The Australian agricultural market need is early warning of outbreaks of pests and disease. Large area surveillance using machine learning analytics and big data to provide earlier warning that is publicly available in Australia. Earlier warning allows earlier action, which in turn enables quicker intervention and recovery. This will minimize negative impacts and enables faster recovery. Big Data Visual Analytics for Biosecurity is all about developing intelligent decision support frameworks to help deal with the threat of pests and diseases on our farming and agriculture industries. Detection and early intervention of salad leaf related disease is a challenging problem for the salad-growing farmers with severe economic consequences. Sudden change in environmental condition, extreme weather condition, such as hail storm, high wind, very low temperature with humid condition or severe solar radiation can cause a series of scenarios, which can cause different diseases in salad leaves. The ultimate challenge in agricultural decision support systems is to overcome the data unavailability and uncertainty to improve the natural resource management efficiency and achieve better business objectives. Uncertainty factors in the agricultural and environmental monitoring processes are more evident than before due to current technological transparency achieved by most recent advanced communication technologies. Poor data quality and uncertainties make most agricultural decision support systems unreliable and inefficient. This inefficiency leads to failure of agricultural and environmental resource management.