Ecofisiologia da germinação e do crescimento inicial de mudas de Campomanesia adamantium (CAMB.) em diferentes substratos e disponibilidades hídricas

Abstract

This work aimed to study the influence of temperature, substrate moisture and storage time on seed germination, emergency and initial growth of Campomanesia adamantium on different substrates and water availability. Seeds used in all experiments were collected from twenty selected trees located in Cerrado region in the Santa Madalena Farm, on highway BR 270, km 45, which connects Dourados to Itahum, in Mato Grosso do Sul. The first chapter studied the influence of temperature, substrate moisture and storage time of seeds on germination of C. adamantium. Two seed lots were used, one consisting of newly processed seeds and other with seeds stored during 18 days in air-tight bottle. The sowing was carried out in “gerbox”, with Germitest® paper moistened with distilled water to the equivalent of 1.5 and 2.5 times the weight of dry paper. Seeds were incubated at alternating temperatures of 20-30°C and constant of 25° and 35°C, under continuous white light. The design was completely randomized in 2x2x3 factorial scheme (initial moisture of substrate x seed lots x temperatures) with four replicates of 25 seeds each. Newly processed seeds showed higher germination and vigor compared to seeds stored for 18 days in air-tight bottle. Seeds of C. adamantium should be sown on moisture of substrate of 2.5 times the weight of dry paper and in temperature of 25ºC for tests of germination and vigor in laboratory conditions. In the second chapter it was evaluated the emergency of C. adamantium on different substrates and water availability. The sowing was performed in dibble tubes containing substrates: soil of embankment, soil of embankment + Bioplant® (1:1), soil of embankment + sand + semi decomposed poultry manure (1) (1:1:0.5), soil of embankment + sand (1:1) and soil of embankment + sand + semi decomposed poultry manure (2) (1:2:0.5). Irrigation was performed three times per week, in the water holding capacities: 25%, 50%, 75% and 100% calculated based on the density of substrates. Morphological characteristics were analyzed at 45 days after sowing. The design was completely randomized in 5x4 factorial scheme (substrates x water holding capacities) with four replicates of 12 dibble tubes containing one seed each. It was observed that the best conditions for the emergency of C. adamantium seedlings were in the water holding capacities of 75% and 100% in substrates of soil of abrupt declivity + sand and soil of abrupt declivity + Bioplant®. In third chapter was assessed the initial growth of C. adamantium seedlings on different substrates and water availability. The sowing was performed in dibble tubes, containing substrates: soil of embankment, soil of embankment + Bioplant® (1:1), soil of embankment + sand + semi decomposed poultry manure (1) (1:1:0.5), soil of embankment + sand (1:1) and soil of embankment + sand + semi decomposed poultry manure (2) (1:2:0.5). Irrigation was performed three times per week, in the water holding capacities: 25%, 50%, 75% and 100% calculated based on the density of substrates. Morphological characteristics and their relations to determination of the quality indexes of the seedlings were analyzed at 52, 83, 114 and 145 days after sowing. The design was completely randomized in 5x4x4 factorial scheme (substrates x water holding capacities x evaluating) with four replicates of 12 dibble tubes containing one seed each. The use of substrates of soil of abrupt declivity + sand and soil of abrupt declivity + BioPlant® in the water holding capacities of 75% and 100% are the best conditions for growth and development of C. adamantium seedlings.