BIOFERTILIZATION OF SAFFLOWER (Carthamus tinctorius L.) UNDER LIMITED SOIL HUMIDITY CONDITIONS

Abstract

In order to determine the influence of inoculation with rhizobacteria Azospirillum brasilense and arbuscular mycorrhizae fungus (AMF) Glomus intraradices, and chemical fertilization (100 kg ha^-1 of N and 60 kg ha^-1 of P²O⁵) (ChF) in safflower (Carthamus tinctorius L.) cvs. ‘Tantoan 91’ and ‘Guayalejo’, two field studies were conducted under limited humidity conditions, in the semiarid region of northern Tamaulipas, México, one under dryland conditions at “El Vaso”, and the other under limited irrigation, CERIB site. At “El Vaso”, no significant effects of ChF or symbionts were observed in safflower plant height, flower number, grain weight per plant, grain yield (kg ha^-1) and mycorrhizal colonization. At CERIB, both AMF and ChF treatments significantly and similarly increased all studied variables, except mycorrhizal colonization. Results of combined analysis from both localities showed that safflower responded only to humidity condition, but no significant differences were registered between AMF and ChF, or safflower varieties. Mycorrhizal colonization fluctuated from 8.7 to 14.4 % and it was not correlated with grain yield or its components. That is, safflower productivity was not influenced by the ChF or the symbionts inoculation, under limited humidity soil conditions.