The effects of different nitrogen doses on herbage and seed yields of annual ryegrass (Lolium multiflorum cv. caramba)

This study has been carried out during the growing seasons of 2003-2004 and 2004-2005 in Turkey, to determine the effects of different nitrogen doses on the herbage (150, 230, 310, 390, 470, 550, 630 and 710 kg ha-1) and seed yields (150, 170, 190, 210, 230, 250, 270 and 290 kg ha-1) of and some agricultural characteristics of annual ryegrass cv. “caramba”. Two different trials were established separately for the production of herbage and seed in the research. According to the two-year research, applications of different nitrogen doses are observed to be important for all properties of herbage yield and properties except for plant height of seed yield. As a result, the highest forage yield in annual ryegrass with the aim of green herbage is obtained to be of (54834 kg ha-1) 470 and (54976 kg ha-1) 550 kg ha-1 at nitrogen levels, plant height (71.9 cm), crude protein ratio (21.2%) and the yield of crude protein is (1982 kg ha-1) 470 kg ha-1. It was obtained for the seed production that the highest number of tiller (626 item/m2), fertile tiller number (483 item/m2) and grain yield are (0.54 mg) 210 kg ha-1, spikelet number per grain is (32.7 item) 250 kg ha-1 and (33.6 item) 270 kg ha-1, the highest seed yield is (343 kg ha-1) 250 kg ha-1 from the nitrogen dose application. In the light of information, the highest values were obtained from total 470 kg ha-1 nitrogen application in herbage production and 250 kg ha-1 in seed production.Key words: Crude protein, fodder crops, herbage yield, seed yield, nitrogen doses

The effect of different organic matters on plant growth regulation and nutritional components under salt stress in sweet sorghum [Sorghum bicolor (L.) Moench.]

Salinity is one of the major constraints of crop production, especially in the world's arid and semi-arid regions. Variations in the nutritional components of Gulseker sweet sorghum (local variety) and the effects of different organic matter on morphological and physiological changes under salt stress were examined herein. The response of sweet sorghum to applications of different organic matter [amino acid (AA), cow/farmyard manure (CM), biochar (BC), humic acid (HA), sheep manure (SM), worm casting (WC), poultry manure (PM), and bat guano (BG)], as well as water irrigation salinity at 150 mM NaCl were evaluated under greenhouse conditions using plastic pots containing 11 L of peat:perlite (2:1). Plants grown under different treatments were then classified as morphological (shoot fresh and dry weights, shoot diameter, shoot length, number of leaves and leaf area per plant) and physiological parameters (relative water content (RWC), chlorophyll (SPAD), malondialdehyde (MDA), Na+, K+, Ca++, and Cl- ion content. The results revealed that salt stress caused reduced growth parameters and chlorophyll, RWC, K+ and Ca++ ion content, while MDA content, Na+ and Cl- accumulation showed an increase. The results showed that the organic matter treatments diminished the damaging effects caused by salt stress via a reduction in the uptake of Cl- and Na+, which enhanced K+ and Ca++ uptake and reduced the MDA levels, presenting a favorable effect in reducing the oxidative stress that emerged from salt stress

The effect of different replications of humic acid fertilization on yield performances of common vetch (Vicia sativa L.)

This study was conducted in a randomized complete block design with three replications in Diyarbakir, Turkey, in 2003 to 2004 and 2004 to 2005 growing seasons, in order to determine the effects of different humic acid treatments (control, soil 100%, seeds 100%, leaves 100%, soil 50% + seeds 50%, soil 50% + leaves 50%, seeds 50% + leaves 50% and seeds 33% + soil 33% + leaves 33% fertilizations) on herbage and crude protein concentration of common vetch. According to the results of this study, humic acid treatments increased the yields, and this increase was found to be significant as well as statistical. According to the two-year research, the highest value for green herbage yield (15180 kg ha-1), dry herbage yield (3045 kg ha-1) and plant height (61 cm) was obtained from soil 100% fertilizations, while the highest crude protein concentration (13.43%) was obtained from seeds 33% + soil  33% + leaves 33% fertilizations.Key words: Crude protein, fertilization, fulvic acid, humic acid and vetch

Antioxidant Enzyme Activities and Abiotic Stress Tolerance Relationship in Vegetable Crops

Climatic changes can cause serious reductions in yield and crop quality. Under the threat of climatic changes, one of the precautions to cope is selection and development of resistant vegetable genotypes to abiotic stresses. Several physiological and biochemical reactions and different tolerance levels can occur according to plant species. When plants are subjected to environmental stresses such as salinity, drought, temperature extremes, herbicide treatment and mineral deficiency, the balance between the production of reactive oxygen species (ROS) and the quenching activity of antioxidants is upset, often resulting in oxidative damage. Since activated oxygen species can disrupt normal metabolism through oxidative damage to lipids, protein and nucleic acids, plants possess a number of antioxidant enzymes that protect them from these cytotoxic effects. To control the level of ROS and to protect cells under stress conditions, plant tissues contain several enzymes for scavenging ROS. The high levels of antioxidative enzyme activities were determined in the tolerant genotypes of tomatoes, eggplant, peppers, cucumbers, melons, squash, beans, okra, etc. to several abiotic stress factors. Both the whole plant and in vitro callus culture experiments gave similar results. Antioxidant enzymes can be useful for screening to determine the tolerant and sensitive plant genotypes against abiotic stresses

