But excluding the 48.5 per cent increase in agriculture supplies, overall sales were unchanged from March, the federal agency said.
The second biggest advance was a 1.1 per cent rise in the machinery, equipment and supplies subsector, which partly offset a March decline.
Sales in the building material and supplies subsector rose 0.5 per cent and the motor vehicle and parts subsector gained 0.2 per cent.
The largest sales decrease in dollar terms came in the personal and household goods subsector, which dropped 2.2 per cent on lower sales in the pharmaceuticals and pharmacy supplies industry.
In April, seven provinces recorded growth in wholesale sales, including the four western provinces.
The average analyst estimate had been for a slight, 0.2 per cent increase, CIBC World Markets said in a note.
However, a huge shipment of fertilizers in April marked a restart to potash sales and exports following a soft first quarter and has confirmed that Q2 should benefit from restarts to stalled resource activity, the bank (TSX:CM) said.
"The 1.3 per cent increase in wholesale volumes suggests that April GDP will get a hearty helping hand from that sector," it said.