Читать книгу Trees, Fruits and Flowers of Minnesota, 1916 - Various - Страница 71

Table of Contents

Fred Cowles at home.

Of the new varieties of plums that I received from the Fruit-Breeding Farm most all have done well. The only one that has borne is No. 21. This one had two plums on last season, and several this. They were a medium size red plum, very good flavor, and seem to come into bearing very young. No. 17 is a very thrifty grower, but when it bears that will tell what it is worth. Hansen's plums are doing well, but we believe they are more adapted to a better drained soil than we have here, as we are on a heavy prairie soil. But these varieties are very thrifty and bear so young.

The grapes have all stood the winter with no protection and have not killed back any. We expect some fruit next season.

The raspberries that we received have all done well. No. 4 seems to take the lead for flavor and is a good grower.

Notwithstanding the cold season our strawberry crop was very good, and we are much impressed with No. 3, it is so strong and healthy; it is just the plant for the farmer, as it will thrive under most any condition. I believe it will fight its way with the weeds and come out ahead.

We reported very favorably on the Heritage when it was in bloom, but it does not set enough fruit to pay for its space. The berries are large but very few on my grounds. I will discard it.

Our apple crop was very good, especially Duchess, Wealthy and Northwestern Greening. We have been trying some of the tender varieties top-worked. Northern Spy gave us five nice apples on a two year graft. We also have Jonathan, Talman Sweet and King David doing well. Delicious grafted three years ago has not fruited yet.

This has been a splendid summer for flowers, and they seemed to enjoy the damp, cool season, especially the dahlia. If you have not tried the Countess of Lonsdale you should; it is a cactus dahlia and a very free bloomer. Everblooming roses did well—we had them in October.

Plant Lice on Blossoms.—Aphids infesting the apple buds appeared in serious numbers during the present season in the Illinois University orchards when the buds began to swell. They were also observed in neighboring orchards. In 1914, apple aphids caused serious damage in certain counties in Illinois, and some damage was reported from many sections of the state.

The aphids attack the opening buds, the young fruits, the growing shoots, and the leaves, sucking the plant juices from the succulent parts by means of long, very slender, tube-like beaks, which they thrust through the skins of the affected organs into the soft tissues beneath. They weaken the blossom buds by removing the sap; they dwarf and deform the apples so that varieties of ordinary size frequently fail to grow larger than small crab apples, and the fruits have a puckered appearance about the calyx end; they suck the juice from the growing shoots, dwarfing them; and they cause the leaves to curl, and if the insects are present in large numbers, to dry up and fall off. They are more injurious to the growth of young trees than of old trees. In old trees their chief injuries are on the fruit.

This species of aphids are easily killed in the adult stage by certain contact sprays. Winter applications of lime sulphur cannot be depended on to destroy eggs. Poison sprays such as arsenate of lead are not eaten by this type of insect, and consequently are ineffective remedies for aphids. Kerosene emulsion is effective but is uncertain in its effect on the foliage of the trees. The best available sprays are the tobacco decoctions, of which the one most widely in use is "Black Leaf 40," a proprietary tobacco extract, made by the Kentucky Tobacco Products Company, Louisville, Kentucky. This material is used at the rate of one gallon in one thousand gallons of spray. It may be combined with lime sulphur, lime sulphur arsenate of lead, Bordeaux, or Bordeaux arsenate of lead, not with arsenate of lead alone.

The ideal time to spray for these aphids is just as soon as all or nearly all the eggs appear to have hatched. Observations made in the University orchards this season indicate that all the eggs hatched before the blossom buds began to separate. After the leaves expand somewhat and the blossom buds separate, the aphids are provided with more hiding places and are more difficult to hit with the spray. Unfortunately, spraying at this time would require an extra application in addition to the cluster bud (first summer) spray (made for scab, curculio, bud moth, spring canker worms, etc.), and would thus add seriously to the cost of the season's operations. Spraying for aphids at the time of the cluster bud spray is, however, highly effective, and in general it is advised that this method be followed. If, however, previous experience has shown serious losses from aphids, or if they are present in extremely large numbers, the extra application may be well worth while.—Ill. Agri. Exp. Station.