Role of Iron in Pome Fruit Production
Iron is required as a precursor to chlorophyll formation and in a number of important plant enzymes. Poor supply restricts photosynthesis and, as a result, reduces leaf growth and resultant fruit yield and quality.
General Guidelines for Iron Application
Deficiencies are rare and because soil or tissue analysis is relatively unreliable, common practice is to base treatment on historical knowledge of the site or when symptoms are seen.
Soil applications with chelates are used early season in calcareous soils, or alternatively in season foliar programs targeting the growing shoots are used to meet iron needs. Care has to be taken with foliar applications to minimize phytotoxicity risks.
Iron Deficiencies in Apples
Deficiency leads to characteristic chlorotic yellowing, and sometimes bleaching, of new leaf growth. In severe cases, leaves become scorched in summer months.
Problems are more common on high pH calcareous soils and often due to transient adverse weather, temporary waterlogging, or high copper levels in the soil.
