GENERAL KNOWLEDGE

GK

ECOLOGY BIODIVERSITY CONSERVATION ENVIRONMENTAL ISSUES

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The soil borne plant pathogens could be controlled by
A
Lowering pH
B
Increasing pH
C
Adding lime
D
All of the above
Explanation: 

Detailed explanation-1: -Plants infected by soil-borne pathogens suffer from root rot, root blackening, wilt, stunting or seedling damping-off. Losses due to soil-borne pathogens can be prevented to some extent by planting the same crop only every 4–5 years and by using pathogen-free seeds.

Detailed explanation-2: -Soil type. Certain pathogens are favoured by loam soils and others by clay soils. Phymatotrichum root rot attacks cotton and some 2, 000 other plants in the southwestern United States. This fungus is serious only in black alkaline soils-pH 7.3 or above-that are low in organic matter.

Detailed explanation-3: -Soil solarization, which is a new method, has proven to be effective for controlling plant parasitic nematodes (7, 9, 14, 16), soilborne pathogens and weeds (1, 8, 9, 11, 12, 15), and to increase plant growth and crop yields (3, 8, 9, 10, 17).

Detailed explanation-4: -Soil pH also affects the host plant. If the pH is too extreme, the plant will be stressed and may be less resistant to attack by the pathogen. Soil pH may affect the composition of the root exudates, which attract soilborne pathogens. Soil pH will also affect the availability of nutrients to the plant.

There is 1 question to complete.