BARBOUR EXPLAINS WORK BEING CARRIED ON BY HARVARD AT SOLEDAD PLANTATION

The following article, reprinted from the Alumni Bulletin, was written by Dr. Thomas Barbour '06, custodian of the Harvard Biological Laboratory and Botanical Garden in Cuba.

The Harvard Botanical Garden, at Soledad, Cuba, has carried on for 25 years research in the breeding of sugar cane and has developed several superior varieties, some for special conditions and others for general commercial cultivation.

Cristalina, the principal variety of sugar cane cultivated commercially In Cuba, is an excellent, all-round cane for general plantings. This variety fails, however, to give a high yield on dry uplands, and the ratoon or sprout plants have a tendency to deteriorate rather rapidly year by year on land which has been for a very long time under cane cultivation.

Recognizing these facts, the Harvard Botanical Garden began its research and experiments in the hope that better varieties of cane might be developed. This work as a whole has been very successful, not alone in producing improved varieties for the shallower uplands, but also in developing varieties better adapted for the fertile lands, several of which have already been recognized as excellent for commercial cultivation.

It is true that one or two of the drought-resistant Harvard types are occasionally slightly lower in sucrose than that of the best Cristalina fields, but this is compensated for by a higher yield in tonnage, on the poor, shallow soils, where Cristalina will not grow at all satisfactorily.

Have Increased Yields

Other Harvard canes, especially Hrvd No. 12.029, have not only produced much greater yields in tonnage per caballeria (33 1-2 acres) than Cristalina cane, but have in addition greatly expected that variety in actual sugar content and purity of juice in the stalk.

Recent normal juice analysis conducted in the Soledad Laboratory on a commercial scale, in combination with tests in field tonnage, showed that Cristalina cane cut from moderately fertile land, rating between 24.146 and 54.1 arrobas (25 pounds each) of cane per caballeria, produced from 290 to 457 bags (325 pounds) of 96 degrees sugar per cab. The shallow uplands and older fields of Cristalina produced from 165 to 257 bags per cab. The decrease in quantity from the shallow uplands was due not so much to an inferior quality of juice as to an inferior growth of the cane plant on the less fertile fields, where the yield recorded was between 15.1 and 24.1 arrobas of cane per caballeria.

Two Canes Especially Good

Two of the Harvard canes, Hrvd No. 9072 and Hrvd No. 1192, included in the preceding analytical tests, for comparison with Cristalina, gave most satisfactory results. Hrvd No. 9072, a tenaciously rooted, drought-resistant variety, physically adapted for cultivation on the uplands, gave a cane yield of 56.2 arrobas per caballeria on a 1922 planting and a rate of 531 bags 96 degrees sugar per cab. Hrvd No.1192, on land similar to the Cristalina test, gave a cane yield of 53.990 arrobas, and a rate of 493 bags of sugar per caballeria.

The ratoon fields of both of these Harvard variants, planted side by side with Cristalina, have always shown superior yields and a much slower depreciation in field value: consequently they require replanting less frequently, which is an important consideration, as new plantings usually cause the loss of a harvest and an outlay of $2,000 to $2,500 per caballeria.

As a cane for general planting on the more fertile lands, Hrvd No. 12.029 is, without doubt one of the very best varsities ever produced, regarding both field tonnage and percentage of sucrose in the juice. The average yield of cane per caballeria is at least 15 percent greater than that of Cristalina, growing under similar agronomic conditions, and, as it is a more persistent grower, the fields do not need replanting so frequently. The cane stalks are solid and of greater weight than Cristalina. A sample of 22 carloads of this cane averaged 239 arrobas per car heavier than an equal number of Cristalina. (Cristalina usually weighs from 1,000 to 1,100 arrobas per carload.)

The Tropical Plant Research Foundation of Washington, which cooperates with the Sugar Club of Cuba, has distributed these Harvard canes to over 30 plantations and experiment stations in Cuba and Central America. The cuttings for these distributions were propagated at the Club's own Experiment Station at Baragua, Cuba, Where they were sent from Soledad.