For Canadian potato growers, nematodes and diseases can reduce yield potential and marketability of their potato crops. Nematodes, especially root lesion, root knot and potato cyst, are a key threat to a potato crop and particularly difficult to control. These microscopic roundworms feed on plant roots and can transmit diseases. Although there are no estimates of yield losses specific to Canada, it is estimated that 10% of the potato crop is lost annually to nematodes in the U.S. It is reasonable to assume that this may also be the case for Canada.1 In addition to nematodes, diseases including early blight and black dot can also rob yield potential and decrease product quality.
There are solutions that can help reduce crop damage from nematodes and fungal diseases for the current season and the next. Velum® Prime nematicide is an innovative non-fumigant nematicide for potatoes with a secondary benefit of fungicidal activity on early blight and black dot. When used together in an integrated, comprehensive nematode management program, Velum Prime nematicide can help increase yield and quality for potato growers.
Velum Prime Nematicide
Velum Prime is a broad spectrum nematicide/fungicide labeled for use in potato and other crops in Canada. It specifically targets root lesion (Pratylenchus spp.), root knot (Meloidogyne spp.) and potato cyst (Globodera pallida, Globodera rostochiensis) nematodes. Velum Prime nematicide has also demonstrated effectiveness in the suppression of early blight (Alternaria solani) and black dot (Colletotrichum coccodes) fungal diseases. It is a nematicide/Group 7 fungicide (fluopyram), with a mode of action that rapidly immobilizes nematodes, killing them one to two hours after contact. The active ingredient then moves systemically throughout plant tissues, suppressing early blight and black dot diseases. Velum Prime nematicide has limited soil mobility and excellent systemic plant mobility. The suppression of nematodes can lead to improved root health and plant vigour.
Velum Prime nematicide can be applied in-furrow during planting. It comes in a liquid formulation that makes it ideal for use with common in-furrow application equipment. In general, Velum Prime nematicide is most effective when the chemical is uniformly applied to soil and targeted toward the future rooting zone of the plant, where the chemical can contact nematodes or be absorbed by the plant. Moist soils, above 12-15%, generally increases effectiveness, while proper tillage helps to mix this relatively immobile chemical through the soil.2 For chemical resistance management, the first foliar fungicide applied after in-furrow application must be a non-Group 7 mode of action. Examples include chemicals such as chlorothalonil or mancozeb.
Always refer to the latest label instructions for proper application rates and procedures.
A Comprehensive Nematode Management Program
Velum Prime nematicide is most effective as part of a comprehensive nematode management program. It is not intended as a replacement for fumigant nematicides. An integrated pest management program begins with soil tests to determine whether pathogenic nematodes are present within a field, what nematode species are present, and whether nematode population densities are high enough to cause economic yield loss. Information on nematode species and population densities, along with the history of the incidence and severity of diseases and insects as well as soil moisture levels during field preparation can help guide management decision making. Growers should use a combination of different control measures since no single measure offers complete protection. Current nematode management considerations include:
Crop Rotation can help reduce nematode populations from fields, but results are dependent on the nematode species. Root lesion nematodes have a wide host range, so crop rotations are challenging. Soybeans and red clover are both good hosts for root lesion nematodes, while annual ryegrass is less so. With root-knot nematodes, crop rotations can be effective since annual ryegrass, timothy and cereals are non-hosts. Potato-cyst nematodes have a limited host range (potato, tomato, eggplant, wild Solanum spp.), so crop rotations that include non-hosts such as cereals and forages are a practical approach to reducing population levels in the soil.
Soil fumigation is a proven broad-spectrum strategy to reduce all species of nematode populations in soil, but these chemicals are expensive, can be dangerous to applicators, and are not always cost effective because they do not provide consistent control at the same level for all pests. Specialized equipment is required for application and effectiveness is highly influenced by soil and seedbed conditions as well as temperatures. Also, the timing of fumigant application can result in planting being delayed.
Other cultural practices can lessen the impact of nematodes. Good plant nutrition can improve plant vigor, reducing nematode damage. Selecting earlier-maturing potato varieties that can be harvested earlier can help limit the time the tubers have in the field, reducing vulnerability to nematode damage.
Practicing sanitation is critical to keeping nematodes from being introduced into fields. Root lesion nematode, for example, can be spread easily via contaminated soil, seed pieces, equipment, and wind-blown soil. Equipment should be cleaned and sanitized before moving between fields. In the case of potato cyst nematode, it is essential to follow quarantine regulations that limit or restrict movement of soil, machinery and vehicles containing soil and plant material to prevent the spread of this nematode into uninfested areas.
Key Features and Benefits of Velum Prime Nematicide
- Broad spectrum nematicidal activity with the added benefit of in-season protection against early blight and black dot diseases
- Simple and easy to apply
- A liquid formulation that offers reliable effectiveness at low application rates make it ideal for existing liquid in-furrow application equipment
- Early season protection and suppression of nematodes and diseases
- Poses less human safety risk and is less restrictive to use than traditional soil fumigants because it is less toxic and has few label restrictions
- Reduces pesticide load versus the use of fumigants
1 Nematodes. Government of New Brunswick. Agriculture, Aquaculture and Fisheries.https://www2.gnb.ca/content/gnb/en/departments/10/agriculture/content/crops/potatoes/nematodes.html
2 Grabau, Z.J., and Noling, J.W. Nematode Management in Potatoes (Irish or White). University of Florida. IFAS. https://sfyl.ifas.ufl.edu/
Best management practices for preventing potato cyst nematode contamination. Government of Canada. Canadian Food Inspection Agency. https://inspection.canada.ca/plant-health/plant-pests-invasive-species-other/golden-nematodes/inspection/eng/1337016451272/1337016555455
Gorny, A. and Grode, A. 2021. Lesion nematode in potato. North Carolina State University Extension. Vegetable Pathology Factsheets. https://content.ces.ncsu.edu/lesion-nematode-in-potato
Root lesion nematode. Ontario Ministry of Agriculture, Food & Rural Affairs. Ontario Crop IPM. http://www.omafra.gov.on.ca?IPM/english/potatoes/nematode/nematode.html#advanced
ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.
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