Series of trials in laboratory, pots and field were undertaken during the period from 2002 to 2005 in Weed Research Centra! Laboratory, Agriculture Research Center Giza, to study the effect of temperature degrees, planting depths and cutting intervals on the regrowth % of the for the perennial weeds i.e., cogongrass "Imperata cylindrica (L.) pers.", bermuclagrass "Cynodon dactyion (L) pers.", nutsedge "Cyperus rotundas L." and field bindweed "Convolvulus arvensis L". The temperature degrees used in germination experiment were as follow: (15, 25 and 35'C), the planting depths 2, 5, 10, 15 and 20 cm and cutting intervals every one, two and three weeks. The main results indicated that, increasing percentage of germination %, germination speed, plumle length, redicale length and dry weight of seedlings for cogongrass, bermudagrass, nutsedge and field bindweed with increased temperature from 15 to 35 C. Progressive and consistent reduction In the germination %, length of the above ground parts, length of the under ground parts and dry weight of the whole plant of all weeds studied occurred with increasing planting depths from 2 to 20 cm. The reduction percentage of the dry weight of the above ground parts of seedlings of cogongrass, bermudagrass and nutsedge increased with decreasing the cutting intervals from three to one week, respectively. However, differences between one and two weeks were significant with respect to cogongrass. |
