Page 70 - Agriculture_Form_3

Agriculture for Secondary Schools

FOR ONLINE READING ONLY

Figure 4.14: Effects of brown spot disease in a paddy plant

Rice dwarf disease (RDD): This is a viral disease
transmitted by leafhoppers. The symptoms
observed in paddy plants include shortened
internodes, dark green leaves, and poor tillering,
which result in stunted plant growth. To manage
RDD, it is recommended to use resistant rice
varieties, control leafhopper populations, and
remove infected plants to prevent further spread.
Figure 4.15 shows a paddy field affected by Rice
dwarf disease.
Figure 4.15: Paddy field
affected by rice dwarf
disease

Rice yellow mottle disease (RYMD): Rice
yellow mottle disease is a viral disease
transmitted by beetles and mechanical contact.
It causes yellow streaks on leaves, stunted
growth, and reduced grain yield. To manage
RYMD, use resistant varieties, control insect
vectors, and practice crop rotation to limit the
spread of the disease. Figure 4.16 shows paddy
plants affected by yellow mottle disease.

Figure 4.16: Rice yellow
mottle disease symptoms

Student’s Book Form Three 61

17/09/2025 14:11
AGRICULTURE F3.indd 61 17/09/2025 14:11
AGRICULTURE F3.indd 61