Evaluation of red and white currant cultivars in Latvia.

摘要

Traditionally in Latvia red and white currants are grown mostly for processing. Until now old cultivars - red currants 'Red Dutch', 'Jonkheer van Tets' and white currants 'Zitavia', 'Werdavia' - are predominant. To improve the assortment of red and white currants in Latvia, an evaluation of 18 cultivars was carried out at the Latvia State Institute of Fruit-Growing (LSIFG) and Pure Horticultural Research Centre (Pure HRC). The trials were established during years 2004-2006. The largest part of the evaluated cultivars were of Russian origin. Their winter-hardiness, phenological traits, yield and its components, as well as quality of berries were investigated. Cultivars 'Red Dutch', 'Nenagladnaya' and 'Viksnes Sarkanas' were used as standard. In Latvian climatic conditions currant cultivars with late flowering time have more utility, because of the risk of damaging spring frosts. Late flowering time was observed for cultivars 'Rondom', 'Daugaviete', 'Rotet', 'Rovada', 'Rolan', 'Rote Spathlese', 'Ustina', 'Orlovskaya Zvezda' and 'Osipovskaya'. On the other hand, for the berry market and processing, cultivars with early ripening time are more interesting. Early time of ripening was found in cultivars 'Zitavia', 'Werdavia', 'Minnesota', 'Varshevicha', 'Asya', 'Belka' and 'Niva'. The latest ripening time of berries was found in cultivars 'Rondom', 'Daugaviete', 'Rotet', 'Rovada', 'Rolan', 'Ustina', 'Prigazhunya', 'Nenagladnaya', 'Orlovskaya Zvezda', and 'Osipovskaya'. The highest quality of berries was in cultivars 'Asora', 'Niva', 'Belka', 'Orlovskaya Zvezda', 'Viksnes Sarkanas', 'Osipovskaya', 'Asya' and 'Rovada'. Cultivars 'Belka', 'Rovada', 'Marmeladnitsa', 'Gazel', 'Orlovskaya Zvezda', 'Asja', 'Niva' and 'Prigazhunya' were the most productive in the trial at Pure HRC. Different leaf spots were the most widespread diseases in the red and white currant trials. The highest level of resistance to these diseases was found in cultivars 'Saharnaya', 'Orlovskaya Zvezda', 'Osipovskaya', 'Asya' and 'Ustina'. On the basis of these results, cultivars 'Orlovskaja Zvezda', 'Osipovskaya', 'Asja', 'Belka', 'Ustina', 'Rovada', 'Marmeladnitsa' and 'Niva' were selected as the most promising for processing and the fresh market in Latvia.