جستجوی مقالات مرتبط با کلیدواژه "growing degree day" در نشریات گروه "اکولوژی"

The present study was carried out to compare the phenology of annual ground cherry (Physalis divdricata L.) and its effect on maize yield ‎ ‎.

A field experiment was conducted in the Research Station of Mahidasht in Kermanshah Agricultural and Natural ‎Resources Research and Education Center, in 2017.‎ Different densities of annual ground cherry, including 0, 8 and 16 plants m-2 and corn were planted.  The competition‎ and their phenological stages ‎were recorded based on GDD (growing degree days) for each growing stage. ‎

The results of this study showed that ‎annual ground cherry ends its phenological stages later than corn. In order to complete its life cycle, ‎‎1262.7 growing degree days and 159 days were needed. Thus, complete life cycle of corn required ‎‎1890.7 GDD and 139 days.Both plants passes the early stages of growth and ‎germination concurrently, Maize, however, ‎comleted Vegetative growth and seed ‎ripening more earlier than annual ground cherry. ‎Also, the results of studying the effect of different densities of ‎annual ground cherry on yield and yield components of corn including 1000-seed weight, number of seeds per ear row, corn harvest index and leaf area index showed that all these traits decreased by increasing density of annual ground cherry. However, the number of seed rows per ear, which is genetically-control trait, was not affected by competition with annual ground cherry. In contrary to the above traits, the density of this weed increased with the effect of increasing the height of corn and as a result, increasing the biomass of corn compared to control. In general, weed densities of the 8 and 16 plants m-2 decreased maize yield by 10 and 14 percentages, respectively.

The results of this study suggest that if corn fields are infected with this weed and we do not ‎succeed in combating it in the early stages, earlier harvest of corn in the fall will allow it to be ‎harvested by cultivation methods or using a general herbicide of this weed before its seeds are fully ‎ripen.