Getúlio Augusto Pinto da Cunha

ALTAS DENSIDADES DE PLANTIO NA CULTURA DO ABACAXI CV. SMOOTH CAYENNE, SOB CONDIÇÕES DE SEQUEIRO

In Brazil, relatively low planting densities have been used to obtain large fruits, with negative effects on pineapple crop yield. However, the international market, what may be followed by Brazilian consumers, is requiring smaller and smaller fruits. This work aimed in evaluating the effect of high densities in double row planting systems on the quantitative and qualitative production of Smooth Cayenne pineapple grown under rainfed conditions. Planting densities varying from 51.280 plants/ha to 100.000 plants/ha, were studied in a randomized blocks experimental design with five replications and 12 treatments in a factorial scheme of 4 x 3, corresponding to four combinations of spacing between double rows and between simple rows within double rows (90 x 40 cm, 90 x 30 cm, 80 x 30 cm, 70 x 30 cm), and to three spacing between plants within each row (30, 25 and 20 cm). The analyses of variance determined statistical difference only for the yield as a function of spacing between plants within the row, being the highest for 20 cm. Average fruit weight, dimensions and quality (sugars, acidity, juice content, sugar/acidity ratio) were not significantly influenced by the densities studied, keeping up the values within the cultivars patterns. For each increasing of 10.000 plants/ha yield grew by 8.27 t/ha and average fruit weight dropped by 102 g. Under the environmental conditions of the Coastal Tableland of North Bahia, Brazil, the Smooth Cayenne pineapple crop showed good potential for the use of high planting densities, even under rainfed cultivation, being possible to get yield above 80t/ha and average fruit weight over 1,0 kg.

Applied aspects of pineapple flowering

Flowering is an amazing, integrated and complex process of multifatorial control, which due to its great importance for agriculture has been extensively studied worldwide. Pineapple is one of the main crops on which many research works about this subject have been carried out, and it was the first one to have artificially induced flowering. However, even with all those studies, pineapple flowering is not yet characterized in many aspects. The main point for the comprehension of the physiologic aspects of flowering initiation is the identification of the factors involved in the differentiation of the apical meristem into floral primordium, as well as how these factors exert their action. This work aimed to describe the flowering process of pineapple plants, including notions about general flowering physiology, pineapple inflorescence, natural and artificial flowering. Flowering relation to several chemical substances which are involved with the vegetative growth of the plant are also discussed, in order to bring out more light on its underlying mechanisms, and also to help in crop management.