Growth and development of Paspalum virgatum L.

Abstract

The objective of the work was to evaluate the growth and development of the razor-blade grass (Paspalum virgatum L.). The experimental design was a randomized complete block design with 17 treatments, and the growth evaluations were performed at 20, 27, 34, 41, 48, 55, 62, 69, 76, 83, 90, 97, 104, 111, 118, 125, 132 days after sowing (DAS) and five replications, considering as sowing date the day the seeds were placed in the plastic boxes. The evaluated characteristics were: total dry mass (Mt), shoot dry mass (Ma) and dry mass of roots (Mr), number of leaves and number of tillers per plant. The quantitative variables related to plant growth were analyzed by applying the F test on the analysis of variance followed by non-linear log-logistic regressions, with the objective of modeling the data in the form of equations. The razor-blade grass (Paspalum virgatum L.) is a weed with slow initial development and growth, but with high dry mass production at the end of the cycle.

Uso dos modelos von Bertalanffy e Logístico na descrição do acúmulo de massa seca das plantas daninhas Amaranthus retroflexus e Amaranthus hybridus

“…Para 𝛽, que está relacionado ao ponto de inflexão, onde a curva passa de crescimento acelerado para desacelerado (FERNANDES et al 2015, JANE et al, 2020, a estimativa mínima aproximada foi de 45 DAS e máxima de 53 DAS, valores próximos aos encontrados por Carvalho et al (2008). Observando as estimativas do parâmetro 𝛼, de acordo com o modelo von Bertalanffy a espécie A. hybridus apresentou maior acúmulo de massa seca total, de aproximadamente 74,4704 𝑔 𝑝𝑙𝑎𝑛𝑡𝑎 −1 , acumulou mais que o capim-navalha que exibiu 45,3 𝑔 𝑝𝑙𝑎𝑛𝑡𝑎 −1 aos 132 DAS (LABEGALINI et al, 2023). Em estudos conduzidos por Carvalho et al (2008) Em relação a massa seca total a espécie A. retroflexus apresentou ponto de inflexão anterior para os dois modelos.…”