Excess of Iron on the Development of Citrus Rootstocks

The objective of this work was evaluated the effects of iron excess on the emergence and initial development of citrus rootstock genotypes. A randomized complete block design (DBC), factorial 5x2, with five rootstocks and two substrates, repeated four times, with useful plot of 15 containers was adopted. Genotypes consisted of the 'Santa Cruz' Rangpur lemon; 'Riverside', 'San Diego' and 'Indio' citrandarins, as well as 'Sunki Tropical' tangerine, grown with or without iron excess in substrate. The percentages of emergency (PE) were analyzed and the rate of emergency (IVE) was calculated. Biometry was performed at 30, 60 and 90 days after sowing (DAS), by measuring the height (H) and stem diameter (D) of the seedlings, determining fresh (MV) and dry mass (DM). The excess of iron induced underdevelopment, and even mortality of already emerged seedlings, which reflected directly in the results, however, all genotypes presented an emergency higher to 75%, standing out 'San Diego' citrandarin, with greater height and more stem thick, and the 'Riverside' citrandarin with greater sensitivity to stress, registering the lowest values. 'San Diego' citrandarin demonstrated stress tolerance and developed satisfactorily, requiring studies that evaluate maintenance of inferred characteristics in combination with cultivar canopy.