Diagnóstico nutricional do abacaxi ‘Turiaçu’ e relação com ocorrência de lesões corticosas nos frutos em pré e pós-colheita

Abstract

The 'Turiaçu' pineapple plantation, located in the municipality of Turiaçu, Maranhão, located in the Gurupi (Amazon Maranhense) micro-region, is basically familiar, in a roving cutting and burning system still undergoing innovations in the production process. A problem that depreciates the commercial value of cv. 'Turiaçu' and makes difficult the conquest of new markets is the presence of corticosteroid lesions in the fruit bark that seems to result from a physiological disorder. The objective of this study was to evaluate the occurrence of lesions in pineapple cv. 'Turiaçu' from the cutting and burning cropping system and to study the relationship between the nutritional status of 'Turiaçu' pineapple plants with the occurrence of corticosteroid lesions in fruits. The data related to the count of lesions in the fruits peel were submitted to Student's t-test at the 5% probability level. The statistical software MINITAB® 16 was used. Percent frequency histograms were used for the total count values of typical corticosteroid lesions and superficial corticosteroid lesions of pineapple cv. 'Turiaçu'. In general, it can be inferred that the 16/17 crop presented fruits with better commercial quality, since it obtained a frequency of fruits without injury and a decrease of the frequency in the grouping ≥ 50 lesions per fruit, in comparison to the harvest 15 / 16. The severity of the situation of the presence of typical corticosteroid lesions was evidenced in the properties that cultivated the pineapple in the field stump situation, where fruits in general, in the two harvests, presented fruits with a large number of typical lesions, characterizing fruits with low potential of market, being a generalized phenomenon in the region and aggravated in crops that do not receive any type of fertilization. The application of boron via leaf gave high levels of boron in leaf D, however, neither boron nor biofertilizer, influenced the chemical and biometric characteristics of the fruits, except for fruit length without crown / fruit mass. The application of biofertilizer reduced the number of typical corticosteroid lesions at the base of the fruits, whereas the application of boron, via foliar and biofertilizer did not reduce the number of superficial corticosteroid lesions.