The Minnesota State Fruit-Breeding Farm.
CHAS. HARALSON, SUPT., EXCELSIOR.
The Minnesota State Fruit-Breeding Farm was established eight years ago, principally for breeding new varieties of fruit adapted to our climate and conditions. The aim of this work is to assist the people in getting better commercial varieties of the various fruits grown in the state, so that better returns could be secured for the people engaged in the various lines of fruit growing. Some of the plant-breeding work is beginning to show results, a few varieties of fruit are being distributed in a small way for trial in different localities.
A great deal of work has been done with apples. Seedlings have been grown by the thousands every year with the idea of selecting some desirable varieties when the trees come into fruiting. Hardiness of tree, long keeping and good quality of fruit are the most desirable points we are looking for in our selections. A great deal of crossing under glass is being done with apples; a number of seedlings, the results of this crossing work, are planted every spring.
Some of the six thousand Malinda apple seedlings planted seven years ago have fruited to some extent for the last three years. These show a great variation in fruit, both in color, quality and long keeping. Some of the fruit ripens with the Duchess, while others will keep until spring in good condition. There is a chance for some desirable varieties out of this lot, but it will take several years to determine whether we have anything better than the Wealthy. The Wealthy is by far our best commercial variety, but we are looking for something that will keep until spring.
Gooseberries and currants are easily raised and are perfectly hardy with us, but we are working to get some improvement on these varieties. Many thousand seedlings are being grown for this purpose. Our native gooseberries are used in breeding work with the cultivated varieties to a great extent, as they are hardy, strong growers and resistant to mildew.
As to cherries, we have none that are satisfactory. Some work has been carried on for several years, but we have not obtained anything of special value so far. The most promising combinations are Compass cherry crossed with the cultivated varieties. None of these have fruited, but we have some hope for a hardy cherry from these seedlings.
Peaches and apricots are not hardy in Minnesota, and consequently nobody thinks of planting them. Some years ago we started crossing the sand cherry with peaches and apricots. The results were a number of seedlings, but all turned out to be worthless; the trees after several years growth were small, or grew mostly in bush form. They blossomed every spring but never set any fruit on account of some imperfection in the flowers. Four years ago we started to use the Compass cherry as the male parent, and this combination is more promising. The seedlings make a good growth and a fairly good sized tree, practically as hardy as the Compass cherry. The seedlings resemble the apricots and peaches in blossom, tree and foliage. This fruit will not be exactly an apricot or a peach, but may take the place of these fruits in a small way.
No. 7 Hybrid Seedling Plum—from Minnesota State Fruit-Breeding Farm, at Zumbra Heights.
The Compass cherry crossed with Prunus Pissardi, or purple leaf plum, is a very interesting combination. We have about fifty seedlings growing. Most of them have the purple foliage and bark, are very ornamental and can be used with effect for lawns and landscape planting where large shrubs are wanted.
The grapes. The Vitis Labrusca, such as Concord, Worden, Moore's Early and many other varieties, are not hardy unless protected during winter. There is a demand for hardy grapes that do not need any winter protection. At the Fruit-Breeding Farm this problem has been taken up on a large scale. The Beta grape is hardy but lacks in size and quality. This variety has been used to grow many thousands of seedlings from, and also used in cross-breeding with the better varieties. A large percent of Beta seedlings come true to seed or nearly so. This gives us several hundred varieties equal to Beta, and some of them are quite an improvement in size and quality over the parent and practically as hardy as the wild grape. Many of these are worthy of propagation where hardiness is the main object. Very few of the hybrid grape seedlings have fruited, but indications are that in a few years we will have grapes equal in size and quality to any of our commercial varieties.
Experiments are being carried on in a small way with pears, roses and nuts. Our native hazelnuts can be improved by selection and crossing with the filberts. The same is true with the Rosa Rugosa and our native roses.
In breeding strawberries we probably have had better success than with any other fruit we have attempted to improve. The breeding work was done in the greenhouse during winter and early spring and seed planted as soon as berries were ripe. The plants were transplanted to flats and later planted out in the field, where they remained until fruiting, when the selections were made. We have fruited approximately 60,000 seedlings. These have been weeded out so there are about 400 left, and these will be cut down to a few of the best varieties. At present we have one everbearing and one June-bearing variety which have proven to be very productive, of good size, good quality and good plantmakers. These plants have been sent out as premiums to members of the State Horticultural Society for the last two years and will be distributed the same way next spring.
In raspberries we have several varieties which are promising. King x Loudan, No. 4, is a variety that has been sent out as premium the last three years. This variety is amongst the hardiest, the berries are dark red, very large and the most productive of all the varieties growing on the place. This has also been sent out as premium through the Horticultural Society.
In plums we probably have had the best success. Some of the first breeding work was with Burbank x (crossed with) Wolf and Abundance x Wolf. We have twenty-eight seedlings of Burbank x Wolf and forty-five Abundance x Wolf which have fruited several years. We have varying degrees of hardiness in these seedlings. Most of them have withstood our winters at the fruit farm without injury, as well as in most of the southern half of the state.
Among the Abundance x Wolf hybrids eight of the seedlings are only partly hardy, while of the Burbank x Wolf only one or two have shown themselves to be particularly weak in this respect.
Type of fruit. In general the Burbank type of fruit is dominant. The flesh of these hybrids runs quite uniformly yellow, varying in degrees, however, from a deep yellow to a yellowish green. Some of them have a yellow skin with a blush or a streak of red, while others are a deep red even before ripe. The fruit in size varies from both smaller and larger than the parents. Firmness characterises most of the hybrids. We are also getting good shipping quality, and in Burbank x Wolf No. 12 we have a plum measuring one and three-quarters inches and more in diameter and a perfect freestone. This plum will be used extensively in further plant-breeding.
In shape of tree the two hybrids differ materially. The Burbank x Wolf hybrids make spreading trees more or less, while the Abundance x Wolf grows more upright and does not need quite as much room.
Tent Caterpillar.—As soon as small nests are detected, they should be destroyed. When in convenient reach, the nests may be torn out with a brush, with gloved hand, or otherwise, and the larvae crushed on the ground, care being taken to destroy any caterpillars which have remained on the tree.
The use of a torch to burn out the nests will be found convenient when they occur in the higher parts of the trees. In using the torch great care is necessary that no important injury be done to the tree; it should not be used in burning out nests except in the smaller branches and twigs, the killing of which would be of no special importance. Nests in the larger limbs should be destroyed by hand, as the use of the torch may kill the bark, resulting in permanent injury.
Tent caterpillars are readily destroyed by arsenicals sprayed on the foliage of trees infested by them. Any of the arsenical insecticides may be used, as Paris green, Scheele's green, arsenate of lead, etc. The first two are used at the rate of one-half pound to 50 gallons of water. The milk of lime made from 2 to 3 pounds of stone lime should be added to neutralize any caustic effect of the arsenical on the foliage. Arsenate of lead is used at the rate of 2 pounds to each 50 gallons of water.
On stone fruits, such as cherry, peach, and plum, arsenicals are likely to cause injury to foliage and must be used with caution if at all. On such trees the arsenate of lead is preferable, as it is less injurious to foliage, and on all trees sticks much better. In spraying for the tent caterpillar only, applications should be made while the caterpillars are yet small, as they then succumb more quickly to poisons than when more nearly full grown, and prompt treatment stops further defoliation of the trees.—U. S. Dept. Agri.