Temprate Fruits (1+1)

SPECIAL PROBLEMS: Low Productivity in apple

Low Productivity in apple

• Decreased productivity of apple orchards in the recent years has become a serious concern of the growers in all the apple growing areas.
• The apple productivity has been fluctuating year to year between 2 MT to 8 MT/ ha.
• The factors which influence yields are climate, soil, cultivar, rootstocks and cultural management practices.
• Most of factors influencing yield are manageable to a large extent but the climatic factors are beyond the control.
• The appearance of certain diseases and pests in epidemic form has also adversely affected yield in recent years.
• The out break of red spider mite attack and premature defoliation of apple in the past 9-10 years has remained persistent problem in apple orchards.

Causes of Low productivity

1.Climatic factors:

• The low temperature at the time of flowering and fruit setting adversely affects production of fruits.
• The areas most vulnerable to the influence of low temperature are located between 5000 to 6000 feet elevation where good spring season with adequate sunshine promote apple flowering during mid March to mid April
• Fluctuating temperature during this period particularly rains accompanied by low temperature inhibits the cross pollination due to restricted bees activity and washing off pollen and poor pollen tube growth.
• It is well established that the flowers are killed below 2.20C and bee activity is completely inhibited below 4.4oC.

2.Varietals factors:

• In Himachal Pradesh, Delicious group of apple varieties constitutes more than 80 per cent of the total production of apple.
• The predominant varieties like Starking Delicious, Red Delicious, Rich-a-red and certain improved bud sports and spur types are self unfruitful and require cross pollination for fruitfulness.
• Moreover, these varieties have strong tendency of alternate bearing ,which is also one of the reasons for low production during the off years.

3.Inadequate pollinizer:

• In Himachal Pradesh, 25 to 33 per cent proportion of pollinizing varieties in orchards is recommended for adequate fruit set.
• But actual proportions of these varieties is only 5-10 per cent. The problem is further compounded due to predominance of Golden Delicious as a pollinizing variety, which does not synchronize in flowering of the Delicious varieties in many agro climatic situations, and strong tendency of alternate bearing.

4.Lack of pollinators:

• Honey bees are the major agents besides other wild pollinators for effective pollination in apple.
• Over the years the population of honey bees and other pollinators have declined due to indiscriminate use of pesticides.
• Placement of honeybees in the orchards has also not picked up due to scarcity of beehives.

5.Inadequate nutrition:-

• Apple cultivation is mostly done on the slopes which poses serious problem of water and nutrient losses.
• Frequent dry spells during April-June and September –November make the nutrients unavailable to the plants even if applied adequately in the soil.
• Contrarily leaching of the nutrients during rainy season from July –August further affects the health of the trees.
• It has also been noticed that the fertilizers are not applied according to the requirement of the trees.

6.Poor soil conditions:-

• In orchards which are planted on the slopes, run off losses render the soils nutritionally and structurally poor. In many orchards, soils which do not have adequate drainage, temporary water logging conditions develop during the rainy season killing feeder roots and temporarily restricting the uptake of the nutrients. All these factors adversely affect the plant health and productivity.

7 Poor canopy management:

• Dependence of the orchardists on hired pruners is increasing day by day. The plants are not properly trained and pruned by these untrained pruners resulting in poor canopy development.
• At lower elevation where the vegetative growth is excessively more due to warm conditions, hard pruning promotes more vegetative growth and reduces reproductive growth is considered a wrong orchard practice.
• In such conditions lesser heading back and more thinning out of shoots as per tree behavior is required to balance cropping and growth.

8. Senile orchards:

• Orchards more than 40 years of age face the problem of unfruitfulness more seriously than the young orchards.
• Such orchards do not produce adequate annual extension growth and usually have foliage of small size.
• The old orchards have also been planted under traditional systems of planting at a spacing of 20-25 feet, which take 15-20 years to come to come to commercial fruiting after planting.
• Use of ethephon for early maturity and colour improvement at lower elevation has also proved counter productive. Continuous use of ethephon beside poor orchard management practices is a cause of senility and poor shelf life and quality of the fruits.

9. Pathological factors:

• The number of disease has been found affecting the apple orchards. The most serious among these is apple scab .Besides apple scab others diseases are premature leaf fall, root rot, color rot, replant problem. Powdery mildew, cankers and viruses. Most of the pollinizing cultivar like golden Delicious and Red Gold have been found to be higher susceptible to scab.

10. Entomological factors:

• The magnititude of pest in incidence varies from region to region and orchard to orchards. Aphid is most dominant one affecting 82 per cent orchards followed by San Jose Scale (71%),blossom trips (70%),European mite (62%), apple leaf roller(43%) root borer(26%) stem borer(9%),defoliating beetle(6%) and hairy cater pillar (5%).

Suggested Remedial measures:

1. Among the standard varieties there should be more proportion of regular bearing varieties than the Delicious cultivars.
2. Adequate proportion of pollinizing varieties should be compensated with has not been provided, top working of the trees with pollinizing varsities.
3. Proper orchard soil and canopy management practices should be given adequate priority.
4. There is an urgent need to go for high density plantation in different temperate fruit crops.
5. Indiscriminate use of insecticides, pesticides and fungicides should be avoided in order to maintain the population of natural predators and avoid problem of tolerance by pests.