&lt;b&gt;Defoliation patterns and tillering dynamics in Italian ryegrass under different herbage allowances

Larissa Arnhold Graminho,Marcela Machado,Luciana Pötter,Marta Gomes Da Rocha,Aline Tatiane Nunes Da Rosa,Tuani Lopes Bergoli

doi:10.4025/actascianimsci.v36i4.24021

<b>Defoliation patterns and tillering dynamics in Italian ryegrass under different herbage allowances

Larissa Arnhold Graminho, Marcela Machado + Show 4 more

Open Access

https://doi.org/10.4025/actascianimsci.v36i4.24021

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Abstract

This work was carried out in order to generate information on the tillering process and to contribute for the understanding of the defoliation process on Italian ryegrass (Lolium multiflorum Lam.) grazed by lambs under different herbage allowances: 6, 8 and12 kg of dry matter per100 kg of animal live weight per day. The grazing method was intermittent. The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two area replications. The intensity of defoliation is greater at 6 and 9% herbage allowances. The defoliation interval is higher at 12% herbage allowance, intermediate at 9% and lower at 6%. The rates of tiller emergence, survival and death, stability index the tiller population are similar for the different herbage allowances and differ according to the phenological stage of ryegrass. Structural changes caused by canopy management with low herbage allowance and/or due to the advance in developmental stage of ryegrass alter defoliation strategies, with more intense and frequent grazing.

Highlights

In recent years, studies on forage crops have sought to relate plant response to management, based on criteria associated with abundant biomass, such as herbage allowance
There was no interaction between herbage allowance and phenological stage for the defoliation intensity of leaf blades (p = 0.3225)
There was a difference between herbage allowances for defoliation intensity (p = 0.0544)

Summary

Introduction

Studies on forage crops have sought to relate plant response to management, based on criteria associated with abundant biomass, such as herbage allowance. This allowance plays an essential role in animal performance and in the productive response of pastures; depending on its value, it can influence the defoliation process by altering canopy structure. According to Lemaire et al (2009), the amount of herbage removed results from the growth rate of new plant tissue and the efficiency of the harvesting process. Knowledge of the defoliation process allows management with greater harvesting opportunities and improved efficiency of produced herbage

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Conclusion