Resumen

ADAY-DIAZ, Osmany de la Caridad et al. Temporary   distribution   of   symptoms   of  the sugarcane  leaf  yellowing  in  Cuba. Agron. Mesoam [online]. 2012, vol.23, n.1, pp.107-116. ISSN 2215-3608.

The   objective  of this  study  was  to  determine  the  temporal  distribution  of the physiological symptoms  of leaf yellowing disease of sugarcane and its relationship with weather variables in the central  region of Cuba. Field evaluations were conducted in three  experiments  in  two  locations,  during  the  period from 2003 to 2007. Monthly evaluations  were carried out starting with the appearence of the  first symptoms, using a  hand  refractometer  to  record  values  of  refractometric brix of the basal third of the third leaf with visible dewlap (TVD).  Correlations of the values of observed brix were with climatic variables were obtained. The first  symptoms of leaf yellowing appeared in plants of five months of age, independently of the time of sowing, at the beginning of the winter season, and then decreased with the beginning of the spring. The brix of the leaf increased from November and reached a maximum in April, after which the plants became asymptomatic.  The  decrease  of  the  maximum,  minimum and monthly average temperatures below 30, 21 and 25°C, respectively, as well as monthly precipitations lower than 50 mm,  favored the expression of the symptoms, which  were more related to climate than to crop age, in  coincidence with the dry period of maturation and  harvesting time of sugarcane.

Palabras clave : Leaf  yellowing  syndrome; climatic variables; phytoplasma; Brix.

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