PhD

An investigation entitled “Nutrient and moisture optimization in banana (Musa AAA. Grand Nain)” was undertaken with the objectives to standardize the nutrient and irrigation schedule of Grand Nain banana, to study its phenology in relation to various agro-meteorological parameters and to work out the economics. The investigation comprised two separate experiments. The first experiment on „Nutrient - moisture interaction study‟ was conducted for two years from June 2014 to May 2016. The second experiment on „Phenology study of Grand Nain banana‟ from January 2014 to December 2015. Both the experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani.
The first experiment was laid out in split plot design with sixteen treatments and four replications. The main plot treatments were four irrigation levels, viz., I1, I2, I3 and I4 based on IW/CPE (Irrigation water/ Cumulative pan evaporation) ratios of 0.4, 0.6, 0.8 and 1.0 and subplot treatments were four combinations of two nutrient levels (N) and two times of application (S). The two nutrient levels were N1: 200: 200: 400 g N: P2O5: K2O plant-1 year-1 (KAU, POP for varieties other than Nendran and modified as per soil test values of the experimental site) and N2: 160: 40: 640 g N: P2O5: K2O plant-1 year-1 (Based on nutrient uptake values of banana cv. Grand Nain). The treatment N1 was modified as 212: 50: 332 g N: P2O5: K2O plant-1 year-1 based on soil test values. The two time of applications (S) were S1 (N and K in 2 equal splits at 2 and 4 months after planting (MAP)) and S2 (N and K in 4 equal splits at 2, 3, 4 and 5 MAP). Drip irrigation was given based on cumulative pan evaporation. The second experiment was laid out in RBD with twelve treatments (twelve dates of planting) and four replications. Planting was done on 28th day of every month from January onwards. Except the initial establishment stage, the crop was raised as rainfed. Tissue culture plants were planted at a spacing of 1.8 m x 1.8 m. Entire FYM @15 kg plant-1 and P were applied as basal in both the experiments.
Analysis of the crop growth characters at different growth stages (4 and 6 MAP and at harvest), yield attributes, quality parameters and shelf life revealed the superiority of the irrigation level I4 and nutrient level N2. The time of application and N x S and I x N interactions were also significant. The treatments I3 and I4 recorded the highest bunch weight in first and second year respectively. I3 was on a par with I4 during first year. The bunch weight was the highest in N2 during both the years. Application of nutrients in 4 splits (S2) recorded the highest bunch weight and significantly superior to S1 in second year. Pooled analysis also revealed that the bunch weight and yield were the highest in I4 (26.20 kg plant-1and 80.85 t ha-1), but on a par with I3. Among the nutrient levels, N2 recorded the highest bunch weight and pooled yield (24.60 kg plant-1and 75.92 t ha-1). Irrigation and nutrient levels also had significant influence on the plant nutrient uptake and nutrient status of soil after the experiment. The total water requirement (WR) was the highest in I4. Water use efficiency (WUE) was the highest in I3 during both the years and was on a par with I4, while water productivity was the highest in I3 during first year and in I4 during second year. Gross income, net income and B: C ratio were the highest in I3 and I4 during first and second year, respectively. Sigatoka leaf spot disease was the major disease observed during the study. No pest was observed during the crop period.
The study on phenology revealed that planting dates have significant influence on growth characters, yield attributes, shelf life and yield. The bunch weight plant-1 was the highest (29.50 kg) in February (T2) planting which was on a par with July (T7) planting. All the quality parameters except total soluble solids (TSS), ascorbic acid and non reducing sugars varied significantly with planting dates. Fruit quality was superior with February (T2) and July (T7) plantings. The Agro meteorological parameters such as growing degree days (GDD), heliothermal units (HTU), photothermal units (PTU) and heat use efficiency (HUE) were computed. The GDD for vegetative phenophase varied
between 2765 0C d and 3921 0C d and for reproductive stage it was 968 0C d and 1446 0C d. The HTU and PTU requirements were the lowest and the HUE was the highest in February (T2) planting. February (T2) planting recorded the shortest crop duration (277days) with the shortest period for shooting and emergence to harvest (E-H) while November (T11) planting the longest.
It is concluded that application of nutrients @ 160: 40: 640 g N: P2O5: K2O plant-1 (N2) with full P as basal and N and K in two equal splits at 2 and 4 MAP (S1) with irrigation at 1.0 IW/CPE (I4) can be recommended for Grand Nain banana for high yield, economics and quality produce. Last week of February is the ideal planting time for getting high yield and quality produce in Grand Nain banana with shorter phenophases in the southern agro climatic conditions of Kerala.