Impact of high soil pH on potato yields and grade losses to common scab

Abstract

Waterer, D. 2002. Impact of high soil pH on potato yields and grade losses to common scab. Can. J. Plant Sci. 82: 583-586. The influence of soil pH on yields and grade-out due to tuber damage by common scab (Streptomyces scabies) was evaluated over multiple cropping seasons for potato (Solanum tuberosum) grown on land heavily infested with S. scabies. Soils with a native pH of 8.0 were adjusted to pH 7.0 to 9.0 using elemental sulfur as an acidulant and calcitic lime as the liming agent. There was little change in total tuber yields over this pH range, but the incidence and severity of scab lesions declined as the pH increased above 8.5. Marketable yields after grade-out to scab were highest at pH 9.0. This study demonstrates that in alkaline soils losses due to potato common scab may be managed by adjusting the soil pH to a point unfavorable to the scab organism. The economics of this type of pH change and its impact on subsequent crops need to be considered. . L'auteur a évalué l'incidence du pH du sol sur le rendement de la pomme de terre (Solanum tuberosum) et le nombre de tubercules rejetés à cause de la gale commune (Streptomyces scabies). L'étude s'est déroulée sur plusieurs années dans un sol très infesté par le microorganisme. On a ajouté du soufre élémentaire comme acidifiant et du calcaire calcitique comme agent de chaulage au sol d'un pH naturel de 8,0 afin que le pH se situe entre 7,0 et 9,0. Le rendement total en tubercules a relativement peu changé avec la modification du pH, mais l'incidence et la gravité des lésions dues à la gale diminuent dès que le pH dépasse 8,5. Le meilleur rendement commercialisable après écart de triage a été observé à pH 9,0. L'étude révèle qu'on peut réduire les pertes de tubercules résultant de la gale commune dans les sols alcalins en corrigeant le pH jusqu'à un niveau que ne peut tolérer le microorganisme. Auparavant cependant, on devra tenir compte des paramètres économiques associés à la modification du pH et des conséquences de cette pratique sur les cultures ultérieures.

The Importance of Nutrient Management for Potato Production Part I: Plant Nutrition and Yield

“…Although liming can usually increase potato yields, people often refrain from liming these soils as soils with higher pH values could favour the development of common scab (Streptomyces spp.) (van Lierop et al 1982;Waterer 2002). However, other severe problems related to low soil pH conditions may arise: these make it difficult to determine a recommendation for an ideal pH value for growing potatoes.…”

Heavy metals, organics and radioactivity in soil of western Serbia

“…The extremely acidic soils in the study area are considered unsuitable for potato cultivation. The optimal values of pH are in the range 5.5-6 [19][20][21].…”

Phenolic acid content in potato peel determines natural infection of common scab caused by Streptomyces spp.

“…Various control measures, viz., application of chemicals like Terrachlor and Terrachlor-X, acidification by sulphur (Davis et al 1974), soil amendments (Mishra and Srivastava 2005), organic amendments (Lazarovits et al 2001), soil fumigation, green manuring (Mishra and Srivastava 2005), crop rotation, soil pH regulation (Waterer 2002), excess irrigation during tuber formation (Loria et al 1997), potato seed bacterization and use of agrochemicals (Neeno-Eckwall et al 2001) have been suggested but so far no full proof management practices for common scab of potato is available. It is now widely accepted that satisfactory and ecofriendly management of common scab cannot be accomplished without genetic resistance, which is most ecofriendly and stable method to manage any disease.…”