Produ??o de mudas de caramboleiras 'B-10' e 'Golden Star': II - marcha de absor??o e acúmulo de nutrientes

摘要

Brazil's participation in the external market of fruits has increased considerably with the potential to grow further. The constant rise of the Brazilian exportation data is the result of a combination of technological advances in the productive sector and access to new markets. The star fruit is presented as an excellent option for cultivation of exotic fruits, with great potential to attend the domestic market and exportation. Thus, the objective was to assess absorption rate and accumulation of nutrients in star fruit seedlings, grown in nutrient solution. The experiment was conducted in split plots being used as part of the two cultivars of star fruit ('B-10' and 'Golden Star') and as subplots, five plant collecting periods, realized at 208, 233, 258, 283 and 308 days after transplanting to the nutrient solution. The experimental design was completely randomized with three replications. The seedlings were grown in pots (8L) with nutrient solution (pH = 5.5 ± 0.5) with aeration. The experiment started on 08.24.2005. In different plant organs (leaves, stems and roots), absorption rate, accumulation of nutrients and nutritional indices were determined. It did not have differences in the accumulation of nutrients in the star fruit seedlings for both cultivars, the decreasing order of the nutrients in each 'B-10'seedlings, in the end of the experimental period, was: N > K > Ca > Mg > S > P > Fe > Mn > B > Cu > Zn. For 'Golden Star' the decreasing order was: N > K > Ca > Mg > P > S > Fe > Mn > B > Cu > Zn. For the two cultivars, the average accumulation was bigger in leaves > stem > roots. The period of bigger requirement for 'B-10' was between 208 - 233 and, for 'Golden Star', between 233 - 283 days after the transplantation. The different rates of nutrient liquid accumulation, in the different organs of star fruit trees, not always followed the nutrient accumulation rate of the respective organ.