The incidence of fusarium foot-rot occurrence on the winter wheat cultivars Roma and Sakwa was examined in the years 2001–2003. Strict plot experiments were set up by the method of random sub-blocks in Tomaszkowo near Olsztyn. Fungicides were applied on the growing plants during the periods of shooting and heading. The control plots were sprayed with water. The sanitary state of leaf sheaths was evaluated at heading phase (GS 55). The symptoms of fusarium foot-rot were examined at the phase of milky maturity (GS 75) and waxy maturity of grain (GS 87). The study aimed at assessing the average index of infection of the winter wheat stem base caused by the species of Fusarium genus, assessing the vulnerability of the Roma and Sakwa cultivars to these fungi and determining the effectiveness of pesticides in control of fusarium foot-rot. Fusarium foot-rot (Fusarium spp.) of winter wheat dominated on the winter wheat stem base. Most of the examined stems were severely infected. The Roma cultivar was more susceptible to infection by Fusarium fungi than the Sakwa cultivar. The effectiveness of fungicides in controlling fusarium foot-rot on the winter wheat was satisfactory, but largely depended on the cultivar and weather conditions. Mirage 450EC and Sportak Alpha 380EC fungicides were the most effective. The species F. culmorum and F. avenaceum dominated in the fungal populations colonizing the stem base of winter wheat with visible symptoms typical of fusarium foot-rot.

In Poland, about sixty fungicides are registered for chemical protection of potato crops against late blight (Phytophthora infestans) and some of them are effective against early blight (Alternaria spp.). Time of appearance of pathogens in potato crops depends on climatic conditions. In Bonin climatic conditions in the years 1998-2002, early blight was observed at the earliest date i.e. 41-56 days after potato planting. Trials carried out at the Plant Breeding and Acclimatization Institute Bonin have shown different usefulness of fungicides in control of some pathogens of potato. The tested fungicides varied in their mobility (contact, translaminar, systemic) and activity against pathogens (protectant, curative, eradicative). All tested fungicides were effective in control of late blight in potato crops. They inhibited the rate of late blight development and in most cases the differences of their effectiveness were not significant. Systemic fungicides with slower mobility have the best efficacy in control of late blight infections occurring on potato stems. In laboratory tests, mancozeb, propineb and mixture of metalaxyl and mancozeb were significantly more effective in inhibiting the development of Alternaria. Fungicides, which are effective in the control of different pathogens, are particularly useful in potato protection programs.

Biological activity of 6 fungicides in the inhibition of Phytophthora ramorum sporulation and development of blight on rhododendron leaves and stems were evaluated. All tested compounds at dose 8 μg o fa.i./cm³ already inhibited zoosporangia formation at least in 73%. On leaf petioles and leaf disks, taken from rhododendron one week after treatment with fungicides, formation of chlamydospores was especially suppressed by fenamidone + phosetyl Al and oxadixyl + mancozeb whereas development o fspores was not inhibited by cymoxanil + famoxate. All tested compounds significantly inhibited the development and spread of twig blight on rhododendron. However, furalaxyl, applied as spraying of plants 48 hrs before or after inoculation of leaves and stems by P. ramorum was the most effective.

A total of 15 isolates of B. tulipae collected from home grown tulips without chemical protection and two commercial tulip plantations were examined by RAPD fingerprint analysis. The first tulip plantation was protected by bulb treatment and foliage spraying with fungicides in the growing period and the second plantation – only by the application of fungicides in the growing period. In the previous study, a set of isolates obtained from a plantation with an extensive use of fungicides demonstrated a higher pathogenicity level measured by the inhibition of plant growth, the percentage of bulb and root necrosis in flower pot tests on forced tulips, and by the necrosis size in tests on leaf disks. The relationships between the groups and among isolates were determined by cluster analysis of mean character differences using UPGMA and NJ methods. Similarity index values ranged from 0.872 to 1; on average, the index value was 0.933. A mean similarity of genotypes indicated the highest genotype uniformity of isolates obtained from a plantation with the extensive use of fungicides. 3 groups of clusters, could be observed in the obtained dendrograms. The first cluster contains exclusively genotypes of isolates obtained from a plantation with an extensive use of fungicides, the second one only genotypes of isolates obtained from a plantation protected only by the application of fungicides in the growing period and the third – one genotype of previous group of isolates and four genotypes of isolates obtained from home grown tulips without chemical protection. The most distinct differentiation between the groups of isolates was observed by the amplification using primers G4, H20 and J13. The results of this study revealed genetic similarity between isolates which were obtained from chemically protected plantations and demonstrated a higher degree of pathogenicity in comparison to the isolates which were obtained from unprotected plants and showed a lower degree of pathogenicity.

