Real time laboratory and field monitoring of the effect of the operational parameters on seed falling speed and trajectory of pneumatic planter

•All of the measurements were carried out in the laboratory as well as in the field conditions.•The measurements of investigated parameters and data transformation were conducted on-line.•Laboratory test measurements were performed in a real condition; therefore, the effect of tractor vibration was taken into consideration.•The main reasons of non-uniformity of seed spacing were speed of falling of seed and hitting of seed to the runner opener.•Speed of falling of seed decrease with increase of vacuum pressure value, under lower operational speeds.