Effect of iron deficiency on growth, micronutrient status and chlorophyll content of vinca rosea grown in calcareous soils

Abstract

Field experiments were conducted to control lime‐induced Fe chlorosis, Zn dwarfness, and N deficiency in a chlorosis‐susceptible ornamental plant, inca rosea L. FeEDDHA, ZnEDTA, and urea were added to the soil or to the foliage. Soil application of fertilizers was superior to the foliar application in correcting chlorosis, increasing chlorophyll content and improving foliage growth and flowering. Effect of FeEDDHA applied to the soil started to diminish after six to eight weeks; therefore, frequent application of Fe chelate was advised. Fe application was found to enhance the uptake of Zn, Cu and Mn by the plants. The use of total Fe contents as an index for Fe status in plants was reliable when these contents were based on fresh weight and was misleading when based on dry weight. The use of dry weight led also to erroneous results regarding the interrelationships between micronutrients. The determination of active iron (HCl‐extractable Fe) improved the diagnosis of Fe status in plants. Chlor‐otic leaves had less active Fe than green leaves.

Key words:

• Vinca rosea L
• Fe‐chlorosis
• chelates
• foliar applications
• soil fertilizer applications
• chlorophyll
• active Fe
• Fe status
• dry weight versus fresh weight basis