Saturday, July 15, 2017

Summer maintenance and pest management

The last round of rains that went through southwest Indiana was too much of a good thing - 2 inches a week ago Friday with hail and winds, then another two inches early last week, it finally turned sunny yesterday and today.   The long bouts of overcast weather are rough on the vegetable plants.   Fungal diseases take hold in the damp and the plants don't get the sun they need to stay vigorous and fight off the pathogens.  I have been waiting for the rains to stop before spraying the plants.

All in all this is not a bad year for pest problems, and the tomatoes, peppers and eggplant (Solanacae) are doing the best I've ever seen.   When the eggplant seedlings were first set out, they were set on with flea beetles the next day.  I sprayed them twice with pyrethrins, and since then the beetles have not been a problem.  Very strange.  Are the plants so healthy that they are able to manufacture the necessary chemicals to fight off the beetles?  Usually it's an ongoing battle to keep the flea beetles from destroying eggplant.

The cucumber plants are already going downhill, with yellow dying leaves.  Yesterday I sprayed them with a solution of potassium bicarbonate, which I purchased at a winemaking shop.  Bicarb is supposed to be most effective against powdery mildew, but I thought I might as well give it a go on this unknown pest.  I don't know if it has had any effect.  The sunshine probably helps more. 

Another new thing for me is the use of insecticidal soap, the potassium salts of fatty acids.   Household soap is mostly the sodium salt of fatty acids, so this is not much different, except the potassium ions can actually be used as a nutrient by the plants.  I mixed the insecticidal soap with Neem oil to make a spray for the apple trees.  The soap can also be mixed with horticultural oil. 

Both chemicals are nontoxic.  The soap works by mechanical action, while the Neem works at a biochemical level and by mechanical action.   A nice thing about this mixture is that the insecticidal soap helps the oil disperse better in the water.

The apple trees have been beset by what looks like a scale insect on the underside of the leaves.   After spraying yesterday, today I saw no evidence of any scale on the leaves.  It looks like it worked really well.  The cedar apple rust is another matter.  It has hit the Golden Delicious tree very hard.  In the spring I did 2 preventative sprayings of Mancozeb but that was not enough to stop it this year.  At least the tree has one less pathogen to deal with.

Japanese beetles like pole beans.  They collect at the top of the vines where they shred the leaves.  There's not much I can do about these beetles.  Pyrethrins are the only organic chemical that will kill them, and I don't want to spray them with that since I pick them every other day, also they are constantly flowering and bees are pollinating them.  I've thought about setting out the traps but that may just bring in more beetles.  So I'm resigned to the beetles getting their cut.

This bed was this year's brassica bed.  The brassicas are all gone now and the bed was sown with a cover crop of inoculated cow peas.  There's a replacment summer squash growing in the foreground, which will be needed since the first squash plant is dying.  At the other end of the bed are 2 rows of bush beans.  The pole beans usually have a slowdown for a few weeks in August, so I'm planting these bush beans as insurance. 

I've mentioned earlier that tomatoes are doing much better than they have in years, and they are still looking good.  These are the determinate paste tomatoes.  I put them in the old 2 foot diameter cages with 2 per cage.  This was the first time growing determinate tomatoes and I had no idea how bushy they can be.  Next year I'll plant just 1 per cage.   I've been trying to remove excess foliage and suckers so the light can reach the tomatoes, but it's still a jungle in there.

After last weeks hail storm, some of the winter squash are still on life support, but this butternut squash has recovered and is growing rapidly.  Maybe I'll get some squash after all.

*For those of you interested in mixing your own sprays:  For the insecticidal soap/Neem spray I used 1 oz of Neem and 2.5 oz of insectical soap in a gallon of water.  For the potassium bicarbonate spray I used 1 TB of bicarb in a gallon of water.  Many articles recommend mixing the bicarb with an equal amount of insecticidal soap as a 'sticker/spreader.'


Margaret said...

We have similar Japanese beetle issues - I do the "pick them off and drop them into a tub of soapy water" bit. I leave a yoghurt container by the bean bed for this purpose and only empty it out every 2-3 days. Apparently if you leave it near the bean plants, it may also act as a deterrent - not too sure about that, but it is convenient. Picking them off doesn't get rid of them altogether but I do find that, even if you only pick them off a handful of times once they start arriving in force, it does reduce their population as well as the damage they do.

Kaman said...

I have learned so much from your blog and Dave's blog Our Happy Acres and Michelle's blog from Seed to table. Thank you and keep up the good work!

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