I have addressed this subject before, but I could not pass up the opportunity to review it again. The field in which this was taken is in an area where scum (algae) has been a problem before. Often soils where algae grow well will produce an algal bloom every time they are flooded. This is especially if crawfishing is part of the rotation because longer periods of flooding create more opportunity for algae to grow. If this had happened when this rice was younger we would have had a serious problem. This would have been especially true if it was windy because often wind will push the scum over young plants. In this case the algae will simply shade out any weeds that might try to emerge and in a few weeks will disappear as the rice plants get larger and produce more shade. So scum or algae can be either a problem or a solution depending on when it happens.