With the support of sugar mills and growers, Cenicaña is promoting a series of measures to counteract the increase in the disease.
In October 2015, the Cenicaña Disease Diagnosis Service reported the highest distribution values of the yellow leaf virus (SCYLV) (41.2%) of the last 15 years. Of course, the alarms went off and actions began to be taken to counteract the increase in the disease in sugarcane crops in the Cauca river valley. According to Freddy Fernando Garcés, director of the Varieties Program, the strategy includes the implementation of three measures: strengthening the Disease Diagnosis Service, increasing the promotion of the use of healthy seeds and sanitary practices, and speeding up the multiplication of seeds.
1 Strengthen the Diagnostic Service
It was proposed to follow up the incidence levels as additional data to the distribution. The Diagnostic Service uses a qualitative technique that is RT-PCR for the detection of yellow leaf virus. For the diagnosis, all the leaves are combined in a single sample and if the sample is considered infected, it is classified as positive. That is, there are only two results: positive or negative.
Although the technique is very sensitive, it is unknown how many leaves are infected by the virus. For this reason, Cenicaña began to offer quantitative results again using the TBIA technique, in such a way that only fields with incidence levels greater than 5% are discarded.
Today, the mills periodically receive data on the incidence of the affected lots that they have sent to the Diagnostic Service for permanent monitoring.
"Thus we have shown that the general averages of the levels of incidence and distribution of the disease have been decreasing in different varieties," said Dr. Garcés. Today, reports from the last few months show that the disease has slowed its progression by passing its incidence from 9.6% to 8.5%.
2Information and training
The increase in the disease was also related to the interest that the varieties CC 01-1940, SP 71-6949 and RB 73-2223 aroused in the agribusiness with high incidence levels.
Initially, Cenicaña identified the areas with the highest presence and incidence of the disease and with historical data a visit plan was initiated to avoid the use of seed from seedbeds with a high incidence of the pathogen. "Today the mills have an additional criterion supported by quantitative incidence data when selecting seedlings," explained the Director of the Variety Program.
Likewise, the trainings carried out within the framework of the Learning and Technical Assistance Program (PAT) have also facilitated the formation of this technical criterion, since the course Recognition of sugarcane diseases it includes the management of healthy seeds and emphasizes the implementation of sanitary measures, along with technological changes that have occurred in the industry such as mechanical harvesting.
3Speed up seed multiplication
Research is currently being carried out in the establishment of seedbeds for the foundation of varieties such as CC 01-1940 and CC 11-600 using plants by in vitro culture to later multiply by the individual bud system and thus guarantee a higher multiplication rate and plant production. .
Historically, foundation seedlings are reinfected with the yellow leaf virus; Therefore, Cenicaña studies the use of measures such as barriers of resistant varieties around the foundation seedlings and the application in the cultivation of resistance inducers to act as vaccines, avoiding reinfection in the field.
Cenicaña will continue with the evaluations to find alternatives that provide healthy foundation seedbeds.
Impact of the disease
Cenicaña is making progress in research on the effect of the yellow leaf virus on production in varieties CC 01-1940 and SP 71-6949. Although the preliminary results, from the statistical point of view, indicate that there is still no significant effect in TCH and sucrose% cane when comparing healthy plots with others with high incidence levels, a 13% decrease in TAH was calculated.
We must take into account that environmental, physiological and crop management factors can generate a change in the performance of any variety in the event of a high virus infection, with possible effects on production, as has been widely documented in research carried out in Colombia and in other growing countries. On the other hand, increasing the inoculum sources can affect future varieties that have a greater impact on production, as happened in the past with CC 84-75.
Change in the Director of the Variety Program
Since last November 9, Freddy Fernando Garcés, Cenicaña plant pathologist, assumed as the new director of the Varieties Program in replacement of Jorge Ignacio Victoria Kafure, Ph.D, who was linked to the Research Center for 36 years.
The new Director of the Variety Program is an agronomist from the National University of Colombia, Medellín headquarters. In 1996 he joined Cenicaña as a young researcher at Colciencias and, later, as a plant pathologist. At the end of 1998 he joined the Ecuadorian Sugar Cane Research Center, Cincae; and between 2007 and 2011 he did doctoral studies at the University of Louisiana, USA As a graduate student, he was awarded the Edgertom award.
At Cincae, Freddy Fernando Garcés worked in disease preventive management projects, included molecular techniques in the process of evaluation and selection of clones resistant to systemic diseases and began work with markers of resistance to coffee rust, participated in the release of varieties local communities, established a quarantine process and a healthy seed multiplication scheme.
KEEP IN MIND
Disease Diagnosis Service Contact: Phytopathology area Telephone: (602) 5246611 ext. 5150, 5139, 5141. email@example.com www.cenicana.org/servicios/
Plant Health Committee Memories
- June 28, 2017: 'Current state of diseases'.
- November 22, 2017: Progress in the establishment of foundation seedbeds.