a. Discuss the root knot disease of tomato plants under the following headings: i. causal...
a. Discuss the root knot disease of tomato plants under the following headings:
i. causal organism
ii. mode of transmission
iii. two symptoms
iv. two prevention and control measures
b. Describe three effects each of the following farming practices on the soil:
i. fertilizer application
ii. clean clearing
iii. overgrazing
c. Mention three agricultural uses of land
Explanation
ai. Root knot nematode/ Meloidogyne spp
aii. Nematodes are soil borne/through the soil
aiii.
-Enlargement of certain cells of the roots in form of knots
-Wilting of plants
-Retarded growth
-Reduction in yield
aiv.
-Practicing crop rotation
-Use of resistant varieties
-Use of nematicides
-Good farm sanitation
-Soil sterilization
bi.
-Adds nutrients to the soil/enhances the productive capacity of the soil
-Continuous use of nitrogenous fertilizers eg sulphate of ammonia increases soil acidity
-Excessive use of fertilizers reduces the availability of some essential plant nutrients eg potassium and calcium
-Prolonged use of fertilizers leads to a reduction in some soil microorganisms
-Excessive use of fertilizers leads to groundwater contamination
bii.
-Destruction of soil structure/soil compaction
-Exposes the soil to erosion
-Encourages leaching of soil nutrients
-Results in increased rate of evaporation
-Leads to increase in soil temperature
-Reduces the activities of soil microorganisms
-Reduces the organic matter content of the soil
-Results in imbalance of the ecosystem
biii.
-Leads to soil compaction
-Exposes the soil to agents of erosion
-Increases the evaporation rate of soil water Results in low soil fertility
-Destroys soil structure
-Reduces the rate of soil water infiltration
-Leads to leaching of soil nutrients
c.
-Crop production
-Livestock production
-Forestry
-Heliculture/snail farming
-Horticulture
-Wildlife conservation/game reserve
-Aquaculture fish farming
-Apiculture/bee keeping