I planted 6 citrus trees this summer. Before I planted them I dug in old horse manure and bio char and clay into my very sandy soil. I have been feeding them Mg and iron as both of these are low in my soil tests. They are being attacked by scale. As they are baby trees I am concerned that the scale could really knock them. I have sprayed with white oil. This seems to kill the scale but only for a very short time and then they are back. I'm thinking that it is probably a soil problem. In that the trees are not growing well enough to beat the scale. Has anyone got any ideas, either to eradicate the scale or improve the health of the trees so that the scale don't effect the trees as much as they are.
Haven't had a scale problem (yet!) so I had to do some "looking up". Do you have 'hard' or 'soft' scale on your trees? "Armored (Hard) – Secrete a hard protective covering (1/8 inch long) over themselves, which is not attached to the body. The hard scale lives and feeds under this spherical armor and does not move about the plant. They do not secrete honeydew. Soft – Secrete a waxy film (up to 1/2 inch long) that is part of the body. In most cases, they are able to move short distances (but rarely do) and produce copious amounts of honeydew. Soft scale vary in shape from flat to almost spherical." https://www.planetnatural.com/pest-problem-solver/houseplant-pests/scale-control/ It seems that scale insects lay their eggs beneath their covering (for protection) and the hatched crawlers are most susceptible to predators (like ladybugs and wasps). I'm wondering whether your trees came from the nursery with scale? The oil sprays seem to asphyxiate the adult insects ... although Neem oil is sometimes recommended and contains a natural insecticide. As far as your soil, you have provided an appropriate mixture to support soil life ... maybe some compost would introduce the diversity of beneficial micro-organisms you need. I think that Elaine Ingham would recommend not only to apply some excellent compost on top of your soil, but to also foliar spray the trees with compost tea. Well made compost will contain all the beneficial micro-organisms needed to give your trees the advantage they need. Some references for compost tea: https://www.soilfoodweb.com/Compost_Tea_Recipe.html In depth .pdf book: www.nofanj.org/LiteratureRetrieve.aspx?ID=104151
also add your support species and mulch in a variety of ways (to give beneficial bugs a start). when repopulating a degraded environment it helps to bring in soils from a healthier environment to help repopulate any new plantings. adding biochar and chemicals isn't adding much to the actual diversity of the system if you aren't also bringing some in somehow. to get rid of scale from a plant can take a lot of repeated treatments. you will have to do it more than once or twice (and you must hit every surface). i know this because i used to have to do it for infected cacti. ouch...
I think they are soft scale because they have ants with them. If I make compost out of "stuff" from here does it still get the right microbes even though there are none in my soil? I was happy to see some earth worms around the citrus trees when i pulled back the mulch to water in seaweed extract. So at least something is starting to happen in my my sad sand. I am adding seaweed extract. Does that have the right microbes?
i think it would help to find another source than "seaweed extract". can you find people around who have organic gardens for samples? most gardeners i know are often happy to help. you can brew from composts derived from those that will help your diversities much faster IMO. if you can find someplace where you can get a few buckets of soil from to start your own piles. i would go for two: one a pile from a wooded area and mulch it well to keep it from drying out then use a few liters of it under each tree planted and replace some dirt and mulch so it can regenerate. after your trees get bigger and make their own mulch/leaves then you wouldn't need this pile any more. the other pile i would take from an existing thriving pasture/field, again a few buckets worth kept in one location to use to innoculate clumps of grasses as they get established. your question about the exisitng biome having much diversity and if it helps to compost from that, well yes, you would increase counts of bacteria, fungi, etc. but your diversity will not increase that much. that is why i would look for some alternative innoculant sources. any materials you bring in from other areas will bring some added diversity, best to bring them in from thriving and healthy sources. and yes, it's usually a good sign to have worms about if you are in an area that can support them.
This whole area has very sad soil. Being very sandy and dry is not a good start and on top of that most areas are or have been heavily grazed and or cropped. So not much hope of getting bucket of good soil from anywhere near.
