اثرات درجه حرارت بالا و مدت نگهداري بذرعلف هاي هرز بر ماندگاري آنها در كود دامي

Effects of high temperature and duration of weed seed in manure on their seed viability

Manure application is one of the most important sources of weed seed for infestation farms and orchards. Temperature and moisture are two important factors influencing weed seed viability within manure. Therefore in order to study the effect of temperature, and duration of weed seed in manure on weed seed viability, a series of experiments were conducted at the laboratory of weed sciences, Ferdowsi University of Mashhad; by using a Completely Randomized Design (CRD) with factorial arrangement and 3 replications. Treatments included different temperatures (25, 40, 50, 60, and 70°C); and duration of weed seed in manure (0.25, 0.5, 2, 3, 5, and 7 days); weed species (redroot pigweed, canarygrass, common lambsquarters, and Flix weed); and manure (cattle manure or no manure).The results showed that seeds of all weed species were killed by keeping at 50°C after 5 days, but seeds of common lambsquarters could survive at 60°C for 12 hours. Also high temperature shortened the mean germination time (MGT) of all species. There were significant differences among weed seed species with regard to temperature tolerance and duration of weed seeds in manure, which may be related to seed structural and physiological properties. In conclusion, seeds of common lambsquarters and flixweed species showed the highest and least tolerance to temperature and durability in manure, respectively.