The characteristics of the new potato cyst nematode (Globodera rostochiensis, pathotype RO1) resistant, medium ripening potato variety ‘Teele’ (‘Cinja’ ´ ‘Paola’) developed at the Estonian Crop Research Institute (ECRI) is discussed in this paper. The variety ‘Teele’ was included in Estonian and European Variety List in 2013.The variety ‘Teele’ passed the preliminary, dynamic and final trials in 2008 - 2012 at the ECRI, where it was compared with standard varieties ‘Maret’ (early), ‘Piret’ (medium) and ‘Anti’ (late). The official trials in Estonia and the technical examination (DUS test) in Czech Republic were carried out in 2011 – 2012. Potato cyst nematode (Ro1) and wart (Synchytrium endobioticum (Schilbersky) pathotype 1 (D 1)) resistance of the new variety were determined in Poland in the Plant Breeding and Acclimatization Institute. Tuber yield and tuber weight of the variety ‘Teele’ were equal to ‘Maret’ and ‘Anti’ but higher than ‘Piret’. The number of tubers per plant was equal in all standard varieties. Tuber yield and yield of marketable tubers of dynamic trials present the medium ripening of the variety ‘Teele’. The potato variety ‘Teele’ had good quality characteristics (shallow eyes, regular shape) and good culinary traits of table potato variety. It had a relatively good resistance to late blight (Phytophthora infestans) (field resistance), overcoming standard varieties ‘Maret’ and ‘Piret’.

Potato is the second important crop in Latvia. The area covered with potato is about 50 thousand hectares. Potato late blight caused by Phytophthora infestans (Mont.) de Bary is the most serious potato disease. Weather conditions in Latvia are very favourable for the development of potato late blight and it is occuring almost every year. The biology of P.infestans was the subject of a number of authors - plant pathologists. Research results about P.infestans population biology and epidemiology are presented in this review, especially focusing on the changes of pathogen biology.

Late blight (Phytophthora infestans) is one of the most serious potato diseases. The light blight forecasting is a very important factor for the protection of potato plants. NEGFRY is a decision support system for scheduling the chemical control of potato late blight. Trials were carried out in 2000-2001 at the Lithuanian Institute of Agriculture (LIA) in Dotnuva in medium early and moderately susceptible to late blight varieties. Ordinary plant protection systems against late blight and different NEGFRY models were compared. Results of two years' investigations show that by using NEGFRY models we can obtain satisfactory protection of potato crop and get higher yield using fewer spray applications.

One of the most serious diseases of the potato crop worldwide is late blight caused by Phytophthora infestans (Mont.) de Bary. Most growers control the disease by applying fungicides at regular intervals of 8-10 days from the time of row closing until the end of the growing season. The NEGFRY model is used for timing the chemical control of potato late blight. The NEGFRY model is based on two existing models, the "negative prognosis", for forecasting the risk of primary attacks, and a model for timing subsequent fungicide applications during the season. The main objective of NEGFRY is to get high yield and quality with minimum use of fungicides. Present work underlies the experiments that were arranged in 2000 and 2001 at the Jogeva Plant Breeding Institute. Two potato varieties with different resistance to late blight were taken to the experiment in both years: susceptible 'Adora' and modarately resistant 'Anti' in the year 2000 and susceptible 'Berber' and 'Anti' in 2001. NEGFRY gave highest economical effect among six tested treatment regimes.