My advice would be to spray the trees with biodiversity through compost teas and other natural farming techniques, possibly IMO based approaches. Also, coming from a nursery/greenhouse background I am familiar with the scale issue. The most effective way I personally treat scale is alcohol. Isopropyl alcohol (90%) at 1:20 ratio. Just be sure you do not get any on the roots, and remember you may need to do either of these techniques more than once. Now if you are in Florida, as I am. You will be up against Citrus Greening disease via the vector of the Asian psyllid, Diaphorina citri, the state has come into a state of despair for the citrus industry. Coca-cola is very upset (Starkist is a huge consumer of our orange products)..The disease Haunglongbing is devastating and is changing the face of our citrus world. "The impact of HLB in Florida was estimated to top $4.5 billion in just the five years between 2006 and 2011. It is the most serious disease a citrus tree can contract. In as little as four or five years later, the tree withers into a brown skeleton and dies. There is no cure." - https://www.rfdtv.com/story/31866113/students-study-asian-citrus-psyllid#.VytAnoQrKUk (7hours ago news) This is why we do what we do! Thanks for reading!
In South Australia so don't have to worry about Citrus Greening. Fingers crossed I seem to be winning the war on scale. I haven't seen any for a couple of weeks. I will keep up the white oil for awhile yet to make sure I have totally got the b's. I definitely have to improve the soil though. It is getting better but still needs a lot of help
i would keep an eye open any time you make a trip away to see if you can get some to bring back. if you have friends around the country they can send you a box. ask a garden center or nursery. etc.
hau Flatland, have you gotten into mushrooms yet? The reason I ask is that if you do raise mushrooms, you have a strata that can really jump start a compost heap and fill it with hyphae which attract beneficial microbes. My research study is showing that when mushroom hyphae are present, many of the bacteria that we want seem to find their way to the hyphae, the two work in symbiosis and that is always a benefit to plant roots. The hyphae infiltrate the roots, the bacteria attach to the hyphae and process minerals in exchange for water, the roots get to pick up both water, minerals and other nutrients that need processing by the hyphae and bacteria. If you are near enough one of the southern cities, you might be able to get some of the soil from a gardener or garden center there to use as a starter should you not be able to find adequate sources close to home. A last ditch method might be to locate someone, Via Internet, in NZ that could and would send you some soil samples.
There are some mushrooms coming up in the paddocks, not near my fruit trees. Would it be worth pulling them up and placing them around the fruit trees?
It never hurts to use "found on the land" fungi to inoculate with, odds are they will be beneficial to your trees. Just whiz them up in water and pour around your trees.
Update on my trees. I seem to have gotten rid of the scale and the orange tree that was the worst affected. (it lost most of its leaves) round so maybe the rain helped to get rid of the ants. i am keeping a close watch on the trees to make sure they don't get attacked again
Crazy computer. I'll try again The orange tree that lost most of its leaves has regrown a lot of new leaves. So I am happy with that. It has finally rained here so maybe the wet helped to get rid of the ants. I haven't seen many around sense the rain started. I'll watch for scale like a hawk. Don't want my poor little trees being eaten again
Sounds like the ants were farming the scales. Address the scales by addressing the ants. If soil is poor, you may want to make a sort of food forest-like guild around each plant. That could really help build up great soil and foster a system that may be ant-unfriendly. You could also add a small patch of wildflower mix nearby plus a water feature which in combo will attract beneficial insects that will help with all sorts of pests, although the ants could still fend them off of the scales.
I am certain that the ants were farming the scale. What do you mean by a food forest like guild? I had planned to plant flowers around the orchard but had forgotten about that thanks for reminding me.
every bit of diversity you can get going on poor land will help. even if it is a short term weed. the radish family is a fast grower along with buckwheat. do you get a cold winter? early fall is a good time to plant winter rye (the grain) which does tremendous good things to poor soil. turn it under in the spring if you don't want a crop. winter wheat is also good, but not quite the same as winter rye. turn them under before the seeds form. glad to hear your plants are recovering.