Soil-borne pathogens
Environmental conditions effect on plant disease outbreak
Denberu's research
In Israel, vegetables are the leading agricultural commodities in terms of production and the second in economic value, accounting for 1.715 million tons and 5.57 billion NIS (Israeli Shekels) during 2022 growing seasons. Potatoes held the largest share of vegetable production, making up 53% of the total volume nationwide. A surplus amount of potato in Israel is produced in the Negev desert and plays a vital role in both the local and national economy. However, recently, potato production in the region is facing a new challenge referred to locally as “Premature Field Collapse.” This phenomenon is uniquely characterized by necrotic lesions on leaves and atypical wilting, followed by a sudden and widespread collapse of entire plants in the plots. Symptoms typically appear between 55 to 70 days after planting, coinciding with the onset of tuber filling. The syndrome primarily affects spring-season potatoes and progresses aggressively, causing the foliage to desiccate and plants to die within 10 to 20 days of symptom onset. While the economic impact of this collapse on the local economy is not yet fully assessed, the Israel Vegetable Growers Organization (IVGO) reported that yield losses due to this phenomenon reached as high as 25,000 tons in a single season in 2023, with an estimated cost of more than $28 million. The exact cause of the collapse remains unknown and needs investigations to design appropriate management strategies. The main purpose of the project is to investigate the causal agent and contributing factors behind the premature field collapse of spring-season potatoes in the western Negev, Israel. Additionally, the study seeks to evaluate potential interventions that could mitigate the impact of this phenomenon and support sustainable potato production in the region.
Samuel's research
​As part of my research in the lab, I am involved in the exploration of green microalgae as potential biological control agents (BCAs) for managing soil-borne plant pathogens. Overreliance on chemical pesticides over the years poses significant threats to human health, the environment, and the ecological system. My goal is to contribute to the development of biological, sustainable, and environmentally resilient alternatives to help reduce chemical usage in agriculture. My project focuses on a green alga isolated from desert biological soil crusts, which has shown remarkable resilience to harsh environmental conditions. Preliminary experiments revealed that this alga significantly inhibits the growth, viability, and melanin production of several fungal pathogens. Among these, Rhizoctonia solani a widespread and economically damaging soil-borne fungus, was selected as a model pathogen due to its high susceptibility to the algal extract. Through a series of in vitro assays, I evaluated how various environmental factors including salinity, carbon source, temperature, and light & dark conditions influence the alga’s antifungal activity. One key finding was that supplementing the growth medium with 0.2M NaCl notably enhanced its antifungal effects, resulting in significant suppression of both fungal growth and melanin production. Building on these findings, this study aims to evaluate the microalga’s ability to inhibit the pathogenic activity of R. solani in planta and to better understand the mechanism of action behind the antifungal compounds. In parallel, I am working to isolate and characterize these bioactive compounds.This research seeks to advance our understanding of algae fungi interactions in the soil and how environmental conditions influence these dynamics. Ultimately, the goal is to support the successful implementation of sustainable strategies for managing soil-borne pathogenic fungi.