Agricultural University, BG-4000 Plovdiv, Bulgaria
KIROVSKY, P., 2003. A Study on the physiological status of in vitro-produced grapevine plants during adaptation in reused organic substrates. Bulg. J. Agric. Sci., 9: 59–63
In the period 2001–2002, a study was conducted to establish the feasibility of two– or three-time use of an organic substrate containing: soil – 5%, farmyard manure – 5%, flax shavings – 15%, sand – 5%, rice husks – 20% and a compost made from grapevine canes, rachises and seeds – 50% in the adaptation of an in vitro produced Vitis berlandieri X V. riparia rootstock. The rates of photosynthesis, transpiration and stomatal conductance were determined. The shoot growth dynamics was monitored and the main substrate reserves of nutrients and organic matter were estimated.
In terms of the main physiological processes, no great differences were established between grapevines grown by the first- and second use of the substrate. No significant differences were either established in their pigment contents and the acclimatization period duration. At the third use of the organic substrate, however, a significant reduction in the contents of nitrogen, phosphorus, potassium and organic matter was observed, accompanied by decreased rates of shoot growth, photosynthesis, transpiration and stomatal conductance. The adaptation period duration in both experimental years was extended by 15–17 days.