This spring we had allready several discussions about type of plants. Are varieties long day or short day or day-neutral or everbearers?
Especially with everbearers / Day-Neutral this had allready quit big consequenses.
An example: a grower has a greenhouse and outdoor table tops in tunnels, about 10 ha. Normally he plants them around the end of march / beginning of april. But early strawberries are expensive, so why not planting the plants first in a greenhouse, let them grow for a month or so and then as a better developed plant, plant them outside.
About 6 weeks after planting the plants in the tunnels, he calls: “i see a lot of runners and only a few flowers, what is going on here. They are everbearers, so i should have flowers in stead of runners”.
If it where everbearers – accordig the word: they ever initiate flowers – then he was right. But do everbearers always initiate flowers, or under every sircumstances?
My experience is totally different: so far i have only seen short day strawberries and long day strawberries. Everbearers and Day-neutral are for what i have seen long day strawberries. :
– Long day strawberry is a variety that produces fruits when the days are longer then a certain number of hours (differs per variety)
– Short day strawberry is a variety that produces fruits when the days are shorter then a certain number of hours (differs per variety).
– Everbearer or Day-Neutral are varieties, that produce fruits independend of the lenght of the day: 6 hours daylenght or 20 daylenght or different, they just produce fruit. To be honest: i have never seen such varieties.
Conclusion for me: We only have Long day varieties or short day varieties – no real day neutral or everbearers.
There is one but: The flowering of varieties does not only depend on daylenght. Factors like vegetative growing and generative growing influence the flowering a lot.
Example: Elsanta is a short day variety. The critical daylenght of Elsanta is about 13,5 hours, that means as soon as the daylenght gets shorter, it will start with flowerinduction. If you give them stress (dry out, no nitrogen, very high temperatures, etc) flowerinduction may start allready at 14-14,5 hours. On the other hand if you pamper them very much (very nice irrigation, high nitrogen and ammonium, nice moderate temperatures, flowerinduction may start only just at daylenght of 13 hours or shorter.
I have the feeling that that daylenght can be that short in some countries and circumstances that generative, that some varieties always induce flowers, but are in fact long day varieties, or short day varieties, because if we grow these in other climates with other day lenghts, they sometimes do initiate flowers, sometimes they don’t.