Stem fasciation

In zucchini and squash, the physiological phenomenon of fasciation is observed occasionally on the stems , sometimes on the fruits .

Rare plants sometimes have entirely flat stems which become wider and wider as one approaches the apex (Figure 1). They also have a more or less fluted appearance due to the joining of the secondary rods (Figures 2 to 3).

It is an extremely rare physiological phenomenon which should be regarded as a curiosity. It is favored by low temperatures and affects few plants at a time, regardless of the variety. Some mutants express this anomaly and pass it on to their offspring who will be affected one hundred percent.