Long-term application of diuron herbicides caused Eleusine indica weeds to become resistant to diuron

Abstract The presence of weeds during the vegetative growth of pineapple plants could reduce production by up to 88%, so weed control is necessary. One way of controlling weeds is by use of herbicides. However, continuous, long-term application of herbicides could result in environmental pollution and weed resistance to the herbicides. This research aimed to identify the resistance of E. indica weeds to herbicide diuron and to compare the growth characteristics of diuron-resistant and diuron-sensitive E. indica. The resistant weeds were taken from the pineapple plantations under continuous, long term application of diuron herbicides, while the sensitive weeds were taken from areas which have never been applied with diuron herbicides. This research was conducted at the University of Lampung, from February to October 2020. It consisted of two experiments, The experiment 1 : the response of E. indica to diuron and The experiment 2: the growth characteristics of diuron-resistant and diuron-sensitive E. indica. In the experiment 1, experiments were arranged in a split plot design with five replicates and the treatments consisted of two factors. The first factor consisted of the diuron-resistant and the diuron sensitive E. indica and the second factor was diuron dosage (0, 1600, 3200 and 6400 g ha-1). In the experiment 2, The resistant and sensitive E. indica were compared using t-test. The study revealed that the diuron-resistant E. indica needed a longer time to be 50% damaged than the sensitive one. The resistance index (RI) of E. indica to diuron was 2.80, indicating low level of resistance. The diuron-resistant and diuron-sensitive E. indica did not significantly showed different growth characteristics.