MSc

Chilli is a very important vegetable crop and has a great demand in the processing industry and export market. Chilli crop is more responsive to fertilizer application. Application of fertilizers in excess not only causes environmental problems but also reduces nutrient use efficiency, increases the cost of production and reduces the benefit-cost ratio. Nanotechnology is a newly emerging tool for solving these problems. Nano fertilizer has a particle size less than 100 nm. Due to its small size and water soluble nature it is easily absorbed by plants. The present study was carried out to understand the influence of soil and foliar application of nano NPK fertilizer and to compare with conventional fertilizers on growth, yield and quality attributes of chilli.

The investigation on “ Physiological studies on growth, yield and quality enhancement of chilli (Capsicum annum L.) under different nutrient management
” was conducted at Regional Agricultural Research Station, Pillicode from September, 2018 to February, 2019. The experiment consisted of nine treatments with three replications laid out in randomized block design. The treatments were T1 : Control (soil test based nutrient management); T2 : Nano NPK granules (4:4:4); T3 : T1 + Nano NPK foliar @ 0.5 %; T4 : T1 + NPK 19:19:19 foliar @ 0.5 %; T5 : T2 + Nano NPK foliar @ 0.5 %; T6 : T2 + NPK 19:19:19 foliar @ 0.5 %; T7 : Organic POP (KAU, 2009); T8 : Organic POP + Nano NPK foliar @ 0.5 % and T9 : Absolute control. Nano NPK granules were applied as a basal dose and also as top dressing at 30 and 60 days after transplanting @ 0.33 g/plant. Foliar spray of Nano NPK and NPK 19:19:19 were given at 35, 65, 80 and 95 days after transplanting.

Morphological observations namely plant height, leaf area per plant, number of leaves per plant, number of branches per plant, number of fruits per plant and fruit length were recorded to be maximum in the treatment, nano NPK granule

with NPK 19:19:19 foliar spray (T6) followed by nano NPK granule with nano NPK foliar spray (T5). Integrated use of nano NPK granules with nano NPK foliar spray application (T5) enhanced the duration of crop and increased the root volume followed by T6 .

Higher values of growth indices such as RGR, LAI and total dry matter production was observed in T6 (nano NPK granule and NPK 19:19:19 foliar spray) followed by T5 (nano NPK granules with nano NPK foliar spray). Physiological parameters such as transpiration rate, stomatal conductance, chlorophyll content, leaf relative water content, specific leaf weight, quantum yield (Y(II)), Fv/Fm and electron transport rate (ETR) were statistically on par in all the treatments and was significantly higher than absolute control (T9).

Differential application of NPK 19:19:19 foliar spray (T6) and nano NPK

foliar spray (T5) along with nano NPK granules increased the fruit yield by 28.07

% and 26.54 % respectively over control (T1).


Organic management (T7) alone and organic management with nano NPK foliar spray (T8) recorded 25.54 % and 16.04 % lesser fruit yield than control (T1). However fruit quality parameters like ascorbic acid and oleoresin contents were maximum in the treatment receiving an organic management with a foliar spray of Nano NPK (T8). Maximum benefit cost ratio (1.73) was recorded in treatment T6 (nano granule with 19:19:19 foliar spray) followed by treatment T5 (nano granule with nano NPK foliar spray (1.61) compared to other treatments.

The results obtained from the experiments indicated that the application of nano NPK fertilizer both as soil and foliar treatments has a direct positive effect on morphological and yield parameters, which is on par with the treatment involving soil application of nano NPK granules and NPK 19:19:19 foliar spray.