Identification and Potential of Secondary Metabolism of Weeds as Bio Herbicides in Environmentally Friendly Citrus Cultivation

Abstract

Production of oranges in Indonesia increased from 1.78 million tons to 2.16 million tons in 2014. In 2016, Indonesia imported 2,212 tons of oranges. Weed plants caused a decline in orange production, leading to a decrease in harvest yields by 61%. The research aimed to identify weed species and the potential secondary metabolism of dominant weeds on orange plants. The research method utilized weed vegetation analysis, focusing on the Summed Dominance Ratio (SDR). The treatments with kirinyuh extract (P0) were as follows: (Control); P1: 20%; P2: 40%; P3: 60%; P4: 80%. Observation parameters included phytotoxicity, wet weight, and dry weight. The research results revealed 10 families, 25 species, and 400 weed individuals. Weeds with the highest SDR value were of the Oldenlandia corymbose type, with a Summed Dominance Ratio (SDR) of 7.28%, and the second-highest SDR value was Euphorbia hirta weed with 7.22%. The lowest was the Richardia brasiliensis weed with an SDR value of 0.633%. Phytotoxicity on kirinyuh leaf plants was highest in P4 with a concentration of 80g/l at 47.33. Wet weight and dry weight influenced P4 concentration, with an 80g/l concentration most inhibiting the growth of kirinyuh leaves. Laboratory analysis of flavonoid, total phenolic, and tannin content showed that Euphorbia hirta weed had higher levels compared to Oldenlandia corymbose weed.