The aim of this research was to compare effects of fertilization with various ratios of N, P and K (N:P:K) on arbuscular mycorrhizal fungi (AMF) infection in roots of Dactylis glomerata in Ca-carbonate (limed) and non-limed meadow plots at the Research Centre of Skriveri, Latvia University of Agriculture. Dactylis glomerata roots were excavated from variously fertilizer plots, a minimum 3 root samples per plot and analysed for two consecutive years. Arbuscular mycorrhizal fungi infection rates were estimated according to accepted scoring tables used for determination of AMF colonization.

Problems in hulless barley growing are caused by a low germination ability and emergence. Grain quality for feed and food are influenced by threshability and infection with fungal diseases. The aim of experiments was to investigate the possible hulless barley seed and grain quality problems under Latvia's conditions. Germination, emergence, test weight, 1000 grain weight and threshability of 77 hulless barley genotypes of diverse origin were determined and compared to hulled control varieties. Correlation between hulless barley germination, grain germ damage and grain infection with Fusarium, Helmintosporium and Penicillum was analyzed. The seed material structure (content of grains with damaged germ, broken grains and grains with undetached hulls) of 5 hulless barley genotypes was determined.

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.