The carbon source is the most expensive nutrient for Spirulina production; effluents from anaerobic digestion contain this nutrient in the form of HCO3-. The aim of this study was to assess the growth kinetics, composition and fatty acid profile of Spirulina sp. LEB-18 grown in standard Zarrouk medium (NaHCO3 16.8 g L-1) and in Zarrouk medium replaced with 20% (v/v) effluent with reduced concentrations of NaHCO3 (5.3 and 2.8 g L-1). The use of effluent and lower concentrations of HCO3 was found to be an alternative to reduce the costs of Spirulina production, because there were no significant differences in growth parameters (µmax 0.324 - 0.354 d-1; Pmax 0.280 - 0.297 g L-1 d-1), in the different culture medium used. Lipids ranged between 4.9 and 5.0%; the media with effluent had higher levels of linoleic acid compared to the standard medium.

Con el fin de determinar la presencia de cinco patologías fúngicas y su comportamiento en relación al manejo agronómico y edad de las plantas en 14 cultivares de caña de azúcar con fines forrajeros, se llevó a cabo una investigación en terrenos de la Fundación Danac, fundamentado en las condiciones agroecológicas existentes para esa zona en el estado Yaracuy. Los cultivares de caña de azúcar evaluados fueron 10 experimentales y cuatro comerciales. Las evaluaciones se basaron en estimaciones visuales antes de cada frecuencia de corte (3, 4, 6, 10 meses) en cada una de las parcelas experimentales durante 32 meses de evaluación. Las observaciones se compararon con las escalas existentes para roya, pokkah boeng, mancha de anillo, carbón y peca amarilla. Los datos se analizaron bajo el método de Frecuencia Cruzada - Chi Cuadrado. Los resultados obtenidos mostraron que el cultivar experimental V99-260 es altamente resistente a las enfermedades evaluadas. Los cultivares V99-250 y V99-258 se comportaron altamente resistentes a la roya. El cultivar My55-14 mostró la mayor resistencia al pokkah boeng al igual que V90-14, V99-8, V99-261 y V99-263. Todos los cultivares tuvieron un comportamiento de alta resistencia a la mancha de anillo, el carbón y la peca amarilla. Las plantas sometidas a frecuencias de corte entre cuatro y seis meses presentaron los menores grados de incidencia. Los niveles de incidencia alcanzados no llegaron a causar daños al cultivo como forraje debido a que en la superficie foliar de las plantas quedan áreas fotosintéticamente activas.

With the purpose of determining the presence of five fungical pathologies and their behavior in relation to the agronomic handling and plants age, in 14 cultivars of sugar cane with forage aims, a research on the experimental field at Danac Foundation was carried out, based on the existing agro-ecologic conditions for that zone in the Yaracuy state. Sugar cane cultivars evaluated were 10 experimental and four commercial ones. Evaluations were based on visual estimations before each harvest frequency (3, 4, 6, 10 months) in each one of the experimental plots during 32 months of evaluation. Observations were compared with the existing scales for rust, pokkah boeng, ring spot, smut and yellow spot. Data were analyzed under Crossed Frequency-Square Chi method. Results obtained showed that the experimental cultivar V99-260 is highly resistant to the diseases evaluated. The cultivars V99-250 and V99-258 behaved highly resistant to the rust. The cultivar My55-14 showed the high resistance for the pokkah boeng like V90-14, V99-8, V99-261 and V99-263. All the cultivars had a behavior of high resistance for ring spot, smut and yellow spot. The harvest frequencies between four and six months presented the smaller incidence degrees. The reached incidence degrees did not cause damages to the cultivation like forage because in the foliar surface of plants remains photosynthetically active areas.