stances by the application of this fungicide, the damage being greater in strong sunlight than that caused by Bordeaux mixture.

These results, while tentative at present, indicate at least that for some fruits and certain sections of the state, Bordeaux m'xture should not be discarded until careful comparisons of the two fungicides are made.

TOBACCO DISEASES

Diseases of the tobacco plant result in serious loss to growers, but as yet, investigators have devoted but little attention to their causes or to possible means of control or prevention. During the past two years Mr. Johnson of the Horticultural department has conducted investigations on the disease known as "bed rot" or "damping off," which causes the rotting of young plants in the seed bed. It has been found that "damping off" in this state is due almost entirely to two fungi, Pythium debaryanum and a species of Rhysotonia. The trouble is brought on by an excess of moisture, high temperature, thick sowing, and poor ventilation. The work done at this Station tends to disprove the value of some of the soil treatments quite generally recommended for the prevention of the disease, and to emphasize the importance of sterilization of the seed bed, which destroys the spores of the disease producing fungi. Burning the seed bed by building fires upon it, or sterilizing the bed with steam, have given success. The latter method is practiced by covering the hed with galvanized iron, and introducing steam.

Study of the stem rot of tobacco has been made from infected plants from various localities. Two types of fungi, Fusarium and Trichothecium, neither of which seems to have been reported before in connection with this disease, have been found. to be present in almost all cases. No practical methods of control can yet be suggested for this disease.

INFLUENCE OF COLD ON SPORE GERMINATION OF CERTAIN RUSTS

The department of Plant Pathology has been studying, the past year, the effect of environmental factors on the germination of the spores of certain rusts, such as the "white rust" of radishes. Mr. Melhus has found that the spores of this fungus germinate better at low than at high temperatures. Germination was se

cured at temperatures ranging from near the freezing point to 75°F, but the most favorable temperature found was about 50° F. Seedlings chilled by artificial refrigeration succumbed more readily to infection than those which were not chilled. Seasonal conditions and the vitality of the host also seemed to influence the rate of germination.

Twenty-two varieties of radish showed no marked difference in susceptibilty to the rust, and Raphanus caudatus, another species of the same genus, was readily infected with rust from the common radish, Raphanus sativus. Of several other crucifers, not of the genus Raphanus, but all known to be hosts of the white rust, only white mustard and cabbage could be infected with rust from the radish.

PLANT DISEASE SURVEY

Prof. L. R. Jones summarizes the situation in the state with reference to plant diseases for this past year as follows:

A quite serious fungus leaf blight of barley (caused by a Helminthosporium), known as blade blight, has caused losses ranging from 25 to 75 per cent in some sections of the southern part of the state.

Orchards this year are unusually free from fungus diseases due to the dry conditions which prevailed most of the summer. Indeed apple scab, which in certain sections is the worst orchard scourge, was almost unseen over much of the state. However, the cherry leaf spot developed, especially in the Door county orchards. The crown gall and hairy root, bacterial diseases of nursery stock, are becoming serious menaces. Recently the communicability of these diseases from plants of one kind to those of another, for example from the apple to raspberry, has been shown. The nurserymen as yet fail to recognize the gravity of this situation.

Climatic injuries have been more or less prominent, due to unseasonable weather conditions. "Sun scald" and canker of tree trunks resulted from the protracted growing season of the fall of 1910. Tip burn in apple occurred last May, due to a hot wave, while the potato crop suffered this season from sun scald in June and July, arsenical poisoning in July, and tip burn associated with the dry heat of mid summer. The early blight of potatoes was as usual quite prevalent, but nowhere serious. Black leg, or basal stem rot, a bacterial disease, is gaining a

foothold. The importance of the potato crop, as a source of seed supplies makes it imperative that the purity and freedom of seed stock should be carefully watched.

Some special crops grown in the state have been subject this year to unusual inroads of disease. The canning industry suffered so far as its pea crop was concerned, from unfavorable weather and accompanying insect pests, but coupled with this has been the development of a "pea blight," caused by fungus parasites (Septoria and Ascochyta), which has, in extreme cases, destroyed large fields.

The ginseng industry, by the methods of culture to which the plant is subjected, is fraught with unusual dangers from disease. Leaf blights and root rots have been prevalent, and the growers have asked for assistance.

The cabbage industry which formerly was very strongly developed in the southeastern portion of the state has of recent years been subject to a variety of troubles. The bacterial black rot in some years has been sufficiently destructive to cause serious losses. This disease has not been so prevalent this season, but a fungus (Fusarium) producing a disease known as the "cabbage yellows' has wholly destroyed the crop in some sections where rotation is not practiced. Another fungus disease known as "black leg" (Phoma) has also been seriously destructive in western Wisconsin.

