Here are a number of scientific abstracts which cover Mycorrhizal effects on plant root growth. Please post a comment if you are interested in finding additional information. LANSAC AR; MARIN A; ROLDAN A. 1995. MYCORRHIZAL COLONIZATION AND DROUGHT INTERACTIONS OF MEDITERRANEAN SHRUBS UNDER GREENHOUSE CONDITIONS. ARID SOIL RESEARCH AND REHABILITATION 9: 167-175. LANSAC AR, CSIC,CTR CIENCIAS MEDIOAMBIENTALES,SERRANO 115 DUPLICADO, E-28006 MADRID,SPAIN. Juvenile plants of Thymus mastichina , Thymus zygis , Lavandula pedunculata , Genista hirsuta , and Cistus ladanifer were transplanted from the field to the greenhouse; the soil used was the same in which they had grown at their natural site. The plants were grown to maturity to determine comparative growth, water status, and mycorrhizal colonization under greenhouse conditions and to determine the influence of drought on the symbiosis. After 24 months, L. pedunculata showed the most developed root system