Growth and development of sourgrass based on days or thermal units

Planta Daninha

B.s. Marques¹  A.p.p. Silva¹  R.s.o. Lima¹  E.c.r. Machado¹  M.f. Gonçalves¹  S.j.p. Carvalho¹ 

[1] ,Instituto Federal do Sul de Minas GeraisMachado MG ,Brasil

关键词: Digitaria insularis;    growing degree days;    phenology;    dry matter;    biology;    Digitaria insularis;    graus-dia;    fenologia;    matéria seca;    biologia;   

DOI  :  10.1590/S0100-83582014000300003

来源: SciELO

【 摘 要 】

This work was carried out with the objective of evaluating growth and development of sourgrass (Digitaris insularis) based on days or thermal units (growing degree days - GDD). Two independent trials were developed aiming to quantify the species' phenological development and total dry matter accumulation in increasing or decreasing photoperiod conditions. Plants were grown in 4 L plastic pots, filled with commercial substrate, adequately fertilized. In each trial, nine growth evaluations were carried out, with three replicates. Phenological development of sourgrass was correctly fit to time scale in days or GDD, through linear equation of first degree. Sourgrass has slow initial growth, followed by exponential dry matter accumulation, in increasing photoperiod condition. Maximum total dry matter was 75 and 6 g per plant for increasing and decreasing photoperiod conditions, respectively. Thus, phenological development of sourgrass may be predicted by mathematical models based on days or GDD; however, it should be noted that other environmental variables interfere on the species' growth (mass accumulation), especially photoperiod.

【 授权许可】

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