ارقام ذرت

In order to investigate the effect of irrigation volumes under drip irrigation condition on grain yield and morphological parameters of corn cultivars, an experiment was conducted during 2018 and 2019 in Gorgan agricultural research station. The experiment was laid out in a randomized complete block design in form of split plot factorial experiment and replicated three times. Treatments were including three irrigation volumes [Irrigation at %100 (I1), %75 (I2) and %50 field capacity (I3)], as A factor, and varieties (SC704, SC705 and SC706) as B factor. The results of analysis varians showed that; effects of irrigation treatments on yield and yield components was significant at %1 probablity and the difference between Varieties was significant at %1 probablity, but intraction effects of two treatments on yield and yield components was not significant. Investigation of grain yield at irrigation treatment showed, the highest yield of I1 treatment was 7.85 ton ha-1, and reduced by %15.03 and %29.68 respectively when the irrigation interval was reduced by 75% to %50 field capacity. Comparison of grain yield at varieties showed, yield of single cross 706 with 7.03 ton ha-1 was%12.84 and %3.68 higher than single cross 704 and single cross 705 respectively. Interaction effect of irrigation value and variety showed, the most grain production was belong treatment of single cross 706 and irrigation at %100 field capacity. Investigation of WUE of showed, irrigation at %75 field capacity and single cross 706 with WUE of 1.15 kg m-3 grain yield had the most WUE compared to other irrigation treatments and varieties. With dimitation of irrigation, plant height and ear length also decreased.

In order to evaluate the SWAP model a study was conducted in 2017 in the farm of the Department of Irrigation and Reclamation Engineering, University of Tehran, located in Karaj as a factorial experiment in a randomized complete block design. The treatments consisted of three maize hybrids SC-704, SC-400 and SC-260 (V1, V2 and V3, respectively) and three levels of irrigation water salinity 0.7, 3 and 5 dS m-1 (S1, S2 and S3, respectively). In each maize cultivar, for the model calibration, the crop yield data measured in the field from the salinity level of irrigation water 3 dS m-1 and for its validation, the salinity levels of 0.7 and 5 dS m-1 were used. Also, to evaluate the model in estimating soil moisture and salinity, field data of V1S2 (calibration) and V1S3 (validation) were used. Based on the obtained results, SWAP model has a good performance in estimating soil moisture so that in the validation stage in three soil layers (0-20, 20-40 and 40-60 cm) with RMSE (Root Mean Square Error) of 0.03, 0.03 and 0.04 cm cm-3 respectively and has a good accuracy in predicting soil salinity of 0-20 cm surface layer (RMSE = 0.67 mg cm-3) but with increasing soil depth, the accuracy of the model decreases so that RMSE of 1.16 and 1.19 mg cm-3 were obtained in two layers of 20-40 and 40-60 cm, respectively. The SWAP model detected the inherent differences between different cultivars of maize and the best simulation results were obtained for SC 704.

Element efficiency is one of the most important characteristics of different plant cultivars for managing nutrition and fertilizer application in plants. This study was carried out to investigate the efficiency of silicon in different maize cultivars in a calcareous soil under greenhouse conditions. Treatments included five maize cultivars (single crosses 400 (ksc400), 410 (ksc410), 704 (ksc704), 705 (ksc705), 706 (ksc706)) and two silicon levels (0 and 100 mg silicon in 1 kg soil from potassium silicate source), which was performed in a factorial arrangement based on a completely randomized design. After eight weeks of vegetative period, plants harvested and factors such as shoot and root dry weight, leaf area, root volume and surface area and plant silicon uptake were measured. Efficiency element indices including adsorption and consumption efficiency of silicon and silicon efficiency of different cultivars were calculated. Among cultivars, ksc706 with 14.54 g yield, root weight of 6.7 g, leaf area of 173700 mm2 and root area of 185185 mm2 had the best results in terms of morphological characteristics and ksc410 cultivar with yield of 10.03 g, root weight of 5.25 g, leaf area of ​​2147900 mm2 and root area of ​​136284 mm2 showed the lowest desirable characteristics, compared to the control treatment. Yield increase of cultivars compared to the control treatment were: ksc400 (20.7%), ksc706 (17.8%), ksc410 (9.2%), ksc704 (8.9%) and ksc705 (4.8%). The highest silicon uptake efficiency was in ksc706 cultivar (85.7%) and the lowest in ksc704 (58.9%), and the highest silicon consumption efficiency was in ksc705 (12.52%) and the lowest in ksc400 (5.44%). With regard of increasing the area of root system in the treatment containing silicon compared to the control, and the effects of silicon on the uptake and transfer of more nutrients from the soil to the shoots, an increase in plant yield is evident. Accordingly, it is suggested to consider the development of planting the effective element plants with the aim of managing input consumption, soil fertility and sustainable agricultural goals.