Rootstock and propagation:-
- Seedlings of some cultivated cultivars like Bruno and Abbott are commonly used as a rootstock in kiwifruit. Seeds of these two cultivars are preferred because of good germination and strong seedling vigour.
Propagation:
- Kiwifruit is commercially propagated through cuttings, grafting and budding and tissue culture.
A.Propagation through cutting :
- This is the most rapid and easiest method.
- Softwood, semi hard and hard wood cuttings are used to raise own rooted plants.
- The ideal cutting is 0.5 to 1.0 cm thick with relatively short internodes, about10-15 cm in length having at least 4-5 buds.
- Cutting should be taken from middle portion of current season’s growth shoot in June-July in case of semi-hard cuttings and from one year old shoot during January-February in case of hard wood cuttings.
- After preparation, the cuttings are dipped in 4000-5000 ppm IBA solution for 10-15 seconds and then planted in mist propagation chamber or in open field conditions for rooting.
B.Propagation through grafting and budding :
- Kiwifruit vines are also propagated by grafting and budding on seedling rootstock. Although this method takes two years to develop a nursery plant, yet is easiest, economical and used for large scale multiplication.
- Before sowing, seeds are stratified in alternate layers of moist sand for 30-35 days at 0-5o C to break dormancy.
- Stratified seeds are sown in the seed beds during February. Germinating and baby seedlings are very sensitive to direct sunlight so they must be protected by creating a shade or using shade nets.
- At three leaf stage the seedlings are transplanted in polybags and then in nursery beds during July-August.
- The seedlings attain a graftable size within a year. Tongue grafting and Chip budding done in last week of January to end of February gave 90-95 % bud-take success.
- Nursery management practices like weeding, irrigation, staking of grafted plants are done at regular intervals.
Planting:-
- Flat land with gentle slope is ideal for planting of kiwifruit.
- Plant spacing varies according to cultivars being grown and training system adopted.
- In general, planting is done at a spacing of 6 m from plant to plant and 4 m from row to row in varieties like Allison, Abbott and Monty trained on T- bar Trellis system.
- Whereas, Hayward is less vigorous and is planted at a spacing of 5m x 5m. In pergola system of training, a spacing of 6m x 6m is recommended for getting better fruit production.
- Planting is done during dormant season ( December to January)
- While planting, the male plants are spread throughout the block with every female adjacent to a male. This is achieved by 1:8 or 1:9 male to female ratio.
Canopy management:-(A) Training:-
- Kiwifruit is a vine like grape, thus require similar training structure but more stronger than grapes.
- A number of training structures are used for training a vine, but T- bar trellis and pergola systems are more popular.
- In T- bar trellis system, the pillars of iron and concrete about 1.8m in height above the ground level are erected at a distance of 6m from each other in a row in straight line.
- A cross arm (1.5m) is fixed on each pole, which carries five outriggers wire at a distance of 45 cm each.
- Vines are trained upto wire as single stem then two leaders in opposite direction along the center wire are selected or developed . From these permanent leaders, temporary fruiting arms 25-30 cm apart are selected at right angle along both sides of each leader.
- Training of vines on pergola system is similar to that of T-bar. A flat topped network of criss-cross wire is prepared on the erected pillars. This systems is costly to prepare but vine trained on this system gives higher yields.
(B) Pruning:-
- The main objective of pruning is to obtain high yield of quality fruits and to manage excessive vegetative growth.
- The following principles should be kept in mind at the time of pruning.
(1) The fruit is developed on current season’s growth arising from one year shoot.
(2) Only the basal buds of the nodes 4-12 on current season growth are productive.
(3) Vines grow 2-3 m every year, which become overcrowded if not controlled by summer and winter pruning.
(4) The shoots developed on older wood by heading back will not fruit normally in the first season.
- Keeping in mind these principles, the vine pruning is carried out in such a way that the fruiting areas are available every year requiring the wood to be young.
- This is achieved by 3-4 years lateral replacement system. In dormant pruning, the fruiting lateral is cut back to 2 vegetative buds beyond the last fruit.
- In the second year, these vegetative buds produce the fruiting shoots, which are pruned again.
- The arm on lateral shoots are pruned and allowed to fruit for 3-4 years.
- After this the lateral is removed from the main branches and other laterals are selected and pruned accordingly so that the balance between vegetative and reproductive growth is maintained for the continuity in the fruit production.
- In summer pruning shoot is cut.beyond 6-8 buds from the last fruit during June-July.
Pollination requirement and role of Pollinators
- The Kiwifruit crop is highly dependent on pollination as the plants are functionally dioecious.
- For effective pollination, one male plant is planted for every 9 pistil late plants.
- Wind and insects play a very significant role in pollination, however, introduction of honeybees in the orchard further increase fruit set and size of the fruit.
- Honeybees colonies about 8-9 per hectare are required in kiwifruit orchard for effective pollination.
- Besides, insect pollination, hand pollination is essential to get fruits of better size and quality.
|
Participants
