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Background: Sampling for monitoring commercial production of kingworm (Zophobas spp.) requires knowledge about optimal sample sizes and methods for projecting yields. Hypothesis and objective: A sequential enumerative sampling (SES) based on larval weight records should present significant levels of productivity prediction under known margins of error and precision. To verify this, it was proposed to evaluate the performance of an SES method in two kingworm’s farms in Tarapoto, Peruvian Amazon. Methodology: Means (m) and respective variances (s2) of larvae number and weight since six sample units (SU) of 500 ml from 35 production units (PU) of 48 l were obtained. Log-transformed data were fitted to Taylor’s Power Law TPL (log s2 =log a +b. log m). A Morisita’s index transformation was applied with original larvae number data to obtain an independent measure of intra-sample spatial arrangement. TPL elements constituted the Green's function optimal sample size for three margins of error E. Sequential sampling simulations were carried out, whose means predicted yields comparing two methods of weight relationship between SU and PU (w/W, linear function), with their respective census. Results: Number of larvae (s2 =1.06 m1.61) and weights (s2 =0.79 m1.53) showed highly significant adjustments in TPL, with aggregation coefficients corresponding crowded spatial arrangement. Larval density and Ip index showed close correlation. Although simulations provided a lower hit frequency than expected, the mean precision increased highly significantly while increasing the error margin, with detection levels of 0.25, 2.23 and 12.57 g to E 50, 30 and 20 %, respectively. Implications: Applying SES, kingworm’s breeders should standardize substrate volume contained in each UP and adjust their w/W conversion factor to avoid plus sampling efforts. Conclusion: The SES suits the needs of productivity monitoring, where using of w/W ratio and 50 % margins of error are associated with greater effectiveness and precision with a sample size of ni

Con el objetivo de determinar la duración de los períodos de incubación (PI) y de latencia (PL) del patógeno Hemileia vastatrix, su comportamiento a través de los años de estudios y su relación con los factores climáticos, se realizó un estudio de enero 2017 a diciembre 2019, en tres localidades de la zona cafetalera en el municipio de Tercer Frente. En el laboratorio se tomaron mensualmente plantas de café variedad Caturra de 6 meses de edad inoculada con el patógeno y trasladada a las zonas de estudios. Después de 15 días de la inoculación se evaluó diariamente: tiempo de aparición de los primeros síntomas visibles de la enfermedad, número de plantas con síntomas, tiempo y número de hojas con lesiones número de lesiones por hoja, número de hojas con lesiones esporuladas y las temperaturas máximas y mínimas. Las temperaturas durante el estudio oscilaron entre los 19 y 34 ºC. Se determinó que el período de latencia e incubación para las zonas de estudio La Mandarina es de 33 y 19 días, Caimitón 32 y 21 días, Monjará 34,4 y 22 días, respectivamente. Palabras clave: Café, enfermedad, incubación. ABSTRACT In order to determine the duration of the incubation periods (IP) and latency (PL) of the pathogen Hemileia vastatrix, its behavior over the years of studies and their relationship with climatic factors, a study was carried out from January 2017 to December 2019, in three locations in the coffee zone in the municipality of Third Front. In the laboratory, coffee plants of the variety Caturra of 6 months of age inoculated with the pathogen and transferred to the zones of studies. After 15 days of inoculation, it was evaluated daily: time of appearance of the first visible symptoms of the disease, number of plants with symptoms, time and number of leaves with lesions number of lesions per leaf, number of leaves with sporulated lesions and maximum and minimum temperatures. The Temperatures during the study ranged between 19 and 34 ºC. It was determined that the period of latency and incubation for the study areas La Mandarina is 33 and 19 days, Caimitón 32 and 21 days, Monjará 34.4 and 22 days, respectively. Keywords: Coffee, disease, incubation.

Two models of increasing complexity were constructed to simulate the interactions between the root-knot nematode (RKN) Meloidogyne incognita and the biocontrol fungus Pochonia chlamydosporia var. catenulata in a rhizosphere microcosm. The models described discrete population dynamics at hourly rates over a 6-month period and were validated using real parasitism and nematode or fungus data. A first, general Pochonia–nematode–root model (GPNR) used five functions and 16 biological constants. The variables and constants describing the RKN life cycle included the rates of egg production, hatching, juvenile (J2), and mature female development, including root or nematode self-density-dependent factors. Other constants accounted for egg parasitism, nematode-induced root losses, growth, and mortalities. The relationship between nematodes and fungal propagules showed density dependence and cyclic variations in time, including an attractor on the propagules and J2 phases space. The simulations confirmed a P. chlamydosporia optimal initial density of 5 · 103 propagules · cc soil-1, as usually applied in assays. The constants used in GPNR showed adherence to the nematode biology, with 103 eggs per egg mass, a 10-day average lifespan of J2, with 2 days required to enter roots, and adult lifespan lasting 24 days. The fungus propagule lifespan was 25 days, with an average feeder root lifespan lasting around 52 days. A second, more complex Pochonia–nematode–root detailed model (GPNRd) was then constructed using eight functions and 23 constants. It was built as GPNR did not allow the evaluation of host prevalence. GPNRd allowed simulations of all RKN life stages and included non-parasitic and parasitic fungus population fractions. Both GPNR and GPNRd matched real J2 and fungus density data observed in a RKN biocontrol assay. Depending on the starting conditions, simulations showed stability in time, interpreted as effective host regulation. GPNRd showed a fungus cyclic relationship with the J2 numbers, with prevalence data close to those observed (38.3 vs. 39.4%, respectively). This model also showed a further density-independent nematode regulation mechanism based on the P. chlamydosporia switch from a non-parasitic to a parasitic trophic behavior. This mechanism supported the biocontrol of M. incognita, also sustained by a concomitant increase of the root density.

