Discuss pests and diseases associated with wheat

      

Discuss pests and diseases associated with wheat

  

Answers


Faith
Pests
-Include wheat saw flies, hessian flies, aphids and cut worms
-Wheat saw flies lay eggs inside stems causing the stem to split and may result in lodging of the plant resulting in heavy losses.
-Can be controlled by use of resistant varieties (Those with solid stems), crop rotation to break the life cycle of the pests.

Diseases
i. Wheat rusts
Two forms of rusts which are caused by many kinds of fungi
a. Black rust ( Pucciniagraminis)
-Mainly in temperate countries and is controlled by use of resistant variety
b. Yellow rust (Pucciniastriformis)
The most common of wheat rust
Symptoms:
-Distinguished from other cereal rusts by the deep cadmium yellow colour of pustules which are closely crowded together in parallel line on the leaves.
-The weather and soil conditions determine the intensity of yellow rust attack. Cool and moist weather favour the development of yellow rust.
-The disease is most severe in fertile soils especially with adequate supply of N fertilizer.
-The disease is controlled by use of resistant varieties.

ii. Smut
-Caused by fungi.
a. Covered smut (Tilleria caries).
-It is only detected when the affected plant come into flower.

Symptoms:
-Attached ears are slightly darker green than healthy ears.
-Wheat grains are deep green and when crushed are found to be filled with geasy mass of spores
with a fishy smell.
Control:
-Seed dressing before sowing with liquid formulation of organo-mercuric compound.

b. Loose smut (ustilagonuda). This is detected when plants are in full flower stage.

Symptoms:
-By the time grains start swelling all that remains of ear of affected plant is blackened mass of fungi spores.

Control:
Seed dress with liquid formulation of organic mercuric compounds
Warm water treatment of seeds. Seeds are first immersed in cold water for 4hours and then taken out for few minutes and submerged in a tank of warm water of 52-540C for 10 minutes.


Titany answered the question on August 16, 2021 at 09:28


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