ISHS Acta Horticulturae 710: International Symposium on Greenhouses, Environmental Controls and In-house Mechanization for Crop Production in the Tropics and Sub-Tropics
RESPONSE OF FERTIGATION ON CAPSICUM GROWTH UNDER NATURALLY VENTILATED TROPICAL GREENHOUSE |
| Authors: | K. Rezuwan, M. Shahid, Mohd, A. Mohd, Soom, F. Abdullah |
| Keywords: | greenhouse, micro-climate, fertigation, capsicum, growth |
| Abstract:
A fertigation system is defined as a combination of fertilizer solution and irrigation water directly applied to the crop root zone. The system is necessary for crop production under a naturally ventilated tropical greenhouse to supply a precise amount of water and fertilizer solution, reduce soil diseases, increase field efficiency, increase crop productivity and quality. A fertilizer recipe by using a Cooper formulation was developed and tested for capsicum growth under greenhouse in the lowlands. The greenhouse was made of galvanized steel tube structural frames, clear polyethylene sheet roofing and polyethylene insect-screen sidewalls. The fertigation system consists of irrigation controller, solution tank, electrical pump, filter, valve, connector, distribution pipes, adapter and drippers. Capsicum of Big Star variety was planted in the coco peat growth media. Water with fertilizer solution was automatically supplied to the root zone for 20 minutes, 6 times per day. The performances of capsicum growth in terms of stem diameter, plant height and leaf width against time were measured. In addition, the solution pH, electrical conductivity (EC), dissolved oxygen (DO) and microclimate were also determined. The relationship between the leaf and stem growth against time were found to be linear, while the height versus time was exponential. The regression equations of plant height, stem diameter and leaf width against time were found H = 5.79e0.24T, D = 0.32T + 0.65 and W = 0.37T + 1.93 respectively. In addition their coefficients of determination were strong: R2=0.995, R2=0.998 and R2=0.983. Stem and leaf growth increased as electrical conductivity (EC) increased from 1.7 mS/cm to 2.5 mS/cm. At all times the pH value was maintained between 5.5 and 7.0. The temperature, wind speed, relative humidity, light intensity and carbon dioxide were found to be in the range of 30-40°C, 0.5-3.0 m s-1, 53-83%, 170-1400 x 103 lux and 300-400 ppm respectively. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
