ENHANCED EFFICACY OF SOIL DISINFESTATION TREATMENTS WITH 1.3-DICHLOROPROPENE AND CHLOROPICRIN UNDER LOW TEMPERATURE CONDITIONS FOR STRAWBERRY MOTHER PLANTS

High elevation nurseries, are still considered critical use in Spain, where disinfestation before plantation is done with soil temperatures about 10°C during application. Main problems are soil fungi and the presence of weeds in springtime and summer with the mother plants still developing. This research intends to study three new formulations of 1,3-dichloropropene 55.2% + chloropicrin 30.3% at 50 g/m² furnished by Agroquímicos de Levante SA. with the addition or not of a herbicide (trifluranyl 48% pv) at 1% and these are compared with a formula of 1,3-dichloropropene 55.4% + chloropicrin 32.7 % at 50 g/m2, nowadays registered in Spain (ANE); methyl bromide 50%.+ chloropicrin 50% at 40 g/m2 and a non-disinfested check. Application has been done by shank injection, as usually done, in mid-March. Crop started beginning of May. All fumigants controlled weeds except in the check treatment where weeds seized the whole plot and finally plants together with weeds were eliminated. Runners harvest results show a minor yield in treatments with herbicide as compared with those without herbicide. The nowadays registered mixture remains in an intermediate position with significant differences with methyl bromide but those without herbicide do not show statistical differences with methyl bromide. We can conclude that some adjuvants may render the mixture of 1,3-dichloropropene + chloropicrin as winter alternative to methyl bromide.