Observed and estimated leaf appearance of landrace and improved maize cultivars

Abstract

The objective of this study was to compare the simulations of leaf appearance of landrace and improved maize cultivars using the CSM-CERES-Maize (linear) and the Wang and Engel models (nonlinear). The coefficients of the models were calibrated using a data set of total leaf number collected in the 11/04/2013 sowing date for the landrace varieties ‘Cinquentinha’ and ‘Bico de Ouro’ and the simple hybrid ‘AS 1573PRO’. For the ‘BRS Planalto’ variety, model coefficients were estimated with data from 12/13/2014 sowing date. Evaluation of the models was with independent data sets collected during the growing seasons of 2013/2014 (Experiment 1) and 2014/2015 (Experiment 2) in Santa Maria, RS, Brazil. Total number of leaves for both landrace and improved maize varieties was better estimated with the Wang and Engel model, with a root mean square error of 1.0 leaf, while estimations with the CSM-CERES-Maize model had a root mean square error of 1.5 leaf.

Agrometeorological models for predicting seedlings development of two native forest species

“…This is an important step to understand the seedling development pattern in native forest species and improve the modeling of forest species. Besides, our results have practical applications and can be applied to understand the effects on CLN and SPD under climate change (Becker et al, 2020;Costa and Streck, 2018;Florencio et al, 2019;Langner et al, 2018;Streck et al, 2011;Streck et al, 2013 ) to simulate the leaf appearance in forest nurseries, and to verify the ideal SD. Moreover, this approach can be used to determine the time for selling the seedlings (Ferreira et al, 2019b;Martins et al, 2014;Monteiro et al, 2014) as well as ideal moments for management nursery practices (Martins and Streck, 2007).…”

“…Both models have been used to predict the LAR in several crops around the world including some regions of Brazil. For example, in Brazil, both models have been used to predict LAR in crops, such as potato (Streck et al, 2007), rice (Streck et al, 2008(Streck et al, , 2011, sweet potato (Erpen et al, 2013), cassava (Samboranha et al, 2013), olive (Martins et al, 2014), maize (Langner et al, 2018), gladiolus (Uhlmann et al, 2017), eucalyptus seedlings (Martins and Streck, 2007), exotic forest seedlings (Monteiro et al, 2014), and guava seedlings (Ferreira et al, 2019b). However, studies of this nature are scarce in native forest species.…”

“…The WE model has been reported to be better than the Phyl model to predict developmental events in several crops, including winter wheat (Xue et al, 2004), eucalyptus seedlings (Martins and Streck, 2007), rice genotypes, red rice biotypes (Streck et al, 2011), cassava (Samboranha et al, 2013), and maize cultivars (Langner et al, 2018). However, in this study, both models predicted the dynamics of leaf development, final leaf number, and SDP time in two native forest species.…”

“…An error lower than two leaves in C. myrianthum is acceptable for practical applications and represents an error inferior than seven days. Thus, this error does not affect prediction of other processes based on CLN, including the planting date (Martins et al, 2014;Langner et al, 2018;Ferreira et al, 2019b).…”

“…In Brazil, models of development are mostly used in agricultural crops (Erpen et al, 2013;Langner et al, 2018;Streck et al, 2007Streck et al, , 2008Streck et al, , 2011Streck et al, , 2013 with little use in forest crops (Ferreira et al, 2019b;Martins and Streck, 2007;Monteiro et al, 2014). In addition, most forest commercial nurseries in Brazil do not use models of development to predict the CLN and SDP, despite their potential (Ferreira et al, 2019b;Florêncio et al, 2019;Martins et al, 2014).…”