Crop Pests/Diseases ( and organic solutions)

[myhobbyis]

It's been quite a while since I started a new thread but I thought it was about time we had one devoted to pests to crops and diseases. So this I imagine will largely be a rogues gallery of insect villains and most importantly any ideas or links that deal with how to combat them organically.

To set things rolling I found this rather nice list of major pests and disease in Japan divided into the plants they attack.
Each pest or condition has it's Japanese, Latin and English name so from here you should be able to wiki or google them to find if that is what you've got.

The Japanese on this index page is set up thus:

Diseases

Pests

Weeds


Index of pests,diseases and weeds (http://www.agro.jp/gakumei/gakumei_top.html)

[myhobbyis]

Ok I admit I had an alterior motive to setting up this thread !

My potato crops have just about failed with the stems keeling over. Initially I thought this was possibly because I earthed them up when the soil was wet and it rotted the stems though I've never seen that before.

However a few negi have done the same and show signs of being nibbled. Slugs I thought and went out at night and salted around the stems but no evidence of them.
The next door granny (our own Granma Yoshida Ken !) knew right away; 'cutworm' or in Japanese often called 根切り虫 (nekirimushi). After rooting around at the stem of the plants we could easily find them. An ugly brown caterpillar of about 2cm that curls up into a ball when exposed.
At night they appear and nibble the stem right at or just under soil level. They attack a large number of plants but the effect is always the same, since they attack the plant at the base it's game over ! or at least is going to take a long time for the plant to come back.
Other than picking them out the commonest organic solution is to wrap a sleeve of card (I'm going to try a milk carton card) around the stem and push it down so it's a few inches above and beneath the soil. I'll let you know how that goes.

It may be just the timing but these attacks occurred with plants only being grown without any top covering to the soil (black mulch, wara etc) so that may disturb their activity.

[KenElwood]

Hey mhi,

Ok I admit I had an alterior motive to setting up this thread !
Ha ha.

Sorry to hear about your veg, mhi. We’re suffering a bit of the same here at the fields where we sow seeds and leave everything alone until we reap veg. We’ve been seeing a growing population of cutworms, slugs, caterpillars, weeds. It reminds me of that newspaper article from a while back about that organic Apple grower who had trouble being ‘organic’ in the midst of ‘non-organic’ neighbors: all the bugs and blight find their way to the natural orchard.

Okay, I’ll be posting my bug strife here.

Cheers,

ken

[myhobbyis]

Hey mhi,

Ha ha.

We’ve been seeing a growing population of cutworms, slugs, caterpillars, weeds. It reminds me of that newspaper article from a while back about that organic Apple grower who had trouble being ‘organic’ in the midst of ‘non-organic’ neighbors: all the bugs and blight find their way to the natural orchard.



Yeah, I hear you !

On the positive side I was pleased I was able to find an easy organic solution to the cutworm with these plant collars just by a quick search on the internet. Let's face it, someone, somewhere has faced the same buggy problem you've got, hope we can pool resources here.

This is my first Autumn planting in Japan and I was really taken by surprise by the number of caterpillars that come at you once the summer heat is over. アオムシ completely had my brussel sprouts. They were skeleton leaves but are coming back now.
I was picking them off every time I find them but the thing is it's a losing battle because the eggs are on the leaves right and once hatched they grow very quickly in size and appetite.
I used hoops and fleece over some crops when planting out and left them like that until the tunnel was cramping the plants too much and those crops have done great. I think that's the way to go against　the アオムシ　for people planting in conventional rows.
The fleece is re-useable, protects from high winds and also retains heat to a small amount.
Here's a pic of a small section of it in my field in the distance:

http://img357.imageshack.us/img357/9878/p1090076ss0.th.jpg (http://img357.imageshack.us/my.php?image=p1090076ss0.jpg)


On the cutworm front,the collars are on around my onions but the jury's out on it. I did notice some evidence of being eaten above the collar so they may have climbed up the collar. I'll wait and see.




Okay, I’ll be posting my bug strife here.

Cheers,

ken


Yes, this is one thread I hope you, me and all the others don't have to post on that much ! :)

[ushikudan]

I have found the best way to get rid of slugs is to drown them in beer. Put out a rice bowl about half full of beer and sprinkle a little yeast on it. Next morning you will find dead or drunk and almost dead slugs. Empty every two days and refill. Put a roof on it in rainy season. Good Luck.

[Travlrsong]

Anyone know which snails are common around here? I've found some empty white shells, but does anyone know if there are any edible snails cruising Japan? I'd like to expand my sansai take.

[FelixD]

A very late reply considering when the topic was started but it might be worth you looking into parasitic nematodes. I'm not sure if they are available to buy in Japan but perhaps they wouldn't cost too much to have sent from abroad. As a treatment for soil bourne pests nematodes are very good and if you have high levels of a pest species the nematodes can persist in the environment for quite a while thus providing continued protection for several months.

