the green leafhopper in the vineyard. This solution, 100% natural and free of chemical residues, is fully aligned with the needs of producers and consumers towards a rational, sustainable and environmentally friendly agriculture.

Enfermedades de madera de la vid

Strategies for grapevine trunk diseases

 

Enfermedades de madera de la vid

Grapevine trunk diseases are among the most serious problems affecting crops at the present time. When summer comes, cultivation of grapevine enters a decisive period. Preserving it in optimal conditons is fundamental, as it results in a pivotal element supporting many local and regional economies.

This is the reason why studies on grapevine trunk diseases proliferate at a key moment for the sector. Farmers are struggling to look after the current harvest, but cannot overlook the following season. In July, the city of Reims (France) hosts an international conference with a large group of experts on this subject.

Grapevine trunk diseases have become more evident in the last decade because of the advances in knowledge concerning fungal species taking part in the process of wood deterioration.

Intensified production, the aging of vineyards and the long period of time that may elapse between the penetration of fungi and the display of the first symptoms (in some cases, grapevine trunk diseases may already exist in those seedlings coming from the plant nursery) are factors that may explain why farmers are increasingly being affected by these diseases.

The absence of registered fungicidal active substances capable of dealing with these pathogens leads to reinforce preventive measures to restrain fungi from entering or penetrating wood. Practices and knowledge developed for years suggest farmers to use a pruning system that minimizes cuts, since the transmission of grapevine trunk diseases is produced through pruning wounds.

In addition to avoiding thick wounds, not only do cultural practices recommend pruning in dry weather conditions but it is also important to let a few days pass after an episode of rainfall.

Advances in grapevine trunk diseases also point to use hot-water treatment as a method to reduce infections caused by wood fungi in propagating material. Application of hot-water treatment has been approached by David Gramaje, researcher of the Instituto de Ciencias de la Vid y el Vino (ICVV) at the international meeting promoted by Phytoma in March 2017.

Grapevine trunk diseases: activation of the defense system

Preventive actions also recommend using treatments capable of stimulating plant’s defense system. Superbrotal is a natural solution produced by Seipasa. This product performs as an activator of the processes involved in sprouting and plant structuring. Superbrotal stimulates the defense mechanisms due to its main compound, which induces the synthesis of those proteins involved in the immune system.

Not only does Superbrotal activate self-defenses, but it also strengthens the vascular bundles of the plant, generating a better translocation of nutrients in favor and against the gravitational gradient. It results in a balanced crop, with a powerful, structured and efficient plant development. Crops gain in size and foliar architecture, improving its ability to overcome stresses.

To set an example, there is a trial conducted by Seipasa in grapevine between 2014 and 2016 (see figure 1). The results show the inducing effect of Superbrotal. The trial was performed on a plot where vascular diseases had been experienced before. After the first campaign in 2014, disease incidence increased in the control area. However, as observed in figure 1, Superbrotal was able to improve sap flow by reducing the percentage of affected vineyards in the following campaigns (2015 and 2016).

Figure 1.- Incidence of grapevine trunk disease.

Grapevine trunk disease

Stimulation of the defense system helps to prevent stresses. Prevention may become a suitable strategy to avoid the penetration or progression of fungal diseases.