Effect of Root Zone Temperature on Accumulation of Molybdenum and Nitrogen Metabolism in Potato Plants

Abstract

Changes in root temperature caused by the application of plastic covers were studied in relation to the uptake and content of molybdenum (Mo) in the different organs of potato (Solanum tuberosum L. var. Spunta) plants (roots, tubers, stems, and leaves) and in relation to nitrogen (N) metabolism. For the semi‐forcing technique of mulching, four different covers were used: T ₁ (transparent polyethylene), T ₂ (white polyethylene), T ₃ (coextruded black and white polyethylene), and T ₄ (black polythylene). The control treatment had no mulch. The results revealed a positive and significant effect of plastic covers on root temperatures: T ₀ = 16°C, T ₁ = 20°C, T ₂ = 24°C, T ₃ = 27°C, T ₄ = 30°C. These thermal differences significantly influenced the Mo concentration, particularly in the T ₂ and T ₃ treatments in the leaves, roots, and tubers. The same temperatures significantly altered N metabolism in both the aerial and underground parts of the plants, and a strong interrelationship was found between Mo and nitrate reductase (NR) activity. The mulching of this crop proved to be a promising technique in phytoremediation.

Keywords:

• Solanum tuberosum
• Mulch
• N metabolism
• Molybdenum
• Phytoremediation
• 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.