Precision farming techniques for tuberose (Polianthes tuberosa L.)

Abstract

A study entitled “Precision farming techniques for tuberose (Polianthes tuberosa L.)” was undertaken during 2022-2024 at Department of Floriculture and Landscaping, College of Agriculture, Vellayani. The main objective of the study was standardization of manuring, drip irrigation, fertilizer levels, spacing and mulching in tuberose hybrid Arka Prajwal. The study consisted of two experiments. The first experiment on “Standardization of manuring, irrigation and fertilizer level in tuberose” was laid out in split-split plot design with 16 treatment combinations and replicated four times. The main plot treatments were two manures (M1-FYM and M2- Poultry manure), the subplot treatments were two levels of irrigation (I1- IW/CPE 1 and I2-IW/CPE 0.8) and the sub sub plot treatments were four levels of fertigation (F1- 75 per cent recommended dose of N and K, F2- 100 per cent recommended dose of N and K, F3- 125 per cent recommended dose of N and K and F4- half N and full K of recommended dose). Control plot was laid out based on conventional farming practices. FYM @ 30 t ha-1 and poultry manure based on nitrogen equivalence were applied. Soil test-based recommendation for fertigation was derived based on 100: 50: 50 kg ha-1 as per KAU POP. Full dose of phosphorus was applied at the time of land preparation. Urea and sulphate of potash were used as fertilizer source for fertigation. Observations were recorded on vegetative, floral, post-harvest characters, plant and soil nutrient content. Among manures, poultry manure recorded superior results as compared to FYM for most of the parameters that were studied. Levels of drip irrigation had no considerable effects on plant characters, however in consideration with moderate water usage irrigation at IW/CPE 0.8 can be recommended. Within different levels of fertigation, drip fertigation of ½ N and full K had given the best results. Application of higher dose of fertilizers had no remarkable effects over growth, yield and quality. Results revealed that combined effect of poultry manuring, drip irrigation and fertigation proved superior to their individual effects. Vegetative parameters viz., plant height, no. of leaves, leaf length, leaf breadth, leaf area and LAI were significantly improved in treatment M2I2F4 (poultry manure+ IW/ CPE 0.8+ ½ N and full K through fertigation). As far as floral characters are concerned, M2I2F4 had positive influence on early spike emergence, minimum days to first floret opening and 50% flowering. Quality attributes of spikes such as spike length, rachis length, girth of peduncle, number of florets per spikes and number of spikes per hill exhibited improvement under M2I2F4. This treatment also had positive influence on length, diameter and weight of florets and loose flower yield. Among post- harvest parameters, fresh weight, vase life, water uptake and concrete recovery also higher under M2I2F4. Hence application of poultry manure, irrigation at IW/ CPE 0.8 and ½ N and full K through fertigation can be recommended for improved growth, yield and quality of tuberose hybrid Arka Prajwal. Synergistic effect of organic manuring, drip irrigation and fertigation with water soluble fertilizers paved the way for effective and efficient utilization of water and nutrients by the plants, thereby resulting in better plant growth. The second experiment on “Standardization of spacing and mulching in tuberose” was laid out in split plot design with eight treatment combinations and each replicated four times. The main plot consisted of plastic mulching (P1- Mulched, P2- Non mulched) and sub plot consisted of four levels of spacing (S1- 20 cm × 15 cm, S2- 20 cm × 20 cm, S3- 20 cm × 25 cm, S4- 20 × 30 cm). The best treatment combination from experiment I were selected for conducting experiment II. The treatment combination P1S4 (plastic mulching + 20 × 30 cm spacing) exhibited superior performances across vegetative, floral and post-harvest characters. Plant and soil analysis also resulted in highest nutrient content in this treatment combination. Planting at wider spacing under plastic mulching can be recommended for improved growth, yield and quality of tuberose. Regarding economics of cultivation, the treatment combination P1S4 recorded highest BC ratio for loose flowers. However, for cut flowers, P1S1 (plastic mulching + 20 × 15 cm spacing) achieved the highest BC ratio, followed by P1S4. A precision farming package of “application of poultry manure @ 10.60 t ha-1 and full dose of phosphorous (30 kg ha-1) as basal at the time of land preparation, along with drip fertigation of ½ N and full K (35.50 kg N and K per ha) at IW/ CPE 0.8 and planting at a spacing of 20 × 30 cm under plastic mulching” can be recommended for improved vegetative, floral and post-harvest characters of tuberose hybrid ‘Arka Prajwal’. A semi-automatic fertigation system that can be controlled and monitored remotely using GSM technology has been developed based on the nutrient utilization model derived in terms of growth parameters of the crop as well as the nutrient content of soil and plant.