Relationship between Soybean Pod Morphological Characteristics with Population and Attack Intensity of Pod Sucking Pest Riptortus linearis F. (Hemiptera: Alydidae)

Abstract

Pod sucking pest, Riptortus linearis, is one of the important pests on soybeans which cause high yield losses. This study aimed to determine the relationship between soybean pod morphological characteristics with population and attacking intensity of the pod sucking pest R. linearis. The research method used was descriptive exploratory in the field with five soybean varieties, namely: Detap-1 (V1), Dega-1 (V2), Anjasmoro (V3), Biosoy (V4), and Dena-1 (V5). Research was conducted from September to December 2020 in Setanggor Village, West Praya District, Central Lombok Regency, West Nusa Tenggara Province, Indonesia. Results showed that the highest population of R. linearis was in the Dena-1 variety (1.9 individuals/plant), followed by Detap-1 (1.7 individuals/plant), Anjasmoro (1.6 individuals/plant), Dega (1 individual/plant) and Biosoy (0.9 individual/plant). Two morphological characteristics of soybean pods that had a correlation with the attacking intensity of R. linearis were trichome density (TD) and trichome length (TL). The lowest attacking intensity was on Biosoy variety (26.08% b, TD:1000.7 (10,000 m2 (10 x 4) and TL: 71.78 µm followed by Dega-1 (27.98% ab, TD:1044.04 (10,000 m2) (10 x 4) and TL: 70.70 µm, Detap-1 (36.36% ab TD: 944.14 (10,000 m2 (10 x 4) and TL: 72.86 µm, Dena-1 (35.02 % ab TD: 957.55 (10,000 m2 (10 x 4) and TL: 73.11 µm and the highest is Anjasmoro (37.56% a TD: 955.24 (10,000 m2 (10 x 4) and TL: 74.67 µm. Furthermore, the correlation analysis showed that the denser and longer the pod trichomes, the lower the attacking intensity of the pod sucking pest R. linearis.