Producing seeds in the organic production system still requires a lot of information regarding the fertilization and nutritional requirements. Thus, the objective of this study was to determine the dry mass and macronutrient accumulation curve in lettuce for seed production, aiming at cultivation in an organic system. The treatments consisted of two phosphorus doses (320 and 800 kg ha⁻¹ of P₂O₅, Yoorin^® thermophosphate source). The crisp lettuce plants, cultivar Solaris, were collected at eight stages (0, 14, 28, 42, 56, 70, 84, and 98 days after transplanting—DAT) for an analysis of the proposed characteristics. A nonlinear sigmoid regression curve was fitted and the results demonstrated continuous plant growth, accompanied by a gradual increase in dry matter throughout the experimental period, regardless of the phosphorus dose studied. The vegetative part of the lettuce plant shows slow initial growth, followed by acceleration up to the beginning of flowering (70 DAT), and stabilization after this period. The reproductive part of the lettuce plant begins to grow from 56 DAT, increasing the daily nutrient demand until the end of the seed maturation and harvest at 98 DAT. The dose of 800 kg ha⁻¹ of P₂O₅, the lettuce plant accumulated 1527.7, 308.2, 2922.6, 1658.4, 416.0, and 197.6 mg per plant of N, P, K, Ca, Mg, and S, respectively. The dose of 320 kg ha⁻¹ of P₂O₅, the lettuce plant accumulated 1743.1, 256.9, 2575.7, 1210.2, 358.8, and 185.5 mg per plant of N, P, K, Ca, Mg, and S, respectively. The greatest demand for nutrients in the plant occurred between 55 and 88 DAT.

Phosphorus compromises seed productivity and quality, highlighting the need for studies that define the nutritional requirements for organic cultivation. Thus, the objective of this study was to determine the dry mass and macronutrient accumulation curve in lettuce for seed production, aiming at cultivation in an organic system. The treatments consisted of two phosphorus doses (320 and 800 kg ha-1 of P2O5, Yoorin® thermophosphate source). The crisp lettuce plants, cultivar Solaris, were collected at eight stages (0, 14, 28, 42, 56, 70, 84 and 98 days after transplanting - DAT) for analysis of the proposed characteristics. The results demonstrated continuous plant growth, accompanied by a gradual increase in dry matter throughout the experimental period, regardless of the phosphorus dose studied. The dose of 800 kg ha-1 of P2O5, the lettuce plant accumulated 1527.7, 308.2, 2922.6, 1658.4, 416.0 and 197.6 mg per plant of N, P, K, Ca, Mg and S, respectively. The dose of 320 kg ha-1 of P2O5, the lettuce plant accumulated 1743.1, 256.9, 2575.7, 1210.2, 358.8 and 185.5 mg per plant of N, P, K, Ca, Mg and S, respectively. The greatest demand for nutrients in the plant occurred between 55 and 88 DAT.

The search for a healthy diet has increased the consumption of kale, a vegetable recognized for its high nutritional value, mineral content, and antioxidant properties. Phosphorus is an essential nutrient in this context, acting in energy transfer and root development, which favors productivity and product quality. This study evaluated the effect of two phosphorus sources, bone meal (BM) and thermophosphate Yoorin^® (TY), and five phosphorus (P₂O₅) doses (0, 160, 320, 480, and 640 kg ha⁻¹) on kale yield and quality. The experiment used a randomized complete block design with four replications and ten treatments in a 2 × 5 factorial arrangement in a protected environment over a cycle of 155 days after transplanting. Marketable yield with BM reached an estimated maximum of 1.54 kg plant⁻¹ at 525 kg ha⁻¹ P₂O₅ (54% over control), while TY showed a linear increase up to 1.57 kg plant⁻¹ (59%). Photosynthetic pigments, antioxidant activity, ascorbic acid, and total phenolic compounds fitted quadratic models, with gains of up to 36%, 73%, 51%, and 57%, respectively. Contents of P, K, Ca, and Fe increased significantly with P doses, with Fe gains reaching 110–180%. Phosphate fertilization with BM, a renewable P source, increases kale yield and nutritional quality, highlighting its potential for organic farming systems.