Yield losses in maize due to parthenium weed
Parthenium hysterophorus (Asteraceae) (EPPO A2 List) is present throughout much of Pakistan where it is an invasive alien plant. The plant often invades maize (Zea mays) plantations (the third most important grain crop in Pakistan after wheat (Triticum aestivum) and rice (Oryza sativa)) where it can have negative impacts on yield. In the present study, the effect of different densities of P. hysterophorus (0, 5, 10, 15 and 20 plants per m2) on maize production was evaluated in a randomized block designed field experiment in Faisalabad, Pakistan. The total plant height of maize and the number of grains per cob was significantly reduced when P. hysterophorus density was higher than 10 plants per m2. Maize grain yield losses varied between 21 and 50 % with P. hysterophorus density ranging from 5 to 20 plants per m2. The results show that P. hysterophorus should be controlled in maize when plant density exceeds 1.3 plants per m2 in order to avoid economic losses.
Safdar ME, Tanveer A, Khaliq A, Riaz MA (2015) Yield losses in maize (Zea mays) infected with parthenium weed (Parthenium hysterophorus L.). Crop Protection 70, 77-82.