Sugarcane Diseases: Futuristic Management Strategies

Historically, sugarcane production worldwide has been impacted by diseases and unfortunately, these threats will continue. Incorporating resistance in varieties still remains the most cost effective and environmentally friendly method of controlling diseases. Almost all major sugarcane industries have breeding and variety selection programs that emphasize the development of high-yielding varieties with sufficient resistance to prevent disease losses. However, the presence of multiple diseases makes it increasingly difficult to develop varieties with resistance to all diseases. Each country and disease has specific challenges for developing disease resistance and control practices. Red rot and viruses in India, phytoplasmas in Thailand, and ratoon stunt and smut in China have been problems for many years. Moreover, new challenges exist to combat emerging diseases, such as smut in the Australian Queensland Industry (2006) and orange rust in both Australia (2000) and Florida (2007). This paper will describe events that are influencing changes and predict/recommend future technologies that should be incorporated in disease control strategies used in sugarcane production. Ongoing social and economic changes are influencing future sugarcane production and disease control practices. Family sizes are decreasing in many countries and this shift to smaller families will probably become a trend in other countries in the future. The economic pull of jobs and educational opportunities in cities are also causing reductions in the number of young people who stay in rural areas to farm. The small family farms will coalesce into larger farm units in developing countries. Larger farm units will influence cultural practices and promote mechanization. Political changes of governments will promote food production to ensure all citizens have sufficient food that is balanced nutritionally. The price of sugar is currently high and is predicted to remain high for at least a few years. Furthermore, the diet in many countries will change as their economic conditions improve. The demand for sugar will increase not only due to population increases but due to increased consumption per capita. Also, the decision to grow sugarcane for biofuels rather than for sucrose will increase the demand for sugar by decreasing its supply. New technologies are available to assist variety development and the entry of major international companies either in developing breeding programs or associating with established public and/or private programs is changing sugarcane production. All these factors are in response to the increased demand for sugar. However, the major factors that will influence improvements in disease control practices are the technological advancements that have occurred in the last few years and that will be developing in the future. Never before have there been the technological means to collect data to diagnose diseases, molecular technology to assist in breeding and selecting resistant varieties, detect pathogen buildups, and the expertise to coordinate all areas. The disease control practices of the future will differ from those of the past. The majority of sugarcane variety development programs still rely on traditional crossing and selection but most are also adapting and developing new technology such as better selection of parental clones, synchronization of flowering, selection procedures, disease screening, and selection of resistant clones. The sugarcane genome is being sequenced and, in time, specific nucleotide sequences will be associated with specific traits. Marker assisted selection will become a routine component of successful variety development programs. The major gene for J. C. Comstock (&) USDA-ARS Sugarcane Field Station, Canal Point, Florida, USA e-mail: jack.comstock@ars.usda.gov