Repellent usage against rodents is almost not provided anymore. Permission to use many rodent repellent substances under European Union (EU) plant protection regulations has not been renewed in recent years. Some approval for chemical substances have not been renewed due to their toxicological properties, and for some biorational approvals have also not been renewed due to lack of financial support together with other concerns. Some other rodent repellent substances possessing accurate properties in a secondary way have also been withdrawn. Thus, the use of almost ten active substances is now illegal. The lack of support and the resultant orphan use may be explained by the relatively small market and possible business together with the expectations of modern substance application requirements. As a result, the opportunity to consider new biorational substances as candidates is therefore open. Plant based food substances are preferred candidates for plant protection considering their favourable toxicological characteristics. Capsicum oleoresin, a mixture obtained from two spice species (Capsicum annuum and C. frutescens), is one of them with appropriate repellent properties. An application under EU Plant Protection Product regulation has recently been submitted and may become a new repellent for biological control agent against seed predators.

Straw, particularly cereal straw, is a valuable by-product of crop production, which can be used for various purposes, e.g. as livestock feed and bedding or for making fuels, however it should primarily be retained on farmland in order to prevent soil organic matter (SOM) losses and thus to maintain or improve soil quality. The aim of this study was to analyze effects of the frequency of crop residues (straw) incorporation into the soil on the content of soil organic matter and on crop yields. There were the following experimental treatments: SR – straw of all crop in the rotation removed, S1 – straw of one crop per rotation incorporated, S2 – straw of two crops in the rotation incorporated, and S3 – straw of three crops incorporated into the soil (loamy sand). After 21 years of crop rotation with straw removal (SR) the SOM level in the soil slightly decreased to 14.4 g∙kg ^–1 soil DM, compared to that in 1997 (14.6 g∙kg ^–1). However, when straw of one crop (rape) per rotation was incorporated (S1) the content of SOM increased to 15.0 g∙kg ^-1 soil DM, and to 15.6 and 16.0 g∙kg ^–1 in S2 and S3 treatments respectively. Straw retention had also a beneficial effect on the content of labile fractions of SOM (hot water extractable C and N). Grain yields and yield components of wheat and triticale, and seed yields of rape in the SR treatment were not significantly different from those obtained in S1, S2 and S3 treatments.