Targeting PCN problems
AHDB estimate UK potao industry losses attributed to PCN to be in excess of £25m a year. The rise in prevalence of the more aggressive species, G. pallida, has created additional challenges for growers and agronomists to address with IPM programmes.
Syngenta Technical Manager, Michael Tait, pointed out the species survives for longer as viable cysts in the soil, which requires longer rotational breaks to achieve a desired significant natural decline in populations. Furthermore, G. pallida tends to hatch over a more protracted time span, compared to G. rostochiensis. That could result in juvenile nematodes emerging much later in the season, when control rates from nematicides may be reduced.
Soil sampling and testing for PCN remains the only way to evaluate the true extent of pest infestation. It is crucial to accurately map any change in populations that could influence rotations and control strategy decisions.
However, AHDB research warns that by the time one cyst is found in soil sampling, PCN populations will be in the millions.
Speciation of PCN soil samples can provide a guide as to the extent of mixed G. rostochiensis and G. pallida presence. Over the past decade, however, G. pallida has become by far the more dominant, and in many instances the only, species present.
PCN hit crops are weaker and stunted that, with poorer rooting, are less efficient in use of nutrients and moisture, as well as more susceptible to stress from heat and drought.
Whilst IPM practices - including trap crops, resistant varieties and extended rotations - can help to suppress PCN populations, nematicides still play a key role in keeping numbers at sustainable low levels for long-term production.
These factors signal the preference for using Nemathorin as part of an integrated approach to PCN control, and the importance of accurate application and incorporation.
Nemathorin is trusted and proven to provide effective control of G. pallida, across a full range of soil types – both for the protection of yield of the growing crop and the reduction of cyst counts at the end of the season. It has also been shown to be more effective in control of later hatching nematodes.
To maintain the highest levels of control, the granules must be evenly mixed in the soil profile surrounding the seed tuber. PCN cysts in the soil are triggered to hatch by the presence of exudates from emerging potato roots – which are then subjected to feeding damage from juveniles and creation of potential entry points for soil-borne diseases.
The Nematicide Stewardship Programme website has a wealth of resources, essential on-line training and a handy six-point plan to help achieve accurate application and best practice approach – www.nspstewardship.co.uk