ESTABLISHMENT OF DRIS NORMS FOR CACTUS PEAR GROWN UNDER ORGANIC FERTILIZATION IN SEMIARID CONDITIONS

Marcelo Batista Teixeira,João Abel Da Silva,Sérgio Luiz Rodrigues Donato,Paulo Emílio Rodrigues Donato

doi:10.1590/1983-21252019v32n411rc

Marcelo Batista Teixeira, João Abel Da Silva + Show 2 more

Open Access

https://doi.org/10.1590/1983-21252019v32n411rc

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Abstract

ABSTRACT The objective of this work was to establish DRIS norms for evaluation of nutritional status of cactos pear of the Gigante cultivar grown under organic fertilization in semiarid conditions. Cladode macro and micronutrient contents and dry matter yield of 72 plots were evaluated. The experiment was conducted in a randomized block design with three replicates, using a 4×3×2 factorial arrangement consisted of four bovine manure rates (0, 30, 60, and 90 Mg ha-1 ano-1), three spacings (1.00×0.50, 2.00×0.25, and 3.00×1.00×0.25 m), and two production cycles (600 and 930 days). The data were separated into high-yield population (HYP) and low-yield population (LYP), above and below 19.93 Mg ha-1 cycle-1, respectively. The mean, standard deviation, coefficient of variation, variances, and variance ratios of all bivariate relations between nutrients were calculated for the establishment of DRIS norms, considering the direct (A/B) and reverse (B/A) form. The selection of direct and reverse relations between nutrients to compose the DRIS norms was based on the variance ratio between LYP and HYP (S2b/S2 a). The sixty-six relations between cladode nutrient contents that presented the higher ratios between the variances in the LYP and HYP (S2b/S2a) were chosen. The DRIS norms established make viable the use of leaf diagnosis as an evaluation method of nutritional status of cactos pear of the Gigante cultivar grown under organic fertilization in semiarid conditions.

Highlights

Cactus pear (Opuntia fícus-indica (L.) Mill) is a crop plant adapted to the adverse conditions of the Brazilian semiarid region due to its morphological and physiological characteristics, mainly, the crassulacean acid metabolism (DONATO et al, 2014a)
The objective of this work was to establish diagnosis and recommendation integrated system (DRIS) norms for evaluation of nutritional status of Cactus pear of the Gigante cultivar grown under organic fertilization in semiarid conditions
The DRIS method based on the evaluation of balance between nutrients contributes to solve this diagnosis problem, since the use of high-yield population (HYP) to obtain the DRIS norms considers that the mean value of the relation between two nutrients will be closer to the physiological optimum in this population (SILVA; CARVALHO, 2006)

Summary

Introduction

Cactus pear (Opuntia fícus-indica (L.) Mill) is a crop plant adapted to the adverse conditions of the Brazilian semiarid region due to its morphological and physiological characteristics, mainly, the crassulacean acid metabolism (DONATO et al, 2014a). The productive potential of cactus pear is maximum when the nutrient relations are adequate and provide normal development of plants. Information on the nutritional balance of plants is important to evaluate their yield potential (SERRA et al, 2010). Leaf diagnosis is used as a complement to soil chemical analysis and visual diagnosis, and shows the dynamics of nutrients in the soil-plant system. This information contributes to a sustainable and economically viable crop production (DONATO et al, 2017b). The leaf nutrient concentration is currently the more relevant, reliable method to assess the plant's nutritional status, since it represents the in -situ condition in a holistic form. The specific combination of nutrient contents to obtain high yields has been considered in some methods, such as the diagnosis and recommendation integrated system (DRIS) (URANO et al, 2006)

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