Abstract Grass species forage yield and nutritional value directly affect livestock production performance. They also vary in response to regional climate and soil conditions. Forage yield and nutritional value in Pennisetum purpureum cv. Cuba CT-115 were evaluated at five regrowth ages (30, 45, 60, 75 and 90 d) in three seasons (dry, rainy and northwinds). A completely randomized block design with repeated measures was used, with four replicates per treatment. In all three seasons, maximum height was reached at 75 d: 127.1 cm in the dry season, 151.6 cm in the rainy season and 137.0 cm the northwind season. Forage yield was highest (27.0 t DM ha-1) at 90 d in the rainy season, with a growth rate of 300.2 kg DM ha-1 d-1, 7.3% crude protein and 37.0% in situ digestibility of dry matter. The leaf:stem ratio was highest at 30 d in all seasons, with a 1.65 average value. Crude protein content was highest in the northwind season at 30 and 45 d, with a 15.6 % average value. In all three seasons, digestibility was highest at 30 (mean= 49.3 %), 45 (51.8 %) and 60 d (48.2 %). Based on forage yield, use of P. purpureum cv. Cuba CT-115 grass for open grazing is recommended for cutting at 90 days’ regrowth and based on its nutritional quality is recommended for grazing at 60 days’ regrowth, both during the rainy season.

Resumen Se evaluó el rendimiento de forraje y valor nutritivo del pasto Pennisetum purpureum cv Cuba CT-115, en cinco edades de rebrote: 30, 45, 60, 75 y 90 días, en tres épocas del año: seca, lluvias y nortes. Se utilizó un diseño de bloques completos al azar con medidas repetidas, con cuatro repeticiones por tratamiento. La mayor altura se registró a partir de los 75 días, en todas las épocas, con valores de 127.1, 151.6 y 137.0 cm, en seca, lluvias y nortes, respectivamente. El rendimiento más alto de forraje (27.0 t MS ha-1) se obtuvo a los 90 días en la época de lluvias, con una tasa de crecimiento (TC) de 300.2 kg MS ha-1 día-1, 7.3 % de proteína cruda (PC) y 37.0 % de degradación in situ de la materia seca (DIMS). La relación hoja:tallo fue mayor a los 30 días de rebrote, con un valor promedio de 1.65. El contenido de PC fue mayor en la época de nortes a 30 y 45 días, con un valor promedio de 15.6 %. La DIMS fue más alta a 30, 45 y 60 días, con valores promedio de 49.3, 51.8 y 48.2 %, respectivamente. Con base al rendimiento de forraje, se recomienda el uso del pasto Cuba CT-115 para corte a 90 días de rebrote durante la época de lluvias, mientras que, por su calidad nutricional, se recomienda su uso para pastoreo a 60 días de crecimiento después del corte.

Summary: Moringa is used for human and animal consumption due to its high content of proteins, vitamins and minerals. The present study analyzed and evaluated the effectiveness of Azospirillum spp. over the nutritional content of moringa (Moringa oleifera Lam.) under nursery conditions. The experimental design consisted of four treatments with six repetitions in complete blocks at random, which consisted of the inoculation at 0.5, 1 and 1.5 mL of suspension with 9.8 × 105 CFU mL-1 of Azospirillum spp. The study variables: biomass, protein, macro (P, K. Ca and Mg) and micronutriments (Na, Fe, Cu and Mn) in leaves and stems were determined 70 days after sowing. The analysis of variance showed significant statistical differences between treatments only for the variables: potassium content in leaves and calcium content, iron and sodium in stem. According to the comparison of means (P ≤ 0.05) the best treatments were those that received 0.5 and 1 mL of suspension. The inoculation of Azospirillum, failed to increase the dry weight and protein contents; however, the highest values (30.2% crude protein) were associated with its application. The absence of significant effects in the other variables evaluated is associated with inoculum concentration, however, higher values are shown in the nutrient contents in relation to results reported in other research.

