engleski

Some Quality Traits of Potato Tubers Produced under the Agroecological Conditions of Croatia

The aim of the field cultivar trial involving 19 potato cultivars of different growing period lengths, conducted in the Gospić region in 2006, was to select the best cultivars for the production of Lika potato. Influence of agroclimatic and agrotechnical factors on market yield of tubers and tuber quality was investigated: bulk specific gravity, content of dry matter, ash, protein and nitrate concentration. The cultivar trial was set up on light, dystric cambisol of acid reaction (pH 4.2), moderately humus-rich (2.7% humus), poor in potassium (13.5 mg K2O/100g soil) and very poor in phosphorus (1.2 mg P2O5/100 g soil). Fresh mass yield of marketable tubers ranged from 7.9 t/ha (Jaerla) to 47.0 t/ha (Rodeo). The highest bulk density (1.101) was recorded for cultivar Mozart, and the lowest (1.069) for Dynamica. The highest dry matter yield of 9.7 t/ha was determined for cultivar Rodeo, and the lowest for Jaerla (1.6 t/ha). At the same time, the highest ash yield (1.98 t/ha) was produced by cultivar Mondial, and the lowest (0.35 t/ha) by Jaerla. Potato cultivars that accumulate more dry matter have lower ash contents, and vice versa. Tubers of early-ripening potato cultivars Jaerla, Fabula, Triplo, Adora contain lower concentrations of nitrates (1100 to 1300 mg NO3/kg) compared to dry matter richer cultivars Courage, Rosara, Desire (1500 to 1700 mg NO3/kg). Early-ripening cultivars (Fabula, Adora, Jaerla, Rafela) also accumulate more protein (10.13 to 10.81 g/kg) than late-ripening cultivars (Mozart, Courage, Rodeo, Victoria), which accumulate more dry matter in tubers, with less protein (8.63 to 9.81 g/kg). Meteorological conditions and cultivar characteristics had a significant influence on the yield, dry matter content and bulk specific gravity. Natural restrains and climate of a region as well as agrotechnical characteristics determine the production potential of cultivars and the potential tuber quality. It should be every producer’ s goal to use high-yielding potato cultivars, with high concentrations of dry matter, and to apply agricultural management practices that will reduce internal and external tuber damage.

potato; environmental conditions; chemical composition; quality

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