The influence of cultivars on the Tuber Yield, chemical composition and diseases incidence of organically grown potatoes

Abstract

Studies of organic potato varieties were carried out in 2011–2012 in Vladas Elsberg‘s organic farm in Jonelaičiai village of Kužiai municipality in Šiauliai district. Research was carried out with the early potato varieties 'Valor' and 'Vineta'. It was found that cultivating potatoes 'Valor' and 'Vineta' no substantial differences in the total and marketable yield as well as in marketable crop yield between these varieties have been identified. Tubers of the 'Vineta' variety contained substantially less nitrates and slightly more dry matter and starch than potatoes of the variety 'Valor'. Tubers of the variety 'Valor', as compared to the variety 'Vineta', contained considerably more phosphorus, while in the amounts of nitrogen and potassium no essential difference were found. Organically grown potato varieties in different years were differently affected by diseases. If in 2011 potatoes of the cultivar 'Vineta' were by 13.3% less damaged by potato rash (Rhizoctonia solani Kuhn., Thanatephorus cucumeris (Frank) Donk.) than potatoes of the cultivar 'Valor', then in 2012 potatoes of the 'Valor' variety were damaged by 2.0% less. Potato tubers of the 'Valor' variety were damaged by common scab (Streptomyces scabies (Thxaxter) Waksman & Heric) by 6.7% less than the cultivar 'Vineta'. In 2011 potato tubers of the 'Valor' variety had by 8.0% higher prevalence of blight (Phytophthora infestans (Mont.) de Bary) than tubers of the cultivar 'Vineta', while in 2012 potato tubers were not affected by blight.