Tropentag, September 11 - 13, 2024, Vienna "Explore opportunities... for managing natural resources and a better life for all"

The effect of potassium fertiliser on the physiological responses of field-grown sweetpotato to salinity

¹University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Germany
²International Potato Center, Flagship 2 - Adapted Productive Varieties and Quality Seed, Mozambique

Abstract

Salinity is a growing constraint for agriculture by limiting both the area available for crop production and its efficient use. High concentrations of sodium chloride in the soil solution, can affect crop growth and yield through the competition of sodium (Na⁺) with potassium (K+) in plant uptake and translocation, resulting in absolute or relative potassium deficiencies in plant tissues. As potassium nutrition in plants is associated with key processes such as photosynthesis, enzyme activation, and phloem loading, salinity-induced K deficiencies may result in reductions in growth and ultimately yield. Sweetpotato varieties maintaining potassium acquisition, retention and a favourable leaf K+/Na⁺ ratio under salinity have been shown to suffer relatively small salt stress-induced reductions in biomass. Thus, increasing the availability of potassium in the soil may be a potential management strategy to improve the K+/Na⁺ ratio via the increased uptake of K+. However, little is known to date on K+ uptake and distribution as well as the effect of adding potassium fertiliser to sweetpotato, under saline field conditions.
This study tested two sweetpotato varieties (CIP 440004 and Huambachero) grown under saline and non-saline drip irrigation and supplied with potassium sulfate at two different levels: 33 kg ha^-1 and 66 kg ha^-1 in a field trial at the CIP research station in Maputo, Mozambique. Destructive samples were taken every 10 days to observe the changes in dry matter content of various plant parts at different growth stages. Sodium, chloride, and potassium concentrations and contents were determined to track salt uptake and distribution in different plant parts within the varieties.
The poster will discuss the development of a potassium fertiliser strategy to improve salinity tolerance and the yield of sweetpotato as a management strategy for marginal lands.

Keywords: Physiology, potassium fertiliser, salinity stress, sweet potato

Contact Address: Jane Cypriyana Pedinedi Jerald, University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Birkheckenstr. 78c, 70599 Stuttgart, Germany, e-mail: janecypriyana.pedinedijeralduni-hohenheim.de