Phytophthora erythroseptica (Pink Rot) Development in Russet Norkotah Potato Grown in Buffered Hydroponic Solutions II. pH Effects

Abstract

Pink rot caused by the pathogen Phytophthora erythroseptica Pethyb. causes severe pre-and post-harvest losses in potato. Severe losses of potato from pink rot infection suggest the need for better information on cultural factors associated with disease development. Soil pH has been regarded as a strong influence on disease development as observed by previous studies and by commercial potato growers. A hydroponic growth system was established to study the effects of pH on P. erythroseptica infection and colonization in Russet Norkotah potato roots. Russet Norkotah plantlets were grown in hydroponic nutrient solutions buffered at pH 5, 6, 7, and 8 and evaluated for infection by means of quantitative Real Time PCR. Acidic pH solutions produced a higher proportion of pathogen to host DNA in root tissue, indicating increased infection and colonization at low pH. Thus, pH has a unique and significant influence on the levels of infection from P. erythroseptica and that commercially grown potatoes would likely develop reduced tuber rot if grown in soils with pH at or above 7.Resumen La pudrición rosa, causada, por el patógeno Phytophthora erythroseptica Pethyb, causa severas pérdi-das pre-y post-cosecha en papa. Las grandes pérdidas por la infección de la pudrición rosa sugiere la necesidad de mejor información sobre factores culturales asociados con el desarrollo de la enfermedad. Se ha asociado al pH del suelo como de una fuerte influencia en el desarrollo de la enfermedad, como se ha visto en estudios previos y por los productores comerciales de papa. Se estableció un sistema hidropónico de crecimiento para estudiar los efectos del pH en la infección y colonización por P. erythroseptica en raíces de papa Russet Norkotah. Plántulas de Russet Norkotah se cultivaron en soluciones nutritivas hidropón-icas amortiguadas a pH de 5, 6, 7 y 8 y se evaluaron para infección mediante PCR cuantitativa de tiempo real. Las soluciones de pH ácidos produjeron una proporción mas alta de ADN del patógeno que del hospedante en tejido radical, indicando un aumento en la infección y en la colonización a pH bajo. En consecuencia, el pH tiene una influencia única y significativa en los niveles de infección por P. erythroseptica y es probable que las papas comerciales desarrollen infección reducida de tubérculo si se cultivan en suelos con pH a o arriba de 7.

Mineral nutrient deficiencies in quinoa grown in hydroponics with single nutrient salt/acid/chelate sources

“…Commonly used hydroponic solutions, such as Hoagland and Arnon (1950) and Steinberg (1953), are readily modified to study chemistry impacts, such as pH, (Bensen et al 2009a) and to create individual nutrient deficiencies, such as N (Geary et al 2015), P (Summerhays et al 2017), K (Hughes, Jolley, and Brown 1992), Ca (Bensen et al 2009b), Fe (Brown et al 1990;Buxton et al 2012;Hopkins, Jolley, and Brown 1992a, 1992b, 1992c, Zn (Hopkins et al 1998), and Mo (Steinberg 1953). Nutrient interaction studies have also been accomplished, such as P and Zn (Barben et al 2010a(Barben et al , 2010cNichols et al 2012), P and Mn (Barben et al 2010b), andP, Zn, andMn (Barben et al 2011).…”

The epidemiology of Pectobacterium and Dickeya species and the role of calcium in postharvest soft rot infection of potato (Solanum tuberosum) caused by the pathogens: A review

“…Goodwin et al (1997) reported that the level of calcium in canola leaf extracts was significantly correlated to disease resistance and to inhibition of PG activity by Leptosphaeria maculans. Increasing calcium content of beans decreased the activity of PG and pectate transeliminase thereby increasing resistance to Pcc (Krauss, 1999) while Benson et al (2009) showed that pink soft rot disease infection and severity decreased with an increase in the available calcium between 3 and 343 mg/L.…”

Soybean Nutrition in a Novel Single-Nutrient Source Hydroponic Solution

“…Many hydroponic solutions are available, such as Hoagland and Arnon [10] and Steinberg [11]. In many cases, the original published solutions have been modified to study chemistry impacts such as pH [12], and various hydroponic solutions have been used to create individual nutrient deficiencies, such as nitrogen (N) [13,14], phosphorus (P) [8,[15][16][17][18][19][20], potassium (K) [21], sulfur (S) [22], calcium (Ca) [23,24], magnesium (Mg) [25], iron (Fe) [21,[26][27][28][29], zinc (Zn) [15,[17][18][19]30], manganese (Mn) [16,18,31], copper (Cu) [32], boron (B) [33], molybdenum (Mo) [11], chloride (Cl) [34], and nickel (Ni) [35].…”