Impact of treated wastewater irrigation on quality attributes and contamination of tomato fruit
O. Al-Lahham, N. M. El Assi and M. Fayyad
Agricultural Water Management. Volume 61, Issue 1 , 6 June 2003, Pages 51-62.
2003
บทคัดย่อ
A field experiment was conducted in 1999 and 2000 to investigate the effect of different treatments of potable and treated wastewater on the quality of tomatofruit(Lycopersicon esculentum L. Mill) in Jordan. Tomato seedlings (cvs. GS12 and RS589956) were furrow irrigated with different mixtures of potable and wastewater (1:0, 1:1, 1:3, and 0:1). The BOD, and SS of the treated effluent used were 34 and 35 mg/l, respectively. Irrigation with treated wastewater did not affectfruitpH, increased their size up to 2 cm in diameter, and weight up to 78.7 g. Additionally, a decrease of 1.5% in the SSC, 0.59 kg in firmness, and 5.1% inweight lossof tomatofruitwere recorded. The 0:1 application of treated wastewater resulted in an increased microbial contamination (TC 1.56×104 and 4.7×102 CFU/100 g; FC 3×102 and 130 CFU/100 g; TBC 188×102 and 205×102 CFU/100 g) on the surface of thefruit(skin) for GS12 and RS599956 varieties, respectively. There was a negligible contamination onfruitscar, and nil infruit flesh. Contamination increased exponentially with increasing the proportions of treated wastewater application. Since treated wastewater was highly contaminated with total coliform (up to 42.0 CFU/100 ml) and total bacterial count (up to 7.820 CFU/100 ml), hence, contamination was aggravated with increasing the percentage of treated wastewater. It is suggested that the treated wastewater can be used as an alternative for irrigation of tomatoes eaten after cooking, but not for those taken as raw provided that the effluent quality is continuously monitored to avoid contamination.