Scientists have developed a new way to identify the presence of nematodes in soil samples on coffee farms.
Details of the new method are published in the journal Phytopathology and researchers hope it will be used to further understand which species live where, so coffee growers can take mitigating action.
Two major nematode species live in soil and damage the roots of the coffee plants but do not produce clear symptoms.
The nematodes feed on the roots of coffee trees, weakening the plant and ultimately cause yield loss.
The nematodes also attack banana and black pepper plants, which are sometimes grown alongside coffee, providing a rich environment for them to thrive.
A team led by the University of Leeds, working with Nestlé agronomists and researchers, as well as international academic colleagues, took soil samples from plantations in Brazil, Vietnam and Indonesia. They analysed the samples to identify DNA from the worms and found them at damaging levels wherever they looked.
The problem of nematode worms targeting coffee has been previously reported. However, this is the first molecular-based study to assess plant-parasitic nematodes in coffee fields by sampling multiple crop plants in three major coffee producing countries.
Peter Urwin, Professor of Plant Nematology at the University of Leeds Faculty of Biological Sciences said, “We found widespread evidence of these parasites. The exact species vary by country and looking at soil samples, I can tell the difference between Vietnam and Brazil or Indonesia. The sad fact is that wherever we take samples, we find plant-parasitic nematodes, which are hugely damaging to coffee crops.”
The average coffee plant has a 20 year lifespan and is a significant investment for a farmer. They are sometimes grown alongside banana and black pepper which gives a broader income stream but may compound the problem.
The researchers say one mitigation method could be to separate the crops so if one gets infected the others are not threatened.
The work was carried out by PhD researcher, Christopher Bell. He said, “We were alarmed by the number of parasites we found in our samples and hope our method will be taken up by others so we better understand what we are facing. Ultimately, farmers and growers should benefit from this work and take appropriate mitigating actions.”
This research was supported by a KTN CASE studentship and by Nestlé.
[photo: University of Leeds]