Corn Grain Yield and Nutrient Response to Foliar Fertilizer Applied during Grain Fill¹

Abstract

Recently there has been renewed interest in foliar fertilization of field crops, but little work with foliar application of nutrients on corn (Zea mays L.) during the grain filling period has been reported. This study was conducted to observe the effect of foliar fertilizer on corn grain yield, yield components, and nutrient content in the grain at harvest, while plants were subjected to moisture stress imposed after silking in one, two, or three successive stress periods. Experiments were conducted in the movable rain shelter facility at Ames, Ia., in 1976 and 1977. In this facility corn plants were grown in containers containing 100 liters of a Nicollet loam soil (an Aquic Hapludoll, fine‐loamy mixed mesic). Foliar fertilizer was applied three times in the post‐silking period with a pressurized hand sprayer. In 1976, foliar fertilizer application commenced 4 weeks after silking, and no significant effect of foliar fertilizer on yield, or yield components was measured. In 1977, foliar‐fertilizer application commenced as early as 2 weeks after silking, and a significant, 6.4% yield reduction occurred in foliar‐fertilizer treatments. This decrease occurred in both hybrids used and in all moisture‐stress treatments. There was no evidence for an interaction between post‐silking moisture stress and foliar‐fertilizer application. In 1977, the effect of foliar fertilizer was to reduce mass/kernel in one hybrid, while in the other, neither mean mass/kernal nor kernels/plant were significantly reduced, but total grain yield was reduced. This difference was related to the number of days after silking when foliar fertilizer was first applied. Foliar fertilizer seemingly produced a stress on these plants, and the deleterious effect of this stress was expressed by the yield component being primarily determined at the time the stress occurred. Foliar fertilizer applications resulted in a significant increase in the percent N (10%) and in the percent P (4.7%) in the grain at harvest. There was, also, an increase in N yield (5.1%) in the grain despite a grain yield decrease in one hybrid.

Effect of in-season application methods of fertilizer nitrogen on grain yield and nitrogen use efficiency in maize

“…The difference in dry matter distribution was associated with differences in weather conditions between the 2 yr. In accordance with this result, previous studies also showed that foliar N spray affected neither the yield nor the stover dry matter of maize compared with the equivalent N applied to the soil (Harder et al 1982a;Below et al 1984a).…”

“…In previous studies, foliar N spray did not consistently increase yield (Harder et al 1982a;Below et al 1984a,b). It was reported that foliar fertilization for winter wheat did not affect grain yield (Woolfolk et al 2002).…”

“…High urea concentration caused considerable leaf burn, which may have led to either a yield reduction or no response (Chesnin and Shafer 1953;Foy et al 1953). Harder et al (1982a) reported that maize yield was unaffected when foliar N spray was conducted 4 wk after silking but it was reduced by 6.4% when sprayed at 2 wk after silking. There are no studies available concerning the effect of ear N injection on maize yield, protein or NUE.…”

Determination of Optimum Rate and Growth Stage for Foliar‐Applied Phosphorus in Corn

“…One consistent result of the study was that all foliar-applied P treatments achieved higher concentrations than the check. In their study, Harder, Carlson, and Shaw (1982) found that percent P in grain was increased by 230 mg kg 21 (4.7% increases) by foliar fertilization compared with the control. However, their analysis did not detect significant differences within foliar P rates.…”

“…Harder, Carlson, and Shaw (1982) found that foliar fertilizer applied after silking did not translate into increased grain yield. On the other hand, Barel and Black (1979b) reported an increased grain yield due to foliar P compared with control (untreated check).…”