Precision farming techniques and Agro meteorological indices for African marigold cultivation in humid tropics of Kerala

Abstract

The study could identify the best precision farming techniques,such as fertigation and drip irrigation, by utilizing two resistant marigold genotypes G1 (Bhagwati –F1 hybrid) and G2 (KAU-M-1, Local collection) in three seasons viz., rainy, winter, and summer, under humid tropical plains of Kerala. Crop raised under drip fertigation recorded enhanced growth and yield compared to the control plot in all three seasons. In the rainy season, fertigation @ 75 % RDF (F1) recorded a yield of 35.26 t/ha for G1 and 13.00 t/ha for G2 which is double the yield obtained in the control treatments of respective genotypes. In winter and summer seasons, irrigation @ 100 per cent Epan and fertigation @ 125% RDF recorded the highest yield in both the genotypes. The highest nutrient uptake was recorded in 75% RDF during the rainy season, whereas in winter and summer seasons, nutrient uptake was maximum in I2 F3 . Water use efficiency was the highest in the treatment I2 F3 for G1 and G2 during the winter and summer seasons. Response of the genotypes varied concerning different meteorological indices like average temperature, average relative humidity, average rainfall, and average Epan in the three cropping seasons. In the rainy season, the majority of the vegetative, flowering (except days to initiation and fifty per cent flowering), as well as yield parameters, were positively correlated with temperature in both the genotypes, whereas in the case of relative humidity, only hybrid Bhagwati was showing positive correlation with a majority of the parameters. Due to cloudiness in the rainy season, the flowering phase was delayed in both genotypes up to an average of 13.45 days. Response of the two genotypes during summer was negative with average temperature and relative humidity whereas epan showed a positive response in both winter and summer.