Combinations of Iron and Manganese Have Variable Effects on the Quantitative and Qualitative Traits of Tuberose (Polianthes tuberosa L.)

Understanding interactions and a balance between iron (Fe) and manganese (Mn) as fertilizers is crucial for optimizing tuberose growth. Here, a field experiment considered the effects of various Fe and Mn concentrations on quantitative features, qualitative traits, microelement absorption, and microelement distribution in tuberose plants. The treatments included Fe concentrations of 0, 15, 30, and 45 kg ha-1 along with Mn concentrations of 0, 10, and 20 kg ha-1 from FeSO4 and MnSO4 sources, respectively. According to the results, high Fe concentrations (30 and 45 kg ha-1) negatively affected the uptake of Mn, Zn, and Cu in aerial parts and bulbs. However, an apt combination of Mn and Fe significantly improved several traits. In the first year, Fe (30 kg ha-1) and Mn (20 kg ha-1) significantly increased spike length (27.19%), floret length (46.22%), bulb count (43.60%), vase life (96.08%), and the percentage of opened florets (26.65%). In the second year, Fe (30 kg ha-1) and Mn (20 kg ha-1) resulted in even more improvements, including flower stalk count (78.48%), floret length (47.44%), vase life (32.02%), percentage of opened florets (41.31%), fresh (41.73%) and dry (54.40%) weights of the aerial parts, and bulb fresh (48.98%) and dry (61.54%) weights. The findings highlighted that the combined application of FeSO4 (30 kg ha-1) and MnSO4 (20 kg ha-1) had significantly positive effects on tuberose growth and relevant parameters. Tuberose development improved significantly in response to this combination treatment over the two years, which provides a valuable guideline for farmers and researchers when aiming to enhance tuberose yield.