33S STATE BOARD OF AGRICULTURE. 



grow; but just as long as it is pievented from producing seed, it will 

 endeavor to do so. Tlie result is that small cucumbers in abundance 

 will continue to lorm until the vines are killed by frost. 



Yield. There are so many factors which influence the yield that it is 

 unwise to try to tell any prospective grower what he will get in bushels 

 per acre. This much is certain, however ; one acre of vines that is kept 

 well picked will produce more bushels and, therefore, a much greater 

 net protit than will two acres of equally good vines which are only in- 

 differently picked. Two hundred bushels of marketable cucumbers is 

 the average yield of one Michigan grower over a period of nearly twenty 

 years. This was on a large acreage, so any fairly intelligent grower 

 who does not plant too extensively should be al)le to secure such yields. 



Insects. There are three or four insects which feed on the cucumber 

 vine or its fruit. The striped cucumber beetle (Diabrotica vittata) at- 

 tacks muskmelons and early planted cucumbers but does not work ex- 

 tensively in the main or late crop plantings. Most growers plant four 

 or five times as many seeds as they desire plants, which allows the 

 beetles to take some without ruining the stand. If the beetles work too 

 badly, the vines may be dusted, preferably while the dew is on, with 

 nine parts air slacked, or better, hydrated lime and one part arsenate 

 of lead powder. Paris green should not be used as it may burn the 

 vines. Coating the plants with a spray of six pounds arsenate of lead 

 paste to fifty gallons of water makes them distasteful to the insects. 



There is a plant louse which attacks cucumber vines. It is a sucking 

 insect, so cannot be destroyed by applying a stomach poison, but must 

 be killed by a contact spray if killed at all. If the first few hills affected 

 are buried, vines and all, it will do much to control the pest. Keeping 

 the vines thrifty is also a decided help since the louse always prefers 

 to feed on sickly and stunted hills. Eight pounds of whale oil soap to 

 fifty gallons of water makes a good spray but usually the enemies of 

 the louse will hold it in check.* 



Diseases. Downy Mildew is a fungous disease causing a yellowing 

 and shriveling of the leaves, starting with the older growth and rapidly 

 extending to the tip of the plant. It is occasionally very severe in hot, 

 moist weather but is controlled by spraying Avith Bordeaux mixture con- 

 taining G pounds of lime, 3 pounds of copper sulfate and 50 gallons of 

 water. 



Authracnose occurs principally on the leaves, where it produces cir- 

 cular brown spots from i/4 to i/^ inch in diameter. These spots may tear 

 out and leave ragged holes as the leaf matures. Spray as for Downy 

 Mildew. 



*Tbere is good reason to believe that the striped beetle and the louse are both concerned 

 with the spreading of disease among cucumbers and related vines. The protection of the 

 plants from these enemies seems therefore to be more imperative than was formerly supposed. 

 It is therefore urged that all remnants of vines be destroyed as soon as possible after the 

 crop is harvested, and that all rubbish in the vicinity of the patch be raked up and burned 

 after cold weather sets in, with a view to killing some of the beetles at least, in their hiber- 

 nating quarters. 



For the plant-lice, nicotine proves very efficient, and is often easier to obtain than the 

 whale-oil soap. Use one part of the 40% nicotine sulphate with 800 times its bulk of soap 

 suds. It will often pay to turn the vines over so as to spray the under sides of the leaves, 

 replacing them afterward. 



