MSc

An experiment was conducted to study the "Effect of major nutrients on
the yield and quality of nuts in graft raised cashew" at Cashew Research Station
Madakkathara Kerala. The treatments consisted of three levels each of N, P and
K on eight year old cashew trees. The salient findings are abstracted below.
The study revealed that increasing levels of nitrogen significantly
increased the height and spread of cashew trees, while the girth was significantly
increased by the interaction effects of nitrogen and potassium.
The yield parameters such as number of flushes, number of leaves per
flush, number of panicles and the number of nuts per panicle were significantly
enhanced by the application of nitrogen at increasing levels, while the application
of phosphorus at increasing levels also significantly increased the number of nuts
per panicle.
The yield of cashew nuts and apples were significantly increased due to
the highest level of nitrogen applications. Application of potassium at the highest
level also significantly increased the apple yield per tree.
Weight and volume of cashew apples was significantly increased by the
application of increasing levels of potassium but nitrogen application was found
to significantly decrease the weight of fruits. The juice percentage was positively
and significantly influenced by the application of nitrogen and potassium.
Potassium applications were found to significantly increase the nut length
and weight while nitrogen applications were found to reduce the nut weight.
Shelling percentage of cashew nuts was enhanced by the application of nitrogen
and potassium at increasing levels. The kernel weight was increased due to the
application of potassium.








Ascorbic acid content of cashew apples was positively influenced due to
the application of increasing levels ofNPK. The Total Soluble Solids of the apple
was significantly enhanced by the application of nitrogen.
Applications of nitrogen alone and in combination with phosphorus were
found to increase the protein content of kernels. The carbohydrate, Non-reducing
sugars and reducing sugars content of kernels were significantly enhanced by the
application of different levels of nitrogen.
Increase in the soil major nutrient content due to the individual effects of
nitrogen, phosphorus and potassium applications were also observed. The leaf
phosphorus and potassium content was enhanced specifically due to the
application of increasing levels of phosphorus and potassium respectively, while
the nitrogen content of leaves was positively influenced by the application of
nitrogen and phosphorus.
The average nutrient off-take through nuts and apples was computed to be
279.43, 4l.58 and I 86.40g of nitrogen, phosphorus and potassium respectively.
The average nutrient off take per tree through nuts from an average yield of 2.89
kg tree" was found to be 93.56, 2.89 and 48.85g of nitrogen, phosphorus and
potassium respectively and through apples was found to be 185.87, 38.69 and
137.54g of nitrogen, phosphorus and potassium respectively from an average
yield of 18.20 kg tree".
In 'general, among the major nutrients applied at different levels
only nitrogen had shown exceedingly high effects in sustaining the growth, yield
and quality parameters. The yield and quality parameters were also seen to be
affected to a certain extent by potassium applications but the response of the crop
to phosphorus was seen to be exceedingly limited.