Using image analysis to accurately determine the number of flowers per bunch for research purposes

Having a reliable method to get the number of flowers in a bunch is critical to analyze the effects of different stresses (biotic or abiotic) on blooming and fruit set. Here, it is presented a simple, yet, accurate method to obtain the number of flowers per bunch using a free software image analyzer. The bunches, are randomly selected at the experimental site and take it to the lab. In the lab, flowers are detached from the calyptra and placed in a black matt plastic sheet. Flowers are gently spread on the plastic sheet to avoid overlapping.  Next, a picture is taken using a camera fixed to a holder. The plastic sheet must have a reference length for the further analysis with the software. The image is processed using the ImageJ software. Once processed, the number and perimeter of each flower are obtained.  The bias analysis gives an overestimate of nearly 10 flowers, which, given the number of flowers per bunch, (for Tempranillo it could be more than 800) it can be considered an acceptable error. However, the bias can be diminished if a specific calibration is set. The images do not need to be clean. Non-desired elements can be removed from the analysis by applying a filtering method. The present methodology provides a simple, fast and precise technique to obtain the number of flowers in a bunch for research purposes.* 

*An abstract presented by Garcia-Tejera, O¹, Oliver-Manera, J¹ , Mata, M and Girona,J¹  at the International Congress on Grapevine and Wine Sciences. To download the post, click here.

¹Efficient Use of Water Program, Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Spain