Song of Jamaica, aka Malaysian Dracaena, Dracaena reflexa. Generally (I say), if brown, crispy lower leaves fall, the problem might be too little moisture and if green, healthy looking leaves fall, the problem could be too much moisture. You will need to give it as much air circulation as possible. Members of the dracaena family prefer to dry out between waterings. The are prone to over watering. Something that I say to everyone is "plants are not machines." They are living things and hence each one (even if it's the same species) has varying
growing requirements unique to itself. You should not measure a certain amount of water and decide to water the plant just because it's _____day (because you always water on ____day each week). You should feel the weight of the pot when the soil is dry, and when you have just watered and the water has drained. My trick is (if it's a small pot 4" or 6") to lift the pot up in one hand (if possible) to determine if it's in need of watering (you can feel the weight difference). Or if it's in a larger pot, you should poke a finger in the soil, and water if the soil is dry in the top inch. Also most plants have growth spurts (like kids lol) Generally, most plants grow faster in
spring/summer and will need more fertilizer and water. While on the other hand, most plants tend to slow growth down in fall/winter, and will need less water and fertilizer, but still the same light (unless you're putting it dormant). in general, dracaena need to dry out between waterings, and should be given lots of air circulation.