In rational nutrition, vegetables play an important role due to their high biological and low energy value. The most widespread vegetables in our country belong to root vegetables. They are grown mainly for bulbs, corms, rhizomes, fleshy roots, and hypocotyl tubers. Root vegetables can be eaten raw or cooked. Carrot (
Cultural plants are an essential part of civilization. Many of them had originally been harvested as wild plants, later on, cultivated and consciously bred. Vegetables generally represent the juicy parts of plants. They can be grown on arable land, but in the tropics and subtropics, some of the vegetables can be collected from the wild (eg. roots, leaves, etc.). In rational nutrition, vegetables play an important role because of their high biological and low energy value (
Proceeding to 2012 – 2014, the total annual crop of carrots was relatively stable, reaching 6,502 t per 232 ha in 2014. Between 2014 to 2015 though, we were experiencing a slight increase in total annual yield which resulted in 10096 t per 312 ha in 2015. Between 2015 and 2017, the total annual yield decreased again, in 2017 it decreased to 5, 730 t per 185 ha. Average hectare yields in Slovakia in the last decade reached 16 t (
The concentration of total carotenoids depends on the variety.
More intense usage of fertilizers can support the synthesis of carotenoids, refractometric dry matter, and total dry matter.
The research was carried out in the form of a small-plot experiment under the conditions of the vegetable sampler of the Department of Vegetable Production in the area of Botanical Garden at the Slovak University of Agriculture in Nitra. We used four soil variants, the size of each was 6 x 7 m (42 m²). Monitored varieties are shown in Figure
Examined carrot varieties, sorted by variety and variant.
Note: left: Kamaran F1, Komarno F1 and Romosa.
Examined carrot varieties.
Note: from the left – Kamaran F1, Romosa and Komarno F1.
1. variant with the application of livestock manure in the amount of 44 t.ha-1 and compost applied in the amount of 44 t.ha-1 (MH K).
2. variant with the application of livestock manure in the amount of 44 t.ha-1 (MH).
3. variant with the application of mature compost in the amount of 44 t.ha-1 (K).
4. variant with non-fertilized soil (control variant) (KON).
By each variant, three experimental trials were carried out.
A profitable late Berlicum variety is characterized by exceptional external and internal root coloring. The roots are of high quality, cylindrical and 16 – 19 cm long. The flesh is juicy and delicious. This carrot variety reaches a vegetation period of 127 days from sowing to reaping. This variety is recommended for storage. It is suitable not only for storage but also for industrial processing. When densely sown, it is also suited for direct consumption (
This is a late and highly productive hybrid of the Berlicum and Flakkee variety. It forms dull-ended roots up to 26 cm long. It has excellent external and internal coloring. The roots weigh 300 – 500 grams and have a diameter of 2.5 – 4.5 cm. Carrots of this variety are suitable for long-term storage. The vegetation period of Kamaran F1 variety in our climatic conditions reaches 135 days. It can accumulate less nitrate and is suitable for industrial processing and storage (
This variety of carrots is a late and very fruitful Flakkee type variety foremost suited for industrial processing. Komarno F1 variety is typical with high yields and high dry matter content. Its typical smooth conical roots with strong and healthy leaves of dark green color are very resistant to fungal and bacterial diseases. The roots have intense dark red coloring and weigh 200 to 500 grams. Vegetation time for this variety of carrots in our conditions is 161 days. This variety is excellent for freezing, production of carrot juice, and wherever an intense dark color of the final product is required. The variety is also suitable for storage (
The extraction of samples has been done at the Laboratory of Beverages, AgroBioTechResearch Center of SUA in Nitra. The measurement of total carotenoid content was realized in the laboratory of the Department of Vegetable Production of SUA (Slovak University of Agriculture) in Nitra. The content of total carotenoids was assessed by spectrophotometric measurement of substance absorbance in petroleum ether extract on Spectroquant® Spectrophotometer Pharo 100 at 445 nm wavelengths (
The refractometric dry matter was measured in triplicate by using a refractometer (type CRUESS DR201-95).
The dry matter content was determined by using a gravimetric weighing method. The analyzed plant material was dried at 105 °C up until the weight became stable.
Statistical analysis was performed by using Statgraphic Centurion XVII (StatPoint Inc. USA). The obtained results were evaluated by analysis of variance (ANOVA) and the average values were tested by LSD test at the significance level of 95%.
