S. litura, E. zinckenella and C. servillia pest predator populations
The mean damage intensity results of armyworms of
S.litura,
E. zinckenella and
C. servillia populations varied in the three soybean varieties The highest level of damage caused by
S. litura was in Dena-1 (10.89%) and the lowest was in Deja-1 (5.99%) (Table 1). The Deja-1 variety is resistant to
S.litura, according to the report of the Indonesian Legume and Tuber Crops Research Institute,
ILETRI (2016), which is mentioned in the Description of Varieties of Soybean Crops.
The current investigation discovered that the Detap-1 type had the highest population of
Aphis sp. (4.08 adults per plant) and the Deja-1 type had the lowest (3.33 adults per plant) (Table 1). According to
Widaryanto et al., (2017), the population of
Aphis sp. might cause seed yield loss has reached 58%. One method for controlling
Aphis sp. pests is to utilize a predator. The predator Coccinellidae is the most common in soybeans, followed by Syrphidae, Mantidae, Chrysopidae and lynx spiders
(Radiyanto et al., 2017). Coccinella sp. can prey on up to 23
Aphis sp. per day
(Efendi et al., 2018). C.tranversalis dragonflies, in addition to the types of
Coccinella sp. as
Aphis sp. predators, play a significant role in managing the
Aphis sp. pest.
C. transversalis is the most abundant predator in soybean, preying on
Aphis sp. and
Bemisia tabaci (Widaryanto et al., 2017).
The planting of four models evaluated for the pest
S. litura revealed substantial variances (Table 2). Pest leaf damage was highest in the
S. litura monoculture system (11.35%) and lowest in the six rows of soybean+two rows of corn intercropping system (5.02%). According to
Indiati and Marwoto (2017), ecosystem structure includes plant species composition, pests, natural enemies and a group of other biotic and abiotic interactions. These interactions between the components of a dynamic management strategy can suppress pest populations at a level that is not detrimental to farmers. The involvement of natural enemies in the ecosystem may range from 65 to 99%, implying that the pest population will be minimal
(Arifin et al., 2016). Pest management through intercropping soybean with cotton can enhance predator populations like ladybugs and spiders (
Nurindah, 2006).
The attack pod borer
E.zinckenella caused the most damage in monoculture (11.83%) and the least damage in six rows of soybean and two rows of corn of intercropping system (9.84%). The lack of predators in eliminating these pests is one of the causes of the high prevalence of pod borer in monoculture. The limited predator role as a pest controller was purportedly owing to low
C. servillia populations on monocultures, which only reached 0.78 adults per 6 m
2. Compared to the intercropping system with six rows of soybeans and two rows of corn, the predator population of
C. servllia reached 3.67 adults per 6 m
2. Furthermore,
Bhusnar and Sathe (2017) reported that
C. servillia can prey on the brown planthopper
Nilaparvata sp. and the
Chilo suppressalis stem borer larvae.
Table 2 shows the average population of
Aphis sp. and
Coccinella sp. in four soybean cropping types.
Aphis sp. had the maximum population in monoculture (4.56 adults per plant) and the lowest in four rows of soybean + two rows of corn (3.33 adults per plant) and six rows of soybean + two rows of corn (2.55 adults per plant). According to the findings of
Siagian et al. (2018), the maximum population of aphids pests was found in green bean monocultures (22.71 adults per plant), while the lowest was found in green bean shallot intercropping system (12.09-18.86 adults per plant). According to
Fattah et al., (2020b), the level of devastation caused by
Aphis sp. in soybean monoculture is higher (20.15%) than in soybean + chili intercropping (11.23%).
The predator population density of
Coccinella sp. was highest in six rows of soybeans + two rows of corn intercropping (3.78 adults per 2 m
2) and lowest in soybean monoculture (2.11 adults per 2 m2) (Table 2). Intercropping soybeans with five rows of soybeans with one row of
Crotalaria juncea ruffles had better insect diversity (18 species) than those without
C. juncea (nine species)
(Rahayu et al., 2018). Kurniawati et al., (2015) found that the Coccinellidae population was abudance (34 adults) in polyculture environments (rice and flowering plantation) than in rice monocultures (19 adults).
E. annulata predator population deliver found the highest in intercropping corn and lowest in monoculture (Table 3). According to
Smith and Sorley (2000), Polyculture enhanced the population of predatory enemies and parasitism. According to
Fitriani et al., (2011), E. annulata may prey
S.litura F. first instar larvae from 3.33 to 4.00 per hour, second instar larvae from 3.30 to 3.67, third instar larvae from 3.0 to 3.33, fourth instar larvae from 2.0 to 2.33 and fifth instar larvae from 1 to 1.67.
The soybean seed yield
The highest yield of soybean seeds from the three varieties studied wastelands to be higher in the Deja-1 variety (1.21 t h
-1) as seen in Table 4. The highest yield of soybean seeds from the three varieties studied was in the Detap-1 variety (2.26 t ha
-1). According to
Ayu and Suharto (2020), the highest seed yield was found in Detap-1 (3.88 t ha
-1), followed by Deja-1 (3.58 ton h
-1) and Dena-1 (2.67t ha
-1). and Dega-1 (2.50 t ha
-1). The description book of the Indonesian Legume and Tuber Crops Research Institute, ILETRI (2016) informs that the highest seed yield potential is the Detap-1 variety (3.58 t ha
-1), followed by Dena-1 (2.90 t ha
-1) and Deja-1 (2.87 t ha
-1).
