Temperature on Annona cherimola Mill. x Annona squamosa L. seed germination

Abstract

In the production of atemoya rootstocks (Annona cherimola Mill. x Annona squamosa L.), the seed propagation is hindered by dormancy resulting in low germination, similar to temperature that affects the percentage, speed, and uniformity of germination. This study aimed to evaluate the effect of constant and alternating temperature on the seed germination of three atemoya genotypes: ‘Gefner’, ‘Thompson’ and ‘PR-1’ at 25°C and 20-30°C (8-16h) using germination paper in absence of light, with four samples of 25 seeds per treatment. The evaluations occurred each seven days up to 35 days, which were assessed: germinated seeds, seedlings, dormant seeds and germination speed index. The experimental design was completely randomized in a factorial arrangement of 3x2, using four replications. The water content, fresh and dry matter of 100 seeds were analyzed in a completely randomized scheme with four replications. The alternating temperature 20-30°C provided favorable condition and higher germination percentage for atemoya seeds, achieving 0.638 for germination speed index and 37% for percentage of germination at 35 days. ‘Gefner’ and ‘Thompson’ cultivars presented higher percentage of germination than ‘PR-1’.