Title : A Proof of Parthethenium hysterophorus is an invasive and allelopathic weed in our sustainable agriculture under climatic condition of Pakistan
Parthenium (Parthethenium hysterophorus L.) is one of the most aggressive herbaceous weeds of the Asteraceae family. It is widely distributed, almost across the world and has become the most important invasive weed. Thee infestations parthenium have been reported to reduce grain and forage yields by 40-90%. The spread of parthenium has been attributed to its alllelopathic activity. Allelochemicals released from parthenium has been reported to decrease germination and growth of agronomic crops, vegetables, trees and many other weed species. Growth promoting effects of parthenium extracts at low concentrations have also been reported in certain crops. A laboratory experiment was carried out to evaluate the germination and germination indices of maize with estimation of maize growth infested with parthenium allelopathy. This trail was conducted in CRD designs with 3 replications. Parthenium dry powder % mixed with soil produced variable responses regarding seed germination and seedling growth. Emergence index, mean germination time, vigor index was significantly affected by various parthenium dry powder percentages. The smaller amount of parthenium powder (5, 10 and 15%) promoted the maize germination and seedling growth.The highest parthenium dry powder (20%) negatively affects the maize germination and seedling growth. Germination %, time to start germination, time taken to 50% could not be affected by parthenium dry powder. In light of this study it is recommended that smaller amount of parthenium dry powder percentage (5, 10 and 15%) promoted the maize germination and seedling growth positively. Therefore the maize can be planted in the field infested with parthenium weed to some extent and its planting should be avoided where the higher population of parthenium precedes the maize planting.
Key words: Allelopathy, Parthethenium hysterophorus, Germination, Growth, Development, Maize.