Category: News
Date published: October 10, 2023

Beneficial nematodes and natural enemies effectively control pests and diseases in garlic, leek and onion

Koppert’s biological control strategy increases yield by acting on both plant and soil health.

Koppert is achieving excellent results in the biological control of pests and diseases in outdoor crops such as onion, leek and garlic. In Spain, the main action areas are the regions of Castilla-León and Castilla-La Mancha, in the centre and north of the country. They make up the largest cultivation areas for these three important domestic and export crops.

Farmers detected that most of the chemical pesticides used on onion, leek and garlic generated resistance in pests. Consequently, they experienced a widespread loss of effectiveness of many chemicals and needed other, safer and more sustainable means to ensure plant protection for their crops. Since the first trials five years ago, Koppert has developed successful biological control protocols for outdoor crops.

Successful biocontrol strategies

Koppert is a pioneer in Europe when it comes to the use of vegetable hedges with Lobularia maritima, that offer Orius laevigatus (a natural enemy of thrips) a natural shelter and food source when the onion plant has no flowers. The strategy has greatly facilitated the installation of Orius in onion crops to control thrips.

The onion strategy is completed with the use of beneficial microorganisms to control thrips larvae that emerge from the soil. The entomopathogenic nematode Steinernema feltiae (Capirel®) has proven to be highly effective and also exerts a double action, since it effectively controls Onion fly (Delia antiqua) at the same time.

Koppert's experience with biological control in leek focuses on organic leek crops, where chemical solutions are no longer available. The combination of Orius laevigatus with the beneficial nematode Steinernema feltiae (Capirel) has worked very well in leek, where the use of Nesidiocoris tenuis (Nesibug®) has also been incorporated to control the psyllid pest Tryoza spp.

Soil and root health

Koppert's biological control protocol for onion, leek and garlic also takes into account soil health and root protection. For this reason, the Trianum® biofungicide (formulated with the beneficial fungus Trichoderma harzianum T-22) takes on special importance, since this 100% natural biofungicide creates a shield of protection against soil diseases transmitted by fungi.

Koppert's exclusive biological control protocol for garlic cultivation begins before planting with the addition of top quality organic matter to the soil, followed by a first application of the Trianum biofungicide. Shortly after sowing, Koppert recommends an application of Panoramix® as protection against fungal diseases such as Penicillium and Sclerotinia.

When the young garlic plant is already visible, a second application of Trianum is recommended. Then, when the plant has a minimum height of 10 centimeters, applications of Vidi Parva and Veni Biosulfur are recommended as a protective measure against aerial fungi, such as Septoria tritici and Puccinia allii.

Every year Koppert implements its biocontrol on more and more hectares. The strategies developed in Spain are already being applied in other European countries such as the Netherlands and Germany.