BT (Bacilus thurigensis) toxin would be another avenue I'd explore, works very well on caterpillars and other insects that munch leaves. The toxin only affects insects and plants sprayed with it can be eatan very quickly after a treatment.

e2a:
Steinernema carpocapsae and S. feltiaeare will control cutworms

[FelixD]

For anyone already growing Rhubarb here's a use for the leaves.

Chop up 1.5Kg (3lb) rhubarb leaves.
Boil for 30 minutes in 3.5 litres (6 pints) of water.
Strain off liquid and cool.
Dissolve 28g (1oz) of detergent soap in 1 litre (2 pints) of water.
Mix and spray on plants.

Source - www.grow-organics.com/organic_pesticides_rhubarb_spray.php

This is for your own personal use only and must not be used on crops that are to be sold.

[johnElarue]

The corn is flowering and sprouting silk, found these little critters on the flowers, NOT on the silk. Also lots of brownish aphid like insects on the flowers as well. Picked off the worms , but left the others. Any ideas what the worms are, good, bad...?


http://2.bp.blogspot.com/_xSjxHv_Dxbc/SjhyAVrWZnI/AAAAAAAAAXQ/LrPh1YS7RXE/s320/earworm+3.jpg

http://3.bp.blogspot.com/_xSjxHv_Dxbc/SjhyAFIsb2I/AAAAAAAAAXI/c7zn24eKK9A/s320/earworm2.jpg

http://3.bp.blogspot.com/_xSjxHv_Dxbc/Sjhx_lU-ewI/AAAAAAAAAXA/BtsXvrs--IQ/s320/earworm.jpg

[Travlrsong]

Cucurbit beetle. Those little orange fkers that love ruining our cucumber leaves. Anyone have a good solution? Pee doesn't seem to do the trick. :)

Sorry I don't know anything about your cornworms, John.

[johnElarue]

http://www.nysaes.cornell.edu/pp/resourceguide/cmp/cucurbit.php


This has tons of info, sorry to anyone if it has been linked to before

[Travlrsong]

http://www.nysaes.cornell.edu/pp/resourceguide/cmp/cucurbit.php


This has tons of info, sorry to anyone if it has been linked to before

Thanks for that John. I've spent the past hour researching, and found what you've posted. Row covers to start, sticky yellow tape a meter above ground, and trap crops. Something else I found was this. Apologies for the pasting, but the link had a ton of information before and after. Hope this helps/inspires you guys as much as me.

Harvesting Greens as a
Strategy to Control Squash
Bugs (Anasa tristis)
Eero Ruuttila
Nesenkeag Coop Farm
Litchfield, New Hampshire

Each season I employ eight to ten field workers,
most of whom are Cambodian immigrants who have
farmed most of their life, both in Cambodia and
the United States. Over the years, they have helped
me procure seeds and cuttings for traditional Southeast
Asian crops and taught me how the crops are
grown and harvested.

My farmworkers enjoy eating
their traditional foods, and by sharing their
lunches, I have learned how their cuisine cleverly
incorporates botanical intervention. Their use of
vegetative plant parts is a model of biological efficiency.
It appears as if every leaf, stem, root, or
flower is fair game as an ingredient for one of their
exotic and flavorful dishes. Young shoots, flowers,
and terminal buds are especially popular in their
dishes. I have eaten traditional dishes made from
pea and hairy vetch tendrils, pepper blossoms, bitter
melon vine, cilantro roots, immature watermelon,
tomato leaves, and tips from squash and pumpkin
vines.

The young tips of pumpkins and squash vines are
harvested along with the male blossoms and incorporated
into wonderful soup with bamboo shoots
and pork. The spiny tough outer skin of the squash
vine is slit and peeled, revealing a mucilaginous
hollow straw-like plant part which is both slippery
and slightly crunchy at the same time, a little like
fresh lotus root.

What does this have to do with managing insect
pests? The young tendrils and leaves of pumpkins
and squashes are favored sites for squash bugs to
lay their eggs. As the eggs hatch the squash bug
nymphs inject toxic fluids into their host leaves,
causing them to wilt, blacken, and die. Harvesting
the egg-laying sites before the eggs hatch significantly
reduces squash bug damage.

On my farm, pumpkin and squash vine tips are
marketed for about six weeks beginning the second
week in July through the end of August. The
July harvests virtually eliminate all squash bug
nymph damage, because we cut about one-third of
the young vines of most squash and pumpkin plants
when the adult squash bug is laying its eggs. The
harvests stimulate the plants to set more flowers,
and it is the female blossoms, which sit closer to
the center of the plant, that bear fruit.

About a third of my income from squash and pumpkin plantings
comes from the sale of the tendrils and male blossoms.
Income begins within 40 days of seed germination,
and harvest contributes to pest management.
This is a new way to look at a crop that normally
requires 100 or more days for fruit maturity and
that, in New England, gluts the market from September
until Thanksgiving.

[KenElwood]

Hi JohnE & travlrsong,

Thanks for the stuff on organic insect and disease management. I especially liked the Cambodian method to just eat all parts of the plant. My method has been two-fold: 1. browsing plants and soil & killing pests with my thumb and index fingers and 2. sound crop rotation & building garten bio-diversity.

