Organic compost and potassium top dressing fertilization on production and quality of beetroot

Abstract

The potassium (K) in top dressing fertilization is used for beetroot production in Brazil. However, most of K studies are made with fertilization before planting, and it is not known the real need of this K top dressing after fertilization with K and organic matter before planting. So this work aimed to evaluate the production and quality of beetroot under different rates of organic compost at planting and K top dressing fertilization. The experiment was carried out in São Manuel-SP, Brazil, with ten treatments (5 x 2 factorial scheme), in a randomized blocks experimental design, with four replications. Five rates (0, 20, 40, 60 and 80 t ha-1) of organic compost applied at planting, in the presence (60 kg ha-1 of K2O) or absence of K top dressing fertilization were evaluated. The traits related to production evaluated were: average weight, diameter and length of roots, yield and K content in shoot and root. For the physicochemical quality of roots, pH, soluble solid content, titratable acidity, index ratio, texture, reducing, non-reducing and total sugar were evaluated. The K top dressing fertilization did not affect the production traits; however, it increases the contents of K in shoot and root and the contents of non-reducing and total sugars. The rates of the compost do not affect the quality traits, but the rate of 49 t ha-1 resulted in the maximum root yield estimated in 43 t ha-1 of roots.