Strawberry Cultivation in Semi-Arid Climates a Manual

Strawberry Cultivation in Semi-arid Climates – A Manual

Lauren Taneyhill Community Environment and Development, Environmental Economics and Policy The Pennsylvania State University December 2010

Introduction

The Children and Youth Empowerment Center has expressed interest in producing strawberries on their land. The first goal of strawberry production at the CYEC would be to supplement the diet of the children and youth living in the Center. A secondary endeavor would be to produce enough of the crop to be able to sell strawberries as an added income for the CYEC. Jams, preserves, juices, or dried strawberries would all potential products to sell under a CYEC brand for CYEC profit.

The content of this report is a guide to strawberry production, including ideal conditions and suggestions to improve cultivation and harvesting.

Temperature and Sun Requirements Temperature Warm, full sun for 6 hours each day Frost Damage can occur at -2 degrees C – should not be a concern in Kenya (Hussain)

Soil Management and Fertilization Drainage Prefer well-drained pH Slightly acidic Between 5.7 and 6.5 Things to avoid in the soil Planting on the same land for many years High pH Nematodes High salt content

1 High calcium content Soil Preparation Begin 1 month before planning Plow deep even though the roots will be shallow Create the beds Raised beds preferred Ensure good drainage Make installation of an irrigation system easier Parameters 25cm high 105 cm wide Convenient length for grower – about 50cm Beds 50cm apart from each other Green manure Use cover crops to put nutrients into the soil High organic matter preferred Helps with poor soil drainage Use compost or highly decomposed cattle manure Apply a few days before planting Apply again after the first harvest to prepare for the second season Water fertilizer to get it into the root zone Do not over fertilize Could cause excessive vegetative growth, reduced yields, and increased loss from disease 50 tons of organic matter per hectare estimated But this is difficult to determine without information about nutrient analysis and moisture content of the manure or compost. Can be supplemented with chemical fertilizers Nitrogen – apply 3 weeks after planting and at time of flowering Phosphorus – incorporate before planting (Hussain)

Propagation and Seedlings Propagation With runners Runners formed after blooming season Runners can be hard to get in semi-arid regions Other methods Cultured planting material Imported from western countries Seed and stem cuttings Buy new plants Important to find disease-free plants from a reliable nursery (Hussain)

2 Information on where to purchase seedlings near Nairobi is not easily available. Less than 5% of roadside nurseries sell strawberry seeds or seedlings. They only stock a few seedlings at one time and have incorrect information about plant management. The price of a seedling at a roadside nursery is about $0.45 to $0.65, or 36Ksh to 52Ksh per plant. In Limuru there is a small-scale agro enterprise that specialized in strawberry seedling production and sells them at a lower price of about $0.35, or 28Ksh per plant. They sell the seedlings unrooted, which makes them harder to establish especially if the planter is inexperienced. They also provide free basic training in Limuru on planting and crop management. For more detailed training it is about $7.00, or 564Ksh per person (Mwangi 2009).

Method and Timing of Planting Strawberries should be planted in areas of full sun, but avoid completely exposed open areas, and do not plant where there have been peppers, tomatoes, eggplants, or potatoes because verticillium wilt could be transferred, which is a serious strawberry disease. Also avoid land the recently had grass growing on it because there may be wireworms there. Plant on ridges to facilitate irrigation. When planting seedlings, ensure that they are rooted already for a higher establishment rate. Also ensure that potting is sterilized to avoid transmitting pests. Transplanting should take place during the rainy season when supplementary water is not required (Mwangi, 2009). When planting runners they should be planted 25 cm by 25 cm with 4 rows in each bed (Hussain). The timing of planting is just as important as the method. Plant early enough that the strawberries can be established before the hottest weather, but do not plant when the soil is wet. It is suggested that planting should ideally take place on a cloudy day in the later afternoon. For more fruit, plant earlier so that runners will establish earlier and there will be an earlier and higher yield of fruit. Stagger planting for longer fruit availability. When fruiting begins, not all plants will fruit at once (Hussain).

