Effect of Microwave and UV-C Radiation on Some Germination Parameters of Barley Seed Using Mathematical Models of Gompertz and Logistic

Abstract

Two separated sets of laboratory experiments were studied for barley seeds treating using a microwave and ultraviolet irradiation. In the microwave set, seeds have been exposed to the microwave radiations (2450 MHz) for 0 sec (control, MW0), 5 sec (MW1), 10 sec (MW2), and 20 sec (MW3), while in the ultraviolet set, seeds have exposed to UV-C radiation (254 nm) for 0 min (control, UV0), 30 min (UV1), 60 min (UV2), and 120 min (UV3). The aim is to study the influences of different exposure time from MW and UV-C radiation on some barley seed germination parameters and to choose the fitting model Logistic (Log) or Gompertz (Gom) suited to cumulative germination curves under the influence of these factors. The results of this study showed higher seed germination percentage (93.33%) at the exposure time MW2 and UV3 (88.33%), whereas the lowest value (66.67%) recorded in MW3 treatment. The results also appeared the best values at MW2 in SG, 6.24 seed day-1; in GRI, 31.19% day-1, and in GI, 87.67, as well as at UV2 in MGT, 3.32 day. The higher value of asymptotic germination barley seeds was found with Gom function (97.24%, and 88.71%) at MW2 and UV3, respectively. Besides, Gom functions at MW1 and UV2 give the highest maximum germination rates at 2,08 and 2.51% h-1, respectively. The results of the Log equation illustrated the highest value of germination percentage of the inflection point has recorded in 43.85 and 47.37 % on UV3 and MW2 treatments, respectively. For the fitting growth curve, the results have proven that the Gom function was shown the lowest values in MSE in all MW and UV exposure times, as compared with the Log function. So, the results of the Gom function were more fit for the growth curve for MW and UV treatments, as compared with the Log function.