As adubações com potássio são essenciais para o desenvolvimento do fruto de melancia desde sua formação, amadurecimento, textura e palatabilidade. O objetivo deste trabalho foi avaliar o efeito da adubação potássica em características agronômicas e pós-colheita de melancia. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições. Foram testados cinco doses de adubação potássica, os quais foram: 0; 60; 120; 180 e 240 kg ha-1 K2O na forma de cloreto de potássio com concentração de 60% de K2O em adubação de base e em duas de cobertura. As demais exigências nutricionais da cultura foram feitas conforme a necessidade nutricional. A cultivar utilizada foi a Manchester®, utilizando-se seis plantas por parcela. A irrigação foi realizada com mangueiras gotejadoras. Para auxiliar no controle das plantas daninhas e umidade, foi utilizado o mulching. Avaliou-se a produtividade média total (em ton ha-1), peso médio dos frutos (em kg), espessura média da casca na região do pedúnculo (em cm), da região distal (em cm) e teor de açúcares totais (°Brix). A espessura média da casca na região do pedúnculo e na região distal não foi alterada pelas doses de potássio. Por ser um fruto que tem a quantidade de brix ou sólidos solúveis como fator importante, o maior valor 10,3°BRIX foi observado na dose de 107,22 Kg de K2O ha-1 sendo esta a mais indicada. O aumento da dose de potásio promove resposta quadrática para as características produtividade, peso médio de frutos e ºBrix. Já a espessura da casca não é afetada pelo aumento da dose de potássio. A produtividade máxima de frutos estimada em 35 ton ha-1 foi alcançada na dose de 156,83 Kg de K2O ha-1.

Among the constituents of Brazilian flora, the ipes, belonging to the Bignoneaceae family, occur widely, and therefore do not occupy a single habitat. This group species has various values, including economic, ornamental and medicinal. The objective of this work was to evaluate the effect of various substrates on the seed germination process of Tabebuia roseo-alba (Ridl.) Sandwith) (ipê rosa) and T. serratifolia (Vahl) G. Nicholson (ipê amarelo). The experiment was carried out with BOD type germinators, adjusted to a constant temperature of 30ºC, with a photoperiod of twelve hours daily. The seeds were distributed in transparent acrylic boxes (Gerbox) and conditioned under the substrates: carbonized rice husk (CRH), commercial substrate (CS) Bioflora, washed sand (WS) and vermiculite (V). The treatments were distributed in a 2 x 5 factorial scheme (two species and five substrates), with four replications. At 30 days, the final percentage of emergence (% E) or the total percentage of seeds emerged up to 30 days after sowing was calculated. In general, T. serratifolia seeds showed relatively higher values of emergence percentage and emergence speed. The treatment containing 100% commercial substrate showed the best results for both species in terms of percentage and emergence speed, however it can be inferred that the washed sand substrate showed similar values for the yellow ipê under the tested conditions.

<p class="Normal1"><span class="fontstyle0">The formation of quality forest seedlings has a direct relationship with the substrates that will be used; the germination of seeds and the formation of the root system and the aerial part are associated with the particular characteristics of each substrate. Therefore, the study aimed to evaluate the influence of different substrates on the formation of ipê-branco and ipê-amarelo seedlings. The experimental design adopted was completely random, with the treatments distributed in a 2 x 5 factorial arrangement (2 species and 5 substrates), with 4 replications. We used the following components to compose the substrates: carbonized rice husks (CAC), fresh rice husks (CA), autoclaved for two hours at 120 °C, commercial substrate (SC) Bioflora, washed sand (AL), and bovine manure (EB). The study was arranged in five treatments: treatment 1 - CAC, treatment 2 - CA, treatment 3 - SC, treatment 4 - AL and treatment 5 - EB. The following morphological characteristics have been evaluated: Collection diameter, height of the seedlings and the Dickson Quality Index (DQI) of the seedlings, which was obtained through the variables: weight of total dry matter (TWMW), weight of dry matter of the aerial part (TWMW), weight of dry matter of the root (RWMW), H and DC. The emergence speed and the emergence percentage index were lower for both species in the treatment containing 100% in natura rice husk. The commercial substrate Bioflora, enabled good performance in the emergence of both species, obtaining satisfactory results in terms of the percentage rate of emergence and a higher speed of emergence between treatments. The bovine manure substrate obtained superior results in the initial development for both Handroanthus serratifolius (Vahl) S.O.Grose and Handroanthus roseo-albus (Ridl.) Mattos.</span><br /><br /></p>