Conyza bonariensis growth and development according to thermal time accumulation and photoperiod

Nereu Augusto Streck,Michel Rocha Da Silva,Giliardi Dalazen,Anelise Da Silva Lencina,André Da Rosa Ulguim,Thiago Schmitz Marques Da Rocha,Alencar Junior Zanon,Nelson Diehl Kruse,Giovana Ghisleni Ribas

doi:10.1590/s1678-3921.pab2020.v55.01683

Nereu Augusto Streck, Michel Rocha Da Silva + Show 7 more

Open Access

https://doi.org/10.1590/s1678-3921.pab2020.v55.01683

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Abstract

Abstract: The objective of this work was to characterize the growth and development of hairy fleabane (Conyza bonariensis) according to thermal accumulation and photoperiod, at different sowing times, and to propose a scale representing the main plant development stages. The experiment was carried out with ten replicates in the 2011/2012 growing season. The sowing dates were: 05/31/2011, 07/04/2011, 08/03/2011, 09/09/2011, and 11/07/2011. Plant height (cm) and phenology were evaluated weekly. The duration of the different stages (days) and thermal time accumulation (°C day) were determined. The linear regression analysis showed that plant height was related to thermal time accumulation. Regardless of the sowing date, the vegetative stage had a longer duration (in days and in ºC day) than the reproductive stage. Sowing on 11/07/2011 promoted the shortening of the vegetative stage, and the rosette stage did not occur. Flowering was induced in the photoperiod between 12.5 and 13.5 hours of light, regardless of the sowing date. Slow growth was observed at lower temperature conditions, when plants accumulated 30.9 and 16.3°C day per centimeter of height for the 05/31/2011 and 11/07/2011 sowing dates, respectively. The phenology scale adequately predicts the development stages of hairy fleabane.

Highlights

Hairy fleabane [Conyza bonariensis (L.) Cronquist] is a weed of the Asteraceae family whose main characteristics are high competitivity and prolificacy, producing more than 800 thousand seed per plant (Kaspary et al, 2017)
It is possible to see a wide variation of hairy fleabane plant growth, which requires a careful description of development, and a phenological scale can contribute to this
The hairy fleabane seedling and vegetative stages began when the cotyledon leaves were visible on the soil surface, described as EM to Vn stages (Table 1, Figure 2)

Summary

Introduction

Hairy fleabane [Conyza bonariensis (L.) Cronquist] is a weed of the Asteraceae family whose main characteristics are high competitivity and prolificacy, producing more than 800 thousand seed per plant (Kaspary et al, 2017). Knowledge regarding bioecology, and the growth and development characteristics of hairy fleabane are essential for more adequate and sustainable management strategies (VanGessel et al, 2009; Moreira et al, 2010a), including the choice of timing, chemical, mechanical, and physical control of more sensitive plants. Recent findings show that the sowing date influences the phenological development of hairy fleabane (Soares et al, 2017). Seed of this plant that emerged under decreasing temperature and photoperiod conditions show an increase of dry matter production and reduced flowering induction, whereas under increasing temperature and photoperiod conditions there is less accumulation of dry matter and more flowering induction (Soares et al, 2017). It is possible to see a wide variation of hairy fleabane plant growth, which requires a careful description of development, and a phenological scale can contribute to this

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