The rules and guidelines for integrated pest management specified in Annex III, sections 2

and 3, state “General principles of integrated pest management”: Harmful organisms must

be monitored by adequate methods and tools, where available. Such adequate tools should

include observations in the field as well as scientifically sound warnings, forecasting and

early diagnostic systems, where feasible, as well as advice from professionally qualified advisors.

As part of Multiannual Programs, the Institute of Plant Protection – NRI in Poznań

has been carrying out work and research for many years to develop or modify guidelines for

monitoring short- and long-term forecasting of pest occurrence on crops. These guidelines

are extremely helpful for farmers and advisers in determining the optimum date of chemical

control of pests on plants. Regularly revised and improved the guidelines deal with pests

which currently pose a threat to crops. They are developed according to the latest scientific

findings and are successfully promoted among professional users and agricultural advisors.

These guidelines are standardized to include descriptions of species, life cycles, symptoms

of damage/infestation of crops, methods of observation targeted at warning of the need

for plant protection treatments, and threshold values of harmfulness. All guidelines include

extensive photographic material. Guidelines for the monitoring of pests on orchard

plants, vegetables and others are prepared at the Institute of Soil Science and Plant Cultivation

− NRI in Puławy and the Institute of Pomology in Skierniewice. Guidelines for about

80 pests of crops are available for public use in the on-line Pest Warning System (Platforma

Sygnalizacji Agrofagów, www.agrofagi.com.pl).

Powdery mildew caused by Blumeria graminis f. sp. hordei is one of the most important diseases of barley in Poland. B. graminis is a genetically diverse pathogen with different special forms and races. The aim of the two-years’ experiment was to assess of B. gramins f. sp. hordei virulence frequency and powdery mildew occurrence on four winter barley cultivars. Virulence frequency of the pathogen depended on place and term of exposition. The occurrence of powdery mildew on four winter barley cultivars depended on virulence frequency of the pathogen and weather conditions.

Monoculture of modern cereal crops are popular due to the technical and organizationa lreasons. They are easier in crop husbandry, qua lity and product use. However, in monoculture chemical protection of crops is a norm, due to the fact that they are more susceptible to diseases, pests and sometimes weed infestation. In order to keep high and stable grain yields and quality in monoculture one has to use high inputs. Experimentally and practically it has been proved that cultivar and species mixtures can constitute an alternative to cultivar growing in pure stands. It has been found that in mixtures opperate different epidemiological and ecological factors, which lead to considerable disease reduction, pest and weed control, which finally result in higher and more stable grain yields than in barley varietes grown in pure stands. The results of two years field experiment designed to evaluate epidemiological and economical effects of winter barley cultivar mixtures are presented. The studies were carried out in two sites – experimental lStation for Variety Testing Słupia Wielka (in Wielkopolska region) and Plant Breeding Station Bąków (Opole District). This two sites were 300 km away from each other, and had different soi land meteorological conditions. In the experiment impact of different barley cultivars and their different two- and three-component mixtures were tested with reduced dosages of fungicidies on grain yield in the mixtures compared with pure stands were evaluated.

Biological diversity within a mixture field allows for better use of habitat and agro-technical conditions by the mixtures, which can be seen by higher and more stable yields than varieties sown separately. Our studies were conducted in the growing seasons 2011/2012–2014/2015 as field experiments with four winter barley varieties (Bombaj, Gil, Gregor, Bażant) and three, two- and three-component mixtures (Bombaj/Gil, Bombaj/Gregor, Gil/Gregor/Bażant). Seven different chemical treatments with fungicides were applied. The aim of this study was to compare the different varieties of winter barley with their mixtures for resistance to powdery mildew infection. To achieve this aim the logistic model for the analysis of data was used. Of the varieties under consideration, the best and the most resistant variety was Gregor, while the weakest and the most susceptible to diseases (powdery mildew) was Gil. This variety was also significantly weaker than any of the other mixtures taken into account. Moreover, it was so weak that when it was included in mixtures with other varieties, it weakened these mixtures as well.

In the four-year experiment the impact of four different winter barley varieties and selected two- and three-component mixtures were tested. Reduced dosages of fungicides on disease reduction in the mixtures compared with pure stands were evaluated. The studies were carried out at two sites: Experimental Station for Variety Testing Słupia Wlk. (Wielkopolska region) and Plant Breeding Station Bąków (Opole District). Observations on powdery mildew occurrence during the vegetation season were done every 7–10 days. In order to compare the disease occurrence levels on different cultivars in pure stands and on their mixtures combined with different fungicide treatments the Area Under Disease Progress Curve (AUDPC) was evaluated. On the base of the AUDPC values the reduction of powdery mildew occurring in the mixtures due to epidemiological and ecological factors functioning in mixed stands were also evaluated. On the base of obtained results it can be stated that winter barley variety mixtures combined with different fungicide treatments do reduce the powdery mildew incidence comparing to pure stands and winter barley variety mixtures can constitute an alternative way of growing winter barley, especially at low-input and ecological agriculture.

In the four-year experiment the impact of four different barley varieties and selected two-and three-component mixtures were tested. The studies were carried out at two sites: Experimental Station for Variety Testing Słupia Wlk. (Wielkopolska region) and Plant Breeding Station Bąków (Opole District) during four growing seasons (2001/2002–2004/2005). The aim of the studies was to evaluate the yield through growing barley variety mixtures in combination with reduced use of fungicide and application dose rates. Positive effects (1–15% yield increase in mixtures compared to pure stands) were observed. On the base of obtained results it can be stated that winter barley variety mixtures can constitute an alternative way of growing winter barley, especially at low-input and ecological agriculture.

The population dynamics of Tetranychus urticae (two-spotted spider mite – TSSM) are influenced by environmental factors, which were investigated to identify methods limiting the development and harmfulness of this pest. This paper presents findings from a laboratory study on the effect of spraying with water-based extracts of Mentha piperita and Tagetes patula plants on the growth rate of TSSM larvae and nymphs. The time required for the transformation of the larvae into protonymphs was longer for T. patula water- based extracts than extracts from M. piperita. Differences in the time of transformation from the nymphal stage to adult TSSM were also observed depending on the plant waterbased extracts, their concentration, and the host plant on which nymphs were developing. The use of 100 g ∙ l-1 French marigold extract was associated with longer transformation time of nymphs on discs of pea leaves than all tested concentrations of French marigold extract applied to sugar beet leaves. Ten percent of the extracts from peppermint plants had a stronger limiting effect on TSSM nymphs on pea leaves than on bean or sugar beet leaves.