Effect of herbicides and hand weeding on weed control in guava cv. L-49.
The efficacy of the following weed control methods was assessed in guava cv. L-49 during 2007 in West Bengal, India: glyphosate at 1.0 and 0.75 l a.i./ha (T1 and T2) as pre-emergence; 2,4-D sodium salt at 1200 and 1000 g a.i./ha (T3 and T4) at 30 days after glyphosate application; glyphosate at 1.0 l a.i./ha + 2,4-D sodium salt at 1200 g a.i./ha (T5) and glyphosate at 0.75 l a.i./ha + 2,4-D sodium salt at 1000 g a.i./ha (T6) at 30 days after glyphosate application; hand weeding at 30-day intervals (T7); and unweeded control (T8). The weeds in the experimental field included monocots (Cyperus rotundus, Cyperus iria, Cynodon dactylon, Setaria glauca [S. pumila] and Echinochloa colonum [E. colona]) and dicots (Commelina benghalensis, Phyllanthus niruri, Solanum nigrum, Alternanthera philoxeroides, Mimosa pudica and Ageratum conyzoides). Among the treatments, T5 was the most effective in controlling the weeds in the guava orchard. This same treatment also recorded the highest values for all vegetative growth, flowering, fruiting and fruit physico-chemical characteristics studied.