Hello and welcome to Yara's grow the future podcast series. My name is Ken Rundle and with me today is Giz Gaskin., Yara's fruit specialist. Giz, this is a time of year when almost every fruit grower has decisions to make, but let's start with strawberries.
Well , June bearing crop, I would imagine is already in flower . It's been quite a good year to be fair. The June bearers would've come out of the vegetative mixture and would have run into their flowering mixture already. For this, you would have seen the EC jump up. Normally it would run into about 1.0 to 1.5, five EC , and drop down into 1.3 EC. Electro conductivity is what it stands for. It's a measure of how much salt is within the bag in the strawberry bag.
In this case, you would expect the vegetative mixture to be higher in EC than the flowering mixture but you'd want to drop the EC into the fruiting time , as that really improves the strawberry flavour. In the case of everbearing strawberries this year, again, as I said, has been a good year. Most everbearing strawberries will be either entering first flush or in first flush.
There's an option here with some of the ever-bearer growers whereby if they were to retain some of their nitrogen inputs , they could use it in the dip between the first and second flush and that would enable them to pull the second flush forward a little bit. So this is sometimes not done as shortening the timing does have an impact. Then on first berries of the second flush as the nitrogen affects the a cid sugar balance,
It's been an early season, as you've already said, heat too has been an issue. So venting is still very much a key key feature.
Yes, certainly all strawberries are a temperate crop. They have a normal rule of thumb temperature maximum of about 28 degrees centigrade. Plastic, as you may know, increases the temperature by approximately four degrees from ambient. So in a good summer's day, you would need to lift the side of the tunnel in order to vent strawberries.
Venting is important because , um, if you didn't vent, what would happen is the strawberries would effectively slow down their nutrient uptake and although you'd be maintaining your irrigation because the strawberries are not uptaking the water, it will just go and sit in the bag and under that saturated condition, what tends to happen is that the immovable nutrients like your calcium and your iron would also sit in the bag unable to be uptaken which leads to problems in the long run, but also
as the situation reverses and you get a drier bag and the plant starts to take up the nutrients because you've effectively pushed away your immovable nutrients of calcium and iron, the plant struggles to uptake them, even after the saturation event. It's very important to monitor venting and fertigation simultaneously.
That's strawberries , the other one at this time of year, obviously raspberries the cane fruit,
Yes, cane fruit berries , raspberries, and blackberries. The same reasons as strawberry really that venting is important. Raspberry is a temperate plant again, it doesn't like to be higher than 28 degrees if it can help it blackberries less so they , they can tolerate more heat but the same raspberry and cane fruit would be very sensitive with regard to EC.
so again, coming out of the vegetative mixture into the flowering mixture , monitoring the EC and watching out for the acid balance is quite important. Raspberries tend to have a slightly shorter shelf life than, than strawberries these days. That's very important with regard to EC but also balancing calcium.
The calcium nitrate is probably a better product to use in the vegetative mixture to get the calcium within the pot so that the plant can uptake it later, but if you've not got enough calcium in the system, you can certainly look at using a foliar applied calcium, s omething l ike STOPIT from Yara, which will allow you to get a much better skin finish and also crucially i mprove some of the firmness in those raspberries.
Skin finish is also important in top fruit in apples particularly. And you've got some messages on that as well.
Yes, apples , this time of year, you would expect to be in Apple drop or Apple drop to have already occurred, but yes, this time of year is all about picking the best apples of the crop or whether the crop has dropped them itself. Or the grower has gone in and selected out what he wants to keep as the best Apple crop. The next question is skin finishes.
You say, and that's, again, the product is Yara STOPIT calcium foliar feed this time of year, you're starting to time applications and rates for it. Aside from stopping blemishes to skin STOPIT is there to control and reduce bitter pit which is an apple disorder, which, which impacts the internal quality of the apple. So yes, this is a very important time of year for top fruits specifically for apple.
Moving on. I suppose we go to Bush fruits, which these days seems to be largely concentrating on blueberry. Although there are obviously other Bush fruits as well.
Yes, there are other bush fruits, currents and gooseberries certainly, fairly big markets in their own, right. But my favourite by far is blueberry. Blueberry, and other bush fruits are an interesting crop. They tend to prefer lower pH's perhaps with the exception of the currents. This means that largely they prefer to be fed on ammonium feeds. Ammonium feeds make things a little bit more interesting in a sense because they run on the principle that you've got to manage the root zone .
Ammonium hangs in the soil, unlike other nitrogens, it doesn't flush through. So having applied ammonium for most of the year till this point, the longest day is approaching and it's important to try and take out ammonium in order for the plant to have time to absorb the ammonium before it goes into dormancy. That's , that's really the crucial part to using ammonium and bush fruits, the ammonium, as it balances in the soil, it doesn't get uptaken so quickly by the plant.
Therefore it has to have time to be uptaken and blueberries in particular, they don't have the same rooting system as raspberries and strawberries. The blueberry rooting system is , is quite matted. It's more like imagine a carpet rather than a taproot . And that means that it very much responds to inputs little and often. So having the ammonium in the soil allows the blueberry to slowly uptake it over a period of time.
The reason as I said that you would aim to stop ammonium at this time of the year is really that you're giving an opportunity for the blueberry to exhaust the ammonium from the soil that enables the plant then to enter in natural dormancy without having too much nitrate available to it, which is important because if the blueberry plants enter winter with green stems, the stems can shatter because they hold too much water.
That's why it's important to make sure that every bush fruit enters its dormancy correctly so that they are effectively brown wood, and as they pass through a very cold winter, they're completely unaffected by the frost and the harsh condition .
Well, that's looking forward as it were. What's the season been like so far from East to West, North to South so far, it's been a good season ?
Agronomically speaking we are certainly further ahead this year than we were in previous years. The June bearing crop is approximately four days ahead. Everbearing crops, interestingly, as much as a week ahead as where they would normally sit. South coast has had the best weather, I would say , certainly very much on the warmer side, temperate, there have been odd frost pockets here and there.
Certainly where top fruit is concerned there was a late frost in April-May that certainly has caused a little bit of damage to cherry , pollination, a little bit of damage, perhaps on the viticulture side of things. And some very early strawberry may have seen some mis-shape, but aside from that, a good year.
Frustrating for growers , a great season, just when there are all kinds of other issues to handle. Still nevertheless, thank you Giz for that. Some good messages and if you've enjoyed listening to this podcast, the next in Yara's Grow the Future series will be on the 9th of July. Join me, Ken Rundle then