Table 2 also summarises recent field and laboratory studies on
phytostimulation for cotton, conducted in the last decade. Many
inoculants (see section 2.4), such as Azospirillum and Pseudomonas
spp. have multiple beneficial traits. Differentiating between plant
growth promotion due to phytostimulation versus biofertilization
can be accomplished by examining whether mutant strains defi-
cient in plant hormone production are still able to promote plant
growth. For example, Azospirillum brasilense mutants with reduced
levels of IAA production are affected in their ability to promote
wheat growth
strains