Integrating starter fertilizer, fungicide timing, and late‐season nitrogen strategies for winter wheat

Abstract Winter wheat ( Triticum aestivum L.) growers are exploring intensive management strategies aimed at overcoming yield plateaus and improving profitability. The interactive effects of starter fertilizer (SF) and late‐season nitrogen (LN) with multiple fungicide applications under intensive management remain unclear. This study evaluated the influence of fertilizer and fungicide strategies on grain yield, protein content, straw yield, and disease assessment. Treatments were arranged in a full‐factorial, randomized complete block design with four replications, including two SF rates, five fungicide timing strategies, and two LN rates applied at Feekes 7. Trials were conducted from 2021 to 2023 in Lansing, MI, following silage corn (SC) or soybean (SB), for 4 site‐years. SF increased grain yield by 35% and 34% in SC 2022 and SC 2023, respectively. LN improved grain yield only in 2022, with increases of 14% (SB 2022) and 4% (SC 2022). Grain protein concentration responded to SF × LN interaction by increasing with LN when SF was applied but decreasing with SF alone in SC 2023. Across site‐years, LN consistently increased protein content (0.7%–0.8%). Fungicide effects were limited, with FK 5–7, 9, and 10.5.1 treatments increasing straw yield by 50% when combined with LN. Results emphasize the potential for intensive management to effectively narrow yield gaps with SF and LN improving yield and grain protein content, while fungicide benefits were minimal under low disease pressure. Further research with greater disease pressure is needed to refine nutrient–fungicide interactions and optimize management strategies for sustainable yield gains.