HIGH DENSITY PLANTING SYSTEM IN FRUIT CROPS
Authors: A.K. Goswami, Madhubala Thakre, A. Nagaraja and Jai Prakash
IARI, New Delhi-110012

India is the largest producer of fruits in the world. The average productivity of fruits in India is, however, low as compared to many developed countries. The main reasons for low productivity are old and senile orchards, low yielding varieties, poor orchard management and inadequate technological up-gradation and adoption by the growers. Presently, the continuing decline in the availability of cultivable land, rising energy and land costs together with the mounting demand of horticultural produce, have given thrust to the concept of high density planting (HDP) of horticultural crops. Furthermore, it is of main concern to the growers with small land holdings. HDP is one of the important methods to achieve high productivity per unit area both in short duration and perennial horticultural crops. High density planting in fruit growing was first established in apple in Europe in the early sixties. High density planting is more efficient since it is precocious, easily manageable, has higher yield potential with better quality fruits and higher returns/unit area. Being an intensive system, it requires more capital to establish and is more productive and profitable, if followed scientifically. The adoption of high density planting systems is revolutionizing fruit growing over much of the world and promises to have a significant effect on horticulture industry. High Density Planting (HDP) is a very intensive form of fruit production which has high relevance to the food and nutritional security of our ever increasing population.

Key aspects of high density planting in fruits:

The HDP can be with one species (mono-species) or with different species (multi-species, multi-storeyed) of crops. The mono-species HDP basically comprise the planting of small tree densely, restricting their vegetative growth by using dwarfing rootstocks, bio regulators or other horticultural technique such as pruning thereby, diverting much of the plant energy to the economical parts. In the multi-species HDP, the interception of incident solar radiation at different tiers by canopies of various species based on their light transmission characteristics and shade tolerance are exploited. Beside, ramification of their root system at different soil depths ensures effective nutrient and water uptake.

Five important components of HDP are (a) Dwarf scion varieties (b) Dwarfing rootstocks and inter-stocks (c) Training and pruning (d) Use of chemicals/PGR (e) Suitable crop management practices. These components are harnessed in HDP which helps in attaining the goals.

Merit of HDP over Normal Planting:

The high density planting has certain definite advantages as well as limitations compared to the conventional low density planting. It is worth mentioning here that under high density planting system the yield per plant in low as compared to low density planting. However, the total yield per unit area of land is several times higher than low density planting. Increasing pressure on land owing to diversion of farm field to various other obvious reasons as well as rising energy and land-costs, together with increased demand for fruits have made it necessary to achieve higher productivity from limited space. High density orcharding appears to be the most appropriate answer and need of the hour to overcome low productivity and long gestation period for early returns and export quality fruits.

• High density planting facilitates better utilization of solar radiation and increase in bearing surface per unit land area.
• HDP plants are precocious, easily manageable and fetch higher return per unit area.
• High density orchards have better amenability to modern, input saving horticultural techniques such as drip irrigation, mechanical harvest etc.
• The use of dwarf trees and managing excessive vegetative growth gives higher productivity and harvest index as well as early economic returns.
• High density planting system is more amenable to horticultural operations such as pruning, plant protection measures and harvesting which reduces the labour cost involved.

Constraints in Adopting High Density Planting Systems

• Poor availability of planting material in dwarf varieties as well as vegetatively propagated rootstocks in different horticultural crops.
• Lack of standardization of production technology in HDP of various fruit crops.
• High density planting needs higher initial establishment cost as compare to traditional system of planting.
• Avoidance in use of inter and mixed cropping system.
• Need for a more professional and scientific approach for management compared to the conventional planting at wider spacing.
• Crowding and intermingling of branches may occur in coming years which can result in poor performance of trees.
• Non availability of complete package for HDP and use of mechanization.

High yield and high fruit quality can be achieved with a high-density orchard when the orchard has good light distribution throughout the tree canopy and there is a balance between vegetative growth and cropping. Planting density is one of the most important factors which determine the yield of an orchard. After the first few years, fertilization regime should be maintained with a balance between fruiting and cropping. Excess fertility often results in excessive vegetative growth, delayed cropping and soft and poorly coloured unmarketable fruit. The goal of HDP is to get the trees into cropping as soon as possible from a limited space. This is best accomplished by following proper pruning and training regime combined with a precocious rootstock to obtained significant production.

Reference:

• Bal, J.S. (2007). Fruit growing Kalyani Publishers, Ludhiana, India.
• Bose, T.K., Mitra, S.K. and Sanyal, D. (2001). Fruits:Tropical and Subtropical (Vol. 1). NoyaUdyog, Kolkatta-6.
• Chattopadhyay, T.K. (2008) A textbook on Pomology, Vol. 4 (Sub-tropical fruits), Kalyani publishers, Ludhiana, India.,
• Goswami, A. M., Saxena, S. K. and Kurien, S. (1993). High density planting in citrus. In: Advances in Horticulture Vol. 2- Fruit Crops, Eds. K. L.Chadha and O. P.Pareek, Malhotra Publishing House, New Delhi
• Ram, S. (1993). High Density planting in mango. In: Advances in Horticulture Vol. 2- Fruit Crops. Eds. K. L.Chadha and O. P.Pareek, Malhotra Publishing House, New Delhi

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