RESUMEN. Las enfermedades bacterianas constituyen un grave problema para la producción de tomate (Solanum lycopersicon) tanto en condiciones de cultivo a campo como protegido. Ante la ocurrencia de condiciones ambientales favorables para el desarrollo bacteriano, se hace muy difícil su manejo pudiendo ocasionar importantes pérdidas en los cultivos. En general, se considera que la estrategia más eficiente para lograr un control efectivo de estas enfermedades es apuntar a un control preventivo, evitando que el patógeno entre en contacto con el cultivo.

ABSTRACT. The apple production area in Uruguay is of approximately 4000 ha, with an average fruit production of 62,000 t per year. Apple is the most important crop within deciduous fruits, and has behaved as the most demanding, in crop technology, during the last years. Local climate and soil conditions in the south of the country, where the major apple producing area is located, can generate sanitary problems to apple trees.

ABSTRACT. Potential of production of pecan under Uruguayan agroecological conditions was estimated. In a pecan orchard representative of the south of the country, with 11-year-old trees, phenology stages were determined and setting was measured, as well as harvest. Determinations were done on two representative branches per tree of a sample of 22 trees. Climatic conditions of Uruguay, even though highly irregular, vary within a range suitable for pecan production.

ABSTRACT. Potential of production of pecan under Uruguayan agroecological conditions was estimated. In a pecan orchard representative of the south of the country, with 11-year-old trees, phenology stages were determined and setting was measured, as well as harvest. Determinations were done on two representative branches per tree of a sample of 22 trees. Climatic conditions of Uruguay, even though highly irregular, vary within a range suitable for pecan production.

ABSTRACT. ?Williams B.C.? pear was grafted on two pear rootstocks:?Farold®40? and ?Farold®69?, and on three clonal quince rootstocks:?BA 29?, ?Adams? and ?EMC? with and without ?Beurré Hardy? as an interstem. To evaluate the performance of these combinations in the south of Uruguay, grafted trees were planted in 2003 at INIA Las Brujas, ?Wilson Ferreira Aldunate? Experimental Station (34°40 S-56°20 W). Rows were 4.5 m apart and variable distance was used between plants according to rootstock:1.70 m (?BA29?, ?Farold®40? and ?Farold®69?), 1.50 m (?Adams?), and 1.30 m (?EMC?).

ABSTRACT. The reduced pool of the abscisic acid (ABA) precursors, ?-? carotenoids, in roots does not account for the substantial increase of ABA content in response to water stress (WS) conditions, suggesting that ABA could be transported from other organs. Basipetal transport was interrupted by stem-girdling and ABA levels were determined in roots after two cycles of WS induced by transplanting plants to dry perlite.

ABSTRACT. Mandarins are characterized, among the Citrus genus, by a large diversity of species and varieties. Genetic evidences indicate that mandarin is one of the ancestral Citrus species, originated from Asiatic regions, and also an ancient parental of orange. This genetic diversity originates the nutritional and nutraceutical properties of mandarin fruits to vary largely among the different species and varieties.