Evaluation of rootstocks for five lemon scions in replant ground

Abstract

In an experiment planted in 1971 at the Horticultural Research Station, Somersby, N.S.W., nucellar lemons (Lambert and Taylor Eureka, Villafranca and Prior Lisbon) and 1 old-line cultivar carrying exocortis (Monroe Lisbon) were compared on 5 rootstocks (Troyer citrange, Narara Rough lemon, Rangpur lime, Smooth Seville and trifoliate orange). In the second experiment, planted in 1973, 2 nucellar lemon scions (Taylor Eureka and Prior Lisbon) were compared on 16 rootstocks (4 Rough lemons, 4 Smooth and 1 Rough Seville, New Guinea citron, citremon 1449, Poorman orange, 3 citranges and trifoliate orange). Eureka lemon selections on Troyer citrange and trifoliate orange rootstocks exhibited symptoms of yellow ring incompatibility. Eureka lemon, however, was compatible with Benton citrange; cumulative yield and cropping efficiency were high and tree canopies dense and compact. Trees on Narara and Watkins selections of Rough lemon had high cumulative yields but their size and vigour made harvest difficult. One of the red Rough lemon selections (57-228-502) produced a high yielding and more manageable compact tree with a large proportion of summer crop fruit. Prior Lisbon lemon on trifoliate orange was a medium-sized, compact tree with high cropping efficiency and good juice quality. Villafranca performed well on all rootstocks except Smooth Seville. The results are discussed with respect to planting densities, proportion of summer and main crop fruit and juice yield and quality.