Influence of cutting frequency on the morphology and the C and N reserve status of two cultivars of white clover ( Trifolium repens L.)

• Published in: European journal of agronomy 2004, Vol.20 (4), p.341-350
• Main Authors: Simon, J.C., Jacquet, A., Decau, M.L., Goulas, E., Le Dily, F.
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Agronomy. Soil science and plant productions; Biological and medical sciences; Defoliation; Fundamental and applied biological sciences. Psychology; Growing points; Leaf area; Life Sciences; Starch; Vegetative storage proteins (VSP)
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/S1161-0301(03)00042-X

The influence of cutting frequency was studied on white clover ( Trifolium repens L.) cultivars (giant-Aran and dwarf-Rivendel) during two experiments set up under field conditions. Clover morphological and biochemical characteristics were measured prior to regrowth in response to various cutting interval treatments (1, 2, 3, 6 and 8 weeks of regrowth between two successive defoliations). The morphology of the aerial parts of the plant was described through the residual leaf area (RLA), the number of total growing points (TGP), stolon length and stolon and root dry matter productions per unit of cultivated area, as well as stolon dry weight per unit length. C and N reserve status was assessed by starch and vegetative storage proteins (VSP) concentration and amount measurements. Cutting frequency largely influenced the different variables. RLA and TGP increased in response to frequent cuttings while all other morphological and biochemical parameters decreased, with the exception of the soluble protein concentrations and protein amounts. Nevertheless, a significant difference in morphology and C and N reserve accumulation was shown between the two clover cultivars. In spite of a few number of leaves and growing points, the giant cultivar Aran showed higher C and N reserves, compared with the dwarf type Rivendel. However, the genetic expression of these differences was tightly linked to the cutting frequency applied to the sward, and was at its maximum in response to the most frequent treatments. Subjected to severe cuttings, both genotypes showed an increase in RLA and TGP, the greater effect of the treatment was obtained with the dwarf-type Rivendel. Frequent defoliations strongly reduced organic reserves but the cutting-induced decreases observed in starch and VSP contents were similar for each cultivar. Overall results confirmed that the morphological development of clover, partly defined by genetic performance, should also be controlled by cutting frequency, and highlighted a tight relationship between morphogenesis, reserve accumulation and sward management. Results are also discussed in terms of the use of C and N reserve contents as a further characterisation of white clover cultivars.