Orchard Management (1+1)

WEED MANAGEMENT IN TEMPERATE FRUIT CROPS

Weed management in temperate fruit crops:

• Weed behaviour as affected by various crop husbandry practices included in the orchard management practices. Weeds compete with the fruit trees for water and nutrients. Therefore, there is a need to control weeds around the tree basin of both young and mature fruit trees.
• Weeds near young trees should be removed periodically as these reduce growth by competing for moisture and nutrients.
• Most weeds complete their life cycle in a shorter period in comparison to fruit trees and compete for light, water and mineral nutrients and reduce yield. Weeds sometimes act as intermediate or alternate hosts to certain pests, diseases which cause heavy losses.
• In India, yield loss due to weeds is approximately 33 per cent of total production, and on an average 30 per cent of the total production cost is spent on tillage operations alone. Therefore efficient weed control is necessary for profitable fruit production.

Weed control methods: Common weed control methods include use of mulches around the tree basins, manual weeding, and use of herbicides.

Use of mulches.

• Mulching is one of the simplest and most beneficial practices that are most commonly adopted in temperate fruit orchards (Plates 6.1 & 6.2).
• It is a recognized practice that saves soil and moisture, and is used in most orchards.
• It is simply a protective layer of a material that is spread on top of the soil (as discussed in chapter 3).

Plate 6.1: Dry grass mulching Plate; 6.2: Black polythene mulching in apple orchard

Sod culture with herbicidal strips.

• Vegetation near the tree competes for nutrients and water, resulting in reduced growth, yield and size of fruit.
• The best strategy for managing the orchard floor is to use a non-competitive grass alley with a vegetation-free strip in the tree row (Plate 6.3).
• The vegetation-free strip can be established and maintained with herbicides in this section.

Plate 6.3: Grass alley with a vegetation-free strip

Benefits:

• The permanent grass sod between the tree rows will minimize soil erosion, increase soil aeration and permeability, and support equipment movement through the orchard during wet weather.
• The vegetation-free strip eliminates competition for water and nutrients.
• Herbicides are directed at the soil and weeds underneath the tree.
• The vegetation-free strip method is superior to all other orchard floor management options. Vegetation under the tree competes for nutrients and water, resulting in reduced growth, yield and size of fruit.
• Another option is the use of organic mulches in the tree row. Examples of mulching materials include straw, wood chips, and grass residue from mowing.

Advantages:

• These mulches will suppress weed emergence.
• Mulches can improve the water-holding capacity of soils.

Some concerns regarding the use of organic mulches:

• The most significant problem is that mulches create an ideal habitat for voles.
• Additional nitrogen may be needed to support the microorganisms that aid in decomposition of organic mulches.
• In poorly drained or water-logged soils, organic mulches increase the likelihood of Phytophthora root rot.
• Mulches can be expensive and difficult to obtain. However, synthetic mulches made from polyethylene, or polyester can be placed in the tree row around the base of the trunk or as a narrow strip down the row. Some newer synthetic mulch allows water and air to pass through the mulch.