Plagues and diseases

PLAGUES

There are reports of sugarcane attacks by insects or rodents in different sections of the plant:

• Root (May beetles, lined click beetles, cicadas, gophers).
• Stump (giant borer)
• Stalk (borer, rats). Leaves (spittlebug, lace bugs, leafhopper, loopers, and acari).

The degree of importance of these attacks depends on the state of development of the crop (phenology), the strength of the plant, the variety of the crop, the time of year, the stage of the plague, and climate and soil conditions, among others.

In total 18 insect and 2 rodent genuses are reported, which damage the crops. The insects belong to 6 orders and 13 families, where the most important ones are approximately 23 duly identified species. The plagues determined to cause greater recurring damage in many of the regions of the country, and for several months a year, are the common stemborer and the spittlebug.

Some plagues require an important investment in financial, human and technical resources to lower their populations to levels that do not compromise the agricultural yields, the quality of the raw matter and with it the economic income of the producers.

DISTRIBUTION

• Damages
• Control methods
• Biological control (ethological control, physical control, cultural control, chemical control)

DISEASES

For sugarcane, diseases represent limiting factors for the production, and their presence, intensity and effects should be promptly identified and diagnosed. Diseases are caused by different agents, mainly fungus, bacteria and virus. These have a negative influence and generate yield problems, as well as uncertainty for the activity, depending on the degree of susceptibility of the varieties, the prevailing environmental and/or biological factors, and crop management aspects.

For sugarcane there are three types of diseases, depending on the causing agent:

Fungal diseases. These are the majority, and in Costa Rica they are the most important ones: sugarcane smut (Ustilago scitaminea), sugarcane rust (Puccinia melanocephala), orange rust (Ustilago kuehnii), Pokka Boeng (Giberella fujikori; Fusarium moniliforme), yellow spot (Mycovellosiella koepkei), ring spot (Lepthosphaeria sacchari), eye spot (Bipolaris sacchari), brown spot (Cercospora longipes), purple spot (Dimeriella sacchari), red rot (Colletotrichum falcatum).

Bacterial diseases. These are very important due to their implications in seed production and their impact on a production level. In Costa Rica we find:

• Leaf scald (Xanthomonas albilineans).
• Ratoon stunting disease (Leifsonia xyli subsp. xyli).

Viral diseases

• Yellow leaf virus (ScYLV).
• Mossaic virus (ScMV).

The behavior of the different varieties of sugarcane to the different diseases is a characteristic that is determined and assessed during the selection phase of the genetic enhancement process. At the same time, there is constant work performing diagnosis and monitoring the commercial plantations, which tends to diagnose changes in the behavior of the diseases that could cause a potential or real threat to the sugarcane activity.