Forcing Of Cucumbers

The commercial production of cucumbers under glass has assumed large proportions. This crop ranks second in commercial importance among greenhousegrown vegetable crops, lettuce only exceeding it in importance. The cucumber crop is ordinarily grown in the spring of the year after two or three crops of lettuce have been removed, and it continues to occupy the ground until the vines cease bearing, due either to poor management, pests or some similar trouble. The cucumber should come into bearing six to eight weeks after setting in the houses. It is the customary plan to plant the seed in 4- to 6-inch clay pots about two weeks before the house to be used is ready for setting. These pots are often placed over manure heat and should always be in a warm house separate from the lettuce. Two weeks should be sufficient to allow the plant a good start, two or three pairs of leaves being all the development desired before setting in the permanent location. Careful management is essential to a healthy growth, for many pests prove more serious in the glasshouse than in the field. A night temperature not below 60° F. is very essential, while the day temperature may go to 90° F. without danger in bright sunshine.

The appearance of the plants will immediately indicate, to the experienced observer, the conditions under which the crop has been grown. A short stocky growth between joints with dark green foliage is desirable. There are localities in which growers make cucumbers the all-the-year-round crop in the glasshouse, usually growing crops from two seedings during the entire season. It requires more skill to produce good cucumbers during the fall and winter months than from February on, and the yield is much fighter in the late fall and early winter than for the spring crop. All cucumbers require an abundance of moisture and food. It has become a common practice in certain sections to mulch the cucumber vines in the greenhouse with good quality strawy manure to the depth of 3 or 4 inches and apply the water directly on the manure. This practice eliminates the packing and puddling of the soil often caused by direct heavy watering, increases the supply of readily available plant-food and gives the roots a good opportunity to grow near the surface where air is available and still be protected from the drying out which occurs when the soil is directly exposed to the sun.

The pruning and training of the cucumbers in the greenhouse is of much importance. A number of methods are in common use, one of the most common and practical of which is: Stretch a wire tightly the length of the house at the base of the plants which may be set in rows 3 feet apart and 18 inches to 2 feet apart in the rows; fasten at the base of each plant a soft but strong twine known in tobacco-growing sections as tobacco twine, securing this single twine to an overhead wire running parallel and directly over the ground wire, but not stretching the string tight. As the cucumber plant grows, it is twined about this string to which it clings by tendrils. When the plant reaches the upper wire it is either allowed to grow at will over wires provided for an overhead support and from which the cucumbers usually hang down where they can be easily picked, or it is pruned and the encouragement of fruiting along the upright stem continued. In the meantime more or less fruit has been harvested and at each joint a lateral branch has appeared. It is necessary to cut these off.

Some growers prefer to take them off back to the main stem, while others, if a cucumber is obtainable on the first joint of the lateral, nip the lateral just beyond this point.

"In the greenhouse, cucumbers are liable to damage from mite, aphis, root-gall and mildew. For the mite, syringe the plant and pick off the infested Ivs.; for aphis, use tobacco fumigation and pick infested leaves; for root-gall, use soil which has been thoroughly frozen; for mildew, improve the sanitary conditions, and then use sulfur."-Bailey, "Forcing-Book."

Yields of twenty-five to one hundred and twenty-five cucumbers have been secured from single plants. The expert growers, under normally good circumstances, may expect to obtain a yield of six to seven dozen marketable cucumbers from a plant.

Varieties Of Cucumber

There are a great many varieties of cucumbers in cultivation. This means that the group is variable, the varieties comparatively unstable, and varietal distinctions somewhat uncertain. Nevertheless, there are certain dominant types which may be separated, and around which most of the varieties may be conveniently classified. The principal types are the following:

Common cucumber, Cucumis sativus. I. English forcing type (variety anglicus): Fig. 1122. Large-lvd.. strong-growing, slow-maturing plants, not suited to outdoor cultivated: fruit large, long, smooth, usually green, with few or early-deciduous black spines. Telegraph, Sion House, Tailby Hybrid, Kenyon, Lome, Edinburgh, Blue Gown.

II. Field Varieties (Hill Or Ridge Cucumbers). A. Black Spine Varieties

1. Netted Russian Type

Small, short-jointed vines, bearing more or less in clusters, small, ellipsoidal fruit covered with many small, black, deciduous spines: fruit green, ripening to dark reddish yellow, on a cracking, chartaceous skin. Early-maturing and prolific. Netted Russian, Everbearing, New Siberian, Parisian Prolific Pickle.

2. Early Cluster Type

Small or medium vines: fruit small, usually less than twice as long as thick, indistinctly ribbed, green, ripening yellow, with scattered, large, black spines. Early Cluster, Early Frame.

3. Medium Green Type

Intermediate in size of vine and fruit between the last and next: fruit about twice as long as thick, green, ripening yellow, with scattering, large black spines. Nichols Medium. Green, Chicago Pickle.

4. Long Green Type

One of the best fixed types, representing, perhaps, one of the more primitive stages in the evolution of the group. Vines large, long and free-growing: fruit large and long, green, ripening yellow, with scattered, large, black spines. Long Green, Japanese Climbing. 6. White Spine varieties.

5. White Spine Type

A strong and important type: plants medium large, vigorous: fruit medium large, about thrice as long as thick, green, ripening white, with scattering, large, white spines. There are many selected strains of White Spine. Cool and Crisp, Davis Perfect and Fordhook Famous belong here.

6. Giant Pera Type

Mostly poorly fixed varieties, having large rather unthrifty vines, bearing large fruits tardily and sparsely, which are white or whitish, smooth or with scattering, deciduous, usually white spines. Chicago Giant, Goliath, Giant Pera, White Wonder, Long Green China. Sikkim cucumber, Cucumis sativus variety sikkimensis. Plant small and stocky, much like the common cucumber: fruit large, reddish brown marked with yellow. (The Egyptian hair cucumber, of Haage & Schmidt, as we have grown it, is apparently an odd form of Cucumis sativus, and may belong here. It has a medium-sized white fruit, densely covered with soft, white hair. The plant resembles the Sikkim cucumber.) Not in general cultivation.

Snake or Serpent cucumber, Cucumis Melo variety flexuosus. Vines resembling those of muskmelon: fruit very long, twisted, ribbed-cylindrical, green, tardily yellowing, covered with dense, woolly hairs.

West India gherkin, Cucumis Anguria. Figs. 1127, 1128. Vines small and slender, somewhat resembling a slender watermelon plant: fruit very abundant, small, ellipsoid, covered with warts and spines, green, tardily whitening. Good for pickles.

These varieties are mostly all good for one purpose or another. The small sorts are naturally preferred for pickling, the medium sorts for slicing, and the large, late varieties for ripe fruits. The White Spine varieties are great favorites for slicing, and only less so for pickling.

F. A. Waugh.

H. F. Tompson.