Physiological aspects of grapevines cv. Carmem under organic and biodynamic management

Abstract

Grapevines cv. BRS Carmem (Vitis vinifera X V. labrusca) were managed in organic or biodynamic system and compared for the following photosynthetic parameters: CO₂ assimilation, Rubisco efficiency, intracellular CO₂ concentration, water use efficiency, Transpiration, and Stomatal conductance throughout a day (9, 12 and 17 h) 15 months after planting. Furthermore, length of all canes from each plant and SPAD index of leaves (chlorophyll content) were also measured. The experimental design was in randomized blocks with two treatments and six replicates with six plants per plant. All plants received the same field management (organic) and biodynamic treatment also received the biodynamic preparations: 500 (manure horn) and Fladen (soil) (100 g 70 L^-1 ha^-1), 501 (silica horn) (plant) (4g 70L^-1 ha^-1) and 502 (Achilleamille folium), 503 (Matricaria recucitata), 504 (Urtica dioeca) 505 (Quercus robur), 506 (Taraxacum officinale) (2 g 25 m^-3) and 507 (Valeriana officinalis) (2 mL 25 m^-3) in the compost. Differences in length and diameter of branches and SPAD index were observed in November, with higher values for the biodynamic treatment. Differences in Rubisco efficiency and Intracellular CO₂ concentration were observed in the evaluation at 17 h. Biodynamic treated plants showed greater Rubisco efficiency and lower intracellular CO₂ concentration, which could have as a result of lower transpiration rate and higher CO₂ assimilation, even at lower concentrations. No differences were observed between treatments for the other evaluations. Therefore, the grapevines conducted biodynamically presented an improving in photosynthetic activity.