Browsing by Author "Paknejad, Farzad"
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Item Effect of concentrations and time of kaolin spraying on wheat aphid(Uludağ Üniversitesi, 2014-01-19) Nateghi, Mohadeseh; Paknejad, Farzad; Moarefi, MaryamCommon wheat aphid (Schizaphis graminum Rondani) is the cereal key pest. To study the effectiveness of different concentrations and times of kaolin spraying on the reduction of S. Graminum damage, a field experiment was arranged based on randomized block design with 4 replicates. Treatments were kaolin concentrations at four levels [0, 1.25 %, 2.5 % and 3.75 %, k1, K2, k3, and k4, respectively], times of kaolin spraying at three levels (concurrently with the stem forming, coincides with the first appearance of spikelets, coincides with dough development, T1, T2 and T3 respectively. The results indicated that the maximum (9914.81 kg ha -1 ) and minimum (6277.76 kg ha -1 ) grain yield were found in plots received 3.75 % kaolin at T2 time and untreated control, respectively. The highest (22666.66 kg ha -1 ) and lowest (16465.92 kg ha -1) biological yield were detected in plots exposed to kaolin 1.25 % at T3 time and control treatment, respectively. The present study showed that Kaolin could reduce wheat aphid damage and had positive effect of grain and biological yields. Therefore, Kaolin can be an important and effective tool to mitigate wheat aphid damage, and could be a good alternative to chemical products.Item Investigation of barley productivity responses to different water consumption by using the CERES-Barley model(Uludağ Üniversitesi, 2016-03-23) Rika, Zeinab Fatemi; Paknejad, Farzad; Amiri, Ebrahim; Ilkaee, Mohammad Nabi; Mirtaheri, Seyed MehdiCropping system models have evolved over the last four decades in response to demand for modeling to address more complex questions, including issues on sustainable production, climate change and environmental impact. The present study is about dynamic mechanistic model (CERES (Crop Environment RE source Synthesis)-Barley that was validated by predicting growth and yield of barley (Hordeum vulgare L.) under different water management conditions. My objective was analysis of barley responses to different water consume for optimizing of biomass and yield productivity. Evaluation of analysis showed that performance of the model was reasonable as indicated by close correspondence of simulated crop phenology, biomass accumulation and grain yield versus measured data. Growth parameters of barley in CERES-Barley were calibrated through field experiments, Karaj (Iran) 2010-2011. Genotypic variables determined for 5 commonly cultivars grown in Karaj. The performance of the models was evaluated using simulated and observed data on anthesis and maturity date, in-season LAI, final yield and its components. Grain yields simulated by model were acceptable when compared with experimental results. The determination coefficient in historical series varied from 0.83 to 0.99 for evaluation of CERES- Barley under normal irrigation. The accuracy of model simulation in dry matter was optimum in based on correlation coefficient 0.91-0.98. Also model acted well for biomass simulation in treatments. As biomass measured data generally have 10-20% error and treatments widely varied in two irrigation system. The objective of this study was determine, whether CERES-Barley model could be forecast yield and biomass in maturity under growing season and ecological management in Karaj.