Observations on the Spacing of Sisal

Abstract

The early field trials on the Mlingano Sisal Experimental Station showed that of all the factors affecting sisal yields, spacing, in so far as it determined the density of plants, was by far the most important. As the population of plants per unit area increased so did the total tonnage of fibre obtained during the life cycle. A paucity of plants, such as 1,500-2,000 per hectare, only yielded about five to six tons against 30 tons reaped from 10.000 plants per hectare. Intermediate populations likewise yielded according to plant number. The total fibre yield and the longevity of the sisal were closely and positively correlated with plant density. It is not proposed to deal with the results of spacing trials in this article beyond pointing out the profound influence of plant density upon yield. The optimum density will vary according to climatic and soil conditions and no hard and fast rule can be laid down beyond stating that one aim should be to have as many plants as possible without seriously impairing the development of the sisal. Within reason, the more favourable the growth conditions are, the greater the density may be, and, conversely, the poorer the conditions the lower the plant population. The proper approach to determining any spacing for an estate, or section thereof, is first of all to decide how many plants the land will carry satisfactorily. Having reached this decision the actual espacement to be adopted should then be considered. Frequently these two factors are dealt with in the wrong order. For example, should a density of 5,000 plants per hectare be settled upon, then the question whether the spacing should be 2 x 1 m., 2.50 x. 80 m., 4 x 1 m. x. 80 m., or any other variant giving 5,000 plants, should be answered afterwards.