Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Chemical weed control in Kinnow orchard.

Abstract

Field trials were conducted at Palampur, Himachal Pradesh, in 1983 to test the efficacy of 15 herbicide treatments, applied post-em. as directed sprays to tree basins on 5 July, and manual weeding for the control of weeds (30.9, 28.8 and 14.3% of which consisted of Imperata cylindrica, Desmostachya bipinnata and Saccharum munja, resp.) in 6-year-old Kinnow [mandarins cv. Kinnow] budded on to rough lemon rootstock on clay loam. By 90 d after treatment, monocotyledonous weed populations were reduced from unweeded control values of 9.7 plants/0.25 m2 to 2.8-7.8 plants, maximally by manual weeding or 4.807 + 0.6 kg/ha dalapon + paraquat. Dicotyledonous weeds were reduced most (from controls of 2.1 plants to 1.0 plant) by 0.75 kg diquat ± 0.8 kg 2,4-D; however, not all treatments resulted in effective control of these plants. The DW of total weeds was reduced from 763.3 g/0.25 m2 to between 43.3 and 430.0 g (i.e. with weed control efficiencies (WCE) of 43.6-94.3%), the best treatment being by manual weeding and the most effective herbicide (resulting in 146.6 g weed DW and WCE of 80.7%) being the dalapon + paraquat treatment.