Effect of aboveground plant conditioner treatment on arbuscular mycorrhizal colonization of tomato and pepper

We aimed to test the hypothesis that treatment with an aboveground plant conditioner has an effect on important vegetable crops inoculated with arbuscular mycorrhizal fungi (AMF) and on their colonization by AMF. Potting experiments were set with pepper and tomato plants inoculated with commercial AMF inoculum and plants were treated with an aboveground plant conditioner. After harvesting, the dry weight of shoots and roots were measured, and the AMF colonization of the roots was quantified. We found a significant effect of the treatment on fungal colonization: the AMF colonization, the hyphal colonization rate and the frequency of the arbuscules in the roots of both vegetables were lower when aboveground plant conditioner was applied. Although the two species differed, no significant effect of the treatment on the growth of the plants was detected. Based on our findings we assumed that the lower AMF colonization more greatly influenced the growth of the pepper cultivar studied. We demonstrated that treatment with a commercial aboveground plant conditioner had an antagonistic effect on AMF colonization, which, in addition to many other effects, might influence the growth vegetable crops. The interaction of different practices applied simultaneously should be tested to effectively help the development suitable agriculture systems.