Fruit analysis as an indicator of the iron status of nectarine and kiwi plant

Abstract

Tissue analysis research for the diagnosis of iron (Fe) deficiency was carried out in nectarine (Prunus persica var. nucipersica) and kiwi (Actinidia deliciosa), two species susceptible to Fe deficiency. An experiment was performed during the 2003-04 growing season at Talagante County, Metropolitan Region, Chile, in 8-year-old 'August Red' nectarine trees growing on a calcareous soil. Eighty midshoot leaves and 20 fruit per tree were collected from four randomly selected trees each with severe, moderate, or no symptoms of Fe deficiency on 7 Jan., 1 month before fruit harvest. Leaf color and chlorophyll varied among trees according to their severity of chlorosis, as did fruit pulp Fe but not leaf Fe. Fruit pulp Fe was highly correlated with fruit yield (R2 = 0.73), while leaf Fe was unrelated to yield. A second experiment was carried out in the 2004-05 growing season in two 'Hayward' kiwi vineyards located in Chile. At each site, 10 midshoot leaves and eight fruit were collected on 15 Mar., 1 month before harvest from three plants either with or without Fe deficiency symptoms. As for nectarine, fruit pulp Fe and leaf color but not leaf Fe were indicators of plant chlorosis. Also, fruit pulp Fe was correlated with leaf color and fruit weight. Consequently, fruit pulp appears a promising tissue, probably better than leaf, for diagnosing the Fe status of nectarine and kiwi plants.