Visiting Keith & Judy Paxton May 2007 - Custard Apple Growers

Keys

AP – African Pride Custard Apple
CA – Custard Apple
DPI – Dept of Primary Industries
FSB – Fruit Spotting Bug
PM – Pink’s Mammoth Custard Apple
IPM – Integrated Pest Management
KJ Pink – Custard Apple developed by us (named after us Keith & Judy & from a Pinks Mammoth)
MB – Mealy Bug
PBR – Plant Breeders Rights
 
Keith We’ve grown Custard Apples for over 30 years and been on this farm for 26 years. It use to be a pineapple farm but pineapples are not a commercial proposition on these small acreages with the gradient of the hills and erosion. We grew strawberries for a while. We planted African Pride Custard Apples which pollinate very well and get quite a nice fruit if grown really well and the fruit have a nice flavour but they also have a  high percentage of seed.

Sheryl  Are there any varieties of AP that don’t get as many seeds?

Keith    There is a strain of AP called Palethorpe and it’s a big AP.

Sheryl   Is it under Plant Breeders Rights?

Keith     No, contact Alan George at the DPI at Nambour. It’s not as heavy a cropper as straight AP.

Sheryl   How many seeds would there be in it?

Keith    As a percentage, it would be a lot less.  Some of you may remember Island Gem but when you got a shower of rain, you had to duck because all the fruit used to split and throw seeds everywhere. One of the original areas of Brisbane which use to grow CA was the Sunnybank/Rochedale/Redland Bay areas. I remember trees 20 mtrs high. Pinks Mammoth or Bullock Heart has always been the preferred eating fruit. Along came Hilary White which was a sport off Pinks Mammoth. A chap called Hilary White at Redland Bay noticed a branch bearing differently on a tree so the DPI monitored it. It produces more fruit but has a softer skin but it’s still the Pinks Mammoth flavour but does tend to set a few more fruit than what straight Pinks Mammoth does but it splits more and has a few other smaller problems but it is very pleasant to eat and has good colour. Our KJ came from a sport on a PM as well. It was the furthermost tree on our property against the scrub and it was the furthermost branch on that tree and we noticed that it had a lot more fruit set on it. It actually got a big ball of fruit and it was a very small branch so we propped it up so it didn’t snap off. It had a ball of fruit you could put your arms around but you couldn’t put your hand in it as it was just solid fruit. Alan George and I watched it for 5 years and then planted some out so it was 7-8 years before we got PBR on it.

Member  Did you propagate by seed?

Keith    No, most varieties of tree crops are not true to type from seed – some are but usually they’re propagated by grafting or cutting shoots or taking budwood to produce that actual tree otherwise you lose the strain. It’s changed custard apple growing because people can plant KJ’s and they know they’ll get a good commercial crop but the biggest problem is that if you don’t thin the fruit off the tree, you get smaller fruit. The industry has now planted around 15,000 trees and it’s exactly the same flavour as PM. We use to grow about 40-50 tonne every year.

Fruit Spotting Bugs

are a major problem in this area and they say that here is the home of the Spotting Bug. Judy and I use to spend about 3 hours every afternoon from the 1st November to February hand pollinating fruit except when it was raining but in January if we got a storm or had a wind change, it would bring the spotting bugs in out of the scrub so we could lose 70-80% of our pollinated fruit. Spotting Bugs sting a multitude of things.  They live in the scrub but you could have a wave of adults go through your orchard and sting your fruit and you can’t find them because they feed on the fruit and lay their eggs and then they’re gone. Then 2-3 weeks later you get all the little nymphs hatching out.

Bob   Can you describe the Fruit Spotting Bug as people get confused.

Keith A lot of people get confused with the nymphs as Assassin Bugs but the difference is that the Spotting Bug has two little antennae with two little lumps on the antennae and also he’ll run and hide from you whereas the Assassin Bug which is exactly the same colour and shape won’t bother to run away.

