MSc

A study was conducted during 1995-96 at Coconut Research Station,
Balaramapuram of Kerala Agricultural University to asses the nutrient status of
.
the soil and plant in West Coast Tall coconuts planted at three different
spacings and manured with three levels of macro nutrients. The treatments
were three spacings (5 m x 5 m, 7.5 m x 7.5 m and 10 m x 10 m) and three
fertilizer levels (control i.e., zero NPK, the lower level i.e., 340 g N + 225 g
P205 + 450 g K20 per palm per year and the higher level i.e., 680 g N + 450 g
P205 + 900 g K20 per palm per year). The basic experiment was started in
1964 and being continued. The data collected during the study (1995-96) was
statistically analysed and the results are presented here under.
Closer spacing increased height of palms. The spacings of7.5 m x 7.5 m
was statistically superior since it gave the highest nut yield per palm per year.
Manuring increased height of palms, girth and leaf production. At the highest
level of NPK closer spacing of 5 m x 5 m could give the highest yield per unit
area. Female flower production was higher under 7.5 m x 7.5 m spacing.
Fertilizer application also increased flower production. Fruit setting was not
influenced by palm density and fertilizer application significantly increased fruit
setting.
Number of nuts per bunch was higher at the spacing of 7.5 m x 7.5 m
and progressively increased with manuring. The weight and volume of
unhusked nut was the lowest at the closest spacing and in unfertilized palms.


There was increase in weight of husk with increase in spacing. Similarly there
was an increase in the ratio of weight of husk to unhusked nut with increasing
spacing. Maximum thickness and weight of kernal was recorded at the spacing
of 7.5 m x 7.5 m. Copra out turn was more at the spacing of 7.5 m x 7.5 m.
In manured palms there was a higher copra out turn per hectare contributed by
the higher yield. The oil content of copra was negatively correlated with per
palm yield.
Available NPK of soil decrease with wider spacing. The soil nutrient
status increased with application of macronutrients and the accumulation of
fertilizer was more in the upper layer of 0 to 25 cm. There was decline in NPK
status with increase in depth. The Ca and Mg content of soil decreased with
increase in spacing up to 7.5 m x 7.5 m. Both Ca and Mg content of soil
decreased with increase in macro nutrient application. Ca content of soil
decreased with increase in depth. However, the decrease of Mg content was
seen only up to 50 cm depth. Available micro nutrients (Fe, Cu, Mn and Zn)
decreased with increase in spacing and application of fertilizers. Available Fe,
Cu and Mn content of soil decreased with increase in depth.
Nand P content of leaf of coconut increased with wider spacing.
However K content decreased with spacing. All the three macro nutrients
increased with increase in fertilizer application. Ca and Mg content of leaf also
increased with increase in spacing and fertilizer application. By fertilizer
application Fe, Mn and Cu content of leaf increased whereas Zn and Na
decreased.