Manipulation of microhabitat by polyculture planting system as ecosystem stabilizer for management of pests and natural enemies in shallot (Allium ascalonicum Linn.)
Shallot (Allium ascalonicum Linn.) is one of important commodities for Indonesian people, yet its production is still limited by pest attack This research was conducted in Banyuputih Village, Wringin Subdistrict, Bondowoso Regency from July to October 2019. This study applied a Randomized Block Design (RBD) with six treatments, namely: P1 = Polyculture of shallot + lemongrass; P2 = Polyculture of shallot + celery; P3 = Polyculture of shallot + mustard; P4 = Polyculture of shallot + lemongrass + mustard; P5 = Polyculture of shallot + celery + mustard; P6 = Monoculture of shallot. Each treatment was repeated 4 times. Observation was started when plant was at the age of 30 days after planting. Data collection was done by directly observing the sample plants. Sampling was carried out using Yellow trap and pit fall trap. A total of 10 samples were collected from each plot with interval of 4 days. Observation included collecting the pest insects and natural enemies that were found, counting the number of populations of each species, and scoring towards the damage plants. The results showed that shallot planting by polyculture with different types of plants affected the population of pests and natural enemies as well as the level of diversity of insects in shallots. Planting shallots by polyculture has been proven to control pest population compared to planting shallots by monoculture. Polyculture planting with two types of plants was found to produce better outcome than polyculture planting with three types of plants with best treatment observed in P1, namely polyculture of shallot and lemongrass which resulted in the lowest pest population of 17.5.