July 2, 1920.] Agricultural Gazette of N.S.W, 619 



Thompson's Improved and Navelencia 



Oranges* 



W. J. ALLEN and W. le GAY BRERETON. 



During tlie past two years there has'been some discussion as to the identity 

 of Thompson's Improved and Navelencia oranges. The United States is 

 the country of origin of both varieties. Describing them, a report received 

 from the United States Department of Agriculture says : " The Thompson 

 strain (frequently called Washington Improved or Thompson's Improved) 

 has been extensively propagated commercially, and is generally recognised in 

 California as an established variety." Then follows strong evidence that 

 the Thompson strain is a sport from the Washington Navel — in other words, 

 a strain of the Washington : — 



The trees of the Thompson's strain [Thompson's Improved] are heavy and regular 

 bearers, have an open and drooping habit of growth, dense foliage and large dark green 

 leaves. As a rule the trees of this strain are not as vigorous growers as those of the 

 Washington under similar conditions. The fruit is similar in shape and size to that of 

 the Washington. It differs mainly in having a very smooth rind of a bright reddish 

 orange colour. The rind of the Thompson's fruit is thinner, and the rag more abundant 

 and coarser than that of the fruit of the Washington. The smooth texture, bright reddish 

 colour and handsome appearance of the fruit is of distinct value from the market 

 st.-!,dpoi' t. The juice usually is less acid than that of the Washington, and is lacking 

 somewhat in flavour. The undesirable characteristic of the rag, and the inferior quaUty 

 0^ the juice are detrimental to the reputation of the fruit of this strain [Thompson's 

 Improved]. The fruit is seedless, and the navel variable in size and arrangement, 

 usually medium to small, occasionally rudimentary. 



The Navelencia is a name which has sometimes been given to the navel strain of the 

 Valencia variety. The trees have habits of growth and production similar to those of 

 the Valencia. The foliage is usually rather dense, the leaves are small and rather pointed 

 in shape. 



The typical fruit resembles the fruit of the Valencia in shape, size and colour, but 

 differs from them in having a smoother texture of skin, thinner rind, more acid juice, 

 feM-er seeds, and a small, often rudimentary navel. This strain occurs occasionally as 

 individual fruit and limb sports in trees of the Valencia. It has been isolated in com- 

 mercial propagation, and is grown to a limited extent under the name of Navelencia. 



This strain is especially interesting from the fact that there is a possibility of isolating 

 from it by bud selection a seedless strain of Valencia. 



The foregoing descriptions can be taken as authentic, as they not only 

 come from the country of origin of both varieties, but also after a very 

 thorough research of bud variation by the United States Department of 

 Agriculture, both in the Washington Navel and Valencia oranges. From 

 them we must conclude that, in by far the greatest number of cases, trees 

 planted in New South Wales under the name of Navelencia have actually 

 been Thompson's Improved. 



In New South Wales Thompson's Imjoroved has proved to be of inferior 

 flavour to Washington. It is earlier and is very liable to lose its juice if 

 allowed to hang after midwinter. For this latter reason it should only be 

 planted very sparingly and marketed early, or there is a danger of its bringing 

 discredit on the much -valued Washington Navel. Observations are being 

 especially directed to the hanging qualities of the directly imported 

 Navelencia trees at Hawkesbury Agricultural College, as the few points of 

 superiority which can be claimed for this variety over Valencia will be of 

 little value if it has not the long-hanging characteristic of that variety. 