Keith  There are two types of Spotting Bugs. One is just called Fruit Spotting Bug and one is called Banana Spotting Bug. The adult FSB is yellow-green and is about 15mm long and the females lay pale green oval eggs about 2mm long.  The banana spotting bug is the same size but tends to be a little bit more yellowish. If you squash it, it smells like nothing else! If you find a Green Shield Bug, it smells quite bad too but the SB is about half an inch long, a round green insect which tends to hide from you and you can  usually see them stinging the fruit. They did tests on FSB stinging the fruit and it’s a ridiculous amount of stings that a bug will do on a fruit in an hour eg. if you get one SP on a custard apple tree with 50 fruit on, then in 2 days virtually every fruit can be damaged.

Col   They’re not laying their eggs?

Keith  They’re feeding but they will lay their eggs on top of a fruit or somewhere else. We didn’t bother to spray the top orchard and they stung 100% of the  fruit on the trees. They also can feed on the tips of foliage as well. We have a big forest of Piccabeans and other rainforest trees and the bugs appear to breed there as it’s a natural home for them.

Sheryl   What do you spray them with?

Keith   There’s a range of insecticides you can use but you have to stay within the guidelines recommended for any insecticide you use. Most insecticides don’t appear to give long residual protection against SB. You could spray with something as heavy as Supracide and a couple of days later you could have reinfestation. It’s just one of those insects that is a real problem in horticulture.

Sheryl  So you really have to net the fruit?

Keith   Some areas don’t suffer as badly as we appear to in this area. We have a tree over the back – the tree that had the KJ sport on it and this year, the tree is covered in fruit and not a single SB on it and yet up here they stung out the whole orchard.  A lot of growers used to go around and physically squash the SB as they might only have one hot spot in the orchard where just a few appear, but here in this area it is worse than anywhere. A lot of growers don’t even spray for SB – they’ll put up with a few stings. They’re also a major problem in passionfruit. In late August/Sept they’ll come out of the forest when we have all new growth on our passionfruit vines, they’ll sting all the tips off the whole orchard if we don’t spray for them.

George   What about something like Confidor which is systemic?

Keith     We have not had any success with Confidor in the trial spraying we did on our property.  Dan Smith, an entomologist with the DPI helped us with Integrated Pest Management in our orchard over many years.  Dan said there was a parasite of FSB and heaven help us if ever that parasite dies but when you have huge populations in the forest, there’s obviously no parasitisation working and with our Passionfruit, we may only spray twice a year with an insecticide. We’re finding a lot of things are deterrents to a degree – we use a lot of IPM in our orchard. We sometimes have Mealy Bug really bad here. Anyone who grows Custard Apples or Passionfruit know MB are quite a problem. We released Anagyrus seven years ago and we did have another insect called Leptomastic which was a tremendous predator of MB in custard apples and other crops but they became unavailable so Dan bought in Anagyrus – another little wasp parasite and we tried that but it didn’t seem to do anything. Last year, we normally buy Cryptolaemus insects (ladybirds) off Bugs for Bugs for controlling MB in the Passionfruit and custard apples but there was a problem getting them for our CA so we had a big infestation of MB but all  of a sudden we noticed something was wiping out all the MB and it was this Anogyrus – he’d been living here and had become so strong that the Anogyrus and another little gnat went through our entire orchard and wiped out all the MB and he’s now moved into our Passionfruit which also suffer from a type of MB – it’s not the citrus MB. The mealy bug predators were surviving even though we were spraying for FSB. We also took them down to a friend’s custard apple orchard at Beerburrum this year and released them.  He also suffers really badly with MB – they leave soot on the fruit and they’re going through his orchard like quicksilver. The gnat lays that many eggs and he breeds a little maggot and it gets around and eats all the MB and the Anagyrus goes round and parasitises it so they multiply and hatch very quickly. They’ve got so much food that when the MB starts to run out, that’s when we’ve always had a problem with other insects because all the MB are killed and there’s nothing for them to feed on but for some reason the Anagyrus is surviving here. We’re not sending any Avocado or Custards to market this year but we do spray them to keep them clean – we use Dipthrex on our Passionfruit for Spotting Bug – it’s not the best thing but it does work. When we spray the Passionfruit, we turn the air blast off and just drive through with the mister up as high as it can get so it just wafts along the top and doesn’t go into the vine and kill the predatory insect because the FSB is all on the outside so it kills the adults out of them. With CA, it’s a developing market and it’s hit a snag with the export and Hong Kong has stopped exporting into China and that is where the good quality of CA were going.

