Stem Nematode testing
PGRO offers a new seed and soil tests for the identification of stem and bulb nematodes based on molecular diagnostics.
Stem and Bulb nematodes, Ditylenchus dipsaci and Ditylenchus gigas, are microscopic worms of great agricultural importance, affecting a variety of crops. Ditylenchus dipsaci is known to infect over 450 crops and weeds, whilst Ditylenchus gigas is mainly found in spring and winter field beans, as well as several weeds.
Infected plants are often stunted, showing thickened and twisted stems. The stems may turn brown or red rust coloured and become swollen, forming blister-like structures. Both nematode species are seed- and soil-borne, hence infested seeds and bulbs or contaminated soils and equipment are potential sources of infestation.
The damage caused by this pest can be devastating since nematodes reproduce rapidly, potentially leading to significant yield loss.
Stem and bulb nematodes are resistant organisms enduring sub-zero winter temperatures, summer soil temperatures of 55°C, and can survive in a desiccated form for years or decades in plant debris, seed, and soil.
Prevention and control of this pest is best achieved by testing seeds and bulbs for the presence of nematodes, crop rotation and equipment disinfection between fields.
For many years PGRO has provided a seed test to detect the presence of stem and bulb nematodes, and we are now able to provide a soil test to determine field infestations. Our new soil test is based on molecular diagnostic tools, detecting the presence of the pest, with a detection limit of 10 nematodes/100g soil, and allowing species identification.
PGRO recommends that only nematode-free seeds should be used, rotations should be at least 5 years, with a 10-year break if nematodes are confirmed in soil or seed, and weed growth is controlled.
To get your bean seeds tested for the presence of nematodes, send an 800 g seed sample to the PGRO lab. This standard test will not provide information on nematode species.If you are interested in the nematode species, the molecular diagnostic test is required.
To test soil for the presence of nematodes, send a 2 kg soil sample to the PGRO lab. Nematodes move with the water table in the soil profile so best sampling times are in autumn or spring after rainfall. Sampling in dry periods or over winter are not suitable. The molecular diagnostic test will provide information on whether D. gigas and/or D. dipsaci are present in the soil.
PGRO is offering a new soil test for the detection of stem and bulb nematodes based on molecular diagnostic methodologies.
Nematode affected beans in crop