Authors:J. García-Suárez, M. Röder and J. Díaz de León
Quantitative Trait Loci (QTL) mapping was carried out in a set of 114 lines of the International Triticeae Mapping Initiative (ITMI) mapping population for null nitrogen fertilization during two agricultural cycles. We quantified phenologic parameters (days to: ear emergency time, flowering time) and components of yield (number of plants and ears, plant height, leaf area, length and weight of ear, spikelet number, number and total weight of grains and by third in the ear, weight of thousand grains and total yield). Interval mapping resulted of 138 QTLs, of which 47 were catalogued as major QTLs (LOD ≥ 3.0) and 91 as minor QTLs (LOD 2.0 >0 2.9). The QTLs were distributed in 14 of the 21 chromosomes of wheat. The data showed that a high percentage of QTLs were in chromosomes 2D (49 or 35.5%), followed by 5A (22 or 15.9%), 1B (10 or 7.2%).
Authors:A. Lugasi, D. P. F. Almedia and E. Dworchák
The chlorogenic acid and the total polyphenol content were analysed in two different potato varieties (Kennebec, Agria) grown under five different nitrogen fertiliser rates (0, 75, 150, 225, 300 kg ha-1). Chlorogenic acid content ranged between 6.0-22.3 mg kg-1 fresh weight and was not influenced by fertiliser levels. The chlorogenic acid in potato tubers accounted for almost 90% of the total polyphenols. Free radical scavenging and antioxidant activities of the tubers were also analysed. Ethanolic extracts if the tubers showed marked hydrogen-donating activity in the experiment using 1,1-diphenyl-2-picrylhydrazyl (DPPH), they had reducing power as measured by the Fe(III)?Fe(II) reaction, but did not exhibit H2O2 scavenging activity assessed with a chemiluminescence method. Potato extracts showed significant, although weak Cu(II)-chelating activity and inhibited the autoxidation of linolenic acid as measured by the thiocyanate method. Chlorogenic acid containing extract of potato, can act as primary and secondary antioxidant in prevention of oxidative stress. The strong correlation between the antioxidant activity and the level of total pholyphenols suggests that the phenolic compounds are important antioxidant components of whole potato tubers. Variety had minimal, while nitrogen fertiliser rate had no effects on the levels of the studied characteristics.
A field experiment was conducted for 2 years at the Indian Agricultural Research Institute, New Delhi to study the effects of duration of variety and nitrogen fertilization on the Ca, Mg and S concentration and uptake in rice. In general, the concentrations of Ca, Mg and S were not significantly influenced by the duration of the rice variety. N fertilization had a tendency to increase the concentration of Ca, Mg and S at 45 days after transplanting as well as at harvest; however, the difference was significant only in the case of the Ca concentration in the grain and only when the N level was raised from 60 to 120 kg N/ha. The duration of the rice variety had a significant effect on the Ca, Mg and S uptake by the straw and grain at harvest, which was higher in the medium duration variety Pusa Basmati-1 than in Pusa Jaldi Dhan-1, mainly due to the higher yields obtained with the former cultivar. Nitrogen application significantly increased the Ca, Mg and S uptake at harvest mainly due to its increasing effects on the grain and straw yields of rice. The average uptake of Ca, Mg and S was 12.6, 13.6 and 3.5 kg per metric ton of grain, respectively.
Authors:R. Zimmermann, U. Bauermann and C. Spedding
the concentration of a neutraceutical lignan in flaxseed. Grey Canadian Literature PPI/PPIC/FAR project
Zimmermann, R., Bauermann, U., Morales, F. (2006): Effects of growing site and nitrogenfertilization on
The cultivation methods used in the experiments resulted in marked differences in the weediness of maize and wheat. The least weediness was found in the conventional tillage treatment. The crucial question in the conservation and no tillage for sustainable agriculture is the weed problem, especially if the technology of weed controls is unaltered as compare to the traditional one. The lower yield in this cultivation system can be attributed to the competition of weeds. To clarify the question, investigations were carried out in the years 2005–2008 in a long-term field experiment set up on brown forest soil at the University of Pannonia, Georgikon Faculty Keszthely. The lowest yields were obtained in the wheat–maize no-tillage system in comparison to the others. This was valid at high and low levels alike (good and unfavorable years). On the average of years the yield decrease was 10–15% as compared to the traditional cultivation. In the spring survey of the weed cover (%) in the wheat trials it was found that the weed coverage increased parallel with the N fertilizer amounts, and then declined in the treatment above 200 kg N. The relation of weeds v.s. N fertilizer is similar to the second power equation of the yield curve. In case of the maize trials, there were no significant differences between the N treatments (25–30%) regarding weed coverage. The gained results call attention to the fact that with the propagation of the reduced soil cultivation systems it is necessary to modify and harmonize the practice of weed control and fertilization. Instead of the schematic weed control and fertilization process, the application of scientifically well-established methods should be urged. In sustainable agriculture the data collection of weeds, the survey of dominant species, special herbicide combinations and the means of precision agriculture have to be taken into consideration.
Authors:F. Gomez-Coronado, M.J. Poblaciones, A.S. Almeida and I. Cakmak
The combined application of nitrogen (N) and zinc (Zn) appears to be a promising agronomic strategy for the biofortification with Zn. To evaluate such efficiency, a field experiment was conducted in south-eastern Portugal under Zn-deficient soil. Four advanced breeding lines and two commercial varieties of bread wheat (Triticum aestivum L.) were fertilized with five treatments: i) control, ii) two foliar Zn applications, iii) one foliar Zn+N application, iv) soil and two foliar Zn applications, and v) soil and one foliar Zn+N application. Grain Zn content varied greatly across treatments and INIAV-1 and the commercial varieties were the most interesting cultivars in all the treatments. Grain Zn concentrations higher than the target level of 38 mg Zn kg−1 were obtained only when two foliar Zn applications were applied, alone or in combination with soil Zn applications, and grain Zn bioavailability also was more adequate (phytate:Zn ratios similar to 15). Soil Zn application resulted in grain yield increases between 7–10%, which virtually offset the extra application cost. The combined soil and two foliar treatment could be a good option for biofortifying bread wheat under Zn-deficient soils.