Bob C    Why did China do that?

Keith     It took over Hong Kong and I guess there was a market feeding into China. In Australia we have lots of bio-security problems – you’ve heard of the Banana importation from the Philippines with moco disease and a friend of mine says that it’s not a case of if we get moco disease, it’s a case of when so that would devastate the banana industry in Australia.  With food in general, the government is only trying to give people an avenue of cheap food – not all Australians can afford to buy the very best and as long as the food is nutritious, the govt is providing a service to people. Another threat to small farmers is managed investment funds – big companies going into horticulture and planting huge areas in which they have unlimited funds and they displace all the small farmers.

Sheryl  So tell us how to get Custard Apples on our trees Keith.

Keith    It’s not as hard as you think!

Sheryl  Oh yes it is!

Keith    If you want to hand pollinate, it’s a lot of fun!

Sheryl  Oh no it’s not!!!  I’m a failure but perhaps it’s the Fruit Spotting Bug attacking as we’re next to bush.

Keith    It is onerous to do it all the time but it is a lot of fun because you get to see what you’ve done – you get a much bigger fruit. The problem with CA pollination is that the flower begins as a female and then it has a transition where the stigma is moist as a female but as it changes to a male flower usually about 3.30 in the afternoon, the pollen releases but if the air is not the right consistency of moisture, then the stigma dries and so it’s not receptive to the pollen so the pollen wafts free. Most CA are pollinated by wind movement of the pollen rather than insects – insects tend to damage them.

Sheryl  Even the Nitidulid beetle?

Keith   We did a trial here – we use to breed them in the orchard by getting baskets of pineapple.

Sheryl   I tried that but the crows ate the pineapple.

Keith    The beetle actually damaged the stigma so it resulted in poor quality fruit so they’re no benefit at all.  With KJs’ it shortened the distance between female to male and the stigma is still receptive.

Sheryl   So how can you tell if the moisture in the air is right?

Keith   Unfortunately with this weather, there won’t be any flowers on the trees but when you open a flower and you can see a little secretion on the stigma and if you touch it, it’s quite wet. It’s very easy to see.

Sheryl   So it’s no use pollinating if it’s not?

Keith   We pollinate regardless because you will still get pollinated fruit even though it’s not visually receptive. It’s fun. You pick your male flowers at 3.30pm – you don’t need a lot of flowers – it’s what you do with the pollen as to why you’re not successful. Get a tray with some brown paper in it, shiny side up, lay your flowers in that and if you want to get the pollen more quickly, put the air conditioner on – it’s a temperature inversion that makes them open so wait until they pop open. I get some PVC dust and that’s the real way to do it - just use a little with the pollen as it has static electricity which the pollen sticks to.  The slightest moisture and it sweats. Get a magnifying glass and look at the pollen ball. If there’s the slightest bit of moisture, the pollen will explode so they’re all spent. Don’t collect the flowers in a plastic bag.

George   Humidity has to be a certain level?

Keith      It probably helps to have higher humidity levels.

Sheryl    How much PVC dust to pollen?

Keith     We pick about 200 flowers in a tray – it’s great if you have an AP as well as the PM because you can use the AP flowers. The pollen of KJs is much more fertile.  Put the flowers in a sieve and you’ll see the stamen which is the little part of the flower where the pollen is on the end of it and you’ll need a magnifying glass to see the actual brown little ball but you have the stamen and the pollen together so you get just a little PVC dust – about a teaspoon and sprinkle it all over your pollen and brush all the pollen down into one corner and brush it into your bottle then use a No. 4 sable brush and dab it in your bottle then open the flower with 3 fingers and very gently dab it in – don’t jamb it up there!!! The female is white around the stigma whereas the stamen appears brown in the male.

Member   In the books they say to do it in the morning.