As farm practices become more intensive, an increasing degree of attention must be given to the control of various crop diseases. Generally speaking, success can be more readily attained in this respect by taking precautionary measures against the introduction of such diseases rather than relying upon the development of curative or control measures. Rational crop rotation must be worked out for each type of special crop, and varieties must be improved by local selection and breeding for disease resistance.

INSECT PEST SURVEY

Conditions with reference to the distribution of insect pests for 1911 have been quite unusual. Following the nearly complete loss of fruit by the late spring freeze in 1910, the majority of fruit insects were left without their normal food, and, consequently, but few completed their life cycle for winter hibernation. The codling moth and plum curculio were almost wholly

eliminated as destructive factors in fruit growing in some regions. This year, perfect crops have, in many cases, been harvested without spraying, but Prof. Sanders of the department of Economie Entomology emphasizes the necessity of close control for the coming season. The great reduction of insect pests has also lessened their natural parasites, which, under normal conditions, more or less effectively check insect development, so that it is readily apparent that unusually rapid multiplication of insects will likely occur for several years until these parasites again attain their normal prevalence.

The pear slug is reaching proportions where much damage is annually occasioned to the cherry and plum. This pest is readily controlled with slacked lime, arsenate of lead, or paris

green.

The apple aphis has been unusually abundant this season and the growth of young trees stunted thereby. The lime-sulphur treatment (one to ten) applied prior to leafing, would have been effective. Thousands of young or newly planted fruit and shade trees have been killed this year by an outbreak of flat-head borers, which could have been prevented by the application of thick whitewash to the tree trunks in early summer. Along Lake Michigan the tussock moth is affecting the shade trees, such as the elm, linden, and soft maple, although not so severely this year as last. The cottony maple scale has again been abundant. The asparagus beetle, a new insect pest on asparagus, has been reported from several sections. The soft, slate-colored larvae. feed voraciously on the succulent young shoots as well as on the older ones. With arsenate of lead this trouble can be effectively controlled.

Both the onion thrips and onion maggot are causing severe losses in the trucking regions in the southeastern part of the state. Special field studies on these onion pests have been under way, and the use of a nicotine solution (Black-leaf-40), one te four hundred parts in water, has proven quite effective. As the thrips hibernate in herbage adjacent to onion fields, and advance slowly from the field margins in early summer when the onion tips are well above ground, efforts should be directed promptly toward the treatment of this pest to save the general crop.

Locusts or grasshoppers have been unusually destructive in some sections, likewise the blister beetles, which have caused no little injury to alfalfa and vetch, but the damage by blister

beetles is partly atoned for by the good which their larvae accomplish in feeding on grasshopper eggs which they destroy by the thousands.

With insects, as with fungus diseases, prevention is much easier of accomplishment than cure, and diminution of losses that are now more or less continuous can only be effected by widespread dissemination of accurate information and its utilization by the growers in the field.

CRANBERRY INVESTIGATIONS

The cranberry investigations at the Cranberry Substation at Grand Rapids under the direction of Mr. Malde have been continued along the same lines as in 1910. The various weeds infesting cranberry bogs have been studied, and efforts are being made to develop methods of eradication. Spraying with a solution of 10 pounds of fresh lime to 50 gallons of water proved very effective for killing sphagnum moss, but the treatment had to be repeated three or four times a season to exterminate the moss entirely. Both acid weed killer and a mixture of acid weed killer and iron sulphate solution proved effective in killing weeds, but neither could be used on the vines without killing them.

On the night of August 28 freezing temperatures occurred throughout the district, but with adequate water supply for flooding, little damage was caused. On the Station bog where clean culture and sanding are practiced, no water whatever was used. No damage from frost resulted, however, although on neighboring unsanded bogs, insufficiently flooded with water, considerable loss occurred.

Investigations of cranberry insects have also been carried on in cooperation with the United States Bureau of Entomology, especial attention being given to the fruit worm and the tip worm. This cooperative work has been concluded and the results are in process of publication by the United States Department of Agriculture. Spraying in June and July to kill the fruit worm resulted in 15 to 20 per cent increase in yield. This, however, represents a net gain of only 3 to 8 per cent after deducting the expense of spraying. Experiments are now being inaugurated to determine whether the fruit worm can be destroyed by flooding in the fall immediately after harvest, and