Silicon can alleviate biotic and abiotic stresses in several crops, and it has beneficial effects on plants under nonstressed conditions. However, there is still doubt about foliar‐applied Si efficiency and Si effects on mineral nutrition, physiological processes, and growth of potato (Solanum tuberosum L.) plants under well‐watered conditions. The objective of this study was to evaluate the effect of soil and foliar application of soluble Si on Si accumulation, nutrients, and pigments concentration as well as gas exchange and growth of potato plants. The experiment was conducted under greenhouse conditions in pots containing 35 dm3 of a Typic Acrortox soil. The treatments consisted of a control (no Si application), soil application of soluble Si (50 mg dm−3 Si), and foliar application of soluble Si (three sprays of 1.425 mM Si water solution, prepared with a soluble concentrate stabilized silicic acid), with eight replications. Both soil and foliar application of Si resulted in higher Si accumulation in the whole plant. Foliar application of Si resulted in the greatest Si concentration in leaves, and soil application increased Si concentration in leaves, stems, and roots. Silicon application, regardless of the application method, increased leaf area, specific leaf area, and pigment concentration (chlorophyll a and carotenoids) as well as photosynthesis and transpiration rates of well‐watered potato plants. However, only soil application increased P concentration in leaves and dry weight of leaves and stems.

Utilization of potato (Solanum tuberosum L.) cultivars with greater phosphorus (P) efficiency and response to application of this nutrient is essential to maximize yield, mainly in tropical soils that usually have low P availability. An experiment was conducted under greenhouse conditions in order to evaluate the P uptake rate and the P efficiency for dry matter (DM) production and tuber yield of five potato cultivars (Agata, Asterix, Atlantic, Markies, and Mondial) under low (15 mg dm −3 P) and high (150 mg dm −3 P) P levels. Plants were grown in pots containing 35 dm 3 of a Typic Acrortox soil (31% clay, 4% silt, and 65% sand). Mondial and Agata produced high tuber yield under both P levels due to a high P efficiency. Mondial and Asterix were responsive to P applied regarding the tuber DM production and tuber yield. At high P levels, Asterix, which was inefficient and responsive to P application, had similar tuber yield than Agata, which was P efficient and nonresponsive. Potato cultivars, such as Markies and Atlantic, which were inefficient and responsive to P application regarding shoot or whole plant DM production, might not produce high tuber yield if the DM partitioning to the tubers is low.

Phosphorus (P) is essential to increase tuber yield and nutritional quality of potato tubers. However, it is unclear whether the influence of P fertilization on quality of tubers produced can vary depending on the cultivar and P availability in soil. This study evaluated the effect of P fertilization on the quality and nutritional composition of marketable tubers of potato cultivars. Experiments in soils with low, medium and high P availability were conducted in a randomized block design, with four replications. Treatments consisted of a 2×5 factorial arrangement of two potato cultivars (Agata and Mondial) and five P 2 O 5 rates (0, 125, 250, 500, and 1,000 kg ha). Phosphorus fertilization increased the contents of P and starch, the size and yield of marketable tubers, with more expressive response to higher P rates in the soils with low and medium P availability. The Mondial cultivar had the highest yield, due to a greater tuber weight and greater increases in this characteristic in response to P fertilization. The Mondial cultivar produced tubers with firmer pulp, with higher dry matter percentage and higher contents of Ca, Cu, and Zn than Agata. In the soil with low P availability, P fertilization reduced Zn content, but, in general, had little influence on the nutritional composition of potato tubers.

No abstract

No abstract