Leaf Litter Decomposition Rate by Utilizing Biological Agents to Control Pests and Increase Plant Growth of Red Chili

Abstract

Decreased yield and quality of chilies were mainly due to the attack of fruit flies and whiteflies as virus-carrying vectors. Until now, to control these pests farmers still rely on the use of synthetic chemical pesticides that leave residues. Efforts to control pathogens and improve yield and quality of red chilies use biological agents Trichoderma sp., Mycorrhizal, and organic materials that have been completely decomposed. The objective of this research was to examine the effect of the level of d ecomposition of leaf litter in combination with the application of different biological control agents and NPK dosage on plant growth. This experiment was conducted at Experimental Garden, Condongcatur Campus, Depok, Sleman, Yogyakarta from June until September 2020. The experiment was arranged according to Randomized Completely Block Design with two factors, each treatment consists of three replicates. The first factor was the d ecomposition of leaf litter with a C/N ratio of 28.52 and decomposition of leaf litter with a C/N ratio of 16.57. The second factor was NPK dosage and/or types of biological control agents with the following five treatments: 1) Only recommended NPK dosage (500 kg.ha -1 ), 2) Combining Trichoderma and 50% recommended NPK dosage, 3) Combining Mycorrhiza and 50% recommended NPK dosage, 4) Combining PGPR and 50% recommended NPK dosage, 5) Pest control, 6) Stimulant. The data were subjected to analysis of variance followed by Duncan’s Multiple Range Test. The result of the experiment showed that the d ecomposition of leaf litter with a C/N ratio of 28.52 significantly improved the plant height at 14, 28, and 42 days after transplanting and shoot dry weight in comparison with chili that was treated by d ecomposition of leaf litter with C/N ratio of 16.57 . The use of decomposition of leaf litter with a C/N ratio of 16.57 in combination with biological control agents + 50% recommended NPK dosage significantly increased the number of branches and had a faster flowering stage. However, there were no significant differences between the three types of biological control agents in affecting the number of branches and the flowering stage. The growth plants treated with NPK fertilizer only has the lowest plant growth compared to other treatments. It is suggested that to increase plant growth and accelerate the flowering stage, chili can be treated with fully decomposed leaf litter combine with biocontrol agents and 50% recommended NPK.