Total chlorophyll and root nodules at various ages of soybean plants (Glycine max L.) in the wet-dry season

Plants have a vulnerability to climate change. Soybean plants must be able to adapt to climate change stresses so that physiological processes and plant development run well and produce optimal soybean seed production. Planting soybean cultivars that can withstand climate change is recommended to maintain soybean production. The effect of soybean cultivars and plant age on the nodules' amount and leaf chlorophyll content planted during the wet-dry season needs to be studied. The study was designed with a factorial randomised block design and was repeated three times. The first factor is soybean cultivars, and the second factor is planting time. Parameters observed were weather data, chlorophyll content, nodules' amount, and nodules' mass. The results showed that the Gepak Hijau and Gepak Kuning cultivars planted at different times had significantly different root nodules' amount and dry mass of root nodules, while there was no significant difference in chlorophyll content. The nodules' amount positively correlated with the total chlorophyll. Relative humidity and rainfall reduce the nodules amount and the total chlorophyll. Solar radiation promotes growth in the nodules' amount and the total chlorophyll.