Influence of Mineral Deficiencies on Growth and Composition of Vanilla Vines.

A root rot disease is the most important factor limiting commercial production of vanilla [Vanilla fragrans (Salisb.) Ames] in Puerto Rico. According to a survey of growers in 1945 (1), the disease was responsible for 40% to 50%o death of vines. In 1927 the causal organism was identified as Fusarium batatatis var. vanilae, Tucker (5). The disease usually becomes more pronounced during the third or fourth year when the first heavy crop of beans is developing. Dry weather, and possibly some mineral deficiency, appear to aggravate the disease, particularly if mulch and shade are inadequate. The purpose of the work reported here was to determine the effect of mineral deficiencies on the growth and composition of the vanilla plant, especially the effects on root growth, with a view to applying this information in the study of the root rot problem.