Enric Melé
Institute for Food and Agricultural Research and Technology (IRTA), Spain
Anna Nadal
University of Girona, Spain
Marina Melé-Messeguer
Maria Pla
University of Girona, Spain
Gemma Capellades and Joan Serra
Fundació Mas Badia (FMB)
Joaquima Messeguer
IRTA, Spain

Coexistence of GM and conventional maize in locations where the two types of varieties are commercially grown would benefit from a tool to estimate and predict the GMO contents of conventional fields that are surrounded by GMO crops. We present GIMI 2 as software to address this need.

Based on experimental data collected along a number of seasons in two regions where GM and conventional maize was concurrently grown, an index (GI) was established to calculate the GMO percentage in a given conventional field based on flowering coincidence and distances between fields. Upon validation (four seasons), we found sub-optimal agreement between in silico and experimentally calculated GM contents in long and narrow fields, so we quantified the effect of the field sizes on cross-pollination.

A new index was developed as an evolution of the GI that additionally compiles the field sizes and shapes, as well as the wind intensity and direction. GM contents calculated with the new index show close correlation with those obtained experimentally both in small and large fields.

To facilitate application of the new index in real agricultural field conditions, we developed the GIMI 2 software. It calculates the GM contents of conventional fields in an interactive and fast manner on the basis of the following data, which can be easily introduced by the user: field vertex coordinates, flowering date and variety (GM/conventional) of each field, and wind. We propose GIMI 2 as user-friendly software to coordinate coexistence in agronomic regions.

Keywords: Coexistence, GIMI software, GMO, maize, prediction.