Fermented Japanese snail fertilizer reduces vapor pressure deficit that improves indigenous corn growth (Zea mays var. Tiniguib)

In the Philippines, native corn substitutes rice during rice scarcity which makes it the second most important staple crop. Japanese snail is considered an economically important mollusk pest but is known to address plant growth problems when used as amino acid fertilizer. The study compared seaweed residue, bamboo shoot residue, Japanese snail residue and their combination with organic pesticide, Guduchi, to commercially available compost fertilizer (10t/ha). These were done in three replications arranged in Randomized Complete Block Design. Photosynthetic parameters were measured using LI-6800 Portable Photosynthesis System. Application of Japanese snail residue improved height from 4th to 8th week by 67.53 cm. Bamboo shoot residue also showed effectiveness in improving the plant height on the 8th week at 139.13±6.28SD cm. On leaf length, Japanese snail residue outperformed the commercial basal organic fertilizer from the second up to the eighth week by 38.5 cm. On reproductive stage, Japanese snail showed the highest weight of ears at 86.6± 20.36SD g and is comparable with seaweed residue in the weight of kernels per ear at 69.60± 1.48SD g. However, in the computed yield, Japanese snail fertilizer has the lowest at 2.13±09SD g but the combination of pesticide and Japanese snail obtained the highest at 3.33±04SD g. Seaweed residue alone attained the highest transpiration rate and the lowest assimilation rate at 1604168655.67±191.66SD µmol H2O m-2 s-1 and 13.16±0.69SD µmol CO2 m-2 s-1, respectively while the combination of Japanese snail and Guduchi was the one that improved stomatal conductance to CO2 and the total conductance to CO2 at 478.6350±34.82SD μmol mol¯ and 47.5083±3.55SD Pa. Japanese snail residue has the lowest vapor pressure deficit at leaf temperature at 4.54±0.02SD kPa which showed significantly strong correlation with increase leaf length and plant height. Hence, Japanese snail residue fertilizer has the potential to be used as solid organic fertilizer for the growth of indigenous corn.