ROOT ZONE TEMPERATURE AFFECTS THE PHYTOEXTRACTION OF Ba, Cl, Sn, Pt, AND Rb USING POTATO PLANTS (SOLANUM TUBEROSUM L. VAR. SPUNTA) IN THE FIELD

Abstract

Three consecutive years of field experiments were conducted to investigate how different root-zone temperatures, manipulated by using different mulches, affect the phytoextraction of Ba, Cl, Sn, Pt and Rb in different organs of potato plants (roots, tubers, stems and leaves). Four different plastic covers were used (T1: transparent polyethylene; T2: white polyethylene; T3: white and black coextruded polyethylene, and T4: black polyethylene), using uncovered plants as control (T0). The different treatments had a significant effect on mean root zone temperatures (T0 = 16°C, T1 = 20°C, T2 = 23°C, T3 = 27°C and T4 = 30°C) and induced a significantly different response in Ba, Cl, Sn, Pt and Rb concentration and accumulation. The T3 treatment gave rise to the greatest phytoextraction of Ba, Pt, Cl and Sn in the roots, leaflets and tubers. In terms of the relative distribution of the phytoaccumulated elements (as percentage of the total within the plant), Pt and Ba accumulated mainly in the roots whereas Rb, Sn and Cl accumulated primarily in tubers, establishing a close relationship between the biomass development of each organ and phytoaccumulation capacity of metals in response to temperature in the root zone.

Keywords:

• Solanum tuberosum L.
• Mulching
• Phytoextraction
• Root-zone temperature

ACKNOWLEDGMENTS

The authors express their gratitude to the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria” (INIA) and the “Dirección General de Investigación Agraria de la Consejería de Agricultura y Pesca de la Junta de Andalucía” for the financial support for this work within the framework of Research Projects “INIA 8505” and “INIA SC93-084” and to the C.I.F.A. (Centro de Investigación y Formación Agraria) for its support in the experiments, and plant and soil sampling. The authors would like to thank David Nesbitt for the translation into English, reviewing and constructive comments.