Determinación del índice de madurez de tres cultivares de caña de azúcar y caracteres asociados con la producción.

Abstract

Sugarcane (Saccharum spp.) is currently the most productive food crop in the world, due to the chemical and biochemical nature of the raw material it produces, which presents great potential for productive diversification. It is a crop considerably distributed worldwide and is currently produced in more than 130 countries and territories, with Brazil being the main world producer, followed by India, Pakistan, Mexico, Thailand and Colombia, taking into account that the area harvested worldwide is 25'976.939 hectares, and its production is 1841'528.386 tons. In the Ecuadorian agriculture is the fundamental source of raw material for the elaboration of sugar, ethanol and panela, the production of cane is centered mainly in four provinces, these are: Guayas, Cañar, Carchi and Imbabura, its greater production is concentrated in the province of the Guayas with 87.1%, generating more than 30 000 direct positions of work and about 80 000 indirect ones in all the country. There are three sugar mills that work together with the Ecuadorian Sugarcane Research Center (CINCAE) and these are the most important; these are COAZUCAR, San Carlos and Valdez which have a storage capacity of 50,000 sacks of 50 kg. The research to develop the present thesis work was carried out in the experimental area of the Santa Inés farm, belonging to the Faculty of Agricultural Sciences of the Technical University of Machala, located at km 5.5 of the Machala-Pasaje road. Observations were made on sugarcane cultivars ECU-01, C87-51 and Ragnar, which were evaluated to determine the maturity index and the characteristics associated with production in the soil and climate conditions of the area where the research was carried out. The variables evaluated were: upper and lower brix degrees of the stem (maturity index), length (m) and width of the leaf (cm) + 1 or the first visible dewlap; diameter in the middle part of the stem (cm); height of the stem (m) from the soil surface to the first visible dewlap; length of the internode (cm) in the middle part of the stem; weight of the stems (kg); population density and cane production in t/ha. These parameters were correlated with the maturity index. One of the main problems that this crop has had in Ecuador is the dependence on a single cultivar (Ragnar). This monoculture represents a constant risk due to the effect of pest or disease attacks and why it has not increased in yield in the last 20 years, currently 66% of the cane planted for sugar production in the country is of the Ragnar cultivar of Australian origin, In order to guarantee a good production in the long term, it is crucial to use new cultivars that adapt to the characteristics of the different production areas. The ECU -01 cultivar is a good option to implement it in the soils of Granja Santa Inés (inceptisol with good drainage) since these conditions are favorable for the establishment of this cultivar at a commercial level. The most outstanding results confirmed that cultivars C 87-51 and Ragnar by the determination of its maturity index reflect that the cutting dates are from mid-July and August as these reached their optimum maturity, while ECU -01 is later reaching its optimum maturity in mid-August and September. In production the cultivar ECU-01 is the best since it has the highest population density (69524 grindable stems/ha) and its yield is (125, 83 t/ha) compared to C 87-51 (78095 grindable stems/ha - 123.39 t/ha) and Ragnar (56191 grindable stems/ha - 97.77 t/ha). There is no correlation between the maturity index and the following production-related characteristics; leaf length, leaf width, stem diameter, internode length and stem length, but there is a relationship between the maturity index and the age of the crop, since as the age increases the index increases, it is maintained and decreases.