Superação de dormência e desenvolvimento inicial de plântulas de pequi (Caryocar brasiliense) com e sem espinhos no endocarpo

Abstract

The “pequizeiro”, Caryocar brasiliense Cambess, is a native species of the Brazilian Cerrado, its fruits are widely used in regional cuisine and has potential application in the pharmaceutical and cosmetics industry. The “pequizeiro” without thorns in the endocarp was discovered in 2004 in the north of Mato Grosso and, in addition to this characteristic, fruits are fleshier and a little sweeter than the common pequi trees. Since its discovery, the pequi without thorns in the endocarp has been researched, however, there are still no published scientific works on germination and scientific literature. The objective of the research was to understand the effects between pre-germination treatments and the presence or absence of spines in the endocarp of pequi pyrenes (Caryocar brasiliense) on germination and initial development of seedlings; and provides strategies that maximize the research of pequi seedlings with and without thorns. The experiment was carried out in a completely randomized design, in a 5 x 2 factorial scheme, the first factor being related to pre-germination treatments (T1: cleft in the endocarp of the pyrenes; T2: pyrenes without any treatment (control); T3: immersion of the pyrenes for 96 hours in GA3 solution at a dose of 50 mg L-1; T4: immersion of the pyrenes for 96 hours in GA3 solution at a dose of 100 mg L-1 and T5: immersion of the pyrenes for 96 hours in water) and the second factor, presence or absence of thorn in the endocarp, with four repetitions, being 25 pyrenes per plot, totaling 40 plots. Germination percentage, average time, average speed, emergence speed and uncertainty were evaluated. In the initial development of seedlings, they were evaluated for height, stem diameter, at 30 and 90 days after emergence, and seedlings were classified as normal and abnormal, at 30 days after emergence. Regardless of the presence or absence of thorns, the creation of a cleft in the endocarp of the pyrenes provided a higher percentage of germination and higher emergence speed. The presence of spines on the endocarp showed a higher percentage of germination, however, the absence of spines on the endocarp resulted in faster germination. For pyrenes with cleft in the endocarp, the absence of thorns led to the development of larger seedlings at 90 days after emergence than in the presence of thorns in the endocarp. In the presence of spines in the endocarp, the pyrenes immersed in GA3 at a dose of 50 mg L-1 for 96 hours provided seedlings with the highest heights at 90 days after emergence.