Previous studies have reported that phosphorus transporters are involved in glyphosate uptake by plants, so phosphorus fertilization might act as an attenuator of glyphosate effects on a possible drift. The objective of this study was to evaluate the influence of phosphorus fertilization on the initial growth of Pinus taeda genotypes submitted to glyphosate subdoses applied during two growing seasons, warm and cold. Four experiments were conducted in an open area using 10-L pots, two in the warm season (during 180 days after application on Genotypes 1 and 2) and two in the cold season (during 81 days after application on Genotypes 3 and 4). The treatments consisted of a 2 × 4 factorial scheme, with presence or absence of phosphorus fertilization (25.2 kg ha⁻¹ P₂O₅) and four subdoses of glyphosate (0, 72, 144 and 288 g ha⁻¹ acid equivalente), using five replicates. For warm season, glyphosate subdoses provided a stimulatory effect on the plant growth of both P. taeda genotypes independently of the fertilization condition. The supplementary phosphorus fertilization increased plant growth characteristic in both warm and cold season, regardless of the exposure to glyphosate subdoses. However, the plant response is dependent on the genotype. Glyphosate subdoses did not negatively affect P. taeda genotypes growth at both experimental seasons, regardless of phosphorus fertilization.

先前的研究报道磷转运体参与植物吸收草甘膦，因此磷肥可能会降低草甘膦对可能的漂移的影响。这项研究的目的是评估磷的施肥对在两个生长季节（温暖和寒冷）施用草甘膦亚剂量施用的针叶松基因型初始生长的影响。在空旷地区使用10 L盆进行了四个实验，两个在温暖的季节（对基因型1和2施用后180天），两个在寒冷的季节（对基因型3和4施用后81天）。处理包括2×4阶乘方案，有无磷肥（25.2 kg ha ^-1 P ₂O ₅）和四个亚剂量的草甘膦（0、72、144和288 g ha ^-1酸当量），使用五次重复。在温暖的季节，草甘膦亚剂量不依赖于施肥条件而对两种taeda taeda基因型的植物生长均具有刺激作用。不论暴露于草甘膦亚剂量下，补充磷肥都能在温暖和寒冷的季节提高植物的生长特性。但是，植物的反应取决于基因型。草甘膦分剂量并没有产生负面影响火炬松基因型生长在两个实验的季节，无论施磷量。