One of the factors that often becomes an obstacle to the productivity of maize plants is the attack of plant pests. The use of refugia plants such as kenikir is alternative pest control that can be tried. Therefore, this study aims to determine the effect of kenikir plant spacing to the intensity of pest attacks on local Muna maize pulut plants, which was carried out at the Field Laboratory of the Faculty of Agriculture, Halu Oleo University, using a Randomized Block Design (RAK) consisting of 4 treatments and 4 groups so that there were 16 treatment plots. The treatments tested were no treatment (P0), kenikir plant spacing was 50 cm (P1), 75 cm (P2), and 100 cm (P3). The variables observed were the pest population and the intensity of the attack. The results showed. Plant spacing of kenikir affects the population and intensity of pest attacks on local Muna maize rice plants. The lowest population average of Spodoptera frugiperda was found in the P3 (100 cm spacing of kenikir) of 4,00 individuals with an average attack intensity of 16,03% (5 weeks after planting). In comparison, the lowest beetle population average found in P1 (planting distance of kenikir 50 cm) was 0,25 and 0,50 individuals (for Apogonia sp. and Adoretus ranunculus, respectively), with an average attack intensity of 15,89% (9 weeks after planting)

Abstract. Widodo CJ, Taufik M, Khaeruni A, Mallaranggeng R. 2023. Determination of Begomovirus on chili plants (Capsicum sp.) in Buton and Muna Islands, Southeast Sulawesi, Indonesia. Biodiversitas 24: 741-751. Begomovirus disease is one of the main factors inhibiting chili cultivation which could harm plants and result in crop failure. This study aimed to determine the symptoms of begomovirus disease in chili plants in Buton and Muna, Southeast Sulawesi. The methods used are disease incidence survey, insect vector observation, molecular identification using the polymerase chain reaction (PCR) technique, and Sanger sequencing (Applied Biosystem 3500). The survey was conducted in Southeast Sulawesi province, covering Bau-Bau City, Buton Regency, Central Buton, North Buton, Muna, and West Muna. The results showed that the incidence and severity of Begomovirus disease were observed highest in Buton islands, 73% and 49.5% (Buton City), followed by North Buton, Central Buton, and Buton, with the incidence and severity of Begomovirus, respectively, of 71.74% and 59.5%; 69.32% and 51.5%; and 68% and 61.5%. While in Muna Regency, 63.16% and 38.5%, West Muna, 73.79% and 53.50%. On the other hand, the highest percentage of the whitefly population was in Bau-Bau City, 24%, while the lowest was in West Muna, 15.5% supporting this observation. Furthermore, PCR analysis successfully amplified symptomatic isolates from Buton and Muna islands at a band length of 580 bp. On the other hand, Sanger sequencing analysis revealed the existence of the Indonesian Pepper Yellow Leaf Curl Virus (PepYLCIV) with more than 96% genetic homology to the Gene Bank data of MN094866 PepYLCIV Capsicum annuum Indonesia and MN738463 PepYLCIV Chili pepper Indonesian. This information is the first report of the presence of Begomovirus on the two islands.

This research motivated by the Fusarium oxysporum which is a soil borne fungus that can infect cultivated plants. F. oxysporum is a facultative parasite that is part of its life as a saprophyte and becomes a parasite if there is a host plant. This study aims to determine the potential of endophytic bacteria from wild plants as biological agents control of F. oxysporum in-vitro. This research was conducted at the Laboratory of Plant Protection, Phytophatology Unit, Faculty of Agriculture, Halu Oleo University from September 2020 to March 2021. The results showed that endophytic bacteria isolated from wild plants such as as Jamaica cherry/kersen (Muntingia calabura), Suruhan (Paperomia pellucida), and Markisa Hutan/Rambusa (Passiflora foetida) have the potential as biological agents to control F. oxysporum in vitro, with the two best isolates, namely ASR-7(3) and BK-3(2) which were to inhibit the growth of F. oxysporum through the mechanism of antibiosis and competition, produced enzyme bioactive compounds (amylase and protease) which degrade of pathogenic fungi, and are able to produce volatile compounds.