Resumo

MENDEZ, Juan Carlos; BERTSCH, Floria  e  CASTRO, Oscar. Effect of fungicides propineb and mancozeb on the nutritional status of banana plants growing under hydroponic culture. Agron. Costarricense [online]. 2013, vol.37, n.1, pp.07-22. ISSN 0377-9424.

The effect of reiterative and/or alternate application of propineb and mancozeb fungicides on the nutritional status and growth of banana seedlings produced in vitro culture was evaluated. The greenhouse experiment was conducted under hydroponic culture with 2 different nutrient solutions, with high and low contents of Mg and Zn, high content of Mn and optimal amounts in the other mineral nutrients in both solutions. The foliar treatments were: a control, propineb in water, propineb in water:oil-emulsion, propineb alternated with mancozeb, mancozeb, and mancozeb + Zn (all of them applied as emulsion). Variables evaluated were: dry matter (g) and concentration and absorption of Mg, Mn and Zn in leaves, pseudostem and roots. Highest Zn concentration in leaves and pseudostem was obtained with treatments including propineb (twice that found in the control treatment), regardless of Zn amounts in the nutrient solution. The concentration of Zn in the root was affected only by the level of this element in the nutrient solution. The concentration and total absorption of Mg in all plant tissues was significantly increased when the amount of this element increased in the nutrient solution, while Mn showed the opposite behavior, the reason why the Mg:Mn ratio in the tissues (specially in the root) was affected. Neither of these 2 elements was influenced by the foliar application of fungicides. The highest dry weight of the aerial and root biomass was obtained with the nutrient solution with low levels of Mg and Zn. Ca concentrations in all tissues were halved when Mg concentration increased eight-fold in the solution.

Palavras-chave : Banana nutrition; propineb; mancozeb; micronutrients; magnesium.

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