Phyllochron and leaf appearance rate in oat

Gabriela Görgen Chaves,Daniela Barbieri Uliana,Rafael Vieira Pezzini,Bruna Mendonça Alves,Cleiton Antonio Wartha,Jéssica Andiara Kleinpaul,André Lavezo,Alberto Cargnelutti Filho,Ismael Mario Márcio Neu

doi:10.1590/1678-4499.090

Abstract

Abstract Phyllochron and leaf appearance rate are both important parameters in the production efficiency of agricultural crops. The objectives of this study were to determine the phyllochron and leaf appearance rate in 4 oat cultivars (Avena sativa L.) in 3 sowing dates and verify the variability of phyllochron and leaf appearance rate among cultivars and sowing dates. The experimental design was the completely randomized with 12 treatments and 20 repetitions. Treatments were formed by the combination of 4 cultivars (URS Charrua, URS Taura, URS Estampa, and URS Corona) and 3 sowing dates in 2014 (April 28, May 28, and July 14). In each plant (repetition) of each treatment, the number of expanded leaves (NEL) was counted 3 times per week from the first leaf emission until flowering. For each plant, cultivar, and sowing date, linear regression was adjusted between NEL and accumulated thermal time (ATT) and between NEL and number of days after emergence (DAE). Phyllochron was determined by the inverse of the angular coefficient of the linear regression between the NEL and ATT. The leaf appearance rate was determined by the inverse of the angular coefficient of the linear regression between NEL and DAE. In oat, there is variability of phyllochron and leaf appearance rate among cultivars and sowing dates. Phyllochron oscillates between 95.88 and 117.70 °C day∙leaf−1 and leaf appearance rate, between 6.41 and 9.65 days∙leaf−1. The oat cropping management in function of phyllochron and leaf appearance rate is dependent on cultivars and sowing dates.

Highlights

The oat (Avena sativa L.) belongs to the Poaceae family (Cronquist 1988)
The accumulated thermal time (ATT, in °C day) from the plant emergence date was obtained accumulating the values of DTT
Linear regression of the number of expanded leaves (NEL) in function of the ATT was adjusted for each cultivar in each sowing date, in each

Summary

Introduction

The oat (Avena sativa L.) belongs to the Poaceae family (Cronquist 1988). It is a grass with double purpose, i.e. grain and forage production, being used for human consumption and animal feed. Oat is extremely important among the winter cereals in Brazil, being the fifth most cultivated cereal (IBGE 2014). Oat presents adaptability and its multipurpose gives important contribution of this species to the sustainability of many agricultural production systems. Characterization of oat plants development is important to identify crop responses to distinct environmental stimuli during its productive cycle (Castro et al 2012)

Objectives

Methods

Results