Resposta da batata cv. Cupido à fertilização organomineral

Potato crop cycle is relatively short and presents high yield per area; therefore, it is a very demanding culture for available nutrients in the soil solution. Despite its importance and the large number of studies about the crop, there is little research on plant nutrition regarding the use of organomineral fertilizer. This study evaluated potato, cv. Cupid, development and productivity as a function of fertilization with pelletized organomineral fertilizer. The experiment was done in Perdizes, Minas Gerais, in the rainy season of 2014/2015. The experimental design was a randomized blocks, with factorial arrangement of 4 x 2 (doses x management) and a control with mineral fertilizer, with 3 repetitions. Organomineral fertilizer doses were 25, 50, 75 and 100% of the conventional mineral dose, which was 600 kg ha-1 K2SO4, 850 kg ha-1 NH4H2PO4, and 300 kg ha-1 (NH4)2SO4 of topdressing 19 days after planting (DAP). Fertilization managements were with or without topdressing at 19 DAP, when the potato was hilled. Two plants per plot were sampled at 36, 50, 64 and 81 DAP and analyzed for leaf, stem and dry matter contents. DRIS - Diagnosis and Recommendation Integrated System was applied at 36 DAP and the potatoes were harvested 112 DAP and subjected to tuber classification. Throughout the cycle, stem, leaf and tuber dry mass showed no significant differences between the fertilization managements. The doses of organomineral fertilizer and topdressing management does not affect productivity, and the lower doses (25%) were similar the greater ones and the control, with an average of 16.8 t ha-1, demonstrating that it is viable to make a single application of organomineral fertilizer at planting due to operational efficiency. The low yields observed were due to high rainfall and temperature, creating favorable conditions for the incidence of pests and diseases. According to DRIS, the organomineral dose 75% for topdressing, presented the best nutritional balance.

Biometria de frutos e sementes, crescimento e produção de mudas de Campomanesia adamantium Blume e Campomanesia pubescens O. Berg

Campomanesia adamantium and Campomanesia pubescens are morphologically similar, occur in the same regions of the Cerrado, are difficult to differentiate and exhibit naturally slow growth and development. The objectives of this study were to analyze fruit and seed biometric data, emergence capacity and seedling growth characteristics. Fruit from both species was collected and used to measure biometric data of the fruit and seeds and to set up two emergence and two seedling growth experiments. C. adamantium fruit is round and has wider, pale yellow seeds while C. pubescens fruit is ellipsoidal to pyriform with yellow gold seeds. C. adamantium’s greater fresh fruit mass and biometric variability favors selection of promising material for commercialization. Seed drying reduced the speed and rate of seedling emergence of C. adamantium, but had no effect on C. pubescens. Leaf number, height, shoot dry weight and the ratio of shoot dry weight to root dry weight were greater in C. adamantium than in the slower growing C. pubescens. Increases in substrate volume favor seedling development. Slow-release fertilizer application at 1g per 115 cm3 substrate increased leaf formation, plant height and shoot dry weight of seedlings of both species and lateral budding in C. adamantium. Until 120 days after transplant, lateral budding was not observed in C. pubescens seedlings. For all traits evaluated in this experiment, C. adamantium seedling growth was greater than that of C. pubescens.