Development of Crown and Root Rot Disease of Tomato Under Irrigation with Saline Water

Abstract

We studied the effect of water salinity on the incidence and severity of crown and root rot disease of tomato, as well as on the pathogen and on the plant's response to the pathogen. Irrigation with saline water significantly increased disease severity in tomato transplants inoculated with Fusarium oxysporum f. sp. radicis-lycopersici, and mineral fertilization further increased it. In one field experiment, disease incidence in plots irrigated with saline water (electrical conductivity [EC] = 3.2 +/- 0.1 dS m(-1)) and in those irrigated with fresh water (EC = 0.4 +/- 0.1 dS m(-1)) was 75 and 38%, respectively. Disease onset was earlier and yield was lower in plots irrigated with saline water. In a second field experiment, final disease incidence 250 days after planting, was 12% in plants which had been irrigated with saline water (EC = 4.6 +/- 0.1 dS m(-1)) and 4% in those irrigated with fresh water (EC = 1.2 +/- 0.1 dS m(-1)). Irrigation of tomato transplants with 20 mM NaCl did not inhibit plant development, but partial inhibition was observed at higher NaCl concentrations. Growth of the pathogen in culture or survival of conidia added to soil were not affected by saline water. Plants which were preirrigated with saline water were more severely diseased than those preirrigated with tap water. It was concluded that disease increases effected by saline water are associated with the latter's effect on plant response.

Combined biotic and abiotic stress resistance in tomato

“…Increased soil salt concentration results in enhanced susceptibility to soil borne diseases in tomato (Triky-Dotan et al 2005) and other crop species (Al-Sadi et al 2010;You et al 2011), and similar trends are observed under water deficit (Jordan et al 1984). Observations of the effects of abiotic stress on foliar pathogens are on the other hand mixed, with studies reporting either enhanced (Achuo et al 2006;Wiese et al 2004), or decreased resistance (Roubtsova and Bostock 2009;Sanogo 2004).…”

Management of tomato diseases caused by Fusarium oxysporum

“…Lateral spread of Forl within field rows has been observed and may occur through root contact and movement in irrigation water (McGovern and Datnoff, 1992). Symptoms of FCRR are enhanced by cool temperatures (10e20 C), water-logged soil, irrigation with saline water (Triky-Dotan et al, 2005) and, as with FW, by low soil pH and ammoniacal nitrogen.…”

Marine Isolates of Trichoderma spp. as Potential Halotolerant Agents of Biological Control for Arid-Zone Agriculture

“…Crops tolerant to salt, like cotton and barley, can withstand EC levels above 7 dS m Ϫ1 ; most soils have an EC ranging from 2 to 4 dS m Ϫ1 , and seawater has an EC of 54 dS m Ϫ1 . High salinity may increase the severity of diseases caused by a variety of plant pathogens (15,43), and the search for new Trichoderma strains capable of overcoming extreme environmental conditions is timely.…”