Our knowledge and understanding of the complex interactions of phytohormones and other non-phytohormone interactions between rhizobacteria (or other organisims eg fungi) and particular species of plants is not sufficient to enable a predictive assessment of what levels of particular combinations of compounds will result in growth promotion. It is therefore better to directly screen the growth of your conifer seedlings against different cultures of rhizobia and then analyse for the exudation of phytohormones in the best growth promoting lines of rhizobia.

Ok thank you! That makes more sense Charles H Hocart

It is also much quicker. You can screen many seedlings in parallel for growth enhancement. Phytohormone analysis is technically demanding and time consuming and you can only do the MS analysis one sample at a time. Good luck.

This is an important and growing area of research as agriculture is going to have to, amongst other things, move to biological fixation of nitrogen, reducing its dependence on energy demanding industrial scale Haber-Bosch reduction of atmospheric nitrogen.

Interesting...Following

Naturally, you should choose the most potent isolates for your work, and the best bacteria are those that have the ability to dissolve insoluble organic and inorganic phosphates, the IAA production capacity, the siderophore production capacity, and the ACC-deaminase production capacity. If you do these tests and choose the best bacteria, you will eventually get better results.