The research aimed to (a) figure out the effect of Gadung (Dioscorea
hispida dennst) tuber extraction concentration to the intensity of pest attack,
soybean growth and yields.It also to (b) figure out the effect of soybean variety
toward intensity of pest attack, soybean growth and yields, and (c) to figure out
interaction of soybean variety and Gadung (Dioscorea hispida dennst) tuber
extraction concentration toward intensity of pest attack, soybean growth and
yields.
The research was conducted in Langgar village, Kejobong sub-district of
Purbalingga regency on 179 meters above sea level in October 2016 to January
2017. The research design was Complete Random Design consisting of two
factors. The first factor was soybean varieties of (Dena 1) V1 and (Gema) V2. The
second factor was Gadung tubers extract concentration consisting of four levels of
0 g/L (G0), 25 g/L (G1), 50 g/L (G2), 75 g/L (G3). Every treatment arrangement
was made two units and repeated four times.
Gadung (Dioscorea hispida dennst) tubers extraction concentration did not
affect factually toward intensity of pest attack, soybean growth and yields. The
use of of soybean varietydid not affect factually toward intensity of pest attack,
soybean growth and yields. The interaction of allotment of Gadung (Dioscorea
hispida dennst) tuber extraction concentration and soybean variety affected
factually toward weight of seed per-plant, and it affected very factually toward
number of seed per-plant. The variety of Gema variety treated with Gadung tuber
extraction 50 grams (V2G2) resulted the heaviest weight of seed per-plant 11.55
grams per-plant. The allotment of Gadung tuber extraction in average could
decrease intensity of pest attack toward soybean crops.