Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California

onion's root rot is the most important disease in the trinidad valle, baja california, mexico. in orderto evaluate strategies to control this disease, three experiments were conducted during 2007, 2008 and 2009. in experiment i (2007) the treatments were: 1) thiophanate methyl; 2) smicobac (trichoderma+bacillus sp. + azospirillum sp. + pseudomonas sp.); 3) cattle manure (eb); 4) waste of onion (rc); 5) clear plastic solarization (spt); 6) black plastic solarization (spn); 7) spt + eb; 8) spt + cr; 9) spn + eb; 10) spn + so; 11) trichodef (trichoderma harzianum); and 12) control. in experiment ii (2008), treatments were the same except treatment 2, replaced by a protective agent (plant extracts), and in experiment iii (2009) the treatments were: 1) spt + sheep manure (eo); 2 ) spn + eo; 3) spt; 4) spn; 5) biological control (trichoderma spp.); and 6) chemical control (2 - (thiocyanomethylthio) benzothiazole 30%. the results indicated that the clear plastic solarization treatments with or without organic amendments showed significant increases (p<0.05) from 22 to 34%yield and diameterwith respect to biological and chemical control, but the latter two treatments in the incidence and severity decreasedsignificantly (p<0.05 ), so that the clearplastic solarization and biological control, are viable alternatives to control root rot in onion crops in baja california, mexico.