Eng. Nabeel Gnayem - Extension Specialist, Ministry of Agriculture - Israel

Beit Alfa cucumbers are a major vegetable, produced in the Middle East, in several eastern European countries and world wide where Middle Eastern ethnic populations exist. Beit Alfa cucumbers excel in flavor and in crispiness compared to other cucumber types.

Growing Structures and Optimal Climate: Greenhouse cucumbers adapt to variable climates and can achieve economically feasible yields in both hot and cool weather (between 8 and 37 Centigrade). Extreme conditions beyond this range can cause stress, lower yields and lower fruit quality. Heating or cooling to readjust the greenhouse climate in extreme conditions can improve yield and quality.

Day Length: Parthenocarpic cucumbers are not sensitive to day length.

Humidity: Cucumber plants develop well in relatively high humidity(65-85%). They suffer in extremely dry weather. In desert conditions, adding humidity should be considered.

Light: Cucumbers develop well in conditions of high light intensity (250 to 1000 watts/sq meter). In higher light intensity, there is a need for shading. Lack of light (below 100) severely decreases plant development.

Soil Types: Cucumbers are adaptable to different soil types if provided with a fairly deep profile and a pH between 6.5 and 7.5. Calciferous and alkaline soils require constant attention to microelement levels.

Structures: High structures are preferred (above 4 m) and spacious structures facilitate optimal humidity levels. Tropical and subtropical climates require a ventilated roof. In places where the temperature drops below 5 centigrade, heating is necessary. It is necessary to choose structures that enable trellising up to 2.5 meters high. Anti-insect nets should be used in order to decrease virus infection and physical insect damage caused by aphids and white flies. Plastic should be chosen according to local growing conditions, and it is usually recommended to use thermal plastic (IR and anti drip).

Planting Recommendations: Plant density should be selected based on season and the characteristics of the particular variety. Average plant density in spring/summer conditions is between 2.4 and 2.6 plants/m2.
When planting in double rows, row spacing should be 50-60 cm, and bed spacing should be 1.8 meters center to center, plant spacing within the row being 35-40cm. During winter/autumn, plant density is decreased to 1.8 to 2.2 plants/ m2. This density can be achieved by planting 40 cm between plants in double rows.

Fertilizer: Levels should be adapted to growing stage, soil type and climate conditions. The fertilizer recommendation will be based, in addition to the above parameters, on soil and irrigation water analysis.
Intensive planting of greenhouse crops requires pre-plant fertilization based on soil analysis, followed by continuous supplemental fertilization. General fertilizer recommendations for Israel can be found in the following tables.

General Plant Protection Recommendations
During the growth stage, all diseased plants or parts of plants should be removed to maintain sanitation within the greenhouse. At the end of growth, plants need to be removed in their entirety and disposed of outside of the greenhouse. Resistant varieties should be used wherever possible. Greenhouse should be well ventilated to prevent diseases. Foot baths should be used at the entrance of the greenhouses with 1% bleach to prevent mechanical spread of viruses. Hands should be disinfected by using soap during harvest and other chores. Pesticides should be used according to manufacturer recommendations including harvest intervals, and only those registered for use on cucumbers. Aphids and white flies can be controlled by use of Imidacloprid - based compounds according to recommendations. Every 5 days, plants should be inspected for diseases and insects. One day after spraying, effectivity should be evaluated. Formulation of spray materials (pesticide doses, spray volumes, etc.) should be adjusted to obtain maximum effectivity while using a necessary minimum amount of pesticide.

Harvest and Post-Harvest Handling
Harvest begins from 23 to 45 days after planting according to weather conditions and the variety. Harvest lasts between 50 and 120 days. Harvest is done by hand by removing fruit with stem attached. Flowers should be removed at harvest time to improve shelf life and to reduce breakdown of the fruit. Harvesting should be done early in the morning while the fruit is firm and cool, not hot and soft. Cartons should not be stacked too high to prevent crushing of fruit on the lower levels of the stack.

Grading of fruit- defective fruit, insects, etc should be removed before packing. Size grading can be done by machine in the packing house, the fruit then washed by water at 55 to 58 centigrade for 20 seconds, then dried by cool air to improve appearance and shelf life.

Packing will be done according to needs of wholesalers. It is common to place a foam pad on the bottom of each box to maintain freshness and reduce shrinkage. Cucumbers can be held in coolers at 10-12 centigrade and relative humidity of 90-95% for up to 10 days.