Impacts of Manures and Manure-Based Composts on Root Lesion Nematodes and Verticillium dahliae in Michigan Potatoes

Abstract

The interaction of the root lesion nematode Pratylenchus penetrans and the fungal plant pathogen Verticillium dahliae causes potato early die (PED) complex, which induces premature vine senescence and dramatically reduces yield in potatoes. Management of PED is often achieved through the use of soil fumigants and nematicides, but their adverse effects on soil, human and environmental health, and strict regulations worldwide require alternative control tactics. In this study, we investigated the effects of multiple composts and manures on nematode mortality and PED. In lab assays, root lesion nematodes were exposed to poultry manure, layer ash blend, Dairy Doo, or wood ash for 7 days at rates of 0, 0.1, 1, 10, and 20% by volume of product and assessed for nematode survivorship. Additionally, these products were evaluated for volatile fatty acid content to determine if fatty acid content affects nematode control. In a field trial, the composts and manures were evaluated at two different rates, high (11.2 t/ha) or low (2.8 t/ha), and populations of P. penetrans and V. dahliae were quantified. Our results show that a 1% application rate of poultry manure and layer ash blend provided the greatest nematode control in lab assays with 24.5 and 38.2% reduction, respectively, with greater control at higher rates. In the field, plots treated with poultry manure had significantly higher potato yields and significantly fewer nematodes than control plots. Taken together, our results suggest that poultry manure could be a promising amendment to control PED.

“Exploring the synergistic relationship between Pratylenchus penetrans and Verticillium dahliae in potato cropping systems: recent developments and research gaps”

“…Microbial communities produce volatile fatty acids (VFAs) during the decomposition process of manure-based composts, which act as a mechanism of control (Cole et al, 2020). Studies have demonstrated that even small concentrations of VFAs found in liquid swine manure can have lethal effects on V. dahliae and nematodes (Cole et al, 2020).…”

“…Microbial communities produce volatile fatty acids (VFAs) during the decomposition process of manure-based composts, which act as a mechanism of control (Cole et al, 2020). Studies have demonstrated that even small concentrations of VFAs found in liquid swine manure can have lethal effects on V. dahliae and nematodes (Cole et al, 2020). Unfortunately, the majority of VFAs do not exhibit long-term persistence within composts or manures, due to their rapid breakdown by microorganisms, degradation, or absorption, which significantly reduces their antagonistic properties over time (Cole et al, 2020).…”

“…Studies have demonstrated that even small concentrations of VFAs found in liquid swine manure can have lethal effects on V. dahliae and nematodes (Cole et al, 2020). Unfortunately, the majority of VFAs do not exhibit long-term persistence within composts or manures, due to their rapid breakdown by microorganisms, degradation, or absorption, which significantly reduces their antagonistic properties over time (Cole et al, 2020). Incorporating green manure into soil may not lead to a significant decrease in pathogen count or their survival rate, particularly in highly infested fields (Perez et al, 2008), however, it has been found to promote the growth of microorganisms with the potential to combat these harmful pathogens by releasing pesticidal agents or ITCs from the amendment and into the soil (Molina et al, 2014).…”

Irreplaceable Role of Amendment-Based Strategies to Enhance Soil Health and Disease Suppression in Potato Production

“…After being applied to soil, most organic amendments need to be further decomposed and turned into various small molecules through a process of microbial degradation before taking effect, although some of them are active elements that affect plant growth and soilborne pathogens immediately. Compost is unique because it is ready to use, as most organic matter that it is composed of is already degraded [ 90 ].…”

Management of the soil-borne fungal pathogen – Verticillium dahliae Kleb. causing vascular wilt diseases

“…Fatty acids were more easily released from the fertilizer when applied to dry and heated soil (Conn et al 2004). Cole et al (2020) demonstrated that poultry manure could be a promising amendment to control potato early die complex which induces premature vine senescence and dramatically reduces yield in potatoes. The disease is caused by complex of V. dahliae and nematode Pratylenchus penetrans.…”