Ornamental Horticulture (Apr 2018)
Substrates and fertilizations in the initial growth of the desert rose
Abstract
The desert rose (Adenium obesum) has been highlighted in the internal market, however there are not many studies related to its demands regarding its nutrition and substrates. The aim of this study was to evaluate the effect of different fertilizations and its interactions with different substrates in the initial growth of the desert rose. The seedlings of desert rose with 60 days have been potted transplanted with a capacity of 0.415 L, filled with two kinds of substrates: sand + coconut fiber and sand + composted pine powder. Four different fertilization managements have been done: without fertilization, application of the Hoagland & Arnon nutrient solution; application of NH3 NO4 at 590 g L-1 of nitrogen (N); and the application of the Hoagland & Arnon nutrient solution modified through the addition of NH3 NO4 , increasing the concentration of N to 800 g L-1. The solutions have been applied biweekly adding 50 mL per pot. The experiment has been entirely randomized in a 2x4 factorial design, with 10 repetitions. After 150 days from the beginning of the fertilizations the phytometrical parameters evaluated were: height of the shoot; diameter of the basal caudex; number of shoots; dry mass of the roots, caudex and leaves; and determination of the levels and accumulation of macronutrients in the shoot, and the pH and electrical conductivity of the substrates. The evaluated data have been submitted to an analysis of variance and the Tukey test compared through the test at 5% of error probability. For all the evaluated parameters, when the composted pine mixture was used, the seedlings showed a higher development compared to coconut fiber mixture. The seedlings had a better performance with the modified Hoagland solution for height, number of shoots, caudex diameter and leaf dry mass in both substrates. The use of the sand + pine powder (1:1 v v-1) and the fertilization with Hoagland & Arnon solution combined with the NH3 NO4 solution provided a better initial growth on the desert rose.
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