Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Interference and estimation of economic threshold level of alternanthera philoxeroides in maize (Zea mays L.).


Knowledge of economic threshold of emerging invasive weed Alternanthera philoxeroides (alligatorweed) is important to implement timely, efficient and economical weed control method for profitable maize production. Two-year field study consisting five density levels of A. philoxeroides viz. 0, 1, 2, 4 and 8 plants m-2 was conducted to estimate the maize grain yield losses at different density levels and to determine economic threshold level (ETL) of A. philoxeroides. Maximum weed dry biomass (44.28 g m-2), N (9.02 kg ha-1), P (7.91-6.86 kg ha-1) and K (7.99 kg ha-1) were observed at 8 plants m-2A. philoxeroides density. The same weed density caused highest reduction maize plant height, number of grains per cob, 100 grain weight, grain weight per cob and biological yield of maize. Higher A. philoxeroides density also caused up to 62% reduction in maize grain yield and 21% reduction in grain protein contents as compared to weed free. ETL of A. philoxeroides was estimated to be 0.47 plants m-2, if this weed controlled chemically. Based on current findings complete control of this weed using chemical weed control is suggested to tackle yield losses in grain maize.