Sisal Plant Research Articles

The possibilities of breeding long fibre agaves with a high rate of leaf unfurling and a high rate of increase in leaf length.

The vegetative development of the sisal plant is described with particular reference to the rate of leaf unfurling and the rate of increase in leaf length. The significance of these characteristics, particularly the latter, for fibre production is discussed. It is shown that a high rate of increase in leaf length is a desirable characteristic of a long-fibre agave. Observations made on a number of Agave hybrids, however, indicate that there is a marked negative correlation between rate of leaf unfurling and rate of increase in leaf length. The consequences are discussed.-Sisal Res. Stat., Mlingano, Tanzania. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Health status of sisal plants (Agave sisalana) as related to soils and the mineral composition of their leaves

AbstractLeaf samples from healthy and diseased sisal plants and the corresponding topsoil samples were analysed. The results show that K deficiency is the main cause of ‘banding disease’, whereas manganese is probably involved in ‘purple leaf tip roll’.For healthy growth, the important factors are good content of organic matter, pH 6–7 and a well balanced uptake of nutrients with no excess of one or more elements.

Steroid sapogenins. III. Distribution of steroid sapogenins in the sisal plant

The steroid sapogenin constituents of Agave sisaluna at various phases of growth have been identified. It is suggested that, in the bulbils, gitogenin—as first generation in sapogenin biogenesis—gives tigogenin—as second generation—which transforms m the cousre of the long life of the plant to hecogenin and neotigogenin—as third generation. At the end of the life cycle, neotigogenin and hecogenin of the old leaves are transformed by a reverse mechanism to tigogenin in the flowering top which, as the new life approaches, changes to gitogenin. It has also been shown that hecogenin is most abundant (0.235%) in the leaves of the old plant.

Efeito da frequência e severidade de corte das fôlhas sobre a duração de vida do sisal

The present paper deals with the influence of four different leaf-cutting cycles combined with three levels of severity of cutting upon the life cycle of sisal plant (Agave sisalana Perrine). According to the results obtained, it may be concluded that less frequent cutting induces the plant to pole earlier, and greater severity of cutting prolongs its life eyele.

A experimentação do sisal: parte I - experiências de espaçamento

Sisal (Agave sisalana Perrine) accounts for about one half of the world's production of hard fibers. In spite os its economic importance pratically no research work has been carried out on this plant. Very little is known about the agronomic problems of its cultivation, while the physiological and genetic problems are nearly unknown. This is perhaps due to the fact that A. sisalana is a perennial plant with a life cycle of 5-8 years and the carrying out of field research work requires a great deal of time and is very expensive. This paper, the first of a series to be published on the agronomic problems of sisal cultivation, presents the data obtained from field trials on distance of planting and its relation to weight and number of leaves produced. The experiments were carried out at the Ribeirao Preto and Pindorama Experiment Stations of the Instituto Agronomico de Campinas. Sisal bulbils about one year old were planted in the latter part of 1939 in 4 randomized blocks of 9 plots each where different distances between and within the rows were used. Production data were obtained by cutting the leaves at one year intervals begining 2 1/2 years from date of planting in the field. Only those leaves that were attached to the plant at an angle greater than 45.° in relation to the main axis of the plant were cut each year. Only in the trial at Ribeirao Preto the leaves were counted and weighted by plants. In the poling plants all leaves than existing were taken off, even the youngest ones adjacent to the pole (flower stalk). Descorticator machine for fiber extraction was not available, so that reliable data on fiber yield could not be obtained. A probable fiber yield was obtained by using 3% of leaf wreight as a basis for calculations. This percentage is recognised as an average fiber content usually obtained from sisal leaves. From the data obtained from the spacing trials described in this paper the following conclusions can be drawn : 1. The life cycle from date of field planting to poling stage of most of the sisal plants in these trials varied from 5 to 8 years. A very small number of plants however had not poled even after 8 years when the present experiments were ended. 2. The life cycle of the sisal plants showed a close relationship to planting distances. At the greater planting distances the plants tended to pole much earlier than at closer planting distances. 3. It was observed that there was a marked seasonal incidente of poling. The flower stalk of almost all plants have appeared during the period of January to March. 4. A marked effect to the distance os planting on plot yields, as measured by total leaf weight, was observed. The greater the density of plants per unit area the greater the leaf production. 5. Under present leaf cutting practice, e. g., to cut yearly only the leaves at an angle greater than 45.° in relation to the main axis of the plant, the shorter distances between the rows are not recommended. The narrow spacing between rows not only restricts the passage of workers, but also hinders adequate cultivation (weeding and sucker growth control). 6. The planting distances of 2 x 2 meters (2500 plants per hectare) was the worst spacing tried. Besides giving a low plant density per unit area it prevents ingress to the planting from any direction. 7. To increase plant density per unit area the closing up of plants within rows is more indicated than closing up the distance between rows. 8. The advantages of the distances of planting between rows of 2.40 or 3.00 meters and 1.20 meters within rows, under present leaf cutting practice, are many. It facilitates weeding, control of suckers growth, and leaf cutting operations.

A severidade de corte no sisal e analise tecnológica da fibra

In this paper it is presented a detailed fiber analysis of leaves of twenty mature sisal plants taken from four positions on the plant: 1) first developped leaves (75°); 2) leaves usually cut for fiber extraction (50°) ; 3) leaves adjacent to the central bud (25°) ; and 4) young leaves not yet unfolded from the central bud (0°). The results herein reported are against the prevailing opinion that the sisal leaf only matures after it has unfolded from the central bud. Neither the physical nor the chemical fiber characteristics were adversely affected even if cutting was carried out up to the very young leaves. This practice, however, cannot yet be advised, as it desirability also depends on the effects of the severe cutting upon the subsequent rate of growth of the new leaves. A cutting trial including the cut of all leaves every four months is still in progress. Preliminary results have shown that the plants of this treatment were able to develop eight leaves until the second cut, with an average fiber content of 3,7%.

A influência do espaçamento sôbre o ciclo vegetativo do sisal

The present paper deals with the influence of different rates of spacing on the poling of sisal plants (Agave sisalana Perrine). The results were obtained from spacing trials (four randomized blocks of nine treatments) carried out at the Ribeirao Preto and Pindorama Experimental Stations. The percentages of poling plants, up to the 5th leaf cutting, were 20,0% and 91,7% for the narrowest (1,2 x 2,0 m) and widest (2,0 x 3,0 m) spacings tried in Pindorama, while in Ribeirao Preto they were 12,5% and 02,5%, respectivelly. According to these results it may be concluded that the narrow spaced plants were less liable to early poling than the wide spacing ones. The trial at Ribeirao Preto also indicated that among the plants, grown under the same conditions, those producing leaves at a faster rate were the first to pole. At that Station, the yearly average lenf production per plant (for all treatments) up to the 4th leaf cutting, has been 41,5 leaves for those plants poling after 63 months ; 38,0 leaves for those poling after 74 months ; and 35,3 leaves for those plants not poled up to 5 th cutting.