Influence of rootstocks on Navel orange yield and tree growth at Mildura, Victoria

Abstract

Two experiments with Navel orange scions (CV. Washington and Leng) on a number of rootstocks were done on three sandy Mallee soils in the Mildura irrigation district. Rootstocks included sweet orange (eight cultivars), rough lemon, mandarin (two cultivars), trifoliate orange, and citrange (two cultivars). In experiment 1 (1949 to 1963) eight sweet orange rootstocks gave similar results in terms of yield and tree size. Leng produced more but smaller fruit than Washington, but total weights were similar. In experiment 2 (1959 to 1969 and continuing) Leng trees were larger, produced more fruit, and on one soil a greater weight of fruit per tree than Washington. Sweet orange rootstocks were usually superior to other rootstocks on each soil type, although rough lemon gave results that were similar and, for a few combinations, superior. Trees on mandarin rootstocks were low producers and small in the early part of the experiment, but by the end of the period were yielding as much fruit as those on sweet orange. Trifoliate rootstocks were unsatisfactory, and citrange intermediate between sweet orange and trifoliate. No fruit quality differences ascribable to rootstock were detected.