MSc

A field experiment was conducted at College of Agriculture, Vellayani)
to assess the effect of varying levels of solar radiation and silica on the
performance of upland rice cultivars. This study also aimed at computing the
economics of upland rice cultivation and silica application. The treatments
included three shade levels (0, 20 and 40 per cent), two levels of silica (no
silica and 100 kg ha-' silica) and four varieties (Swarnaprabha, A4-4-2, A4-1-
3 and Matta Triveni). Shade was imposed by using shade nets of appropriate
shade levels and silica was applied as sodium silicate. The experiment was
laid out in split-split plot design.
The results of the investigation are summarised below.
Solar radiation influenced growth attributes significantly. A
significant reduction was observed in tillering, LAD, proline content, SL W,
LAI, culm strength, root weight, root length and root-shoot ratio as the shade
advanced to 20 and 40 per cent levels. Among the growth attributes only
plant height and chlorophyll content increased significantly with increase in
shade level.
Yield contributing characters were also significantly influenced by
solar radiation. Maximum number of productive tillers, spikelets per panicle,
thousand grain weight, length and weight of panicle was observed in the open
situation.
A significant reduction in grain yield was observed with increase in
shade level. Maximum productivity was registered at 0 per cent shade level
which was 68 and 387 per cent higher than 20 and 40 per cent shade levels.


Same trend was observed in DMP. Maximum straw yield was recorded at 20
per cent shade which was on par with zero per cent shade.
Application of silica increased total chlorophyll content, chlorophyll
a/b ratio, root length and root weight significantly. Grain and straw yield
increased significantly by 22 and 18 per cent with the application of silica.
In the open situation A4-4-2 recorded maximum grain yield. At 20
per cent shade level A4-4-2 and Matta Triveni top seeded other cultivars.
Swarnaprabha recorded maximum straw yield In the open situation.
Compared to open situation at 20 per cent shade level straw yield increased
significantly in A4-4-2 and Matta Triveni.
Sodium silicate was found as an un-economical source of Si for upland
nee. Silica nutrition can be made economical by substituting sodium silicate
with a cheaper source of silica.
B : C ratio reduced significantly with increase in shade level. The
treatment LoS I V I registered maximum B : C ratio of 1.35.