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The Central Region of Cuba has been affected by the yellow leaf syndrome (YLS). During 2005 in Villa Clara were evaluated 3 011,63 hectares in 6 sugarcane enterprises and in Cienfuegos, 2 641,7 hectares were evaluated in 5 enterprises. During 2006 the study included 3 641,92 hectares belonging to 4 enterprises in Villa Clara. It was used refractometric brix in the central midrib and symptoms on leaves, to detect the presence of YLS and a four degrees scale was applied to express the disease severity in field conditions Infected fields in Villa Clara reached 47,1 and 32,6% of incidence during 2005 and 2006 respectively, while in Cienfuegos it was 38,7% during 2005. The presence of the YLS was recorded in 73,6 and 83,1%, during 2005 and 2006, respectively, in evaluated areas belonging to Villa Clara and in 91,4% of the area evaluated in Cienfuegos, which indicates its wide propagation in commercial plantations of sugarcane. Cienfuegos howed higher incidence and severity of YLS, affecting a wide range of varieties, mainly C1051-73, C87-51, C120-78, SP70-1284, C86-12, Co997 and C132-81. It is recommended to continue observing the evolution of the YLS in Cuba, fundamentally in the Central Region of the country and accomplish studies to determine the damages to sugarcane production. [ABSTRACT FROM AUTHOR]

Harvesting of sugarcane at a proper time, by adopting right techniques, is necessary to make better use of the available genetic material. By determining the harvesting time period for each sugarcane variety to show its highest potential, both yield and sugar quality, higher levels of profitability are achieved. The aim of this study is to identify the harvest time of sugarcane cultivars, as well as the stability of the cultivars studied in five localities. The study was conducted at the Sugarcane Research Stations in Villa Clara, Sancti Spiritus, Camagüey, Holguin and Santiago de Cuba. Five experiments were planted (one for each locality), in a randomized complete block design with three replications under rainfed agriculture. Two harvest times were established, time 1 (M1), according to the harvest data from November to January (beginning of harvest), and time 2 (M2) taking into account the data collected from February to April (average stage- end of harvest). The discriminant analysis results allowed establishing two harvest times (November to January and February to April) in these five localities, where the effectiveness of each cultivar-Iocality-harvest time combination was higher than 74%. In general, it is advisable the use of cultivars C86-12 and C92-514 during M1 in these five localities, as well as the use of C90-530 in specific zones; and the use of cultivars C92-514 and C89-165 during M2. [ABSTRACT FROM AUTHOR]

The frequency of the appearence of atypical dry and rainy seasons periods in the last years, has put up with the establishment of a new conception for the evaluation and management of sugarcane varieties, with a view to framing correctly the harvesting stage and its possible lengthening in certain places. Under those new premises 48 experiments in blocks totally at random were designed and established in four contrasting regions of the country. The behavior of three representative varieties of sugarcane of three different maturity periods (early, middle and late), harvested during the whole year, with ages between 9 and 24 months, in the variable t cane/ha,% pol in cane and t pol/ha was studied. The results corroborated the approach of maturity of the studied genotypes, the counties of Camagüey and Matanzas reached the highest values in the pol percentage in cane at the beginnig of the harvesting period, while Holguín achieves them in the period from April - July. The results of the Factorial Analysis, showed that the best results in the cultivars were reached in Camagüey, followed by Holguín with ages among 13 - 16, 17 - 20 and 21 - 24 months fundamentally in the periods (February - March, April - May, June - August and September - October), the environmental effect was the one that bigger contributed to the total phenotypic variation. [ABSTRACT FROM AUTHOR]

Were evaluated 46 varieties at two locations in the central region of the country in two types of soil, plant cane between 13 and 19 months during the months of November 2010 to May 2011 in the variables t cane / ha,% pol t cane / ha. Three stages were established harvest; cultivars were grouped into families according to their sugar behavior, defining moments of harvest and groups of families of varieties in each harvest period. One Discriminant Factorial Analysis was performed, the qualitative variable used in the first case being the so-called time and the second group of the cultivars. Obtained results allowed the discriminant group the harvest time and the families of varieties for each harvest period with higher percentages of good classification to 75%. The Complete Model confirmed the existence of genotype - environment interaction and quantified a high contribution of the environment, mostly attributed to the towns and the experimental error for cane and pol t / ha, while for the sugar content was the time of harvest. The Reduced Model offered that for t cane / ha Moment in one and three, the variance of genotype - environment interaction was higher than ambient. [ABSTRACT FROM AUTHOR]

The frequency of the appearance of atypical dry and rainy periods in the last years, has put up with the establishment of a new conception for the evaluation and management of sugarcane varieties, with a view to framing correctly the harvesting stage and its possible lengthening in certain places. Under those new premises 48 experiments in blocks totally at random were designed and established in four contrasting regions of the country. The behavior of three representative varieties of sugarcane of three different maturity periods (early, middle and late), harvested during the whole year, with ages between nine and 24 months, in the variable tons cane/ha, percentage of pol in cane and tons pol.ha-1 was studied. It was obtained as a result that the counties of Camagüey and Matanzas reached the highest values in the pol percentage in cane to harvest beginnings (November-December) in the three evaluated cultivares, while Holguín achieves them in the period from April-July. In accordance with the obtained results is possible to harvest with a bigger sugar content, if the crop age is increased and this is made in early time for traditional harvests (November-January) and varieties corresponding to the «families» of early and intermediate maturation are used, suggesting the possibility to contain crop ages and to determine the best combinations «family-age-moment» for edafoclimatic region, in such way that can guide the composition varietal and of stumps to be able to take place with the biggest efficiency. [ABSTRACT FROM AUTHOR]