Growth potential of basal and aerial tillers: ecological significance of responses and management implications

• Grant number: 16/09719-6
• Support Opportunities: Scholarships abroad - Research
• Start date: November 03, 2016
• End date: September 02, 2017
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Lilian Elgalise Techio Pereira
• Grantee: Lilian Elgalise Techio Pereira
• Host Investigator: Cory Matthew
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Institution abroad: Massey University, New Zealand

Abstract

Tropical perennial grasses are able to change their growth through adjustments and changes in perennation pathways, i.e. basal and aerial tillering. Increases in aerial tillering appears to be a means to maximize the number of tillers per integrated physiological unit (IPU) when swards are subjected to restrictive growth condition that impair increases in the number of IPU's per unit area through basal tillering. The importance of such changes in growth strategy and their ecological consequences for tussock-forming grasses are only slightly discussed in the literature. The objective of this study is to compare the growth potential of basal and aerial tillers in three important tropical forage grasses: marandu palisade grass, mulato grass and Napier elephant grass. The strategy is based on the combined analysis of their morphogenetic and structural characteristics, data having being collected in conformable experiments using analogous experimental protocols. The data set to be used was generated in rotational grazing experiments carried out from December 2004 to April 2012 at E.S.A. 'Luiz de Queiroz' (ESALQ), University of São Paulo, Piracicaba, SP, Brazil. Canopy light interception during regrowth was monitored using a LAI 2000 canopy analyzer. Morphogenetic and structural characteristics of individual tillers were obtained from tillers specifically marked for that purpose. Monitoring was performed throughout the entire regrowth period, during all grazing cycles, and data were grouped into two seasons: late spring (November-December) and summer (January-March). The exercise will provide the opportunity to comprehend: (1) if the growth potential of basal and aerial tillers is similar for the different grass species; (2) if not, what are the differences and what is their biological and ecological meaning and (3) if growth potential of each tiller category is affected by the manipulation of the light environment within the sward through manipulation of defoliation frequency (i.e. grazing management). As a result, the relationship between growth mechanisms, growth potential of basal and aerial tillers and the plant's persistence strategy can be explored. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

TECHIO PEREIRA, LILIAN ELGALISE; PAIVA, ADENILSON JOSE; GEREMIA, ELIANA VERA; DA SILVA, SILA CARNEIRO. Contribution of basal and aerial tillers to sward growth in intermittently stocked elephant grass. GRASSLAND SCIENCE, v. 64, n. 2, p. 108-117, APR 2018. (16/09719-6)