Fenologia e germinação da casaqueira [Campomanesia rufa (Berg) Nied]: uma fruteira dos cerrados

Abstract

The "casaqueira" or "casaca" [Campomanesia rufa (Berg) Nied.] belongs to the family Myrtaceae, is a fruit of the "cerrados" which geografic distribution is found generally in the State of Minas Gerais. Thus, the objective of this research was to study the phenology, the effects of light and plant growth regulators (GA3 and 6-BA) on the germination, and also the time and type of harvesting on the longevity of the seeds. Phenology Phenological observations (leaf flushing, leaf fali, flowering and fruiting) were realized in 30 plants of a population of "casaqueira", located in the municipal district of Coqueiral (MG), in the period of september 1991 to august 1992. A leaf fali was detected between may and august, however insignificant, because this espécies do not loose their leaves totally. The leaf fali coincided with the period of few precipitation and low temperature. The leaf flushing was very active on the end of the cold and drought season. Flowering ocurred concomitantly with the leaf flushing, reaching a maximum on the second fortnight of october. Fruiting was started in november and was extended till april. Ripening of the fruits coincided with the end ofthe raining season. Germination The experiments of germination were conducted in Petri dishes with a diameter of 9 cm, keeped in germination chambers FANEM mod. 347 at a temperature of 25°C. Every treatment was constituted of 100 seeds, devided in four replications. A completely randomized design in a 2 x 7 factorial scheme with four replications was used. The treatments were: continuous light and total darkness, GA3 and 6-BA at the concentrations of 0, 100, 200 and 300ppm. In the first experiment the effects of light and plant growth promoters (GA3 and 6-BA) were studied. The freshly collected seeds were indifferent to light and the highest percentage of germination was reached when lOOppm of 6-BA was used. In the second experiment the seeds were harvested for 30, 60, 90 and 180 days in two environments [refrigerator and natural environment (laboratory)] and two package materiais (paper and polietilene sacks). A completely randomized experimental design in a 4 x 2 x 2 factorial scheme with four replications was used. The percentage of germination and germination rate (IVG) were evaluated with the use of 100 ppm of 6-BA. The harvesting of seeds in natural environment generally proportionated the highest percentage of germination and IVG. The seeds harvested in natural environment and in polietilene sacks for a period of 180 days presented the highest percentage of germination and IVG, and showed to be the most efficient way to conserve the seeds.