Examinando por Materia "Corn"

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Detecting adventitious transgenic events in a maize center of diversity
(Pontificia Universidad Católica de Valparaíso, 2011-07-15) Rimachi Gamarra, Luis Fernando; Alcántara Delgado, Jorge Enrique; Aquino Villasante, Yeny Natali; Ortiz Rios, Rodomiro Octavio
Background: The genetic diversity of maize in Peru includes several landraces (within race clusters) and modern open pollinated and hybrid cultivars that are grown by farmers across various regions, thereby making this country a secondary center of diversity for this crop. A main topic of controversy in recent years refers to the unintended presence of transgenic events in locally grown cultivars at main centers of crop diversity. Peru does not yet have biosafety regulations to control or permit the growing of genetically modified crops. Hence, the aim of this research was to undertake a survey in the valley of Barranca, where there were recent claims of authorized transgenic maize grown in farmers fields as well as in samples taken from feed storage and grain or seed trade centers. Results: A total of 162 maize samples (134 from fields, 15 from local markets, eight from the collecting centers of poultry companies, from the local trading center and four samples from seed markets) were included for a qualitative detection by the polymerase chain reaction (PCR) of Cauliflower Mosaic Virus (CaMV) 35S promoter (P35S) and nopaline synthase terminator (Tnos) sequences, as well as for six transgenic events, namely BT11, NK603, T25, 176, TC1507 and MON810. The 134 maize samples from farmers fields were negative for Cry1Ab delta-endotoxin insecticidal protein and enzyme 5 enolpyruvylshikimate-3-phosphate synthase (EPSPS) using lateral flow strips. The PCR analysis did not detect any of the six transgenic events in samples from farmers fields, local markets, seed trading shops and the local collecting center. There were four transgenic events (T25, NK603, MON810 and TC1507) in grain samples from the barns of poultry companies. Conclusions: This research could not detect, at the 95% probability level, transgenes in farmers' fields in the valley of Barranca. The four transgenic events in grain samples from barns of poultry companies were not surprising because Peru imports maize, mainly for animal feed, from Argentina and the United States that are known for growing transgenic maize.
Tillage practices and liming: comparative study of soil properties and forage corn production
(MDPI, 2024-03-09) Ocaña Reyes, Jimmy Alcides; Gutierrez Tang, Marco Antonio; Paredes Espinosa, Richard; Riveros Lizana, Christian Alonso; Cárdenas Rengifo, Gloria Patricia; Bravo Morales, Nino Frank; Quispe Tomas, Astrid Chilsy; Amaringo Cordova, Luiz Paulo; Ocaña Canales, Juan C.; Zavala Solórzano, José W.; Huamaní Yupanqui, Hugo A.; Cruz Luis, Juancarlos Alejandro; Solórzano Acosta, Richard Andi
Tillage conservation practices (CA), traditional agriculture (TA), and liming influence soil properties and crop yield. However, it is essential to demonstrate which tillage and liming practices improve soil properties and forage corn yield. This study compared soil properties and forage corn production in two tillage systems with the addition of dolomite and lime, which formed four treatments. The tillage in the first three days surpassed the TA soil CO2 emission, with 64.8% more CO2 than in the CA soil, and the TA hydraulic conductivity and bulk density were more suitable than those in the CA soil. The CA soil had 233 earthworms m−2 more than in TA. The TA green forage corn yielded 6.45 t ha−1 more than in CA, with a higher P, Ca, and Mg foliar content than in CA, but in the CA, the foliar N and K were higher than in TA. The liming increased soil cations (except K), highlighting the lime on dolomite with—52% Al and + 4.85 t ha−1 of forage corn compared to the control. Soil CO2 emission was far lower in CA than in TA, with a slightly lower forage yield, and other soil properties were improved, meaning lower land preparation costs and time savings than in TA. Lime improved acidic soil faster than dolomite, generating higher forage yields.
Use of vegetable covers as a strategy to reduce soil erosión and increase the yield of corn (Zea mays L.)
(Universidad de Tarapaca, 2023-12-31) Sanabria Quispe, Samuel; Mendoza Dávalos, Katia; Palomino Paccua, Luz Angélica; Figueroa Venegas, Deyanira Antonella; Pocomucha, Vicente; Cosme de la Cruz, Roberto Carlos
Soil degradation is a problem facing agriculture, with water being the most important erosive agent, affecting, among others, crop yields. The objective of this study was to know the effect of four plant covers on soil erosion and starchy corn yield, in three locations in the Ayacucho region (Peru) during the 2018 - 2019 agricultural season. Five treatments were assigned: control, clover cover, vetch cover, vetch-oat cover, and mulch, in corn plots under a randomized complete block design (RCBD), with four blocks. Combined analysis of variance was used to evaluate the results. It was observed that soil erosion and corn yield were significantly (P < 0.001) influenced by plant cover and locations. Vetch-oat and clover cover significantly reduced soil erosion (–53 and –36%, respectively) due to the higher leaf biomass produced by both (6131 and 6052 kg ha–1, respectively). Clover cover produced the highest corn yield (3749 kg ha–1; +78%); while vetch-oats produced the lowest (1955 kg ha–1), without significant differences with the control. The highest production of biomass, N and C of the foliar coverages was produced in the location with the least slope; while the highest performance occurred in steeper areas. Clover cover turned out to be a better option to reduce soil erosion and increase corn yield.