This week some more pictures and some graphs of the current situation in the Norther part of the Netherlands.
Overpressure Among the pictures you see one picture with black flower buds: Overpressure due to a combination of very active roots (good condition, high temperatures + no evaporation (high humidity). In this case pressure causses tissue damages on the weak tissue in the plants (generally: flower buds, young leafs and very young runners).
Below the development of the aphid population this year. The level is the following: 0 = nothing 1 = every now and then an aphid 3 = limit of acceptable 5 = totally full with aphids
Milldew development can be seen in the graphs below. It is very clearly, that the coincidence of milldew is increasing. Althoug the highest level is still on 2 (acceptable), but action is needed.
Those graphs is one of the things i like in my scouting app (FarmQA).
Fruit Growers Tasmania is an organisation for the support of their member growers in the total range of growing and marketing fruit. I admire the way they assist their growers in almost everything a grower might face (contacts with government about corona, labor; export regulation; growth technical information etc). Fruit Growers Tasmania yearly organizes conferences about the crops they support. This year i could do a presentation about covercrops and flower borders in strawberries.
Withgoing the presentation and pictures used for a presentation about covercrops below table tops / gutters outside, in rain coats (open tunnes) and greenhouses and flower borders in order to attract predators close to strawberries.
Grass / Clover or another cover crop can be a huge camechanger. I see more and more growers changing from an artificial soil cover to a cover crop. Main reasons are: – much better climate: – in hot summers it can be till 6 oC cooler with an active cover crop – higher humidity or better a humidity buffer – causing less problems with mildew
Much better climate:
In hot summers it can be till 6oC cooler with an active cover crop
Higher humidity or better: a humidity buffer with smaller differences between higher and lower humidities. Causing significant less problems with mildew
Hiding place / buffer for predators. I normally see more and more predators like:
aphidius and aphidoletes – sometimes together with some aphids
Aphidoletes. A very small fly, but capable of quite some cleaning work in Strawberries. Below you see some pictures of: – eggs (orange-red color) – larvea: – 1 with an eaten Ahpid – 1 just starting to eat an aphid Last year we had some problems. Predatory mites against white fly and thrips eating the eggs of the Aphidoletes, thus a growing Aphid population.
For me eastern – pascha is the most meaningful celebration i know. It is about our future. For some the step out of a past in slavery, for all a view into a future without all current troubles. just like a flowering strawberry stands for a future beautiful, nice tasteful strawberry. – Like the small chicks stand for future chickens and maybe new eggs – Like the lambs stand proof the future sheeps, with wool, meat and milk
So is Eastern / Pascha the proof of the new life to come. We have a future. A future much greater and more beautiful as the current. And in this future: – no death – no diseases – no pain – no war Boring? I don’t think so. We will once find out what we will do. Happy for sure. But i do hope that there on the new earth we may grow Strawberries as well. And we may offer God of these our beautiful and delicious fruits.
One of the growers i visit in Northern Germany has builded 3 greenhouses for about 4 years ago. She and her husband decided they don’t want to expose themselves nor their workers to chemicals. So that means no spraying at all.
Therefore they use predators, they seeded a mix of grass and clover under the table tops. And yes, it functions very nice. No problems with pests, a better climate (moisture buffer), so hardly problems with mildew. Therefore they also use modern varieties, that can handle mildew and several other diseases that may be an issue in strawberries.
And yes, about 4 weeks after planting the first aphids on the grass the table tops. Very few aphids on strawberry plants. But, also predators: predated aphids by Aphidius, Lacewing, Ladybug and Aphidoletes.
Very interesting to see how a population of predators builds up by just stopping to spray.
Right now in a lot of areas in Europe climate is quite cold – temperatures are low. Whereas some growers have flowering crops in unheated tunnels and night temperatures from around -8oC.
For soil grown strawberries there are some possibilities to prevent damage: – normally i count for every 5oC of frost at least 1 cover with fleece (if no wind) – During flowering every minus is allready dangerous – A wet soil helps a lot in radiation of heat out of the soil and keeps temperatures better under a cover – Close and cover early, so the soil has time to warm up.
Below 2 pictures of strawberries covered with fleece. The first one with old fleece, the second with new fleece. color: the more in the direction of blue, the colder; the more in the direction of orange, the warmer.