The research was carried out in the La Peticera Production Unit, located in El Rosario Sector, San Antonio Parish, Miranda Municipality, Falcón State, in order to evaluate the biomass production of two cultivars of Pennisetum purpureum, Dwarf and CT -115, with organic and mineral fertilization, The experiment was carried out in plots divided into a completely random scheme. The evaluated treatments were: Dwarf / manure 0.5 kg / m2, Dwarf / manure bovine 1.0 kg / m2, Dwarf / manure bovine 1.5 kg / m2, Dwarf / Urea 0,015 kg / m2, CT 115 / bovine manure 0.5 kg / m2, CT 115 / bovine manure1.0 kg / m2, CT 115 / bovine manure 1.5 kg / m2, CT 115 / Urea 0.015 kg / m2 ,The treatments had not significance differences which indicate by organic fertilizing with bovine manure, in the studied P. purpureum cultivars is possible decrease the production costs and the environmental affectations caused by the use of chemical products, without affecting the biomass yielding

The research was carried out in the production unit Tacarigua, located in El Mene de San Lorenzo, Acosta municipality, Falcón State. The experimental design was completely randomized, with four treatments and four replications. The treatments were: neem oil 5%, neem oil 10%, neem oil 15% and control, Iodine solution. For analyzing the differences on the prevalence of subclinical mastitis, a proportion comparison test was conducted using the program SAS (2001). There were no significant differences among the neem oil treatments with the control treatment, demonstrating the potentiality of neem oil for the control of subclinical mastitis. as a substitute of chemical agents, aggressive to human health and the environment; which are tradicionally used as post milking disinfectants

Objetivo. Determinar el impacto de aplicaciones de biocarbón enriquecido con abonos orgánicos sobre los grupos de nematodos de suelo. Materiales y métodos. El estudio se desarrolló en el Organopónico Vivero Alamar, Habana del Este, Cuba. Se evaluó el efecto de las aplicaciones de biocarbón sobre el crecimiento y producción de tres hortalizas y una planta aromática. Se realizaron muestreos de suelos antes de la siembra y después de aplicado el biocarbón. Se tomó 100 g de suelo por muestra, a las 72 horas se recolectaron, mataron, fijaron y contabilizaron los especímenes. Los datos del número de géneros al inicio y posterior a la aplicación se vertieron en una base de datos en Excel. Resultados. Se encontraron ocho géneros de nematodos (Cephalobus, Pelodera, Aphelenchus, Aphelenchoides, Tylenchus, Dolichodorus, Mononchus y Pratylenchus) y especímenes de las familias Rhabditidae y Dorylaimidae. La presencia del grupo de los bacteriófagos (Cephalobus sp.) y de representantes de la familia Rhabditidae se encontró en todos los cultivos evaluados posterior a la aplicación del biocarbón. No hubo presencia de fitoparásitos y el número de nematodos fungivoros (Aphelenchus sp.) aumentó. Conclusión. El uso del biocarbón demostró ser una alternativa útil y sencilla para elevar la estabilidad de los suelos.

Objetivo. Establecer la capacidad como hospedante de once cultivares de frijol negro más extendidos en la provincia Mayabeque y determinar su límite de tolerancia. Materiales y métodos. Para la preparación del inóculo se utilizaron raíces de tomate (Solanum lycopersicum L., var Cambell-28) infestadas con Meloidogyne incognita, en macetas de 1 kg de capacidad con una mezcla de suelo ferrasol éutrico y estiércol vacuno como abono orgánico (en proporción 1:1). Se establecieron siete tratamientos y un testigo (sin inocular), los niveles poblacionales fueron 0.125; 0.25; 1; 4; 16 y 64 J2/gramo de suelo. Se calcularon los factores de reproducción (FR) e índice de reproducción (IR) de cada genotipo, evaluando la resistencia y el efecto de densidades poblacionales del nematodo sobre la masa foliar de cada genotipo evaluado. Los datos se procesaron través del paquete estadístico R y se graficaron. Resultados. Se verificó que los cultivares BAT-304, BAT-306, CUFIG-48, CUL-156, Tomeguin-93, PL-8, P-248-1, Caujeri-2170, Milagro Villareño y Güira-89, fueron susceptibles a M. incognita (FR≥1), mientras que Triunfo-70 fue resistente. BAT-306, tuvo menor límite de tolerancia (LT) (0,002 J2 /g de suelo y Triunfo-70 el más alto (0.75). La mayor pérdida de masa foliar (85%) la alcanzo BAT-306 y la menor Triunfo-70 (20%). Conclusión. Los cultivares CUFIG-48, CUL-156, Tomeguin-93, PL-8, P-248-1, Caujeri-2170, Milagro Villareño y Guira-89 fueron susceptibles a M. incognita.