Superação térmica de dormência de mudas de embiratanha em substrato orgânico.

Abstract

Pseudobombax marginatum (A.St.-Hil., Juss. & Cambess.) A. Robyns is a plant of the Malvaceae Family and Bombacoideae subfamily, popularly known as Embiratanha, which occurs in the semiarid region of Northeast Brazil. It presents itself as a species with relevant socioeconomic and environmental potential, however, the slow and uneven germination process is a problem for the production of seedlings. In this sense, the objective was to investigate the overcoming of dormancy of seeds subjected to different temperatures and vegetative growth in different concentrations of pultry manure. The experiments were conducted in the botany and biochemistry laboratories and in the greenhouse of the Federal University of Campina Grande- Education and Health Center, in the municipality of Cuité - PB, starting on April 19 and ending on July 27, 2021. The experimental designs were completely randomized (DIC) with four treatments and eight replications for the first experiment, where, T1= water at 25°C; T2= water at 50°C; T3= water at 75°C and T4= water at 85°C, and five treatments and four repetitions for the second, T1= 100% soil; T2= 95% soil + 5% poultry manure; T3= 90% soil + 10% poultry manure; T4 = 85% soil + 15% poultry manure and T5 = 80% soil + 20% poultry manure. The analyzed variables were the Emergency Percentage (%E), Emergency Speed Index (IVE) and Dickson Quality Index (IQD). Seed germination was evaluated according to the Rules for Seed Analysis (RAS). The collected data were submitted to analysis of variance, and the means of the characteristics compared by the Tukey test, at 5% probability, through the computational application Sisvar. For the first experiment, the results showed that the temperature of 85°C provided a faster and more uniform seed emergence, as well as higher values for %E and IVE. The seeds of the species submitted to immersion in water at room temperature (T1) and at a temperature of 50°C (T2) had their vigor affected due to the occurrence of microorganisms due to the slow and uneven germination. In the second experiment, the best results were obtained for %E and IVE in the treatments 100% soil (T1) and 85% soil + 15% poultry manure (T4), but the addition of poultry manure does not provide good performance for the species. For the Dickson quality index (IQD), treatment 1 corresponding to 100% soil, was the one that presented the best result, however far from the ideal, even with vigorous seedlings, but with the need for further investigation to improve the index itself.