ISHS Acta Horticulturae 449: II International Symposium on Irrigation of Horticultural Crops
BRACKISH WATER AND PHYSIOLOGICAL ASPECTS OF BROCCOLI |
| Authors: | F. Boari, V. Cantore, G. Cucci |
| Keywords: | Broccoli, salinity, photosynthesis, transpiration, W.U.E. |
| Abstract:
Broccoli (Brassica oleracea, var. italica Plenck cv. Gran Vert) plants were grown in pots during the late spring period to study salinity resistance. Irrigation with eight electrical conductivity (ECw= 0.5–4–8–12–16–20–24–28 dS m-1, respectively T0, T4,T8, T12, T16, T20, T24, T28) were compared; the aqueous solutions were obtained diluting sea water with fresh water. At maximum vegetative growth leaf net CO2 assimilation rate (A), transpiration rate (T), stomatal conductance (gs), intercellular space CO2 concentration (Ci), photon flux density (PAR) and pre-dawn leaf potential (  ) were measured.
Data collected between the phenological phase of 8–10 leaves (28/5) and 15 days before the harvest (21/6) showed that A, T and gs decreased significantly with ECw higher than 12 dS m-1 while leaf senescence increased.
During this period an A reduction occurred, varying from 18 to 38% passing from T0 to T20, and 80% in the most salt stressed treatment (T28). Net assimilation reduction respect to the control, due to the salinity increase of the different treatments, during the examined period, has been meanly equal to 8 – 14 – 28 – 37 – 49 – 81 and 85 % of the control, respectively passing from T4 to T28. The water use efficiency (WUE) decreases due to salinity increase were generally lower with ECw ≤ 20 dS m-1 (20–30 % respect to the control) higher, instead, with ECw > 20 dS m-1 (50–60 % respect to the control).
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