The efficiency of wood vinegar added to fermented liquid organic fertilizer to increase yields
and reduce pest infestations was evaluated on a new variety of soybean (Srisamrong1). The
experimental plots were located at the experiment station of the Faculty of Agriculture Natural
Resources and Environment, Naresuan University, Phitsanulok. This study was undertaken
during the rainy season (May to September 2008). The experiment was a split plot in RCBD
(randomized complete block design) with 6 treatments and 3 replications per treatment. The
fermented liquid organic fertilizer from herbs and wood vinegar was evaluated in 6 treatments:
1) water as control; 2) wood vinegar; 3) derris + neem seed + turmeric +molasses; 4) turmeric
+ tobacco + turmeric + molasses; 5) citronella grass + neem seed + turmeric + molasses; 6)
citronella grass + tobacco + turmeric + molasses. A ratio of 5:3:1:5 (kg: kg: kg: mL) was
applied on the 3rd to 6th treatments and were fermented in wood vinegar at 50 mL/25 liters of
water included with 12 gm of a microbial activator (LDD7). All of the treatments were diluted
with water in a 1:200 ratio prior to spraying. Beginning at 15 days after planting the 6
treatments were applied as foliage sprays at 7 day intervals for a total of 8 times. The results
showed that yields and the yield components response to the application of wood vinegar and
fermented liquid organic fertilizer was not significantly different among treatments. However,
treatment 2 (wood vinegar) showed a trend towards a higher efficiency of yield components
such as average height, node length, seed number and weight /100 seeds, which were 65.45 cm,
10.46 cm, 39.99 and 18.57 gm, for treatments 2-5 respectively. The average yields were