Water Use and Water Use Efficiency of Eucalypt Clones Planted on Paddy Bunds in Phanom Sarakham District, Chachoengsao Province

Abstract

A study on water use and water use efficiency of trees from the K7, K51 and K58 eucalypt clones planted on paddy bunds was carried out at Phanom Sarakham district, Chachoengsao province. Diameter at breast height (DBH), total height (H) and water use were determined at two-monthly intervals, over the period when the trees were one to three years old. Daily and annual water use and water use efficiency of the 1,2 and 3-year-old eucalypts were also evaluated.

Daily water use of the 1, 2 and 3-year-old eucalypts gradually increased in the morning and peaked from noon into the afternoon, then decreased in the evening and was lowest during night time. Annual water use tended to increase with tree growth. For the 2-year-old eucalypts, the water use of all clones was high during May-September and low during November-March. In contrast, the 3-year-old eucalypts used more water during November-January and less during March-May. Clone K7 tended to have the highest rate of water use (4,068.58 L/yr). However, clone K58 showed the highest water use efficiency in terms of both economics (WUE_WS) and biology (WUE_WT) with values of 8.78 and 11.87 g/L, respectively.

Keywords:  water use, water use efficiency, eucalypt, clone, paddy bund