|DI GIOIA, FRANCESCO - National Center For Agriculture And Forestry Technologies (CENTA)|
|LEONARDI, CHERUBINO - University Of Catania|
|GIUFFRIDA, FRANCESCO - University Of Catania|
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2017
Publication Date: 3/13/2018
Citation: Di Gioia, F., Rosskopf, E.N., Leonardi, C., Giuffrida, F. 2018. Effects of application timing of saline irrigation water on broccoli production and quality. Agricultural Water Management. 203:97-104.
Interpretive Summary: Salt water intrusion is increasing in prevalence throughout the Mediterranean Basin and in Florida vegetable production regions. Irrigation with moderately saline water is becomingly a necessity in some locations. Irrigation management strategies must be adapted to incorporate the use of moderately saline irrigation water. The changes in yield and quality associated with the use of saline irrigation water can be dependent upon the sensitivity of the crop. Broccoli (Brassica oleracea var. italica), a crop moderately tolerant to salinity stress, was used to evaluate the effects of the application of saline (S) and non-saline (NS) irrigation water during two growth phases in terms of plant growth, water status, floret yield, glucosinolate profile, and quality. Application of saline irrigation water prior to appearance of the inflorescence had a major impact on dry weight accumulation of broccoli heads. Application of moderately saline water after inflorescence formation had a much less pronounced effect on yield, although application of saline irrigation water at any time had a negative effect on yield and caused a shift in the type of glucosinolates produced.
Technical Abstract: Irrigation with moderately saline water is a necessity in many semi-arid areas of the Mediterranean Basin, and requires adequate irrigation management strategies. Broccoli (Brassica oleracea var. italica), a crop moderately tolerant to salinity stress, was used to evaluate the effects of the application of saline (S) and non-saline (NS) irrigation water during two growth phases in terms of plant growth, water status, floret yield, glucosinolate profile, and quality. Use of S-water (4 dS m-1) from transplanting to appearance of the inflorescence, alternated with NS-water (2 dS m-1) from inflorescence appearance to harvest and vice versa were compared with continuous use of S- or NS-water. Irrigation with S-water during the first growth-phase decreased leaf water and osmotic potential, net CO2 assimilation rate, and favoured Na+ and Cl- accumulation at toxic levels causing ion imbalances and reducing broccoli plant growth. Application of S-water exclusively after inflorescence appearance caused only a 22.2% decrease of the head dry biomass compared to NS-NS plants. Regardless of application timing, irrigation with S-water decreased broccoli yield and head mean fresh weight compared to NS-NS plants by 20% and 24%, respectively. Use of S-water in one or both growth stages improved broccoli dry matter and soluble solid content, while had no impact on total glucosinolate concentration. However, application of S-water during the first growth-phase resulted in an increase of indolic glucosinolates (glucobrassicin and neoglucobrassicin) and potential effects on broccoli nutritional properties and flavour.