Agronomic Performance of New Potato Genotypes Submitted to Increasing Doses of NPK

Aims: Estimate the morphological characteristics of potato genotypes grown with different doses of NPK fertilizer 4-14-8.

Study Design: The experiment was conducted in randomized blocks with subdivided plots and three replicates.

Place and Duration of Study: The experiment was carried out in the municipality of Guarapuava – PR, Brazil, during the growing seasons of 2013/2014 and 2014/2015.

Methodology: In the main plots the doses of 0, 2, 4 and 6 t ha-1 of NPK fertilizer 4-14-8 were arranged and in the subplots the genotypes (Ágata, BRS Camilla and clone C0205). Were evaluated: The leaf area index (LAI), percentage of light absorption, number of tubers, fresh mass of tubers. In the first agricultural year the evaluations were performed at 25 and 45 days after the emergency (DAE) and in the second seasson at 28 and 48 DAE. Interaction between potato genotypes and fertilizer rates for LAI was observed at 45 DAE in 2013/14 and absorbance at 25 DAE in 2013/14. For the seasson 2013/14, the genotypes showed a significant difference for LAI, absorbance, number of tubers and fresh mass of tubers at 25, LAI and fresh mass of tubers at 45 DAE, clone C0205 presented the largest differences for these characteristics. Fertilizer doses did not influence LAI, absorbance at 25 DAE and 45 DAE in 2013/14 and, at 2014/15 at 28 DAE, there was no response for tuber number and LAI, and at 48 DAE for tuber number, absorbance. There was no significant interaction between fertilizer doses and potato plant genotypes for the data on number of primary stems and number of secondary stems in both seassons The genotypes responded to NPK fertilizer doses 4-14-8 for LAI, and clone C0205 presented the best results. The genotypes responded to the light absorption percentage, with C0205 presenting the best results, so that plants with greater leaf area presented greater light absorption. The genotype C0205 presents greater productive capacity when compared to the Agata and Camila genotypes, being evident the greater number and fresh mass of tubers produced.