SOIL SALINIZATION AND ITS EFFECTS ON MORPHO-PHYSIOLOGICAL CHARACTERISTICS OF SUGARCANE VARIETIES

Brazil is one of the world’s largest sugarcane producers, and its cultivation has extreme economic importance. The Sub-Mid São Francisco Valley region presents high sugarcane yield indexes, but this region also has areas with high salinity levels. Thus, the objective of this study was to evaluate the effects of salinity on the growth and development of commercial varieties of sugarcane. The experiment was conducted in a nursery, located in the Federal University of the São Francisco Valley, Juazeiro, in the state of Bahia, Brazil. Three commercial varieties of sugarcane—VAT-90212, RB-92579, and SP-791011—were cultivated under two types of soil from areas owned by the agroindustry Agrovale. One of the soils had electrical conductivity (EC) of 4.6 dS.m -1 (saline), and the other had EC of 1.5 dS.m -1 (non-saline). Morphological parameters determining the plant growth and development, leaf chlorophyll content, and gas exchange were evaluated. The results presented that the salinity decreased the morphological parameters of all the evaluated sugarcane varieties. A similar result was found for photosynthetic activity and chlorophyll content

Simulação do efeito da variação da temperatura ambiente na germinação de variedades de milho

Aumentos na temperatura ambiente podem influenciar de forma significativa o processo de germinação de diversas espécies vegetais. Podem interferir diretamente em atividades fisiológicas, bioquímicas entre outras, alterando desta forma a máxima capacidade das sementes em ativar a emergência das plântulas, bem como a formação morfológica das plantas. Nesse sentido, o objetivo desse trabalho foi simular em câmaras de crescimento o efeito de diferentes temperaturas na germinação de três cultivares de milho: BRS Assum preto, BRS011 e BRS033 Asa Branca. O experimento foi implantado a partir da utilização dos tratamentos formados por três temperaturas controladas: 20º, 30º e 40ºC. As variáveis analisadas foram percentuais de germinação; índice de velocidade de germinação; tempo médio de germinação; frequência de germinação; altura das plântulas; diâmetro do caule; número de folhas; clorofila A, B e total; massa fresca e seca do caule, folha e raiz. Para a estatística foi aplicado o teste de Tukey a 5%, nas variáveis quando significativas. A faixa de temperatura de 30ºC é a ideal para a germinação e desenvolvimento inicial de mudas de milho. As variedades estudadas não apresentam diferenças significativas para a produção de massa seca, exceto a das raízes, bem como para as variáveis biométricas estudadas. Não há diferenças entre as variedades na produção de clorofilas. A temperatura de 30ºC foi a que apresentou o maior índice de clorofila A e total; massa seca do caule e das folhas, assim como das variáveis biométricas

Physiological characteristics of grapevine under irrigation and fertilization management

The viticulture in the semiarid region of Brazil stands out in the country due to the expansion of its cultivated area and increased production, especially in the sub-mid São Francisco Valley. However, the supplying of water and an efficient replacement of nutrients to the soil are essential for these crops, due to the intrinsic climatic conditions of this region, such as low rainfall and high evapotranspiration. This study aimed at evaluating the physiological characteristics of ‘Itália’ grapevine (Vitis vinifera L.) under irrigation and fertilization management. The experiment was conducted in a randomized block design, with four replications, in a split-plot arrangement, with four irrigation water depths (0.75, 1.00, 1.25 and 1.5 times the crop coefficient) in the plots and four fertilizer rates (100 %, 75 %, 50 % and 25 %, based on the recommended fertilizer rates for this crop) in the subplots, with addition of organic compounds. The leaf water potential, leaf chlorophyll content, relative water content, photosynthesis, stomatal conductance, internal CO2 partial pressure, leaf temperature and biomass accumulation in the berries were evaluated. The highest leaf chlorophyll contents were found in treatments with fertilizer rates of 70-85 %. Stomatal conductance decreased with the increasing irrigation water depths, thus reducing the internal CO2 partial pressure and increasing the leaf temperature and air vapor pressure deficit. The reduction of 25 % in the conventional fertilization and irrigation of 135 % of the recommended coefficient resulted in the highest average weight of berries. The highest yields were obtained with the lowest irrigation water depths and fertilizer rates of 50-65 %

Composición química y propiedades biológicas de la hierbabuena, Mentha spicata, con fertilización tradicional y orgánica

Introduction: Spearmint (Mentha spicata) is widely used in the pharmaceutical and food industries, thanks to chemical properties largely influenced by genetic and environmental factors, especially soil conditions. Objective: To determine the effect of conventional and organic fertilization on the chemical and biological properties of M. spicata. Methods: We conducted field trials in a randomized block experimental design, with four replications, using unfertilized crops and crops fertilized with urea (0,15 t ha-1) or vermicompost (5 and 10 t ha-1). Results: All fertilization treatments increased essential oil yield, carvone content, and total polyphenol concentration with respect to the control. They also increased the antioxidant capacity and the inhibitory activity of the acetylcholinesterase, butyrylcholinesterase, α-amylase, and α-glycosidase enzymes. The effect was more marked in the crop fertilized with 5 t ha-1 vermicompost. Conclusions: Both conventional and organic fertilization increase the yield and quality of M. spicata essential oils. However, organic fertilization with 5 t ha-1 vermicompost yields rich total polyphenols and carvone. This improves antioxidant and medicinal properties, acting on enzymes related to Alzheimer's disease and diabetes.Introducción: La hierbabuena (Mentha spicata) es muy usada en las industrias farmacéutica y alimentaria, gracias a sus propiedades químicas influenciadas en gran medida por factores genéticos y ambientales, especialmente las condiciones del suelo. Objetivo: Determinar el efecto de la fertilización convencional y orgánica sobre las propiedades químicas y biológicas de M. spicata. Métodos: Hicimos ensayos de campo en un diseño experimental de bloques al azar, con cuatro repeticiones, utilizando cultivos no fertilizados y cultivos fertilizados con urea (0,15 t ha-1) o vermicompost (5 y 10 t ha-1). Resultados: Todos los tratamientos de fertilización aumentaron el rendimiento de aceite esencial, el contenido de carvonas y la concentración total de polifenoles, con respecto al control. También aumentaron la capacidad antioxidante y la actividad inhibidora de las enzimas acetilcolinesterasa, butirilcolinesterasa, α-amilasa y α-glicosidasa. El efecto fue más marcado en el cultivo fertilizado con 5 t ha-1 de vermicompost. Conclusiones: Tanto el abono tradicional como el orgánico aumentan el rendimiento y la calidad de los aceites esenciales de M. spicata. Sin embargo, la fertilización orgánica con 5 t ha-1 de vermicompost produce ricos polifenoles totales y carvonas. Esto mejora las propiedades antioxidantes y medicinales, actuando sobre las enzimas relacionadas con la enfermedad de Alzheimer y la diabetes