EFFECTS OF DIFFERENT CHEMICAL PRETREATMENTS ON CELL WALL COMPOSITION AND ASH CONCENTRATION OF SWEET SORGHUM BAGASSE FOR BIOETHANOL PRODUCTION

Pretreatment is one of the key processes in lignocellulosic bioethanol production, which is needed to improve accessibility of enzymes to cellulose. This study was conducted to investigate the effects of different chemical pretreatments on cell wall composition and ash concentration of sweet sorghum bagasse. 9 different pretreatment methods used in the study can be categorized into 3 different methods such as dilute sulphuric acid (1, 1.5 and 2 % H2SO4 w/v), dilute sodium hydroxide (1, 1.5 and 2 % NAOH w/v) and sequential dilute sulphuric acid and sodium hydroxide (1 % H2SO4 w/v + 0.5 M NAOH, 1.5 % H2SO4 w/v + 0.5 M NAOH and 2 % H2SO4 w/v + 0.5 M NAOH). According to results, while 2 % H2SO4 w/v + 0.5 M NAOH gave the highest cellulose (91.51 %) and lowest lignin (1.7 %) concentrations, the lowest cellulose (65.11 %), hemicellulose (0.4 %), and highest lignin concentrations (23.42 %) were provided by 1.5 % H2SO4 w/v among pretreatments. Cellulose, hemicellulose and lignin contents of sweet sorghum bagasse after sodium hydroxide pretreatments ranged from 76.72 to 79.88, 11.75 to 14.62, and 2.05 to 4.11 %, respectively. The most appropriate cell wall composition for enzymatic hydrolysis was derived from sequential dilute sulphuric acid and sodium hydroxide pretreatments due to the fact that they provided the highest cellulose (90.68 – 91.51 %), lowest lignin (1.7 – 3.41 %) and desirable hemicellulose (1.10 – 1.82 %) contents. However, enzymatic hydrolysis must be done to learn which method enables the highest fermentable sugar production

Screening of Tomatoes for Their Resistance to Salinity and Drought Stress

In the study, 55 tomato genotypes have been investigated for their responses against salinity stresses in 48 day old early plant growth stage. For these purposes, several morphological and physiological measurements and analysis have been done in stressed plants. Shoot and root dry weights, plant height, leaf number, leaf area, relative water content, stomatal conductance, leaf osmotic potential, leaf water potential, shoot K, Ca and Cl concentrations were measured and analyzed. Salt and drought tolerant and sensitive (intolerant) genotypes have been found out according to the responses of the tomato genotypes to the above mentioned morphological and physiological parameters. At the end of the study, the fifty-five tomato genotypes were classified as tolerant, mildly tolerant or susceptible. Shoot dry weight, plant total leaf area, leaf water potential, leaf osmotic potential, stomatal conductance, K, Ca, Na and Cl concentrations in shoot and root, K/Na, Ca/Na, membrane injury index and visual appearance of damages were more relevant parameter for screening studies. Keywords: Stress, saline, water, tolerance, selection, breedin

Assessment of AquaCrop Model in the Simulation of Seed Yield and Biomass of Italian Ryegrass

Given that the optimal sowing rate and inter-row spacing of Italian ryegrass raised for seed have not been determined, the objective of this research was to assess the effect of crop density on biomass and seed yields under different climate conditions, applying the AquaCrop model. The data came from experiments conducted under moderate continental climate conditions at Stitar (Serbia) and Mediterranean climate conditions at Cukurova (Turkey). At Stitar, there were three different inter-row spacings (high (Sd), medium (Sm), and low (Sw) crop densities), while at Cukurova there was only high crop density (Sn). In the calibration process, the initial canopy cover, canopy expansion and maximal canopy cover were adapted to each crop density, while the other conservative parameters were adjusted to correspond to all climate conditions. Calibration results showed a very good match between measured and simulated seed yields; the values of the coefficient of determination (0.922). The biomass simulationwas very good for Cukurova (R2=0.97), but somewhat poorer for Stitar (R2=0.72). Other statistical indicators were high such as Willmott index of agreement of both the calibrated and validated data sets, for both study areas >0.916 and normalized root mean square error (NRMSE) in the range from 9%–18%. The AquaCrop model was found to be more reliable for Italian ryegrass biomass and seed yield predictions under mild winter climate conditions, with adequate water supply, compared to moderate climate and water shortage conditions