• Studies clearly show that rescue applications during the late vegetative stages can result in increased yields and economic returns. However, it is important to remember that dry conditions after the rescue N application can limit the effectiveness of additional N because water is needed to move N into the root zone. Is It Too Late? Nitrogen applications after R1 (silking) are generally not encouraged, as some studies have shown that economic yield response to N fertilization seldom occurs after pollination. However, under severe N deficiency, some response may occur to applications of low rates of N (30 to 60 pounds) as late as three weeks afteDue to Nitrogen Dificiencyr pollination (Thomison, 2010).