RESUMEN El cajueiro presenta enorme relevancia económica para el Nordeste Brasileño. Para el establecimiento de huertos de esta espécie, la fase más importante es la formación de plántulas. Por esto, estudios para mejorar aspectos de crecimiento y calidad de plántulas son de gran importancia. En tal sentido, el objetivo del presente trabajo fue evaluar el crecimiento y calidad de plántulas de cajueiro en respuesta a métodos de rompimiento de dormancia, volumen de la matera y aplicación de biofertilizante bovino. Se utilizó el diseño experimental completamente al azar con arreglo factorial 2x2x5, seis repeticiones y la unidad experimental de cinco plántulas. Los tratamientos consistieron en dos métodos de rompimiento de dormancia (escarificación por lija e inmersión en agua), dos volúmenes de matera (1 y 2 kg) y cinco dosis de biofertilizante bovino (0; 2,5; 5,0; 7,5 y 10 mL). El método de rompimiento de dormancia con agua normal durante 24 horas fue el más adecuado para la formación de plántulas de cajueiro. Las dosis 7,5 y 10,0 mL de biofertilizante bovino proporcionaron mayor crecimiento y calidad de plántulas de cajueiro. El volumen 2 kg de sustrato fue el volumen más indicado para el cultivo de plántulas de cajueiro.

ABSTRACT The dwaf cashew tree presents enormous economic relevance for the Brazilian northeast. When establishing orchards of this species, the most important phase is the formation of the seedlings. Therefore, studies aiming to improve growth aspects and seedling qualities are extremely relevant. In this sense, the present study aimed to evaluate the growth and quality of dwarf cashew tree seedlings as a result of methods for breaking dormancy, container volume and application of bovine biofertilizer. The experiment design was completely randomized, with a 2x2x5 factorial scheme and six replicates; the experimental unit consisted of five seedlings. The treatments involved two methods of breaking dormancy (scarification with sandpaper and immersion in water), two container volumes (1 and 2 kg) and five doses of bovine biofertilizer (0, 2.5, 5.0, 7.5 and 10 mL). The method for breaking dormancy with normal water for 24 hours was the most adequate for the formation of dwarf cashew tree seedlings. The doses of 7.5 and 10 mL of bovine biofertilizer provided higher growth and quality in the dwarf cashew tree seedlings. The volume of 2 kg of substrate was the most suitable volume for growing dwarf cashew trees.

RESUMO A salinidade da água de irrigação interfere no crescimento de plantas de pinheira. Relatos indicam que o fósforo interfere no crescimento das plantas, com efeitos positivos na atenuação dos sais. Objetivou-se avaliar os efeitos da condutividade elétrica da água de irrigação (CEai) e doses de superfosfato triplo (SFT), no crescimento e teores foliares de mudas de pinheira (Annona squamosa L.). O experimento foi realizado em ambiente protegido, em delineamento experimental de blocos casualizados, com nove tratamentos, combinando-se doses de fósforo (0,00 g dm-3; 1,10 g dm-3; 3.00 g dm-3; 5,13 g dm-3; e 6.00 g dm-3 de SFT) e condutividade elétrica da água de irrigação (0,50 dS m-1; 1,10 dS m-1; 2,50 dS m-1; 3,91 dS m-1; e 4,50 dS m-1), no crescimento e teores foliares de Na+, K+, Ca+2 e P, em mudas de pinheira. As plantas apresentaram curva crescente de diâmetro caulinar com o aumento do SFT, porém, à medida que aumentou-se a CEai, houve efeito negativo para esta variável. O SFT influenciou positivamente na altura das plantas (2,02 g dm-2/14,50 cm), massa seca (1,25 g dm-2/0,90 g) e massa seca total (2,32 g dm-2/2,00 g). Com o aumento da CEai, houve incremento nos valores de Na+ (16,20 mg g-1), bem como na razão Na+/K+ (1,48 mg g-1), que ocasionam distúrbios metabólicos no meio celular. Doses de SFT melhoram o crescimento das mudas, não sendo fitotóxico; porém, aliados à CEai, reduzem o conteúdo de K+ em plantas de pinheira.

ABSTRACT The irrigation with saline water affects the growth of sugar-apple plants. Some reports indicate that phosphorus affects the plants growth, with positive effects on the salts attenuation. This study aimed to assess the effects of the irrigation water electrical conductivity (iwEC) levels and triple superphosphate (TSP) doses in the growth and leaf levels of sugar-apple seedlings (Annona squamosa L.). The experiment was conducted in a protected environment, in an experimental design of randomized block, with nine treatments that combined phosphorus doses (0.00 g dm-1, 1.10 g dm-1, 3.00 g dm-1, 5.13 g dm-1 and 6.00 g dm-1 of TSP) with irrigation water electrical conductivity (0.50 dS m-1, 1.10 dS m-1, 2.50 dS m-1, 3.91 dS m-1 and 4.50 dS m-1), to evaluate the growth and leaf levels of Na+, K+, Ca+2 and P of sugar-apple seedlings. The increased curve for stem diameter presented by plants was proportional to the amount of TSP. Nevertheless, the iwEC levels were inversely proportional to this variable. The use of TSP directly affected the plant height (2.02 g dm-2/14.50 cm), dry mass (1.25 g dm-2/0.90 g) and total dry mass (2.32 g dm-2/2.00 g). The increase in the iwEC levels was directly proportional to the Na+ values (16.20 mg g-1), as well as to the Na+/K+ ratio (1.48 mg g-1), which cause metabolic disorders in the cellular environment. The TSP doses improve the seedlings growth, proving to be not phytotoxic; however, in combination with the iwEC, they reduce the amount of K+ in sugar-apple seedlings.