Resumen: La moringa es utilizada para consumo humano y animal debido a su alto contenido de proteínas, vitaminas y minerales. El presente estudio analizó y evaluó la efectividad de Azospirillum spp., sobre el contenido nutrimental de moringa (Moringa oleifera Lam.) en condiciones de vivero. El diseño experimental consistió en cuatro tratamientos con seis repeticiones en bloques completos al azar, los cuales consistieron en la inoculación a 0.5, 1 y 1.5 mL de suspensión con 9.8 × 105 UFC mL-1 de Azospirillum spp. Las variables de estudio: biomasa, proteína, macro (P, K. Ca y Mg) y micronutrimentos (Na, Fe, Cu y Mn) en hojas y tallos se determinaron a los 70 días después de la siembra. El análisis de varianza mostró diferencias estadísticas significativas entre tratamientos únicamente para las variables: contenido de potasio en hojas y contenido de calcio, fierro y sodio en tallo. De acuerdo a la comparación de medias (P ≤ 0.05) los mejores tratamientos fueron los que recibieron 0.5 y 1 mL de suspensión. La inoculación de Azospirillum, no logró aumentar el peso seco y los contenidos de proteína; sin embargo, los valores más altos (30.2% proteína cruda) se asociaron a su aplicación. La ausencia de efectos significativos en las demás variables evaluadas se asocia con la concentración del inoculo, sin embargo, se muestran valores superiores en los contenidos de nutrimentos en relación con resultados reportados en otras investigaciones.

Resumo Heliconias têm grande importância comercial devido à durabilidade de suas inflorescências, tamanhos, formas e cores brilhantes. Em relação à sua produção, a nutrição mineral da cultura é um dos aspectos mais relevantes para a obtenção de hastes florais de qualidade. O objetivo foi determinar a influência do N-P-K no crescimento e estado nutricional de Heliconia stricta Dwarf Jamaican. O delineamento experimental utilizado foi o inteiramente casualizado com quatro tratamentos e cinco repetições. Os tratamentos consistiram na fertilização do solo com N-P-K. Os níveis de adubação expressos em kg ha-1 de NPK foram: controle sem aplicação 00-00-00 (T100), 31-31-31 (T231), 62-62-62 (T362) e 93-93-93 (T493). As plantas receberam os tratamentos por seis meses. Variáveis de crescimento e teores de nutrientes da biomassa de helicônia foram avaliadas. A análise de variância mostrou diferenças estatisticamente significativas (P ≤ 0.05) no vigor e na cor da planta, assim como para os teores de fósforo, magnésio e cobre. Os aumentos significativos no vigor e cor foram com as doses 31-31-31 e 62-62-62 do NPK. Quanto ao conteúdo de P, Mg e Cu, esses foram influenciados pelas doses 31-31-31, 62-62-62 e 93-93-93. Este trabalho mostra importantes achados em relação ao diagnóstico nutricional no teor foliar de nutrientes.

Abstract Heliconias have great commercial importance due to their durability of inflorescences, sizes, forms and bright colors. Regarding its production, the mineral nutrition of the crop is one of the most relevant aspects to obtain quality floral stems. The objective was to determine the influence of N-P-K on the growth and nutritional content of Heliconia stricta Dwarf Jamaican. A completely randomized block design was used with four treatments and five repetitions. The treatments consisted in fertilizing the soil with N-P-K. The levels of fertilization expressed in kg ha-1 of NPK were: control without application 00-00-00 (T100), 31-31-31 (T231), 62-62-62 (T362) and 93-93-93 (T493). The plants received the treatments for six months. Growth variables and nutrient contents of heliconia biomass were evaluated. The analysis of variance showed significant statistical differences (P ≤ 0.05) in the vigor and color of the plant, as well as the phosphorus, magnesium and copper contents. The significant increases in vigor and color were with doses 31-31-31 and 62-62-62 of NPK. As for the contents of P, Mg and Cu were influenced by doses 31-31-31, 62-62-62 and 93-93-93 of NPK. This work shows important findings in relation to the nutritional diagnosis in the foliar content of nutrients.