Effect of Iron Micronutrient Fertilizer (Fe-EDTA 12%) on Growth and Yield of Sweet Corn (Zea mays var. saccharata)

Abstract

Sweet corn (Zea mays var. saccharata) is a high-value horticultural crop whose productivity depends heavily on balanced fertilization. This study evaluated the effectiveness of a straight iron micronutrient fertilizer (Fe-EDTA, 12% Fe) applied together with varying rates of standard NPK on the growth and yield of sweet corn. The experiment was conducted at the IPB Sindangbarang Experimental Field, Bogor, from October 2025 to January 2026, using a Randomized Complete Block Design with a single factor and four replications. The six treatments were: control (P0); standard NPK (P1); and 0.25, 0.50, 0.75, and 1.00 NPK-std each combined with one foliar dose of Fe-EDTA (P2–P5), with the micronutrient applied three times at 4, 6, and 8 weeks after planting. During the vegetative phase, growth responses were broadly similar across the fertilized treatments. All fertilized treatments significantly increased stover weight, cob weight with and without husk, cob length, cob diameter, yield per plot, and productivity relative to the control. The highest productivity was recorded in P5 (13.16 t ha⁻¹) and P1 (13.12 t ha⁻¹), which did not differ significantly, indicating that adding Fe-EDTA to a full NPK rate did not further increase yield. Treatments combining Fe-EDTA with 0.50–0.75 NPK-std (P3–P4) produced yields statistically comparable to standard NPK (12.07–12.34 t ha⁻¹), and the highest Relative Agronomic Effectiveness was obtained in P5 (100.87%). These results suggest that, on soils with high native Fe availability, sweet corn yield is governed primarily by NPK supply, and that Fe-EDTA application combined with a reduced NPK rate can maintain productivity comparable to the full standard rate.