Hussein F. Farrag , Abdallah M. Sliai and Tha´ar F. Mhmas
In this paper we compare the allelopathic potentiality of two invasive species; Heliotropium curassavicum and H. bacciferum. The shoot height, root depth and root/shoot ratio for Calotropis procera and Faba sativa plants were generally reduced under mulching of the two invasive plants during different growth stages. Numbers of recorded flowers were 6.66, 2.33, 1.66 and 1 for control, T1, T2 and T3; respectively, for the treated plants by H. curassavicum, while these values increased to 7.66, 3.54, 2.56 and 0.33 for the same treatments but to plants treated with H. bacciferum. The RGRs of the tow test species generally decreased with age as a result of decreased age-specific LAR and slow NAR. Correlation between RGR and other growth variables demonstrated that RGR positively correlated with NAR, LAR and SLA for all treatments of C. procera, while the test species F. sativa, showed negative correlation between RGR and NAR values and positive correlation with LAR and SLA. On the basis of these results, it was concluded that the mulch treatments using H. curassavicum had much inhibitory effect than that of H. bacciferum for both test species. The present study recommend the use of the two Heliotropium species for the biocontrol of harmful weeds like C. procera and in the same time alert for the inhibitory effect of these species on the growth of economic plants like F. sativa.
Share this article