Blog.Himachal Fruits™

Information about Horticulture & Agriculture just to help growers

Root Rot,Crown and Collar of Apple

Posted on | August 21, 2020 | No Comments

Symptoms

When (Root Rot/Color Rot) Phytophthora rots are suspected, inspect the of the tree and excavate soil from around the trunk and root system to examine tissues for crown and root rot symptoms. Upon peeling back, the outer bark of the trunk, the normally green cambium will appear orange or brown. Roots may be a dark brown or orange and may slough off from the primary root. If you look at the plant growth is stunned overall as shown in the picture.

Organism and Disease Cycle

Several species of soil borne Phytophthora oomycetes (fungal-like organisms) cause root,color and crown rots. Many of these species are common in most orchard soil.

These oospores are extremely resilient and can remain viable in the soil for long periods of time. When soils are wet oospores germinate forming thin threads of fungal hyphae which can infect plant roots. When soils are saturated another type of spore called a zoospore develop within sporangia.

Zoospores are swimming (moving) spores. They can move through the soil water to find new roots to attack.

Spores can also move with water across the surface of the soil, thus transmitting the pathogen over large parts of a block quickly.

The longer the soil stays wet the higher the risk of infection.

Cultural Controls

  • Control soil moisture.
  • Better choose well drained soils for orchards.
  • Improve and maintain healthy soil structure.
  • Reduce irrigation water.
  • One of the best solutions, choose resistant rootstock.

 Biological and Bio-pesticide Controls

Maintain large, active beneficial populations in soil, it means reduce synthetic fertilizers. hhrt

Many soil bacteria and fungi can be antagonistic to root rot fungi. For example, a fungus called Trichoderma, pseudomonas fluorescens has been seen to reduce soil-borne disease infections. In general, additions of organic matter such as compost, grass clippings, and other material provide a food source for the soil food web helping to maintain large active populations of beneficial antagonists.

Biopesticides and biological pesticides. Biopesticides are certain types of pesticides derived from natural materials, such as animals, plants, bacteria, and certain minerals. One group of biopesticides are biologicals. Biologicals are composed of beneficial microorganisms, including specialized fungi, bacteria, and actinobacteria. Use of biopesticides (including biologicals) applied as a pre-plant dip or through the dripline on newly planted trees may help defend young trees from soil-borne disease infection.

Himachal Fruits Recommended products*

1.Emrald Nivaran + Emrald Maulika.

2.Rot Arrest (Used after Fermenting).

3.G5 Granules application has root rot preventive properties also condition soil.

*Consult Himachal Fruits before use.

 

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