Rm. Stevens et al., Irrigation of grapevines with saline water at different growth stages - 1.Effects on soil, vegetative growth, and yield, AUST J AGR, 50(3), 1999, pp. 343-355
Mature field-grown grapevines, Colombard on Ramsey rootstock, grown in a se
mi-arid climate were irrigated with saline water during any one of 4 growth
stages within the season: pre-flowering, during berry development, during
berry ripening, and post-harvest. At other times, plots were irrigated with
river water (EC 0.5 dS/m) as was the control throughout the season. Saline
water (EC 3.5 dS/m) with a high sodium absorption ratio was produced by ad
dition of sodium chloride brine. Soil cation exchange capacity was 14 cmol(
c)/kg, and at the end of the trial, the soil exchangeable sodium percentage
in the control was 6%, in the treatment salinised pre-flowering 13%, durin
g berry development 20%, during berry ripening 20%, and post-harvest 19%. T
reatments were applied for 6 consecutive seasons. Vines were highly product
ive, with the average yield in the control equal to 62 t/ha of grapes. Sali
ne irrigation caused significant, but small, declines in yield in 3 seasons
, in pruning weights in 2 seasons, and in berry weights in 4 seasons. Effec
ts on growth, once established, often persisted unchanged through one or mo
re subsequent seasons of saline irrigation. The growth stage shown to be mo
st sensitive to saline irrigation was berry development; saline irrigation
during berry development reduced the yield by 7% and during berry ripening
by 3%, and pre-flowering it reduced the berry weight by 1%, during berry de
velopment by 6%, and during berry ripening by 4%. The amounts of irrigation
applied in each of the 4 growth stages were not equal, and hence, treatmen
ts did not receive equal additions of salt. Normalising data to remove this
effect showed that the rate of yield decline per unit dS/m increase in the
seasonal average salinity during berry development, 7%/dS.m, was 3-fold gr
eater than the 2%/dS.m during berry ripening. We conclude that this scion/r
ootstock combination, grown under these conditions, can maintain high produ
ctivity despite 'slugs' of saline irrigation.