Investigation of leaf rust disease on spring crops of triticale (× Triticosecale Wittm.), it sdi stribution dynamics, as well as the efficacy of two fungicides, different application doses and timing was carried out at the Lithuanian Institute of Agriculture during 2000–2002. Differences in the disease development were determined by the meteorological conditions, especially the amount of rainfall, and growth stage of plants. Precipitation during 2000 was close to the mean, and the development of leaf rust was moderate. In June of 2001 the rainfall was twice as high as the norm, which created favourable conditions for pathogen development. In 2002 a long droughty period till flowering inhibited the development of leaf rust. The triazole fungicides Juventus (metkonazole 60 g l^–1) and triazole and strobilurine mixture. Allegro (kresoxim-methyl 125 g l^–1 + epoxikonazole 125 g l^–1) were used at full, two-third and half doses once and twice. Both of the fungicides were very effective against leaf rust. Biological efficacy of Juventus applied at any dose or time against leaf rust was 88.3%–99.7%. Allegro efficacy against this disease was slightly higher 94.7%–100%. Application of 1.0; 0.75 and 0.5 l ha^–1 doses twice showed a better efficacy than a single application. The higher doses of fungicides were not markedly superior to the lower ones.

The aim of the presented investigations was to examine changes in the intensity of dehydrogenase and acid phosphatase activities as well as of the dynamics of selected groups of microorganisms in the soil under the cultivation of winter triticale following the application of the following seed dressings: (a.s.) flutriafol 2.5% + fludioxonil 2.5% in two doses and (a.s.) carboxin and tiuram. The experiment had a field character. The number of microorganisms (total bacteria, fungi, oligotrophic, copiotrophic and Azotobacter) was determined by the plate method on adequate agar substrates. Activity levels of the selected enzymes were defined using the spectrometrical method.

The obtained results indicate a change in the dehydrogenase and phoshatase activity in soil depending on the seed dressing applied in the experiment as well as at the date of investigations. The number of microorganisms in the soil underwent fluctuations depending on the developmental stage of triticale and the applied fungicide. The performed experiment demonstrated that counts of microorganisms in the soil underwent fluctuations depending on the developmental stage of triticale and the applied fungicide.

The aim of the study carried out during 2002–2004 was to assess the effects and economic effectiveness of application of fungicides and insecticides in winter triticale crops. Its leaves were attacked by pathogenic fungi in 43.2% to 52.2% and the damage to leaf blade surfaces by cereal leaf beetle (Oulema spp.) ranged from 23.6% to 34.4%. The effectiveness of applied fungicides ranged from 44.7% to 90.8%, and that of insecticides was within 70.1% and 94.4%. The saved crops were evaluated for PLN 198 to 1 171 per ha. The cost coverage ratio ranged from 0.7 to 9.9 and the treatment profitability index ranged from 0.9 to 7.4. Cost index in percentage ranged from 0.8 to 8.5, with its average value of 4.2.

In this study, we examined whether and to what extent oxidative stress is induced in seedlings of two winter triticale (Triticosecale Wittm.) varieties (susceptible Tornado and resistant Witon) in response to infestation by the cereal grain aphid (Sitobion avenae L.) and bird-cherry-oat aphid (Rhopalosiphum padi L.). We compared the level of hydrogen peroxide (H2O2) and lipid peroxidation products as well as markers of protein damage (protein-bound thiol and carbonyl groups). The studied parameters were measured at 6, 24, 48 and 96 h post-initial aphid infestation compared to the non-infested control seedlings. Our studies indicated that the cereal aphid feeding evoked oxidative stress in the triticale seedlings. Cereal aphid feeding increased the H2O2 level in triticale tissues, with maximum levels observed at 24 and 48 h post-infestation. Triticale infestation with aphids also increased lipid peroxidation products in triticale seedlings, with the maximal levels at 48 or 96 h post-infestation. Further, there was a reduction in protein thiol content and an increase in protein carbonyl content in the triticale seedlings after infestation with female aphids. Stronger triticale macromolecule damages were evoked by the oligophagous aphid R. padi. There was a more substantial protein thiol content reduction in the resistant Witon cultivar and higher accumulation of protein-bound carbonyls in the tissues of the susceptible Tornado cultivar. The changes were proportional to the aphid population and the time of aphid attack. These findings indicate that the defensive strategies against cereal aphid (S. avenae and R. padi) infestation were stimulated in triticale Tornado and Witon seedlings. Our results explain some aspects and broaden the current knowledge of regulatory mechanisms in plant-aphid interactions.

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important foliar diseases of cereals. Infection by this pathogen on triticale has intensified in Poland in the last few years. In this study we examined resistance to powdery mildew in triticale hybrids possessing resistance genes Pm4b and Pm6 introduced from common wheat. The materials tested were hybrids derived from triticale crosses with common wheat cultivars carrying the desired resistance genes. The presence of the transferred genes was reflected in increased field resistance and shown by the use of molecular markers. The paper discusses the potential introduction of the genes to improve powdery mildew resistance.