Examinando por Materia "Seasonality"

Mostrando 1 - 3 de 3

The distribution of cadmium in soil and cacao beans in Peru
(Elsevier, 2023-04-11) Thomas, Evert; Atkinson, Rachel; Zavaleta, Diego; Rodriguez, Carlos; Lastra Paucar, Sphyros Roomel-Luciano; Yovera, Fredy; Arango, Karina; Pezo, Abel; Aguilar Zapata, Javier Neptali; Tames, Miriam; Ramos, Ana; Cruz, Wilbert; Cosme, Roberto; Espinoza, Eduardo; Chavez, Carmen Rosa; Ladd, Brenton
Peru is the eighth largest producer of cacao beans globally, but high cadmium contents are constraining access to international markets which have set upper thresholds for permitted concentrations in chocolate and derivatives. Preliminary data have suggested that high cadmium concentrations in cacao beans are restricted to specific regions in the country, but to date no reliable maps exist of expected cadmium concentrations in soils and cacao beans. Drawing on >2000 representative samples of cacao beans and soils we developed multiple national and regional random forest models to develop predictive maps of cadmium in soil and cacao beans across the area suitable for cacao cultivation. Our model projections show that elevated concentrations of cadmium in cacao soils and beans are largely restricted to the northern parts of the country in the departments of Tumbes, Piura, Amazonas and Loreto, as well as some very localized pockets in the central departments of Huánuco and San Martin. Unsurprisingly, soil cadmium was the by far most important predictor of bean cadmium. Aside from the south-eastern to north-western spatial trend of increasing cadmium values in soils and beans, the most important predictors of both variables in nation-wide models were geology, rainfall seasonality, soil pH and rainfall. At regional level, alluvial deposits and mining operations were also associated with higher cadmium levels in cacao beans. Based on our predictive map of cadmium in cacao beans we estimate that while at a national level <20 % of cacao farming households might be impacted by the cadmium regulations, in the most affected department of Piura this could be as high as 89 %.
Season and breed effect in fresh semen parameters at a bull semen production center in Peru
(Unique Scientific Publishers, 2024-07-14) Dipaz Berrocal, Deysi; León Trinidad, Silvia Eliana; Figueroa Venegas, Deyanira Antonella; Mamani Chullo, Rolando; Ramirez Hernandez, Juan; Alvarez García, Wuesley Yusmein; Estrada Cañari, Richard; Quilcate Pairazaman, Carlos Enrique
In the present study, the effect of breed, season, and their interaction on semen volume, sperm concentration, and motility was tested. Nine bulls were tested: three Braunvieh, three Simmental (B. taurus), and three Gyr (B. indicus). These bulls were managed equally in a cold semi-arid climate, divided into hot (from November to April) and cold (from May to October) for maximum and minimum temperature and relative humidity. Semen was collected twice a week for 24 consecutive months. MANOVA by ranks was used to determine significant effects; breed had a significant effect (P<0.001) on semen parameters, and seasonal variations were not significant (P>0.05). However, there was a significant effect (P<0.001) for the interaction between breed and season. To evaluate differences between breeds, we performed Tukey's post-hoc test; all pairwise comparisons (Braunvieh-Gyr, Braunvieh-Simmental and Gyr-Simmental) showed significant differences (P<0.001). Nonparametric one-way analysis showed significantly higher B. taurus breeds’ sperm concentration and B. indicus breed’s semen volume. For interaction between breed and season, Gyr reported higher sperm volume than B. taurus breeds in both seasons (P>0.05), but B. taurus breeds had higher sperm concentration in the cold season. The findings will help management make better decisions in semen collection, especially during peak season.
The nutritional contribution of potato varietal diversity in andean food systems: a case study
(Springer Nature, 2019-04-15) De Haan, Stef; Burgos, Gabriela; Liria, Reyna; Rodríguez, Flor; Creed Kanashiro, Hilary M.; Bonierbale, Merideth
Potato is the backbone of agriculture and diets in high-altitude food systems of Peru, where farmers grow diverse varietal portfolios. Here we report on the role of diverse landraces and modern potato varieties in the Andean diet. The dry matter, energy, protein, iron and zinc content of 12 floury and 9 bitter landraces was determined. The contribution of varietal diversity to the dietary intake of energy, protein, iron and zinc was established during two contrasting periods of overall food availability. Results show that the potato and intraspecific diversity make an important contribution to nutrition. Most floury landraces contain higher concentrations of protein and iron compared to the reference value reported in the 2009 Peruvian food composition table for a boiled and peeled floury landrace. Traditional freeze-drying of bitter landraces doesn’t affect energy or iron concentrations, but reduces protein and zinc content considerably. Protein and iron contents in boiled chuño derived from the bitter landraces are lower compared to the mean value reported in the food composition table. The contribution of varietal diversity ideally needs to be taken into account when conducting nutrition studies in diversity hotspots like the Andes where potato is a main staple. The potato adds positively to the nutritional balance and the recommended requirements for energy, protein, iron and zinc of women and children. Floury landraces and modern varieties complement each other in light of seasonality, providing valuable nutrients during contrasting periods of the year. The potato thus contributes positively to food security. However, the overall diversity of the diet was found to be poor, resulting in micronutrient deficiencies. Options to strengthen food based approaches to attend undernutrition are discussed.