Abstract

The increasing availability of low-cost and reliable substrate moisture sensors offers interesting perspectives for rational and automatic rrigation management of soilless greenhouse crops and for research on plant water relations. The knowledge of the effects of different substrate volumetric water content (VWC) levels on plant growth is crucial for the determination of proper irrigation set-points. An experiment was conducted to assess the effects of different VWC levels on soilless tomato growth and water relations. Tomato plants were grown in a greenhouse in perlite bags. An automatic irrigation system used substrate moisture sensors to control irrigation solenoid valves, in order to keep growing media at four different VWC levels (0.15, 0.20, 0.25 and 0.30 m3?m-3). The system was able to get the substrate VWC at the desired different set-points. Substrate water potential was monitored during the experiment using tensiometers. The four VWC levels resulted, respectively, in a mean substrate water potential of -130, -101, -42 and -34 hPa. Plant growth was similar for plants grown at 0.30 and 0.25 m3?m-3 in terms of leaf area, fresh and dry weight, with higher values than plants grown at 0.20 and 0.15 m3?m-3. Plant water status was affected by the VWC level in the substrate, with higher and similar values of total leaf water potential for plants grown at the two highest VWC levels thanthose grown at lower VWC. The most severe effects of water stress were observed on plants grown at 0.15 m3?m-3 which showed the lowest leaf relative water content (respectively 64.4% vs 84.8% at higher VWC levels) and membrane stability index (respectively 68.6% vs 83.9% at higher VWC levels). The water retention curve and hydraulic conductivity analysis performed on the perlite substrate used in this experiment revealed little or no available water below a VWC of about 0.15 m3?m-3. However, plants grown at 0.15 m3?m-3, were able to uptake water from the growing media and thus to survive, although showing reduced growth and symptoms of water stress. Results seem to confirm that soilless growing media generally hold easily available water in a matric potential range from 0 to -100 hPa, with the majority of free available water present between matric potentials of 0 to -50 hPa.

Autore Pugliese

• Parente Angelo , Boari Francesca , Montesano Francesco Fabiano , Cantore Vito

Tutti gli autori

• A. Parente; M.W. Van Iersel; F. Boari; V. Cantore; F.F. Montesano

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2015

ISSN

Non Disponibile

ISBN

2-85352-549-X

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

Non Disponibile

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile