Quality characteristics of Burley tobacco irrigated with saline water

The effect of irrigation with saline water on quality of Burley tobacco (cv. C 104) was investigated in Southern Italy over four consecutive years. A rainfed control (RC) was compared with treatments irrigated with volumes equal to crop evapotranspiration of saline waters at 0.5 (NW), 2.5 (SW1), 5 (SW2) and 10 (SW3) dSm1 electrical conductivity (ECw). In 2000 and 2001 an additional salinity treatment (15 dS m1 ECw) was included (SW4). The amounts of Cl added to the soil by irrigation ranged from 36.3 kg ha1 (good quality water in 1999) to 16.2 Mg ha1 (saline water at 15 dS m1 ECw in 2000). Saline irrigation did not affect yield and yield components of cured leaves. In 1998 and 1999 the filling power of Burley tobacco did not change significantly with increasing salinity of the irrigation water. In 2000 and 2001 the filling power of SW2, SW3 and SW4 treatments was significantly less than that of NW. The Cl content of tobacco grown with SW2 was significantly greater than that grown with NWand there were no differences between SW1 through SW4 treatments. The filling power and the leaf Cl content were inversely related to the amount of Cl applied in the range between 40.3 kg ha1 and 5.1 Mg ha1. The filling power decreased and Cl increased up to the SW2 treatment; beyond that level neither Cl nor filling power changed in response to increasing amounts of Cl applied. The leaf alkaloid content was unaffected by salinity. Total N was unaffected by either the growing season or the saline treatments. Cigarettes obtained from saline treatments did not burn during the smoking test in 1998. In 1999 cigarettes made from SW1 and SW2 did burn, but those from SW3 did not. In 2000 and 2001 the smoking test was performed only on commercial blends containing 10 or 30% of cut tobacco from saline treatments and both blends burned similarly to cigarettes made entirely from tobacco grown under non-saline conditions. In conclusion, quality of Burley tobacco was unaffected by irrigation with saline water at 2.5 dS m1 and the inhibitory effect of salinity on burning properties could be overcome by appropriate mixture in commercial blends.