INTRODUCTION.
A grape is a berry that’s falls off on maturity. The crop is a woody perennial vine having the ability, to live beyond 500 years.
There are a number of grape varieties; French grapes also known as Vitis vinifera, American grapes- vitis labrusa and Mediterranean grapes.
The most common and widespread grapes species is Vitis vinifera and it’s a native of Europe grown worldwide. Flowers and fruits are produced in clusters of 6 to 300, and can be black, blue, golden, green, purple-red and white. Grapes can be eaten raw as fruits or can be used to process wine and other grapes products, e.g jam.
CROP ESTABLISHMENT.
They require acidic conditions/soils of about 5PH if your soils are not acidic it’s advisable to lower the PH. It’s advisable to plant dormant, bare-root grape vines. Most grape varieties are self-fertile. A good site with direct, unfiltered sunlight for at least 6 hours a day, deep, well-drained, and loose soils and proper air circulation. In Kenya, growers import Seeds from South Africa and root in a quarantine space for a period 6 months. They are then transplanted to the fields. Grapes require a trellis system to support the weight of the fruit on the vines, trellis system also increases air circulation and reduces diseases in the canopy. Supporting your grape vine can be done immediately when planting. The vines can reach lengths in excess of 30 m and can live for many years with proper management. Before planting grapevines, soak their roots in OPTIMIZER for 3 hours, this opens ups the roots and ensures speedy crop establishment. Spacing of vines should be around 6 to 10 feet and for each vine, dig a planting hole 12 inches deep and 12 inches wide. Fill with 4 inches of topsoil. Cut off broken roots and set the vine into the hole slightly deeper. Cover the roots with 6 inches of soil and press down. Fill with the remaining soil avoiding more pressing and water at the time of planting. Planting can be done in blocks of one HA, around 38 beds. Training is important in order for grape vines to develop strong root systems and support heavy loads of fruit, new vines should not be allowed to produce fruit for the first 2–3 years after planting. Kenyan season starts at September and the grapes are harvested after 6 months after which the crop goes into dormancy. Usually one crop/harvesting a year. During the dormant period, you are advised to stress the crop. It then shades of leaves, this enables the crop to get new food stalks. The most common pruning practice is cane pruning, in this, 7-9 buds are removed. This pruning enables the crop to give more canes in future. After pruning flowering starts in a month’s time. This is the best time to do canopy management where thinning, spacing, defoliation is done to allow the berry to grow.
DISEASE, WEED AND PEST MANAGEMENT.
When establishing the crop, its advisable to do manual weeding, Non selective herbicides (CATAPULT 480 SL) can be used to on already established crops. Depending on your soil analysis, basal fertilizers are to be applied on specifications. DAP, NPK. One can use drip irrigation for fertigation. Powdery Mildew, Downy Mildew and botrytis are major crop diseases that attack the crop especially after fruiting.
ANHTRACNOSE
Is a fungal disease favored by warm weather. The symptoms include dark red lesions on grapes; sunken gray lesions with a darker edge on grapes; lesions on the leaves causing leaf to curl; lesions on shoots may cause a ring of damage which will kill parts of the plant; lesions may also be present on tendrils, fruit stems, and leaf stems. It’s advisable to Plant less susceptible cultivars; Application of ABSOLUTE, DOMAIN fungicides while vines are dormant may be necessary for management and Control.
BOTRYTIS
Is a fungal disease favored by high levels of moisture. The symptoms include, brown lesions on the stem early in the season; grapes covered with a gray to tan powder; stems and grape clusters shrivel. Planting less susceptible varieties; reduce amount of vegetative growth on vines; do not over fertilize; use suitable trellises to increase air circulation in canopy and expose grape clusters to sun; Application of ABSOLUTE STAR 400 SC at 10ml in 20L of water and alternate with FASTRUNO 500 SC at 20ml in 20L of water may be necessary for management and control.
POWDERY MILDEW.
Fungal disease favored high humidity and mild temperature characterized by Red patches on canes; yellow patches on top surface of leaves; white powdery growth on leaves; white powdery growth on fruit. Planting vines in sites with good air circulation and sun exposure; use of a training system that promotes air circulation through the canopy; application of SOUVENIR, GREENCOP, SPARROW for management and Control.
BLACK VINE WEEVIL.
It’s an insect that feeds damages the stems, leaves, buds and flowers causing less plant vigor. The larvae live in soil and feed on roots.
GRAPE CANE GILDER.
It’s an Insect that causes holes and punctures the canes causing great injuries to vines especially during establishment
GRAPE MEALYBUG.
It’s an insect that causes Sooty mold on fruit. Sugary secretions by the insect drop onto fruit and encourage growth of mold. Application of appropriate insecticide such as LOYALTY. JAMBOCLEAN may be important for management and control.
