Integrated Pest Management, Plant Pathology

Episode 15: IPM in Plant Pathology

Join Emily as she and Bob discuss what Integrated Pest Management looks like within the context of plant pathology.

This transcript has been slightly edited for clarity.

0:19 Emily: Hi folks, and welcome back to Farm Sci-Ed,
the show where we go into the science and education behind farming. We’re continuing on our discussion about integrated pest management. We’re talking to Bob today about plant pathology, the disease triangle, and integrated pest management and how all three of those topics intersect.

0:37 So Bob, how does integrated pest management use the disease triangle to make decisions in plant pathology?

Bob: As a review, let’s go back to the disease triangle. There are three points on that, and without all three of them moving at the same time, disease will not occur. So that means that there must be a susceptible host, a conducive environment, and then the pathogen to be present all at the same time. And what – the way I look at IPM is it’s – it’s integrating more than just one particular item for for control. So it it integrates several different ones, multiple ones and then hopefully the combination of all these will be better than any single one.

Present examples of this would be genetic resistance, so this also removes or tries to remove the point with the susceptible host. Another thing that that’s done with this is that the fungicides that we use, this is trying to remove the pathogen. But there’s always a resistance problem with the pathogen developing resistance so that’s why that – you you must also integrate a number of different chemicals with different chemistries. And lastly, the thing that we also try to do is forecasting. Forecasting would predict what the time period was when the environment would be ready for the pathogen to begin. So if we know when that time is, we can predict when it is and then that way we can better monitor the presence of the pathogen. And then you put all these things together, and that’s really how we try to implement different types or to integrate different types of control measures.

2:27 E: Can you explain how IPM might be used in systems where cercospora specifically is present?

B: Okay, well, like – like we’re saying, if you’re going to control this this disease to the best of our abilities, we need to continue to use cultivars that have resistance, rotating different fungicides and then trying to predict the time period when those pathogens would be present. For example, like what we did this year with the spornado: we tried to catch spores to know if they were actually there. One last thing in terms of cultivation is if there are fields that are severely affected, then it would probably be better not to leave that residue on the surface of this – of the soil, because pathogen can overwinter to some degree. And so then, if you plant new crops the next year anywhere near this, then that could serve as a point source for infections later on with the wind blow – wind and water movement.

3:27 E: Are there other examples of cultural control that you could use within the context of IPM?

B: Well, the only thing I can really think of is is trying to – if there was a problem, get rid of that the remains of the uh of the plants because that that that will remove the pathogen from that that location. Something else that you can do late in the season, is reducing the sprinklers again if – unless they really need it. That also keeping the foliage wet, will also enhance the pathogens ability to germinate – regerminate and cause further problems.

4:01 E: So really, integrated pest management practices in plant pathology are pretty self-explanatory?

B: Sure, but it’s also very – people may be doing it without even knowing that they’re doing it.

4:13 E: Do you find that common?

B: I think so, because people know what what kind of – if they’ve had a train wreck in the past, and so they don’t use that particular variety. They try to select varieties that have resistance to whatever they might be concerned about.

4:28 E: Thanks Bob! Well folks, there you have it. Today we talked to Dr. Bob Harveson about integrated pest management and how it relates to plant pathology decisions. Join us next time as we go into a more in-depth conversation on integrated pest management with all three of our specialists, and continue our exploration into the science and education behind farming. Find us on twitter @TheFarmSciEd and visit our website at for transcripts and more details. Have a good one!