Carotenoids are an important group of biologically active compounds attributed to a wide range of health benefits. These are natural pigments that occur mainly in vegetables but also in other natural resources such as fungi, algae, microorganisms, crustaceans, fish, birds but also mammals (
Based on our results (Figure
Total carotenoids content (mg.kg-1) in varieties Kamaran F1, Komarno F1 and Romosa according to the variants. Note:The values in the columns with different letters are significantly different from each other.
The results (Figure
The dry matter content in (%) in varieties Kamaran F1, Komarno F1 a Romos aaccording to the. Note: The values in the columns with different letters are significantly different from each other.
In the case of the other variants (Kamaran F1 variety), the decreasing trend in the order of Kam. KON by 2% (13.88%), Kam. MH by 3.3% (13.69%) and Kam. MH K 6.4% (13.26%) can be noted in the dry matter contents. In the Romosa variety, other findings were detected in terms of variation effects. The highest dry matter content was determined in the Rom. MH K (13.82%) variant. In the case of the other variants (Romosa variety), the decreasing trend in the order of Rom. K by 4.2% (13.24%), Rom. KON by 8.9% (12.59%) and Rom. MH by 13.97% (11.89%) can be observed in the dry matter contents. The highest dry matter content of Komarno F1 was determined in the variant Kom. MH K (13.26%). In the case of other variants (Komarno F1 variety), the decreasing trend in the order of Kom. MH by 0.83% (13.15%), Kom. K by 3.3% (12.82%) and Kom. KON by 3,7% (12,77%) can be stated in the dry matter content. Variants fertilized with compost and a mixture of compost and livestock manure had the highest impact on the dry matter content. Bach et al. (
The highest refractometric dry matter content was determined in the Kamaran F1 variety (Figure
Refractometric dry matter content in Brix (°) in varieties Kamaran F1, Komarno F1 a Romosa according to the variants. Note: The values in the columns with different letters are significantly different from each other.
The highest refractometric dry matter content was determined in the Rom. variant MH K (11.22 °Brix ). Other variants of the Romosa variety showed a decreasing trend in the following order: KON by 3.48% (10.83 °Brix ), Rom. K by 4.46% (10.72 °Brix ) and Rom. MH by 12.84% (9.78 °Brix ). Slightly different conclusions can be drawn from researching the Komarno F1 variety. The highest content of refractometric dry matter was determined in variant Kom. MH K (10.63 °Brix ). In the case of other variants (Komarno F1 variety) a similar decreasing trend was recorded in the refractometric dry matter content which declined in the following order: MH by 0.28% (10.6 °Brix ), Kom. KON by 6.21% (9.97 °Brix ) and Kom. K by 7.06% (9.88 °Brix ). Variants fertilized with compost and a mixture of compost and manure had the highest impact on the refractometric dry matter content. Valšíková et al. (
Machewad et al. (
In four soil variants model varieties of carrots (Romosa, Kamaran F1, Komarno F1) were evaluated in terms of qualitative parameters (total carotenoids, dry matter, and refractometric dry matter). The study of total carotenoid content in carrot varieties shows that the most significant effect on the synthesis and carotenoid content was detected in the variants fertilized with compost and a mixture of compost and manure. Averaging the results from all four variants, the best source of carotenoids in terms of varieties was measured in the Romosa variety (167.48 mg.kg-1). The lower content of total carotenoids was found in Kamaran F1 (153.19 mg.kg-1, 9% lower) and Komarno F1 (144.13 mg.kg-1, 14% lower) varieties. The variants with compost and a mixture of compost and livestock manure had the highest influence on the content of dry matter. The Kamaran F1 variety was found to have the highest average dry matter content (13.75%). Lower dry matter content was found in Romosa variety (12.88%, by 6.33% lower) and Komarno F1 variety (13%, by 5.46% lower). What regards the refractometric dry matter, the highest effect on the varieties had variants fertilized with compost and a mixture of compost and livestock manure. Averaging the results of all the variants for the specific variety, the highest refractometric dry matter content was detected by the Kamaran F1 variety (11.33 °Brix ). A lower dry matter content was found in the Romosa variety (10.64 °Brix , lower by 6.09%) and Komarno F1 (10.27 °Brix , lower by 9.36%).
This publication was supported by the Operational program Integrated Infrastructure within the project: Demand-driven research for the sustainable and inovative food, Drive4SIFood 313011V336, cofinanced by the Euruopean Regional Development Fund, KEGA 018SPU-4/2020 and by AgroBioTech Research Centre built in accordance with the project Building „AgroBioTech" Research Centre ITMS 26220220180.