Sweet sorghum is a multi-purpose crop due to the use of all plant parts. The research was carried out under controlled conditions to evaluate the effect of fertilization management on growth, grain yield and yield characteristics of sweet sorghum grown as a second crop in Mediterranean climate conditions. The experiment was carried out two-factor randomized plot trial with 20 treatments combination of 5 nitrogen levels (0, 50, 100, 150, 200 kg N/ha) and 4 phosphorus levels (0, 50, 100, 150 kg P/ ha) with 3 replications. Some properties were investigated in the study such as, plant height, harvest index, thousand grain weight and grain yield per plant and some characteristics related to yield. The results shown that plant height of sweet sorghum increased with increasing N and P levels up to 200 kg N or 150 kg P per hectare, respectively, but increase beyond 100 kg N or P/ha was not found significant in general. Other features related to yield followed almost the same trend. Grain yield per plant of sweet sorghum increased linearly with increasing levels of N and P up to 200 kg N and 150 kg P/ha in both years. The combined application of 150 kg N + 150 kg P/ha produced highest grain yield.

Biyoetanol kaynaklarından biri olan tatlı sorgum son yıllarda önemi giderek artmaktadır. İçerdiği yüksek orandaki şeker nedeni ile biyoetanol üretiminde kullanılmaktadır. Bu çalışma, 2013 ve 2014 yılları arasında, Ege Üniversitesi, Ziraat Fakültesi Tarla Bitkileri Bölümü’nün deneme tarlalarında, iki faktörlü tesadüf parselleri deneme desenine göre üç tekerrürlü olarak yürütülmüştür. Denemede farklı azot (0, 50, 100, 150, 200 kg N/ha) ve potasyum (0, 50, 100, 150 kg K2O/ha) seviyelerinin tatlı sorgumda etanol verimi üzerine etkilerini araştırılmıştır. Azotlu gübreler iki eşit dozda uygulanırken, potasyum tek seferde ekimle beraber toprağa karıştırılarak uygulanmıştır. Çalışmada, sap ve özsu verimi, şeker oranı ve teorik etanol verimi gibi özellikler test edilmiştir. Sonuçlar, azot ve potasyum uygulamaların tüm özellikler üzerinde önemli etkilerinin bulunduğunu göstermiştir. Yüksek N ve K uygulamaları, kontrol uygulamasına göre etanol verimini yükseltmiştir. N150-K100 kombinasyonu Akdeniz ekolojik koşullarındaki İzmir’de, tatlı sorgumun etanol verimini yükselten en iyi gübre seviyesi olduğu ortaya çıkmıştır.

Sweet sorghum, which is one of the bioethanol sources, has been increasing in importance in recent years. It is used in the production of bioethanol due to the high content of sugar in it. This study were carried out at Ege University, Faculty of Agriculture, Department of Field Crops, Izmir/Turkey on the experimental fields, two-factor coincidence plots were carried out in the form of a three-repeated potting experiment according to the trial pattern during the summer growth seasons of 2013 and 2014. Effects of different nitrogen (0, 50, 100, 150, 200 N ha-1) and potassium (0, 50, 100, 150 kg K2O ha-1) levels of on ethanol yield of sweet sorghum were investigated, in the experiment. In the study, some traits were investigated such as plant height, dry matter yield, silage pH, crude protein content. The results of the experiment revealed significant effect of different N and K levels on growth, yield and some silage quality parameters. Increasing N and K levels increased plant height, dry matter yield, crude protein content and silage pH compared to the control (N0-K0) treatment. It is concluded that sweet sorghum crop performed better in N150-K100 level and hence recommended for further studies to authenticate higher forage yield and quality in the agroclimatic conditions of Izmir.

Sweet sorghum, which is one of the bioethanol sources, has been increasing in importance in recent years. It is used in the production of bioethanol due to the high content of sugar in it. This study were carried out at Ege University, Faculty of Agriculture, Department of Field Crops, Izmir/Turkey on the experimental fields, two-factor coincidence plots were carried out in the form of a three-repeated potting experiment according to the trial pattern during the summer growth seasons of 2013 and 2014. Effects of different nitrogen (0, 50, 100, 150, 200 N/ha) and potassium (0, 50, 100, 150 kg K2O/ha) levels of on ethanol yield of sweet sorghum were investigated, in the experiment. N was applied in two equal doses in the experiment. K2O was mixed with soil and supplied as a single application. Some parameters were tested in the experiments such as stalk and juice yield, sugar content and theoretical ethanol yield. Results indicated that the effects of N and K treatments on all characteristics tested were significant. Application of the higher rates of N and K increased the ethanol yields compared to the control treatment. Based on these results the combination of N150-K100 were proved to be the best fertilizer level for ethanol yields of sweet sorghum grown under Mediterranean ecological conditions of Izmir.