DIFFERENTIAL TOLERANCE TO ZINC DEFICIENCY IN COFFEE-PLANT PROGENIES

摘要

The tolerance of different coffee-plant progenies to zinc (Zn) deficiency was studied in a green house experiment arranged in a completely randomized design, in a 14 x 2 factorial scheme (14 progenies and two Zn concentrations), with four replications. Coffee-plant seedlings were grown. for ten months in nutritive solution with or without Zn. There were evaluated for growth characteristics, zinc concentrations, and zinc requirement. The grouping involving growth characteristics allowed discriminating the progeny 'UFV 4066-3' as highly zinc-demanding and 'IAC 4376-5' as low zinc-demanding. The data on plant dry matter and zinc accumulation showed that the progenies VAC 4376-5' and 'UFV 4066-5' had low zinc requirement when 'Caturra Amarelo1', 'UFV 4066-3', 'Caturra Amarelo 2' and 'Caturra Vermelho 2' had high zinc requirement. Leaf area reduction (%), leaf number, active zinc content in completely expanded leaves and total zinc in roots were the variables of highest relative importance in discriminating coffee plant progenies.