Row Spacing When planting in the beds there are a variety of row systems that can be used. In planting for all row systems, the soil should just cover the tops of the roots, and the crown should not be covered. Runners and daughter plants should produce after about 4 or 5 weeks (Hussain).

Matted Row System Daughter plants root freely Set plants 46 – 76cm apart Set rows of plants about 1 meter apart Spaced Row System Limits the number of daughter plants Provides higher yields, larger berries, fewer diseases More care needed Some daughter plants should be pulled our or cut from the mother plant Create a space of 10cm between each plant.

3 Set plants 46 – 76cm apart Set rows about 1 meter apart Hill Row System Gives the best yields All runners or daughter plants must be removes Causes mother plant to develop more crowns & flower stalks Should be several rows in groups of 2, 3, or 4 plants Important to weed and mulch in the first 2 – 3 weeks of growing Set plants 30cm apart in multiple rows (Hussain)

Water Requirements and Irrigation

For watering strawberry plants, the suggested practice is to use micro-irrigation system with a micro sprinkler during planting and early growth for 2 to 3 hours each day, and a drip irrigation system during flowering and fruiting, but it is more than likely that a drip irrigation system would be just as sufficient for all phases of cultivation and the two different systems would not be necessary. A micro-irrigation system is suggested within a plasticulture system (more plasticulure techniques discussed later). Micro-irrigation is best for strawberries because water management for this plant is crucial because it is a low surface creeping plant and it has shallow roots. However, the two-part system is an ideal scenario and is likely to be costly, and unnecessary for adequate strawberry production at the CYEC. Micro-irrigation involves a drip system and a micro sprinkler system, which help supply more precise amounts of water to the crop according to the stage of growth. It should be installed after the beds are prepared. The micro sprinklers should be spaced 3 meters apart for uniform application and should water the strawberries for 2 to 3 hours each day during planting and early vegetative growth. The drip system should be set up as 2 lateral lines on each bed with the drippers spaced at about 50 cm apart and it should water the crop 2 or 3 times each week (Hussain). There are various suggestions for irrigating depending on the stage of growing. Irrigation should be frequent after planting new runners. In the first two months after planting the strawberries should be irrigated twice a week if there is no rain. In the third month they should be irrigated every 2 weeks. When fruiting starts irrigation should increase because more frequent irrigation results in larger fruits. It is estimated that 46 cm of water would be used in a 200-day growing season, including natural precipitation, which is approximately 83 liters per plant per season, although this is dependent on plant density. This requirement would be greater during extended warm and dry conditions (El- Farhan). Strawberries are susceptible to water stress, which interferes with photosynthetic activity and reduces growth. Deficiencies in the plant from water stress can accumulate over a season. Without enough water ripening is accelerated and the size of the fruits

4 would be smaller. Also the number of fruits per plant will decrease significantly if water stress is consistent. It is important to maintain moist soil. It is best if soil moisture does not fall below 50% of field capacity. This can be measured with a tensiometer. Placing a bucket over the plant at night can also test soil moisture. If there are beads of water on the younger leaves in the morning then the soil is moist enough (El-Farhan).

Plasticulture Plasticulture techniques can increase strawberry yields in semi-arid regions. Plasticulture often uses plastic in various ways, and for that reason strawberries have sometimes been named “plasticberries.”

