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:
predatory mites
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.
Yes analytics in strawberry growing. Every day we make decissions. Based on experience, based on research, based on knowledge of suppliers. You can also make decissions based on processes on your own farm, or gathered data. Below some of my own experience. In the following link the companies information on Analytics: FarmQA
Advice For advizing growers i use FarmQA. I can make my own templates for gathering data (on smartphones, tablets etc) and based on that make the reports and give advice. I gather for example: Development stage of the plant, EC, soilmosture content, number of flowertrusses, diseases on a scale (0-5), pestst etc. etc. For advizing growers this is very important: fast reliable information about fields of my clients. Growers can make their decissions based on this information. (below an screenshot of the template for registration of all the important subjects in strawberries).
Advantages for me: – time saving – about 5-10 minutes per scouting location – about 30-45 minutes for an averages report for growers – more acurate data about the fields – possibility to analyse
Analytics Recently FarmQA added an analytics option. Analyse all the data you gathered. Get a good picture of the number of aphids: going up/down? More then comparable growers? And take or advice an action. During the season i don’t need to check all the numbers. With the graph’s i get easy and good inside in what is going on. Do i need to intervene, or will the problem solve itselve.
Above you see a graph from Analytics. Easy to see, that most populations of aphids decline. Only for two growers i am doubt if further action is needed: one population is increasing, one is too stable.
With this analytics i could very easy check the population development for different ways of growing, or the use of bankerplants. Growers that work with flower borders around the strawberries for example had clearly less problems with aphids.
Heat maps It is also possible to make heatmaps: an inside in the location of pests or diseases. In my case because growers are quite far away from each other this doesn’t make that much sense. For growers with largere areas and multiple fields or multiple scouting locations this gives a lot of insight in the spatial development.
Yes again some bugs. This time not all from among the strawberries. My dad has sent me a nice one and i couldn’t let it go. Just the beauty of this dragonfly. Unbelievable what a creation.
Predators predating Predators
This week i had an interesting subject related to predators: predators eating predators. It makes pest control with predators a level harder. One grower had quite some aphids, but with the Aphidoletes (mainly, but also some Aphidius) they could controle the aphids last weeks quite well. Spidermites became a little problem because they had changed their strategy to fewer introduction of predatory mites. So the didn’t establish quite well. As a correction of the they introduced quite a huge number of Limonica. Untill that introduction, Aphidoletes eggs where found everywhere, after introduction of Limonica no eggs of Aphidoletes, and an increasing population of Aphids…
All this makes brings the use of predators to the next level. This is in line with a research from Wageningen University (WUR) which shows the complex relations between different predators and different pests.https://edepot.wur.nl/121105 and in Dutch: https://edepot.wur.nl/166164
The whole relation between plants, insects, climate is an interesting and complex one. Same structures, same greenhouses, same varieties and yet completely different development, balances in the plant. Last week: 2 greenhouses from one grower. One greenhouse with gras between the rows, one with anti rooting cover between the rows.
Not only the strawberry plants develop completely different, also the predators. With the anti rooting cover on the soil, or the widely used white plastic in glasshouses it is not always easy to establish predators in the crop. With grass between the rows, in a lot of cases natural predators occur.
Climate – predators What i have seen so far over the years, that in moderate outside or greenhouse climates predators develop easily. Climates a little more humid, with temperatures and humidity not going up and down, is much better for the predators.
predators – predators Another interesting item is predators eating predators. Recent research from Wageningen WUR showed there is quite a strong interaction of predators eating predators. Not only orius eating eggs of Aphidoletes. But also orius eating aphids. And different predatory mites eating each other, or each others eggs. The same i used to see in greenhouses without chemical controll of insects. Spider populations developing quite fast. Good for some predation of at least flying aphids. But unfortunately also Aphidius types of predators of aphids. If you would like to read something more about hyperpredation of predators among each others: https://link.springer.com/content/pdf/10.1007/s10526-012-9462-2.pdf
Climate strawberries As all plants do, also for strawberries climate is very important. Especially stability of the climate. As soon as the fluctuations in the climate are getting big (high-low temperature / high-low humidity) plants don’t develop very good, health problems (milldew). In Western Europe, we have tried to solve this with highpressure humidification, but in contrary to what we would expect: more milldew. Plants seemed to get a kind of lazy and as soon as we were to late with humidification, got milldew. In greenhouses with table tops and grass underseeded, inside temperatures can be till 7oC lower as outside temperatures. In greenhouses with black anti rooting cover, temperatures used to be 3-5 oC or more higher as outside. A huge difference.
Habitat / hidingplaces / food In case of tabletops (outside), areas with a lot of flowers may stimulate orius, aphidius, hoverflies, lacewings. A lot of natural predators occuring and settling in a field. Several growers in the Netherlands started with using non productive areas for seeding flower combinations attractive for predators. I have seen balances within this flower areas of orius – thrips, aphids – hoverfly+lacewing.
Summary Growing biological strawberries is much more as just introducing predators. Possible hidingplaces, climate, interaction between predators is very important. Try to think of as much interactions between strawberries – predators – climate – habitat etc as possible and use them to optimize your IPM strategy.
