ABSTRACT. Forage legumes are essential for an efficient animal-based agriculture. This chapter describes microbial-based strategies for improving legume establishment. It focuses on the use of root nodule bacteria for growth promotion and rhizosphere pseudomonads for disease management. The technological system for biological nitrogen fixation deployed in Uruguay is discussed as a model. We analyze the significance of the characterization of rhizobial strains, selection and culture collection, as well as inoculant production and quality control.

ABSTRACT. Although deoxyribonucleic acid (DNA) markers have provided useful information on genes with moderate to major effect on carcass and meat quality, early approaches for marker-assisted selection did not have the expected impact on breeding programs. Current DNA sequencing and high-throughput genomic technologies enable the implementation of genomic selection and genome-wide association studies, which offer advantages for the genetic improvement of carcass and meat quality. New insights into gene networks underlying the traits of interest are also possible.

ABSTRACT. The sensitivity of Venturia inaequalis to trifloxystrobin and difenoconazole was studied in Uruguay. Populations of V. inaequalis were collected from apple orchards with different histories of trifloxystrobin use. Sensitivity of populations to trifloxystrobin was analysed using a method for testing spore germination published by FRAC, using a discriminatory concentration of 2.0 mg a.i./l. Resistance to trifloxystrobin was widespread in the region of commercial apple production with resistance detected in all orchards examined, the incidences ranging from 3% to 95%.

SUMMARY. Togninia minima (anamorph Phaeoacremonium aleophilum) is one of the main fungi responsible for trunk diseases of grapevines and other woody hosts worldwide. Sequences of protein-coding genes of isolates from countries in different continents have been published, presenting a useful resource for examination of the diversity and spatial distribution of T. minima genotypes.

ABSTRACT. Chemical communication among kin bacteria modulates diverse activities. Despite the general consensus that signaling among non-kin organisms is likely to influence microbial behavior, there is limited information on the potential for microbial interactions to alter microbial phenotypes in natural habitats. We explored patterns of interaction that alter inhibitory phenotypes among Streptomyces isolates from distinct communities.

ABSTRACT. Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB). The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal worm egg count (FEC). A total of 29 Corriedale lambs were experimentally infected with 10.000 larvae of H. contortus.

ABSTRACT. The objective of the present study was to characterise the behaviour of Holstein steers in three different production systems. Forty-eight castrated Holstein males were randomly divided into three groups and allocated to the following three outdoor treatments:(T1) animals confined in a yard with an area of 210 m2, (T2) animals confined in a similar-sized yard but with 6 h of access to a pasture plot, (T3) animals maintained throughout the experiment on a pasture plot.

ABSTRACT. Soil quality improvement by reducing soil tillage is one tool of sustainable agriculture. Covers crops left on soil surface prevent soil erosion, reduces evapotranspiration and weeds, and improves soil infi ltration; key factors for a successful vegetable production on heavy clay soils. The objective of this research was to evaluate the effect of cover crops plus ridge tillage on soil water content, soil, physico-chemical and biological properties and on vegetable yield.

RESUMEN. La solarización es la cobertura hermética del suelo, humedecido a capacidad de campo con polietileno transparente ultravioleta (UV) durante un tiempo variable. Mediante la captura de energía solar se aumenta la temperatura del suelo, perjudicando las semillas de malezas anuales. Esta técnica fue evaluada en almácigos de cebolla con excelentes resultados por INIADIGEGRA-FAGRO en 2005-2006 en tres localidades.