Effect of four irrigation rates on growth of six fig tree varieties

The fig tree is an attractive fruit crop for and zones because of its tolerance to water deficit. However, there is very little information about its water requirements. A trial was conducted to determine the response of 4(th) leaf fig trees, in six varieties, to four irrigation rates in relation to estimated crop evapotranspiration (ETc), adapted for young trees and based on,Class A" pan evaporation data. The irrigation treatments were TO (not irrigated), T25 (25% ETc), T50 (50% ETc) and T100 (100% ETc). Rainfall in the region was 37 mm in the year of the study. The varieties were Brown Ischia (BI), Brown Turkey (BT), Kadota (K), Kennedy (KE), Larga de Burdeos (LB) and Royal Vineyard (RV), planted at 6 x 4 m. Significant differences in TCSA increase were observed in some treatments, except for var. BI and RV. Variety BT under T100 increased twice as much as under T50. In variety K, only TO was different from T25. Regarding foliar area, significant differences were found only in varieties RV and LB, but in all others a good correlation between foliar area and TCSA increase, shoot length and leaf number was observed. In relation to shoot length only varieties BI and RV showed differences among treatments: T100 was significantly different to TO and T25. In all treatments a good positive correlation between irrigation rate and shoot length was found. In xilem water potential, differences between TO and T25, T50 and T100 were observed, but not between T50 and T100. In most varieties no differences between treatments in relation to phenological phase length were found. Most parameter showed no difference between T50 and T100. In conclusion, in the trial area, it's possible to irrigate 3-year old rig trees with 220 mm/year (2,200 m(3)/ha-year), equivalent to 17% of,Class A" pan evaporation.