Weed vegetation of poppy (<i>Papaver somniferum</i>) fields in Hungary: effects of management and environmental factors on species composition

Abstract

Pinke G, Pál RW, Tóth K, Karácsony P, Czúcz B &amp; Botta ‐ Dukát Z (2011). Weed vegetation of poppy ( Papaver somniferum ) fields in Hungary: effects of management and environmental factors on species composition. Weed Research 51 , 621–630. Summary Poppy ( Papaver somniferum ) is a sporadically cultivated crop species, with idiosyncratic life history traits, management systems and highly specific and under‐researched weed communities. This study aimed to assess the management and environmental factors determining the weed species composition of poppy fields over a relatively large area (Hungary in central‐eastern Europe), one of the focal regions of poppy production worldwide. The abundance of weed flora was measured in 102 poppy fields across Hungary, along with 41 management and environmental factors. The set of explanatory variables was reduced by stepwise backward selection to a minimal adequate model containing 15 terms, which explained 34.3% of the total variation in species data. The net effects of 10 variables on species composition were significant. Sowing season was found to be the most important explanatory variable, showing a clear distinction between the weed flora of autumn‐sown food poppy and spring‐sown alkaloid poppy fields. Other management factors, such as preceding crop, herbicides mesotrione and isoxaflutole, fertiliser N and row spacing, were also significant. Only four environmental variables (temperature, soil texture, soil Mg and Ca content) were significant, which can be attributed to the narrow ecological tolerance of poppy, resulting in short environmental gradients.