EFFICACY OF VARIOUS HERBICIDES FOR MANAGEMENT OF WEED FLORA IN CITRUS ORCHARDS

To determine the efficacy of different post-emergence herbicides against weed flora in citrus orchards, experiments during July-Aug (summer) and Oct-Nov 2009 (autumn) were laid out in a randomized complete block design with three replications. The experiments comprised of five treatments including four herbicides and a weedy control. The four herbicides were glyphosate (Title 95%SG, a candidate product of the Auriga Chemicals Enterprises), glyphosate (Round up, used as standard product), gramoxone (Remote 20%SL, a candidate product of Ali Akbar Enterprises) and gramoxone (Gramoxone 200SL, used as standard product). Statistical analyses of the data indicated that the herbicides had a significant weed control and weed canopy reduction. The herbicides, Title 95%SG, Round up, Remote 20%SL and Gramoxone 20SL decreased the total weed density to 2.6, 6.5,23.3 and 31.4 weeds m-2, respectively in summer; whereas the respective values in autumn were 1.6, 1.5, 4.1 and 5.2 weeds m-2. Similarly the total weed canopies were 3.0, 5.8, 10.8 and 13.2% weeds m-2, respectively in summer; and 2.2, 1.4, 3.6 and 4.8% weeds m-2 in autumn. However, their effect onindividual weeds was statistically at par. The herbicide, Title 95%SG had a statistically similar performance in comparison with that of Round up. Similarly, Remote 20%SL performed statistically at par with Gramoxone 200SL. The highest values for weed canopy coverage were in the weedy check i.e. 87% m-2 in summer and 83% m-2 in autumn; whereas lowest values were 3% and 2.2% recorded in Title 95%SG in summer and autumn, respectively. Both experiments disclosed that all theherbicides significantly decreased the canopies of all the weed species as compared to control treatment and that no injury was recorded on the citrus trees.