Onion (Allium cepa L.) is highly sensitive to post-emergence herbicides, which limits chemical weed management, particularly under direct-seeding systems. In this context, organomineral fertilizers with biostimulant properties may represent a promising strategy to mitigate herbicide-induced phytotoxicity. This study evaluated the potential of an organomineral fertilizer to reduce phytotoxicity caused by post-emergence PPO-inhibiting herbicides in direct-seeded onion. A field experiment was conducted using a randomized complete block design with four replications. Treatments consisted of sequential applications of oxyfluorfen, flumioxazin, and oxyfluorfen + flumioxazin, combined with organomineral fertilizer application either as a tank mix or 3 days after herbicide application (DAA). Oxyfluorfen showed the highest crop selectivity, with phytotoxicity remaining below 15% throughout the experimental period, whereas the oxyfluorfen + flumioxazin combination caused the greatest injury, reaching 35% at 7 days after the first application. Treatments containing flumioxazin resulted in greater reductions in photosynthetic pigments and bulb yield. The organomineral fertilizer reduced phytotoxicity to as low as 5% in flumioxazin-treated plants and increased total bulb yield by 21.46% when applied as a tank mix and by 16.18% when applied at 3 DAA. These results indicate that organomineral fertilizer application can reduce visible injury and increase bulb yield under PPO-inhibiting herbicide treatments in direct-seeded onion.

Water scarcity in the Brazilian semiarid region impairs the production of fruit crop rootstocks. Thus, the use of new technologies, such as superabsorbent polymers, becomes essential to improve water management and crop performance. In this context, this study aimed to evaluate different applications of a superabsorbent polymer and irrigation frequencies on the production of guava rootstocks. The experiment was conducted in a rootstock nursery, following a randomized block design in a 4 × 3 factorial scheme, corresponding to four doses of the superabsorbent polymer (0.0, 1.0, 2.5, and 5.0 g L-1) and three irrigation frequencies (F1 - daily irrigation, F2 - irrigation on alternate days, and F3 - irrigation every two days), with four replications. Plant height (PH), stem diameter (SD), number of leaves, root length (RL), rootstock dry mass, PH/SD ratio, PH/SDM ratio, SDM/RDM ratio, and total chlorophyll index (CI) were evaluated. The application of the superabsorbent polymer had a negative effect on rootstock growth under F1, regardless of the dose. However, RL decreased with increasing hydrogel doses under all irrigation frequencies. The application of superabsorbent polymer, combined with reduced irrigation frequencies, resulted in higher total dry mass accumulation in the rootstocks. A superabsorbent polymer dose of 1.9 g L-1 increased CI when rootstocks were irrigated on alternate days and every two days. The dose of 1 g L-1 of the superabsorbent polymer combined with irrigation on alternate days provided the best performance in guava rootstock production.