Raised bed cultivation Helps with drainage and makes installing the irrigation system easier Micro irrigation system (Discussed above) Plastic mulching Proven to produce a higher yield Conserves soil moisture Controls weeds Keeps fruit clean Protects against rotting Use black polyethylene Construct after runners established, before flowering begins 30 – 45 days after planting Replace micro sprinkler with drip system before mulching Place holes in mulch Allows plants to come above the film Drip irrigation system remains below the plastic Plastic tunnels Give a higher yield Not needed when temperatures are high Should be 50cm high, made of transparent polyethylene Keep open during the day, close at night for higher soil temperatures Helps with earlier flowering and higher yields (Hussain)

Harvesting Fruiting occurs after 3 or 4 months. Harvesting should begin when half to three- fourths of the fruits are a natural crimson color. Higher altitudes can lead to later ripening. When preparing to harvest look for a uniform bright red color, slightly soft fruits with darkening seeds. Harvest daily in the morning in dry conditions. Pinch each fruit between the thumb and forefinger and pull with a twisting motion. Leave the stem on the fruit. Strawberries are highly perishable so it is important to collect them in shallow containers to prevent bruising, and do not wash them because water contributes

5 to spoiling. If sending strawberries to the market, try to pick them early in the morning and send them to the market the same day in the afternoon. In ideal conditions, yields are expected to be about 15 tons per hectare (Hussain).

Post-Harvest – Storage and Market Information Strawberries should be stored in flat, shallow containers, preferably of plastic, but could also be of cardboard, bamboo, or paper. They should be washed only right before eating or used within a day after washing. They should be used within a week of harvesting. Strawberries should not be left at room temperature for many hours because warm temperatures cause browning and loss of vitamin C. Also post harvest solar drying would be a feasible technique to preserving strawberries if a solar dryer can be obtained (Hussain). There is a market for strawberries that readily exists in Kenya for those interested in cultivating strawberries as a way to generate income. There is a high demand in urban areas, and in foreign markets like the European Union. Strawberries are scarce in Kenyan markets, and therefore are very costly. The scarcity is due to limited production with farmers unable to engage in enough production to be able to sell the fruit, and production constraints, such as expensive planting materials, lack of knowledge for planting and crop management, and low awareness of the potential for strawberries in the available markets and for income generation (Hussain). Additional information needs to be gathered on location about the details of the market structure for the buying and selling of strawberries and strawberry products, as well as transportation options and transportation costs.

6 Works Cited

Hussain, Abid. "Strawberry Cultivation in India." Scribd. Tamil Nadu Agricultural University. Available at: http://www.scribd.com/doc/2297087/Strawberry- Cultivation

← Mwangi, M., and Sarah Mwaura. 2009. "Challenges in Strawberry Seedling Production in Kenya." Journal of Applied Biosciences. Available at: www.biosciences.elewa.org

← El-Farhan, A.H., and Marvin Pritts. "Water Requirements and Water Stress in Strawberries." The New York Berry News. Cornell University. Available at: http://www.fruit.cornell.edu/Berries/strawpdf/strwaterreqstress.pdf

7 Diagrams & Pictures

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Hoover, Emily. 2008. “Commercial Strawberry Production in Minnesota.” University of Minnesota Extension. Available at: http://www.extension.umn.edu/distribution/horticulture/m1238.html

8 QuickTime™ and a decompressor are needed to see this picture.

Warmund, Michele. “Fruit Production.” University of Missouri Extension. Available at: http://extension.missouri.edu/publications/DisplayPub.aspx?P=mg6

Row Systems:

Matted Row

Warmund, Michele. “Fruit Production.” University of Missouri Extension. Available at: http://extension.missouri.edu/publications/DisplayPub.aspx?P=mg6

“For the Love of Organic Strawberries – Part 2.” 2009. Ask Farmer Phoebe. Available at: http://askfarmerphoebe.wordpress.com/2009/02/18/for-the-love-of-organic-strawberries- part-2/

Handley, David T. “Growing Strawberries.” 2003. University of Maine Cooperative Extension. Available at: http://umaine.edu/publications/2067e/

“Growing Strawberries – Introduction to the Growing Strawberries Page.” Monthly Growing Strawberries Guide. Available at: http://strawberryplants.org/2010/05/growing- strawberries/

Spaced Row

No Available diagram

Hill Row

“Growing Strawberries – Introduction to the Growing Strawberries Page.” Monthly Growing Strawberries Guide. Available at: http://strawberryplants.org/2010/05/growing- strawberries/