The studies conducted in two different localities revealed variable time of occurrence and severity level of potato early blight (Alternaria spp.). Each year at Stare Olesno the early blight caused considerable destruction of potato plants (90.2%-95.4%) while at Bonin the disease severity differed in particular years and ranged from 50.0% to 97.5% of destructed plants at the end of the growing season. Field trials showed good efficacy of fungicides selected for controlling the early blight compared with an untreated control. Spraying with fungicides limited development of the disease and increased tuber yield in the range from 21.9% to 60.9% for Bonin and from 13.0% to 101.9% for Stare Olesno surveys. The mixture of zoxamide with mancozeb showed the greatest efficacy.

In order to assess the economic benefits of reduced fungicide application for the control of paprika diseases under dryland conditions, on-farm experiments were conducted in the Chinyika Resettlement Area in the Eastern province of Zimbabwe in the 2000/2001 and 2001/2002 seasons. The six fungicide application regimes that were assessed include: weekly interval sprays; Sulphur at 2 weeks after transplanting (WAT) and copper oxychloride-Mancozeb mixture at 6 WAT; spraying after scouting; alternating Sulphur and copper oxychloride- Mancozeb every two weeks; Acibenzolar-s-methyl and unsprayed check. Parameters recorded were disease severity and yield; after harvest an economic analysis was performed. The highest added profit of Z$ 75 930/ha was recorded in the weekly sprayed plots which was not statistically different (p > 0.05) from Z$ 59 410/ha achieved by alternating copper oxychloride and Mancozeb fortnightly at Dengedza site in 2000/2001 season. There were no statistical differences (p > 0.05) between spraying after scouting and Acibenzolar-s-methyl application treatments as they added the least profits of Z$ 990/ha and Z$ 17 250/ha respectively at the same site in the same season. These have serious implications for smallholder farmers in terms of cost savings. Neither were there differences (p > 0.05) in added profits from different spraying regimes at Dengedza site in the 2001/2002 rainy season.

The influence of different nozzle types and adjuvants on the biological efficacy of fungicides in potato was investigated in four growing seasons in the years 1997-2000. The studied foliar plant disease was late blight (Phytophthora infestans). The biological efficacy of fungicides (alone or with adjuvants) applied with coarse air induction nozzles was comparable to fine standard flat fan nozzle. The differences between the nozzle types tested were small in control oflate blight in potato with systemic and contact fungicides. Coverage of upper side of leaf blades was from three to four times higher than lower side of leaf blades. In general, the highest coverage of upper and lower side of leaf was achieved when the full dosage rate of fungicide (copper oxychloride) was used with both the flat fan XR 110-03 and air induction DB 120-03 nozzle. Adding Atpolan 80 EC and Zero Piany 62 SL to 50% dosage rate of copper oxychloride decreased the spray coverage on lower side ofleaf as well as with both the XR 110-03 and DB 120-03 nozzles. However, addition of adjuvants to spray solution did not decrease the deposition on upper side of leaf blade. In general, adjuvants did not considerably influence the biological efficacy of the fungicide treatments sprayed with both the flat fan and the air induction nozzles but had favourable influence on potato yield.

The objective of the present study was to identify the dynamics of Alternaria blight spread on spring oilseed rape lower, middle and upper leaves and siliques, to determine the disease incidence (DI) and severity (DS) on leaves, stems, siliques and seeds under the effect of prochloraz and tebuconazole. Efficiency of the fungicides was compared in relation to their application time. Field experiments with the spring oilseed rape cv. 'Star' were conducted at the Lithuanian Institute of Agriculture during 1997-1999.