Keith      Quite often the pollen could have gone off – you might have moisture in the house. Every morning there’s usually high humidity, moisture, dew, mist and if you bump a leaf and look into the sun, and that dew goes into your bottle, you’re wasting your time. You could also get it on your brush so that is why we collect the male flowers at 3.30 – you’ve usually got about half an hour before they pop open although it does vary with the temperature. If it’s a really hot day, you’re wasting your time because they won’t pop open. You need a nice normal afternoon.

Sheryl   What temperature would you say don’t bother.

Keith    Over 30º but the temperature may drop very rapidly in the late afternoon which makes it pop really well.  So after you’ve prepared the pollen, you pollinate later on that same day but quite often, the females won’t open until just on dusk. A lot of growers use headlights and pollinate in the dark. Some days are good and some days are a waste of time.

George   Do they have an insect pollinator in South America where they are native to?

Keith    When you hand pollinate, you don’t want the insects/beetles in there. European bees don’t pollinate because they’re too big to get in.

Sheryl   What trees have you seen the native bees on?

Keith    They’ll collect Custard Apple pollen from the male but they won’t go in to a female flower as there’s no pollen there for them to collect.

George   So the tree is not suitable for insect pollination at all.

Keith     Not at all.

Bob C    How long is the pollen viable for?

Keith     We use the pollen that same afternoon. Some people use it the next day. With PM if you have a tree that is 5-6 years old and you’ve been pruning it every year and you’re not getting any fruit, just leave it alone – don’t prune!!  It may get some water shoots and you may have to take some out but just leave the laterals to grow and then it will form into an umbrella canopy with fine little branches and the tree will be just covered in fruit you won’t believe it. You might not get a lot of evenly shaped fruit, but you will get a heap of CA to eat.

Fertiliser

I use either Rustica or Nitrophoska and that’s all you need to use. Don’t give it any Nitrogen at all.

Sheryl   When do you put it on?

Keith    We found it was better to put it on in the middle of winter rather than after pruning because Alan George did a lot of root zone trials as to when root movement starts and we found that root movement starts a lot earlier than what the shooting does so you need the fertiliser on late winter (beginning of August) or even a bit earlier to allow it to dissolve and get in to the root zone so the nutrient can be taken up.

Sheryl   Would you put the fertiliser on 2-3 times a year or a little and often?

Keith    Because they have such a big aerial root system, probably 2-3 times a year. Once you get your crop on, you can be a bit more liberal eg if it’s a big tree, use 2-3 kgs around the drip zone – don’t put fertiliser anywhere near the trunk of any tree as it doesn’t like it. We don’t use copper on our farm.  We haven’t used it for 10-12 years. Somebody told my wife to put copper around our Poinciana and it would it flower and 2-3 weeks it was dead!! A neighbour had algae in his dam so he got 2 pieces of Copper Sulphate the size of my fist and the water was crystal clear in 3 weeks but there wasn’t a living organism in that dam – it killed all the shrimp, fish, everything. Since we’ve stopped using it on the farm, we’ve noticed a huge difference in the worms and soil. Our ground is just alive with earthworms under our passionfruit.

George   Do you use Mancozeb?

Keith     Yes when CA are getting black spots over them – most of it is Cecospra, and Mancozeb will stop that but when you’re growing them for yourselves, I wouldn’t spray them at all.

Sheryl    Do you mulch?

Keith     Yes. We replant half our farm with passionfruit each year – about 2000 vines and sameside them (plant them back into the same spot) and we put a 25kg bag of mushroom compost at each planting site. We use 60 tonnes a year.

Member   There’s a mushroom farm at Woodford – 50 cents a bag.

Keith     After you put it out and it breaks down and you get a second lot of mushrooms coming up, you can then eat this second lot of mushrooms.

Joe   If you’ve got a single tree, how many days would you wait before you re-pollinated. I use a clothes peg to delineate the flowers I have hand pollinated.

Keith   Two.

Member   How long is the flowering season?

Keith    If you wanting more flowers, you can break off some leaves on your laterals where you want some fruit and you’ll get a shoot there with flowers. A friend of ours has only just stopped pollinating.  It depends how many fruit you want – in January, if you’re wanting more flowers, then break off some leaves.

Sheryl   How much water do you use?

