Yoshida - 1981 - Fundamentals of Rice Crop Science
Yoshida - 1981 - Fundamentals of Rice Crop Science
Yoshida - 1981 - Fundamentals of Rice Crop Science
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NUTRITIONAL DISORDERS 191<br />
Table 4.9. Nutritional disorders <strong>of</strong> rice reported from various<br />
rice-growing countries. a<br />
Country Physiological disease Possible cause(s)<br />
Burma Amiyi-Po K deficiency<br />
Myit-Po<br />
P deficiency<br />
Yellow leaf<br />
S deficiency<br />
Ceylon Bronzing Fe toxicity<br />
Columbia Espiga erecta ?<br />
Hungary Bruzone ?<br />
India Khaira disease Zn deficiency<br />
Bronzing<br />
Fe, Mn, H 2 S toxicities<br />
Yellowing ?<br />
Indonesia Mentek Virus disease<br />
Japan Akiochi H 2 S toxicity, K, Mg,<br />
Si deficiencies<br />
Akagare I<br />
K deficiency<br />
(Fe toxicity)<br />
Akagare II<br />
Zn deficiency<br />
Akagare Ill<br />
I toxicity<br />
Aodachi ?<br />
Hideri-Aodachi ?<br />
Straighthead ?<br />
Korea Akiochi H 2 S toxicity, K, Mg,<br />
Si deficiencies?<br />
Malaysia Penyakit Merah (yellow Virus disease<br />
type)<br />
Pakistan Pansukh ?<br />
Hadda<br />
Zn deficiency<br />
Portugal Branca Cu deficiency?<br />
Taiwan Suffocating disease Virus disease<br />
United Straighthead H 2 S toxicity<br />
States Alkali disease Zn deficiency<br />
a Modified from Tanaka and <strong>Yoshida</strong> (1970).<br />
If a soil is high in active iron, especially when it is also high in easily reducible<br />
manganese, it resists the lowering <strong>of</strong> redox potential, and the iron level remains<br />
low. Such soils have a high phosphorus absorption coefficient especially when<br />
they are high in active aluminum; phosphorus deficiency therefore tends to<br />
develop. If such soils contain a large amount <strong>of</strong> organic matter, the iron content<br />
can be very high and the rice plant may suffer from both phosphorus deficiency and<br />
iron toxicity. These disorders occur on soils formed from the early stages <strong>of</strong> the<br />
laterization <strong>of</strong> basic rocks.<br />
If a soil contains a large amount <strong>of</strong> easily reducible manganese, manganese<br />
toxicity may develop. However, such cases are probably not common because the<br />
rice plant tolerates a tissue manganese content as high as 7,000 ppm.<br />
If the active iron content is not high, the soil redox potential falls quickly, the<br />
iron concentration in the soil solution rises sharply, and iron toxicity may develop.