DOI: 10.25829/bexis.26586-5
title: Trifolium pratense regrowth measurements on test field 2017

description: Plants are exposed to various biotic and abiotic factors which they cannot evade due to their sessile nature. Therefore, they adapt their growth behaviour to local environmental constraints leading to phenotypic variation owing to their open bauplan. A major factor inducing phenotypic plasticity is the loss of biomass through herbivory or cutting. The Fabaceae Trifolium repens reacts to cutting by producing more but smaller leaves compared to uncut plants. As T. repens is a common fodder plant this effect might be of agronomical importance, as repeated cutting could reduce the amount of harvested biomass. A close relative to Trifolium repens, Trifolium pratense L. (red clover), is used in many parts of the world as high-quality fodder plant due to its naturally high protein content and its deep root systems and high yield which give T. pratense preference over T. repens. It is grown in monocultures or in a grass mixture where it increases the nitrogen content of the surrounding plants. In a previous study, phenotypic plasticity of red clover during regrowth after cutting/mowing was analysed in a common garden experiment. After cutting, red clover produces, similar to T. repens, more leaves than uncut plants but they are of the same size than before cutting. Only the length of newly formed petioles is reduced when compared to uncut plants.
description: Theory: Here, we investigated the native response of wild red clover plants to cutting and how different mowing regimes influence leaf morphology. Specifically, we asked the questions (i) if it is possible to transfer the results of the common garden greenhouse experiment from Herbert et al. (2018) to the common practice field experiment, (ii) whether and how plants compensate cutting losses during regrowth, (iii) if different mowing regimes influence the harvested biomass, (iv) whether nitrogen content, as a marker for protein content and food quality, differs in the leaflets after mowing. We grew T. pratense plants on 36 plots (each 6 m²) in monocultures on a test field in Rauischholzhausen. Each plot belonged to one of 12 mowing regimes, differing in number and time points of mowing. Control plots (1) were not mown, whereas all other plots (2-12) were mown 1-3 times per year. D. B. Herbert, K. Ekschmitt, V. Wissemann, A. Becker (2018): Cutting reduces variation in biomass production of forage crops and allows low‐performers to catch up: A case study of Trifolium pratense L. (red clover). Plant Biology 20 (3): 465-473. |Measurements Type: Morphological data (plant height, number of inflorescences, leaflet length, leaflet width).|instruments: Plant height, leaflet length and width were measured with rulers.|procedures: The phenotypic measurements were performed 19-20 days after mowing. Per plot 10 randomly chosen plants were used for phenotypic measurements. Plant height was measured from ground to top of the shoots. Per plant, 5 leaflets were measured. The middle leaflet was used for length and width measurements. Leaflet length and width were measured in the middle of the respective leaflet. |