investigations were made on the relationship between plant density and plant height, and on the yield, thousand seed mass, and ratio of diseased and broken seeds of varieties with different seed sizes. Experiments were carried out to analyse the effects of potassium on the yield, bacterial diseases and nutritive quality of the seed of bean varieties. Three dry bean cultivars representing the small, medium and large seed size groups were investigated. Six plant density treatments were chosen based on theoretical seed norms, taking the germinative value of the seeds into consideration. The correlation between plant density and yield average showed that the volume of yield increased for varieties with large and medium-sized seeds up to a plant density of 285-400 thousand/ha, after which it declined. On the basis of the results, yield averages at plant densities of 285-334 thousand plants/ha were 0.17 t/ha higher than those achieved at low density (200 thousand plants/ha). At greater plant density the plant height increased in the case of large-seeded varieties and there was a considerable decrease in the thousand seed mass. With an adequate water supply a high level of potassium decreased the number of pods and seeds per plant compared with the basic level, which gave a yield of 2.5 t/ha. The use of high rates of potassium fertilizer decreased the number of infected seeds, but the differences were only significant for the small-seeded variety. A moderately high potassium level was advantageous for food quality, particularly during drought.
Authors:Z. Pék, H. Daood, A. Lugasi, L. Fenyvesi, and L. Helyes
Quantification of red pigment content of fruits using destructive techniques is expensive and it enables only the analysis of batches but not of individual items. This study examined the feasibility of using non-destructive, spectrophotometric method to predict one of the most valuable internal quality indices, lycopene, in individual tomato fruits. An open field experiment was conducted to study the effect of irrigation and potassium supplementation on the yield and lycopene content of processed tomato fruit. Three different treatments (regularly irrigated RI, irrigation cut-off 30 days before harvest CO, and rainfed RF unirrigated control) and two different potassium fertilisations (P) were applied. Regular irrigation significantly decreased the lycopene content of tomato fruits. The CO treatment resulted in the highest total lycopene without potassium supplementation. Potassium supplementation, given at the time before fruit maturity, significantly increased the lycopene concentration of cultivar Brigade F1, independently of irrigation. The closest correlation was at 700 nm R2=0.38 and R2=0.45, between reflectance and the (all-E)-lycopene and the (9Z)+(13Z)-lycopene isomers, respectively.
Authors:Marko Josipovic, Vlado Kovacevic, D. Petosic, and Jasna Sostaric
Kovacevic, V., Basic, F. (1997): The soil potassium resources and the efficiency of potassiumfertilizers in Croatia (Country Report 10). International Potash Institute, Coordinator Central/Eastern Europe, CH
Authors:Á. Illés, Cs. Bojtor, A. Széles, S.M.N. Mousavi, B. Tóth, and J. Nagy
The presented research aimed to confirm that the differences in the lipid peroxidation of three maize (Zea mays L.) hybrids with different genotypes and maturity are due to different nitrogen levels, which was observed based on the amount of malondialdehyde (MDA) measured in the leaves at the main phenological stages of plants. The experiments were performed in a multi-factorial long term fertilisation field trial. In the study, phosphorus and potassium were constantly provided at the optimal level for the plants. The phosphorus and potassium fertilisation were applied in autumn. However, N levels varied from 0 to 300 kg ha−1. Sampling was done at different growth stages 5 times during the growing season (4 leaves, 6 leaves, 8 leaves, 14 leaves, silking). The 300 kg ha−1 N (dose 3) resulted in a significant increase in lipid peroxidation (MDA level), but not a statistically significant difference between the control (dose 1) and the 120 kg ha−1 (dose 2) N doses. The H1 hybrid had the lowest level of lipid peroxidation at the first sampling date. High volume nitrogen fertilisation (dose 3: 300 kg ha−1) increased lipid peroxidation in the hybrids. Averaging the values obtained for the same hybrid at the different sampling times, the medium (dose 2) 120 kg ha−1 N treatment had no significant effect on the lipid peroxidation of the hybrids compared to the values of the control plants. Based on the lipid peroxidation response of the hybrids to N treatment, the exact N dose inflection point can be determined to make the fertiliser utilisation of plants more efficient. Based on our results, we found that inadequate, low (120 kg ha−1) or high (300 kg ha−1) nitrogen fertilisation could affect the MDA levels of plants, thereby affecting the functioning of the lipid peroxidation mechanism.
Sangakkara, U. R., Frehner, M., Nösberger, J. (2000): Effect of soil moisture and potassiumfertilizer on shoot water potential, photosynthesis and partitioning of carbon in mungbean and cowpea.
J. Agron. Crop Sci.
Authors:Gergő Péter Kovács, Péter Mikó, László Nagy, and Csaba Gyuricza
Pholsen , S. – Higgs , D. E. B. – Suksri , A. : 2001 . Effect of nitrogen and potassiumfertilisers on growth, chemical components and seed yield of forage sorghum ( Sorghum bicolour L . Moench) grown on oxic
Authors:Ray L. Frost, Sara J. Palmer, and Ross E. Pogson
, Valarelli , JV , Cekinski , E , Pereira , SCC . Use of alkaline rocks from Pocos de Caldas (Brazil) and phosphogypsum in the production of potassiumfertilizer and sulfur dioxide . Fertilizantes . 1985 ; 7 : 4 – 8