Studies on the Plant Growth Regulatory Effect of Pyroligneous Acid to Turf grasses Part 1: Some characteristics of pyroligneous acid

Abstract

We studied the effects of pyroligneous acid (PA) on the growth of turfgrass using several culture methods.
1) Seeds water culture: PA accelerated the root elongation at 0.01%-0.25% for kentucky bluegrass (KB), at 0.01%-0.1% for bentgrass penncross (BC) and bentgrass penneagle (BE), and at 0.05% for bentgrass pennlinks (BL), whereas PA reduced the shoot growth in concentration-dependent manners. At higher concentrations (>0.5%), PA strongly inhibited the root elongation. Therefore 0.05% PA is adequate for the shoot and root growth of the turfgrasses tested.
2) Sods water culture: PA at a concentration of 0.05% promoted the root elongation of the sods of bentgrass penncross (BC), kentucky bluegrass (KB) and manilagrass (ML) regar Bless of pH control of culture solution. PA inhibited the root elongation at >0.25% and pH 6.25 for BC, at >0.25% and >0.5% for KB and ML, respectively regardless of pH control. At the concentrations ranging 0.01-0.5%, PA showed a promotive effect on the shoot growth, although the effect varied with the variety of turfgrass and the pH of culture solution. For KB and ML, PA at higher concentrations (>0.5 %) reduced the shoot growth regardless of pH control.
3) Soil culture; The effects of the monthly application of PA at 0.1-50l/a for one year on bentgrass penncross (BC), manilagrass (ML), Japanese lawngrass (JL) and kentucky bluegrass (KB) were evaluated. PA at 0.1-1l/a increased the foliar dry weights (FDW) of ML, JL and KB, but PA at 1l/a decreased the FDW of BC by 85% of the control. PA at 0.1-1l/a increased the root dry weights of all turfgrasses tested.
4) Cold tolerance: PA at 1-5l/a increased the cold tolerance of manilagrass.
5) These results suggest that PA, within optimum concentration ranges, has promotive and protective effects on the growth of turfgrass. We are conducting field trials to confirm these effects.