IMPACT OF BIOFERTILISERS ON VEGETATIVE GROWTH AND LEAF GAS-EXCHANGE OF PEPPER SEEDLINGS (Capsicum annuum L.) IN ORGANIC FARMING
Published in AgroLife Scientific Journal, Volume 3, Number 1
Written by Veselka VLAHOVA, Vladislav POPOV
Biofertilisers emerged as a successful alternative to mineral fertilizers in maintaining soil fertility in organic farming. The aim of the study was to examine the impact of biofertilisation on vegetative growth and indicators of leaf gasexchange (rate of net photosynthesis, intensity of transpiration, and stomatal conductance) of pepper seedlings. An experiment was carried out in 2009-2011 in a polyethylene greenhouse at the biological farm at the Agroecological Centre at the Agricultural University-Plovdiv. It included pepper variety 'Sofiiska Kapiya' and selected biofertilizers that were tested for their effectiveness, i.e. Seasol (Earthcare), applied on two basic fertilisations- Boneprot and Lumbrical. The biofertilisers’ active substances fall in the list of allowed soil fertility additives according to Regulation (EC) No. 889/2008. The results from the biometric measurements of pepper seedlings (plant height and number of leaves) showed the highest values for the variant fed with the combination of biofertiliser Seasol applied on the basic fertilisation with Boneprot (2009, 2011). The positive impact of this combined application was shown by the higher rate of net photosynthesis (2010, 2011) in comparison to the single application of the basic fertilisation with Boneprot. An overall improvement of the physiological status of the seedlings was observed. The highest value of the the intensity of the transpiration was observed for the treatment with optimum concentration of basic fertilisation with Lumbrical (2010, 2011). The stomatal conductance had a high value upon combined application of biofertiliser Seasol on the basic fertilisation with Lumbrical (2009, 2010). The highest values of stomatal conductance were observed in the treatments, which showed also a maximum intensity of transpiration that can be attributed to the supply of nutrients in easily accessible form with the liquid biofertiliser Seasol and its good combination with basic biofertiliser applications.