The toxicity to plants of flue dusts containing cyanides and thiocyanates

The toxic or harmful effects resulting from the use of flue dust containing different amounts of cyanides and thiocyanates as a potassic fertilizer for a variety of different crops have been studied. Tomato plants have been found to be particularly susceptible to flue dusts containing cyanides and thiocyanates. For all other crops examined 1% of potassium cyanide and 1% of potassium thiocyanate appear to be safe limits for these compounds in flue dust. Quantities of cyanide and thiocyanates in excess of these amounts have been found to be generally toxic. The experiments have shown, however, that both cyanides and thiocyanate arc rapidly destroyed in the soil; so that application of flue dust to the soil some weeks before sowing the crop will afford a safeguard against these toxic substances.