I’m getting tired…….but as long as we have food the hunt and struggle can continue.

ken

[kirinclassic]

Cucurbit beetle. Those little orange fkers that love ruining our cucumber leaves. Anyone have a good solution? Pee doesn't seem to do the trick. :)
.

Hey Travlrsong, in case you don't want to go to the expense of tape or Cambodians ;), here's a few alternatives found worked for me.

1. Opaque plastic shopping bags, the bottom cut off and staked (4) around the plant. Beetles still get in, but not nearly so many of them. When the plant outgrows the bag, it should be hardy enough to withstand attacks.

2. Interplanting (camoflague netting). I put some (zuchinni) seedlings in among mature broadbeans. As I harvested the beans, the zuchinni was untouched by beetles. Now the broadbeans are over, and the zuchinni is big enough to handle pests. This is my favoured method.

3. Nasturtiums with kukes. A Seymour recommendation.

What I did find through unwelcome experience is that cukes/zuchinni on a clean (ie unweeded) bed serve as a homing beacon for beetles, so even weeds are good for them in their early stages.

Cheers,

KC

[Travlrsong]

Hey Travlrsong, in case you don't want to go to the expense of tape or Cambodians ;), here's a few alternatives found worked for me.

1. Opaque plastic shopping bags, the bottom cut off and staked (4) around the plant. Beetles still get in, but not nearly so many of them. When the plant outgrows the bag, it should be hardy enough to withstand attacks.

2. Interplanting (camoflague netting). I put some (zuchinni) seedlings in among mature broadbeans. As I harvested the beans, the zuchinni was untouched by beetles. Now the broadbeans are over, and the zuchinni is big enough to handle pests. This is my favoured method.

3. Nasturtiums with kukes. A Seymour recommendation.

What I did find through unwelcome experience is that cukes/zuchinni on a clean (ie unweeded) bed serve as a homing beacon for beetles, so even weeds are good for them in their early stages.

Cheers,

KC

Great information KC. Thanks.


Now on to the apple(?) tree. There a a few young fruit trees that look like apple trees in the garden. I noticed yesterday that a couple of them have red spots all over the leaves. My first thought was Nitrogen deficiency. But found another tree with red spots actually distoring the shapes of the leaves (like concave blisters) and with white hairs sprouting from the underside of each red blister. All over the damn tree. Makes my skin crawl just picturing it. Anyone have any clues? I'll snap some pics this afternoon and post them. My first instinct is to put on a hazmat suit, snip the tree down and burn it. But the garden actually belongs to a nice widow friend, and her husband planted those fruit trees before he died.

Any ideas?

[Travlrsong]

Man, I've got goosebumps just looking at these photos. What the hell is wrong with this tree? I've never seen anything like it, but am assuming it's either viral or fungal. I think the tree is a young stone fruit, not apple. I don't know if it's peach, plum, ume, or what though. Any ideas at all?

http://s581.photobucket.com/albums/ss251/Trvlr_bucket/Sick%20tree%20leaves/

[kirinclassic]

I think the tree is a young stone fruit, not apple. I don't know if it's peach, plum, ume, or what though. Any ideas at all?

http://s581.photobucket.com/albums/ss251/Trvlr_bucket/Sick%20tree%20leaves/

Certainly none of the above, the leaves don't match.

[Travlrsong]

I sent the photos and explanation to a professor of horticulture in America, and he said the tree looks like a crabapple, and is 95% sure the spots are from a rust fungus. He said the tree can be saved if I apply triazole. I'll do a search on it here and see what's possible. Thanks for your input KC.

[FelixD]

Hadn't ever heard of this before but was talking to one of the oldtimer's down at the allotments at the weekend and he was just planting out a load of agricultural mustard. So I asked him why he was planting them at this time of year. Now his reply was quite interesting, he grows them as a normal green manure and digs them into the ground as you would normally but apparently as the mustard plants decompose they release toxic gases that kill many soil borne pests such as nematodes and soil dwelling slugs, etc.

Seemed to me a good organic method of keeping soil pest numbers down, here's some further reading in case anyone else is interested

http://www.infonet-biovision.org/default/ct/237/recipesForOrganicPesticides

[Travlrsong]

I have found the best way to get rid of slugs is to drown them in beer. Put out a rice bowl about half full of beer and sprinkle a little yeast on it. Next morning you will find dead or drunk and almost dead slugs. Empty every two days and refill. Put a roof on it in rainy season. Good Luck.

Hola Ushikudan and All,

I've been using beer pits + boards (turning and picking in the afternoon) in the peas and lettuce gardens. They've been working. The beer pits have filled up with yeast and slug slime, and now need to be emptied. Here's my question.

What do I do with the sluggy yeast foam? I've got about 3 liters of it. Do I dump it into a new compost pile? That's what I'd assume, but the compost pile is inside the back yard near where the kids play. It's not remote, so I don't know if it would be okay.

What do you think? Anyone?