Keith     I haven’t watered these at all this year although I sprinkled last week.

Joe        I found the last ones I pollinated, the fruit are not very big but I have over 100 fruit on my tree.

Keith   That’s because you’ve got so many fruit on. My later fruit are by far the biggest because all the other fruit have gone so the later fruit has no competition.


Propagation

Use a cherimoya seed for rootstock, then graft on.

George   AP produces good seedlings.

Keith    It doesn’t have as much resistance to wilt - you want a vigorous rootstock.  If you have a vigorous growing tree, you wouldn’t get any fruit.  We grew Maroochy Gold for about 12 years but it is very attractive to fruit fly and you can’t tell if it has been stung.

Sheryl   What do you use against fruit fly?

Keith   We use a mixture of hymal and yeast autolysate and recommendations for its use are on the label.

Sheryl  Keith is still the owner of the KJ variety and has contracted with Birdwood to propagate his trees.

Keith  For eating quality, just buy a Hilary White CA. If you find something special, patent it as it’s quite quick and it’s not that expensive. Approach someone like ANFIC.   You can patent the tree or you can patent the fruit you produce.

Col   We’d all like to grow a KJ.

Keith   Anyone who buys my trees signs a non-propagation agreement and it’s only sold to commercial growers because if every backyarder can grow one, then the market will diminish. The farmer has to have some advantage to want to continue to grow. The market has been really hurt by the export being cut back but because the KJ produces a huge volume of mediocre sized fruit, it’s a lot better for supermarkets because most people don’t want to buy a big fruit. Because KJ is self pollinating, you do tend to get a bigger percentage of seed but in the trial work, the ratio of pulp to seed was the same in KJs as in PM.

Sheryl    You mentioned that by planting an AP you can use the flowers to pollinate the PM.

Keith     The pollen in AP is probably more fertile than it is in the Pinks.

Sheryl    I’ve read that you should keep your branches off the ground to stop ants from going up.

Keith    True but I’ve never bothered. We don’t need to with Anagyrus and the gnat clearing up the mealy bug.

Sheryl   Do you use Lebaycid at all?

Keith    No, we spray our Lychees with Dimethoate for fruit fly.


Pruning Lychees

We take a couple of substantial branches out of the tree every year to try and keep the height down and keep the tree more open. For picking lychees we have a machine where 4 people stand on a platform It’s hydraulic so it can go into the tree or up and down and we have lights so we start picking at 3am and finish at 8am at the latest because they start to dehydrate  ie the quality of the fruit lessens and it affects shelf life.


Pruning Custard Apples 

If you prune, no more than a 1/3 of your lateral in late winter (August). If you go back past halfway, it will vegetate but with 1/3 off, it will get a whole new range of canes. With young trees, try and open them out so the tree is not too dense in the heart of it. I make my trees into a step letter so I always had an opening and I can walk in and I can step in and walk around up the branches and carry a bucket.

If you cut too much wood off a tree it will vegetate.

How to tell when to pick your fruit   

It will have a greasy feel to it and the carpals have opened up and have a creamy tinge. They take about 3 days to ripen.  The longer you leave the fruit to get bigger, the more volume of flesh to ratio of seed.


Passionfruit

There’s a whole row which is dead  -  got hit by lightning. There’s a 96A variety which is sold to the public. They’re grown on one wire between wooden poles about 2 mtrs high,4 mtrs apart and 3mtrs between rows. Fusarium attacks the roots and Phytophera then gets in and kills the vine so that is why we plant grafted vines which have a fusarium resistant rootstock.

Sheryl    Why don’t you grow Panama varieties?

Keith     It doesn’t have the shelf life.

Sheryl   How do you control Anthracnose?

Keith    We can’t stop it – it’s just one of those things that we have no fungicide to control it.

Sheryl   What do you do about Phytophora?

Keith   I use Naturamin as a soil conditioner once a year on all crops and it seems to be helping against Phytophera.

Authored by: 
Sheryl Backhouse
Sourced from: 
Sub-Tropical Fruit Club of Qld. Inc Newsletter June - July 2007
Date sourced: 
20/03/2013