Researchers from the University of Ljubljana in Slovenia tested the effects of two growth-promoting bacteria, namely, Pseudomonas fluorescens and Azospirillum brasilense, on the yield of three potato varieties. Their findings were published in the journal Acta Agriculturae Scandinavica, Section B — Soil & Plant Science.

• The researchers planted three potato varieties with different longevity of growth periods – “Morgana” (mid-early variety), Sunity (early variety) and “Primabelle” (very early variety).
• A commercial product, Rhizoflo Premium, containing two species of rhizobacteria, P. flourescens and A. brasilense, was used.
• The experimental plots for each variety were divided into three blocks, and each were given one of three treatments:
  • First treatment — tubers soaked for 10 to 15 minutes in a 3 percent solution of the product.
  • Second treatment — tubers sprayed with a solution containing the product during sowing using a backpack sprayer.
  • Third treatment — no soaking or spraying (control group).
• The plots were planted during an unusually hot and dry summer. On most days, the temperature was 2 C higher than the average temperature between 1981 to 2020.
• The researchers observed that all three potato varieties had higher productivity than the control group after treatment with the solution containing the two bacteria.
• In the first group, the Morgana variety was 17 percent more productive, the Sunita variety was 27 percent more productive and the Primabelle variety was 31 percent more productive.
• In the second group, only the Primabelle variety produced a consistently higher yield – 24 percent – than in the control treatment.

The researchers concluded that treatment with a mixture containing P. flourescens and A. brasilense can help increase potato yield under dry conditions.

Journal Reference:

Trdan S, Vu?ajnk F, Bohinc T, Vidrih M. THE EFFECT OF A MIXTURE OF TWO PLANT GROWTH-PROMOTING BACTERIAL FROM ARGENTINA ON THE YIELD OF POTATO, AND OCCURRENCE OF PRIMARY POTATO DISEASES AND PEST. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 28 June 2018; 69:1, 89-94. DOI: 10.1080/09064710.2018.1492628