Grapes. Have you ever wondered where the grapes in your wine or juice grow? Kenya is known for its quality horticultural industry produce, but in grape production, we are a far way off.

This lack of grape production is not surprising considering that very few Kenyans know where this fruit is grown.

If you belong to that group of Kenyans who don’t know where grapes grow, you are not alone.  Grape vines happen to grow well in Naivasha, Mandera, Mombasa, Yatta, and Kibwezi.

Therefore, if you live in these areas, you might consider growing grapes.

The few grape growers are getting huge yields—an indication that Kenya has a high potential to be a leading producer of the crop if Kenyans take its cultivation seriously. By growing grapes, Kenya will save much foreign exchange as over 90% of the fruit used in wine and juice making is imported from South Africa and other countries.

The Varieties of Grapes in Kenya.

There are thousands of grape varieties in the world, and many types in Kenya. However, I can classify all these varieties into two distinct groups.

  1. Table grapes- we use this group of grapes in making various meals for example as sweeteners in cakes.
  2. Wine grapes-used specifically in the production of wine.

The grape varieties classified in the above broad group can either be French grapes also known as Vitis vinifera, American grapes- Vitis labrusa or Mediterranean/ Muscatine grapes.

The most widespread grapes species is Vitis vinifera; a native of Europe grown on the world’s most land acreage.

Grape botany

The crop is a woody perennial vine having the ability, to live beyond 500 years.

Environmental conditions for growing grapes.

The crop is not very exacting about temperature; consequently, it can be the grown practically everywhere in the world making it the fruit with the broadest geographical distribution.

During fruiting, grape prefers warm to hot temperatures; the weather must be sunny and dry. Warm environmental temperatures during fruit ripening, increase the sugar content of berries while reducing their acidity.

The need for warm temperatures during fruiting explains why grapes grown under irrigation in hot deserts or semi-deserts are sweeter than those from cold, humid areas.

The crop can grow in any soil, from sandy to heavy clays but the land should be thick and well drained.

Where the rainfall is scant, supplement it with irrigation of 500 mm of water during the cropping season. In Kenya, the cropping season is September to March.

Irrigation should be withheld after the long rains to force the crop to go dormant.

In August to September, fruit buds form thus it is essential to keep the plant healthy and well manured.

Suitable scions for Kenya are as follows

Table grapes: Dodrilabi, Black rose, Italia, Muscat of Hamburg, Alphonse, LaSalle, Muscat of Alexandria, Perletta, Cardinal, Dalbiki.

Wine grapes: French colombard, Sauzao, Saungnok blank, Cabaret, Alicarte, Grenard, Semillon

Rootstocks

Most rootstocks are adapted to many soil conditions. The selection of a suitable rootstock is based on the following criteria;

  1. Resistance to Phytophthora root rot
  2. Tolerance to drought and other soil conditions like low PH
  3. Adaptation to soil depth and texture
  4. Resistance to crown gall Agrobacterium tumefaciens. This bacterium weakens vines by encouraging the production of large amounts of cytokinins and auxins that induce excessive cell division and elongation.
  5. Adaptation to different PH which affects availability or uptake of nutrients. The scion should be adapted to high PH soils to facilitate absorption of Fe2+Mn2+, and Zn2+ should be tailored to low PH to take in Mg2+, Ca2+, and K+
  6. Phylloxera (grape louse) and nematode resistance. Nematodes are vectors of grape fanleaf virus.
  7. Vigor control- in cold regions vines exhibit indeterminate growth. Such growth results in the diversion of food reserves to vegetative growth at the expense of the fruit development.