AN EXPERIMENTAL COMPARISON OF GROWING MEDIA, PETUNIA QUALITY AND AMOUNT OF WATER APPLIED - AN OPPORTUNITY FOR WATER SAVING?

P. Alexander, R. Williams, I. Nevison
With increasing pressure to improve the sustainability of production, UK professional and amateur growers need sound advice regarding water management in different types of growing media but especially newer peat-reduced and peat-free products. Our understanding of water relations in peat, built up over many years of practice and research, needs to be matched for all of the peat alternative materials being used in growing media. This experiment examined the performance of Petunia multiflora ‘Frenzy Blue’ when grown in four commercially available products (based on either peat, coir, wood fibre or green compost). Five different irrigation regimes, determined by regulated deficit irrigation over the preceding 24 hour period, were studied. The control watering treatment replaced the water lost in this period while the other application rates increased or decreased that amount by 25% and 50%. Dry biomass and plant quality were recorded. Results indicated that, in terms of dry biomass across all irrigation regimes, coir- (P<0.001) and green compost- (P<0.05) grown plants were significantly larger than those grown in peat and wood fibre. Similarly, mean plant quality scores across all irrigation regimes were significantly higher for coir- (P<0.001) and green compost- (P<0.05) grown plants than those grown in peat and wood fibre. It was also evident that the mean quality score was significantly higher (P<0.05) for those plants receiving 100%, 125% or 150% evapotranspiration potential (ETp) compared to 50% and 75% ETp. Whereas plants grown in the green compost-based medium at 100% ETp were of similar or better quality than all other treatments, water use was substantially lower in some cases. For example, production in the green compost-based medium at 100% ETp used eight litres per pot less water over the course of the experiment than in the coir-base medium at 150% ETp but produced plants of comparably high quality. It would appear that, with careful selection of growing media and a detailed understanding of the plant’s water requirement, there is potential for appreciable water saving in plant production.
Alexander, P., Williams, R. and Nevison, I. (2014). AN EXPERIMENTAL COMPARISON OF GROWING MEDIA, PETUNIA QUALITY AND AMOUNT OF WATER APPLIED - AN OPPORTUNITY FOR WATER SAVING?. Acta Hortic. 1034, 211-218
DOI: 10.17660/ActaHortic.2014.1034.25
https://doi.org/10.17660/ActaHortic.2014.1034.25
regulated deficit irrigation, coir, green compost, wood fibre, peat
English

Acta Horticulturae