TY  - BOOK
AU  - Shaji KV
AU  - Rajendran P (Guide)
TI  - Differential Response Of Rice Cultivators to Potash Application In The Rice Soil Of Onattukara
U1  - 631.4 
PY  - 1996///
CY  - Vellayani
PB  - Department of Soil Science and Agricultural Chemistry, College of Agriculture 
N2  - It is known that there exists varietal differences in tolerance to 
nutrient deficiency conditions among rice cultivars. The sandy soils of 
Onattukara region is inherently deficient in K which resulted in a higher 
POP recommendation for rice in terms of K application. So to exploit 
the varietal differences of rice in deficiency tolerance of K, a field 
experiment was undertaken to screen 48 rice cultivars belonging to tall 
indicas and dwarf high yielding groups of varying growth durations. 
The experiment was laid in 384 microplots in "Group Balanced. Block 
in Split Plot Design" with four K levels and two replications. The 
various growth and yield attributes and yield were studied with a view 
to locate varieties which could produce similar yields even at lower 
levels of K. 
The results indicated that in general the varietal influences on 
most of the growth characters in all the four groups were profound. 
Moreover positive and significant effect of K doses were observed. 
However LAI showed no variation with differing levels of K. 
Differential response of varieties to varying K doses as manifested by 
root spread was considerable only in medium duration varieties while 
 
an appreciable difference was noticed in the root spread in all the 
groups. Root length, thin root-thick root ratio and root CEC appeared 
to be varietal characters which increased with increasing levels of K. 
The plant nitrogen content at varying levels of K was more of 
a varietal character. On the contrary, long duration varieties exhibited 
significant variation in P content with differing K levels at all critical 
stages of crop growth. Both K levels and genetic variability of the 
varieties were equally important in deciding the K content in plants and 
the response to added K was of a higher magnitude. 
All but long duration varieties responded positively and 
significantly to K in terms of productive tiller formation and generally 
tall indicas produced relatively longer panicles than dwarf varieties. 
Higher levels of K also led to the production of heavier grains. Yield 
increases over control was comparatively higher in tall short duration 
varieties than. any other varieties for higher levels of K. Differential 
response of K was highly pronounced in tall short duration varieties 
with Ptb23, Ptb29, Cul 7005-6-1, Cul 7004-3-1, and Cul 7006-2-1 giving 
comparable yields at 22.5 kg K20 ha-1 as that of the POP 
recommendation. However as this experiment was done in microplots 
the final recommendation of varieties tolerant to K deficiency could be 
done only after extensive studies in large plots and in farmers' fields 
during various seasons. 


UR  - http://krishikosh.egranth.ac.in/handle/1/5810084659
ER  -