MSc

The thesis work on “Nano nitrogen and custom blended thermochemical organic fertilizer for nutrient management in gerbera (Gerbera jamesonii Bolus)” was carried out inside the naturally ventilated polyhouse in the Department of Floriculture and Landscaping, College of Agriculture, Vellayani during December 2021 to October 2022. The study aimed at evaluation of combined application of nano nitrogen liquid fertilizer and custom blended thermochemical organic fertilizer on growth and yield of gerbera (Gerbera jamesonii Bolus).
Three-month-old tissue culture plantlets of gerbera variety ‘Natasha’ were procured and planted in growbags inside the naturally ventilated polyhouse with UV stabilized roofing. Planting was done in 40x40 cm polybags which were arranged systematically inside the poly house. The experiment was laid out in CRD with 10 treatments and 15 replications. For the treatments from T1 to T8, growbags were filled with soil, coir pith and thermochemical organic fertilizer (TOF) in 1:1:1 proportion on volume basis. The potting mixture comprising equal proportion of soil and coir pith was used for the absolute control (T10). Potting mixture containing equal proportion of soil, sand and coir pith along with PGPR 1 @ 2% of the substrate was used for the control (T9).
The treatments T1 to T8 were applied at fortnightly intervals starting from 3 weeks after planting. Top dressing for T1 to T8 was done with custom blended thermochemical organic fertilizer (CBF), which was produced through the patented suchitha technology. Custom blending was done in three modes ie., blending with rajphos and MOP (CBF-PK), blending with nano-urea, rajphos and MOP (CBF-NPK) and blending with urea, rajphos and MOP (CBF-UPK). Fertilizer application was restricted to supply nutrients in 2 doses ie, 1 g N: 0.8 g P2O5: 1.6 g K2O (T1 to T4) or 1.2 g N: 0.8 g P2O5: 2 g K2O (T5 to T8) per plant at fortnightly intervals starting from 3 weeks after planting. Top dressing was done with foliar nano urea and soil application of CBF-PK (for T1 and T5), soil application of CBF-NPK (for T2 and T6), foliar urea and soil application of CBF-PK (for T3 and T7) and soil application of CBF-UPK (for T4 and T8). The control plants were maintained by monthly soil application of 1.6g N, 1.6 g P2O5 and 1.6 g K2O, bimonthly application of 30 g dried cow dung manure and bimonthly foliar application of 13:27:27 (0.4%) @ 100 ml per plant.
T5 (Fortnightly foliar application of nano urea and soil application of thermochemical organic fertilizer custom blended with rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O per plant) was found to be significantly superior and recorded the highest values for vegetative parameters like plant spread (152.17 cm), number of leaves per plant (12.58), leaf length
(31.09 cm) and leaf area (142.39 cm2). However, leaf breadth (9.53 cm) was significantly higher in T3 (foliar application of urea and soil application of thermochemical organic fertilizer custom blended with rajphos and MOP @ 1 g N: 0.8 g P2O5: 1.6 g K2O per plant). The highest number of suckers per plant (1.49) was also recorded in T5 (fortnightly foliar application of nano urea and soil application of thermochemical organic fertilizer custom blended with rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O per plant).
Regarding the number of days taken for bud initiation, all the treatments were on par with T8 (16.49 days) except T4 and T10. The treatments T6 (11.48 days), T8 (11.54 days), T7 (11.54 days) and T5 (11.55 days) were on par for number of days taken from bud initiation to harvest. More number of flowers were produced during 5th and 6th month of planting.
T8 (soil application of thermochemical organic fertilizer custom blended with urea, rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O) recorded the longest bloom life (11.75 days), the largest flower diameter (7.73 cm) and the longest flower stalk (33.77cm). T6 (soil application of thermochemical organic fertilizer custom blended with nano urea, rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O) and T7 (foliar application of urea and soil application of thermochemical organic fertilizer custom blended with rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O) recorded the highest girth of flower stalk (1.06 cm) and were on par with T5 and T8. The visual appeal was observed based on three characters viz., general appearance, size of the flower and colour development. T8 ranked first for visual appeal.
T8 (soil application of thermochemical organic fertilizer custom blended with urea, rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O) produced the highest number of flowers per plant per month (2.49) and it was followed by T5.
Post-harvest studies indicated that T8 significantly improved the vase life (8.5 days) and water uptake (14.48 ml). It also recorded the lowest value for physiological loss in weight (26.33 g) which was on par with T7.
Analysis of the growing media after the experiment showed that T6 (soil application of thermochemical organic fertilizer custom blended with nano urea, rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O) recorded higher values for pH, EC, organic C, available N, P and K in general.
Plant sample analysis after the experiment revealed that the N content was significantly superior in T5 (3.84 %). For all the treatments except T9 and T10, P content in the leaf samples was found to be on par with T5 (0.55 %) and K content was the highest in T7 and T8 (4.25 %).
The highest BC ratio was obtained for T5 (1.77) which was followed by T8 (1.76).
The study revealed that fortnightly foliar application of nano urea and soil application of thermochemical organic fertilizer custom blended with rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O per plant (T5) improved all vegetative parameters in gerbera variety ‘Natasha’ except leaf breadth and T8 (soil application of thermochemical organic fertilizer custom blended with urea, rajphos and MOP @ 1.2 g N: 0.8 g P2O5: 2 g K2O per plant) significantly improved floral parameters like flower diameter, length of flower stalk , flower yield, bloom life and visual appeal.