1258 



FORCING 



FORCING 



England growers devote a considerable area under 

 glass to cucumbers in the fall and winter months. 

 Eastern-grown cucumbers are sold in western markets 

 at the time of the year at which most of the western 

 growers are devoting all of their glass to lettuce or 

 tomatoes. Some of the vegetable forcers in IlUnois 

 and farther west grow cucumbers in the faO and winter. 



Varielies. 



The long English type of cucumber is not popular for 

 commercial purposes in this country although it is 

 grown to some extent in private greenhouses. The 

 American forcing-man prefers a type of cucumbers 

 for forcing which is of the White Spine order. The 

 first requisite of a good forcing cucumber is prolificacy. 

 It should be from 8 to 10 inches long, even a foot in 

 length not being objectionable, of regular and uniform 

 diameter, not too thick, and free from what some term 

 "neck" ends. It should be dark green in color. The 

 fewer the seeds and the more poorly they are developed 

 the better it will please the consumer. 



Cultural methods. 



Cucumber seed is planted in pots or flats about 

 four weeks before the plants are to be set in the per- 

 manent beds. When planted in pots two to four seeds 

 are placed in each pot. When planted in flats the seeds 

 are sown rather thickly in rows about 2 inches apart. 

 The flat-grown plants are pricked off, when large 

 enough to handle, into pots, one plant in a pot, or into 

 flats about 4 inches apart each way. The plants which 

 are started in pots are not pricked off but they are 

 thinned, when necessary, to not more than two in a pot. 



Cucumbers should be kept growing all of the time to 

 get best results. In order to do this, they must be 

 kept in a warm house. The night temperature should 

 be above 60° and may run as high as 70°. The day 

 temperature should run at least 10° higher than the 

 night temperature and on bright days it can go still 

 higher if the ventilators are open. -The seedlings should 

 never be allowed to dry out nor should they be watered 

 too heavily as damping off is liable to occur when the 

 BoU is too wet. The watering should always be done 

 on bright days. Cold draughts should be avoided as 

 they induce attacks of mildew. Judicious ventilating 

 wiU insure hardy plants. 



The distance apart the cucumbers should be planted 

 depends on the method of training to be used. There 

 are two distinct methods of training, the "A"-shaped 

 treUis and the upright. When tlie trellis is to be u.sed, 

 the plants are set in rows from 10 to 16 feet apart and 

 from 10 to 15 inches apart in the rows. When the vines 

 are to be trained upright, the plants are set from 2 to 



3 feet apart each way, one plant in a place. 



The trellises are made of wire or slats and wire which 

 are run across 2 by 4 pieces of timber placed at wide 

 intervals. When the vines are trained upright, strings 

 are fastened to wires which are run above each row, 

 one string to each vine. When training, the vines are 

 simply twisted around the strings and the "feelers" 

 attach themselves and thus hold the vines in place. 



Some growers use slender sticks, made especially for 

 the purpose, on which to train the vines. The sticks are 

 1 J^ by M inches and from 6 to 8 feet long. A piece about 



4 inches in length is nailed across the bottom to keep 

 the stick from sinking into the soil. The tops of the 

 sticks are fastened to wires run parallel to the rows, 

 one wire above each row. The vines are held in place 

 by pairs of nails driven into the sticks at intervals of 

 12 to 15 inches. One of the naUs of each pair is bent at 

 right angles after being driven into the stick and the 

 bent part is dropped onto the other nail after the vine 

 has been placed between the naUs. 



The pruning of the vines is similar, no matter which 

 method of training is used. All laterals are cut back 

 more or less. One to three female flowers are left on 



each lateral. Best results are usually secured when the 

 laterals are cut beyond the first female bloom. 



Cucumbers in fruiting use an enormous amount of 

 water if it is available. As soon as the supply of water 

 in the soil becomes reduced below the amount required 

 for the maximum growth of the plants and fruit, the 

 number of short runty cucumbers will increase in 

 proportion to the number of long ones. The Skinner 

 system or any other similar system of overhead water- 

 ing is ideal for cucumbers. Care should be taken to 

 do the watering at a time when the foliage will dry off 

 quickly, especially if mildew or any other fungous 

 trouble makes its appearance. Aside from the fact 

 that the soil must be rich in. plant-food, there is no 

 other matter of as great importance as the water-sup- 

 ply. Whether the water be applied a Uttle at a time 

 and frequently or in larger quantities and at longer 

 intervals is not of so much impo tance as the supply 

 itself, which should be sufficient for the needs of the 

 plants at all times. 



Pollination. 



Some form of artificial poUination is necessary for 

 best results with the White Spine type of cucumber. 

 Hand polhnating is very tedious and is seldom em- 

 ployed in large houses. The usual method is to place 

 a hive of honey bees in the house and let them do the 

 work. In large estabhshments several hives are re- 

 quired. One strong hive for each half-acre of cucum- 

 bers will be ample. When first put in, the bees are 

 quite uneasy but they soon quiet down and make 

 themselves very much at home. 



Insects and diseases of cucumbers. 



One of the most formidable insects attacking forc- 

 ing-house cucumbers is the red spider. Some growers 

 are obliged to fight this insect every season. The best 

 way to combat it is to prevent its making an appear- 

 ance. This can often be done by keeping all of the 

 soil, walks and other places where there is enough dirt 

 to permit of their breeding, moist at all times. When 

 these Uttle animals appear on the plants they can be 

 driven off by spraying the plants thoroughly with 

 water. To be effective, the water must be apphed with 

 force and directed against the under side of the leaves. 



Another insect which causes much damage to cucum- 

 bers is the striped cucumber beetle. The stink-bug 

 may be included with it, as the work of the two insects 

 is very similar in its effect upon the plants. The most 

 serious trouble with these insects does not occur 

 when the plants are small, as they can be protected 

 then, but when they are large. The vines which are 

 damaged by these enemies resemble those injured or 

 killed by the bacterial wilt. If the vines are Icilled by 

 the wilt, all of the plant dies at one time: When the 

 damage is caused by the bugs, the upper part of the 

 plant or a lateral branch wiU wilt and dies first, usually 

 but not always followed in a few days by the wilting 

 of another branch or the remaining part of the plant. 

 No effective means has as yet been found for combat- 

 ing these insects. Some growers claim that by keeping 

 the side ventilators and doors closed most of the time 

 the bugs will not get into the houses. To keep them 

 out in some places the ventilator openings would have 

 to be screened. No crops which the bugs work on 

 should be gromi near the forcing-houses. When the 

 insects once gain admittance to the houses, they are 

 very difficult to eradicate. The stink-bugs lay their 

 eggs in clusters on the leaves and these should be 

 gathered and destroyed. 



The white fly is occasionally serious on cucumbers. 

 The remedy is to fumigate with hydrocyanic acid gas, 

 but as this gas is dangerous to both plant and animal 

 life it is used only in extreme cases. 



The green and black aphis occasionally attack 

 cucumbers in the forcing-house. The green aphis can 



