Pest and disease resistance

IPM research has brought together and tested late blight managment components including host resistance, disease forcasting, spore detection, inoculum sources and fungicide programmes.

The use of resistant cultivars is a key component of integrated management of potato cyst nematodes.

Resistance elicitors are generally non-toxic substances that prime a plant’s own resistance mechanisms enabling it to better defend itself against pests and pathogens. Their efficacy is dependent on appropriate use in IPM programmes as they depend on the host plant’s genotype and physiological state.

Soil-borne pathogens of potato cause a number of serious blemish diseases.  By employing appropriate soil sampling strategies in conjunction with a method for soil DNA extraction and real-time PCR assays to detect and quantify target pathogens, we can validate the relationship between soil-borne inoculum and disease risk. The relationship between pathogen detection and disease risk for black dot (Lees et al. 2010 and Brierley et al. 2015) and powdery scab (Brierley et al. 2012) have been determined. Furthermore, the impact of soil-borne inoculum on disease has been investigated in conjunction with other control factors such as host resistance and crop management, for example, crop duration and chemical control (Brierley et al. 2018).

Mixtures of several current recommended varieties of barley, particularly winter types, can be used to partially control many pathogens, particularly splash-dispersed pathogens such as R. commune (causing rhynchosporium or scald), as a control measure in their own right.

Pest and disease damage in soft fruit plantations can lead to significant yield loss, costing the industry millions of pounds annually. Current soft fruit breeding programmes have not fully exploited plant traits that confer resistance to, or tolerance of, the most damaging pests and diseases. Recent research to characterise genotypic variation in root and shoot physical traits of raspberry has highlighted traits that could be exploited to limit yield losses caused by the most damaging pests and diseases.

Blackleg (including soft rot) of potato is a devastating disease for which there are no chemical treatments. Disease control is particularly important for the seed potato industry as the pathogen, once present, increases in population through seed generations. Since the 1960s, disease has been controlled by ventilated storage, seed certification, good hygiene and more recently by managing seed imports (safe haven scheme and Government legislation). While disease incidence is much reduced than 50 years ago, it still remains a major problem both in Europe and beyond.  Over the last 5 years blackleg disease appears to be on the increase although the reasons for this are not clear.  At the Institute we are focussing on 4 control measures to be included in the blackleg IPM strategy.