In the Brazilian Cerrado, P deficiency restricts cotton production, which requires large amounts of phosphate fertilizer.
To improve the yield of cotton crops, genotypes with high P use efficiency must be identified and used. The present
study evaluated P uptake and use efficiency of different
Gossypium barbadense
L. genotypes grown in the Cerrado. The
experiment was carried out in a greenhouse with a completely randomized design, 15 × 2 factorial treatment structure (15
genotypes × 2 P levels), and four replicates. The genotypes were MT 69, MT 70, MT 87, MT 91, MT 92, MT 94, MT 101,
MT 102, MT 103, MT 105, MT 106, MT 110, MT 112, MT 124, and MT 125; P levels were sufficient (1000 mg pot
-1, PS
treatment) or deficient (PD treatment). Dry matter (DM) and P levels were determined in cotton plant parts and used to
calculate plant P content and use efficiency. In general, DM and P content were higher in the PS than in the PD treatment,
with the exception of root DM and total DM in some genotypes. Genotypes also differed in terms of P uptake and use
capacity. In the PS treatment, genotypes MT 92 and MT 102 had the highest response to phosphate fertilization. Genotype
MT 69 exhibited the most efficient P uptake in the PD treatment. Genotype MT 124 showed the best shoot physiological
efficiency, apparent recovery efficiency, and utilization efficiency, whereas MT 110 exhibited the highest root physiological
efficiency.
