Cardinal temperatures and modeling of vegetative development in guava

Abstract

The aim of this study was to estimate cardinal temperatures (base, optimum, and maximum), and simulate the vegetative development of guava crop through phyllochron (linear) and Wang and Engel (nonlinear) models at the seedling phase. The experiment was conducted in Itajubá, MG, Brazil (22° 24’ 46.43” S 45° 26’ 48.94” W), for two years in a completely randomized design with twelve sowing dates and five experimental units per treatment, totaling sixty experimental units. The cardinal temperatures were estimated using twelve methods described in the literature and the values were: base, 10.9 °C, optimum, 17.3 °C and maximum, 51.2 °C. The phyllochron model was superior to Wang and Engel’s model for simulation of vegetative growth of guava, with root mean square error of 1.5 leaves.

Agrometeorological models for predicting seedlings development of two native forest species

“…and B. orellana L., cultivated in 8.0 L white polyethylene pots in 12 sowing dates (SD) (Table 1) performed at 30-day intervals and five replications (replication = pot), or 10 pots per SD. The wide range of SD was selected to have plants developing under different meteorological conditions, especially temperature (Figures 1A and 1B), important for model calibration and evaluation (Ferreira et al, 2019b;Martins et al, 2014). The SD were divided into two groups: the first (SD1 to SD5) was used to calibrate the model coefficients (see details in item "calibrating the model coefficients") and the second (SD6 to SD12) was used to evaluate the models performance (see details in item "evaluating models").…”

“…Seedling quality assessment has evolved to include dynamics of leaf development as a definition of seedling performance. In these sense, models of development are an important tool to predict the dynamics of leaf development, including seedling phase duration (SPD), and to provide quantitative information to support decisions of nursery management at field scale (Ferreira et al, 2019b;Freitas et al, 2017;Martins et al, 2014). Models of development allow obtaining the cumulative leaf number (CLN) on the main stem and SPD through the relationship between the leaf appearance rate (LAR) and air temperature function (f(t)) (Ferreira et al, 2019b;Martins and Streck, 2007).…”

“…In these sense, models of development are an important tool to predict the dynamics of leaf development, including seedling phase duration (SPD), and to provide quantitative information to support decisions of nursery management at field scale (Ferreira et al, 2019b;Freitas et al, 2017;Martins et al, 2014). Models of development allow obtaining the cumulative leaf number (CLN) on the main stem and SPD through the relationship between the leaf appearance rate (LAR) and air temperature function (f(t)) (Ferreira et al, 2019b;Martins and Streck, 2007). Air temperature is the main abiotic factor in forest development (Freitas et al, 2017;Rawal et al, 2015), including native forest species (Ferreira et al, 2019a, b;Monteiro et al, 2014).…”

“…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). Since few studies of this nature have been conducted on native forest species, besides the lack of a development model for C. myrianthum Cham.…”

Soil fertility and yield of ‘Paluma’ guava fertilized with phosphorus, cattle manure, and boron

“…'Paluma' guava is a perennial crop in the Myrtaceae family. The fruits have a sweet, acidified flavor with a pleasant aroma, the main reason for their great variety of products, uses, and forms of consumption (Ferreira et al, 2019). The Southeast and Northeast regions of Brazil stand out as the largest guava producers in the country, being responsible, respectively, for 47.40 and 39.9% of national production, approximately 359.30 thousand t of fruit in a harvested area of 15.8 thousand hectares (Bezerra et al, 2018) Thus, this experiment aimed to evaluate the effects of phosphorus doses in the absence and presence of cattle manure and boron on soil fertility and on the yield of 'Paluma' guava under irrigation with saline water.…”