Dear Erraji, In-vitro is much more precise way to judge the effect as we can control the condition in laboratory.This is not possible in the field as lot of other edaphic and climate conditions take control over there.However one thing is for sure that practical benefits can be significant or non significant and this can be validated from field trials only.

In invitro condition we can give every possible way to perform better as compared to invivo condition to null the effects of weather and soil factors.

I think, the effect of bio-fertilizers both in-vitro or in-vivo can be judged through their fertilizer value, agronomic value, economic value, animal feed value, water gain value, soil conservation value, soil-carbon sequestration value, microbial biomass build up value and ultimately the yield, nutrient uptake and their efficiency to plants including quantum of positive changes in the rhizosphere environment.

Thank you for help all of you