Can Temperature and Nitrate affect Grassy Weed Seeds Germination?

The experiment was conducted at Mizan Teferi Plant and Animal Health Laboratories in Southern Ethiopia during 2009 with the objectives to determine the temperature range at which Grassy weed seeds germinate and to evaluate the effect of nitrate on Grassy weed seeds germination.Weed species, Avena fatua, Bromus pectinatus, Lolium temulentum, and Snowdenia polystachya, which were found to infest crop fields in Ethiopia were used in the study. The seeds of the weeds were subjected to five temperature regimes viz. 50C/150C, 100C/200C, 150C/ 25 0C, 200C/ 300C and 250C/350C for 16 hours followed by 8 hours. Germination behavior of the weed species was determined with and without nitrate solution. Seeds of all four weeds were able to germinate from 5 to 35 0C. Germination behavior of the seeds differed along the temperature and nitrate levels and the weed species. Seeds of all four weeds exhibited dormancy from 5 to 35 0C. The result of the study revealed that the seeds treated with nitrate solution had lower dormancy percentage than non-treated seeds. This may enable farmers to design suitable pre-emergence control tactics to reduce weed problems during the crop-growing seasons.