Cucumber-Spraying that is Harmless to Bees
| Resources Relating to|
One hears more about the evils of reckless spraying than about the methods by which the necessary spraying can be done so as to be harmless. Cucumbers, and many sorts of cantaloup, need to be sprayed with a copper spray for protection against disease. They do not, in my garden at least, need any arsenical spray for protection against biting insects. They sometimes (not every year) need a contact insecticide, such as soap suds, to kill off the plant-lice; but that is not dangerous to any bees except those that are on the vines at the very moment of spraying. I do not know if it is dangerous, even to those. But it is very common to spray them with "pyrox," a mixture of arsenical and copper spray, because the arsenate helps the copper to stick to the leaves, and because pyrox is skillfully made to be as wholesome as possible for the vine, and because it is considered good policy to do whatever will kill bugs at any time. I notice just now that an agricultural paper which always recommends the liberal use of pyrox is complaining that this year there were so few bees that the cucumber crop was short.
This season I have been trying the experiment of spraying late in the evening with the ammoniacal copper-carbonate solution. It has seemed to work well except on some vines which, in my judgment, had the disease from the start because they were not sprayed soon enough. (You know spraying can never cure this disease—only prevent it.) I doubt if this solution, in the very small quantity that is used, would kill a bee or larva, even if nectar were taken from a freshly sprayed flower; and by spraying late at night I feel sure that by morning the copper will all be beyond a bee's reach, even in the few flowers that have not wilted during the night. It will. I am sure, dry on to the leaves firmly, even while the dew is falling, so long as it is not rained on in the first-half-hour; hence it can be used at night and in other non-drying weather. And it is so cleanly that washing it out of a brass sprayer after using it a mere matter of form. Some say it burns the leaves. Perhaps my using it in the dew protects me against that--at least I have no such complaint to make.
To make this solution, get from the druggist a pint or pound of extra-strong ammonia (such as you cannot buy at the grocery), in a glass-stoppered bottle marked "26° B.," and an ounce andthree-quarters of carbonate of copper. This 26° Baume ammonia will squirt when the glass stopper is first taken out; therefore do not have your eye over it or you will wish you were only stung: up by bees instead. Probably, to get the stopper out, you will have to take a twist of paper 01 cloth wet in hot water and hold it around the neck of the bottle a minute or so, which will doubtless make the squirt still more ceitain to come. When you get it open, put in the copper and stir with a wire or stick. It will dissolve as easily as salt in water. Use one part of this solution to 270 of water. If you work on a very small scale, use two level teaspoonfuls to a quart, or two tablespoonfuls to a gallon. The stock solution will keep perfectly if you keep it in a cool place in the glassstoppered bottle in which the ammonia was bought. Don't be seared by reading that it won't keep.
When one needs to use an arsenical spray
on plants which he does not need to have the bees visiting at present, as in the case of those Colorado orchardists who sprayed the trees under which the clover was growing, I think he ought to mix with the spray enough tobacco tea (or any strong-smelling nicotine insecticide) to make the sprayed foliage smell of iobacco till the sprayed flowers have had time to fade. That will warn off the bees, or I am mistaken. And at the same time it will, if strong enough, kill the plant-lice on the sprayed trees.
I was surprised to read about bees gathering bright-green pollen from swampmilkweed. I thought milkweed pollen grew in such shape as not to be useful to bees. Is it certain that it was milkweed and not. some other milky-iuiced plant such as dogbanc? One sort of dogbane is called "honey-plant" according to the botany.
Ballard Vale, Mass.
- Steven T. Byington, “Cucumber-Spraying that is Harmless to Bees,” Gleanings in Bee Culture 42, no. 20 (October 15, 1914): 809-810.