Red Rot Management in sugarcane

Red rot of sugarcane has been a menace for sugarcane cultivation in the subtropics during the past several decades and we have lost several elite varieties like Co 213, Co 312, Co 421, Co 453, Co 1148, Co 7717, CoS 8436, CoSe 92423, CoSe 95422,  Co 0238 etc. 

Management strategies for red rot in sugarcane

• The sugar mills have to focus on seed replacement in large areas. The age-old advice and recommendation to have a mosaic pattern of varieties in the command areas. It is further advised that the sugar mill should restrain from increasing the acreage of a variety beyond 40% in the command area and should have a judicious blend of varieties to realize the productivity and profitability in a sustainable manner.
• A comprehensive disease monitoring is warranted to take up plant protection measures immediately after noticing the disease. A close vigil (regular surveillance) of the apparently healthy sugarcane crop of other varieties adjoining to the affected fields to detect red rot, especially during the summer months (up to July). Many a times, in the affected clump(s) (tillering phase), presence of spindle infections may be visible during this period.
• Removal and destruction of the affected clumps have to be carried out religiously without fail.
• Once an infected clump is detected, the rest of the crop is to be sprayed with a systematic fungicide like Thiophanate methyl (0.1%) at three weeks intervals (2-3 sprays depending on the disease severity). This monitoring is of utmost importance since incipient infectious are very common in the subtropical states and such infections incite the disease as primary source of inoculum. 
• The affected fields along with surrounding fields should (due to the presence of incipient infections) be harvested immediately. The affected fields must be sanitized with application of fungicides, so that remaining soil borne inocula and the inocula dislodged during the removal of affected clumps be killed. In the affected fields, no trace of the affected variety be left and all the stubbles of the affected fields be removed and destroyed preferably by burning. Obviously, there will be no continuation of plant crop to raise a ratoon crop in the affected fields (Even if there is only one affected clump).
• In the affected field, rice-wheat crop rotation may be taken for at least one season or any oilseed crop may be taken during the same period after complete removal of red rot infected stubbles.
• After proper sanitization of the affected fields, a sugarcane crop (other than the affected variety) may be planted at least after one season during the following spring planting season (February March planting).
• The varieties CoLk 14201, CoLk 15201, CoS 13235, Co 15023, CoLk 11203, CoLk 94184, CoLk 11206, CoLk 14204, CoS 14233 and CoLk 12207 are recommended in states like UP, Punjab, Bihar, Uttarakhand.
• In red rot prone areas mechanized sett treatment with systemic fungicide like Thiophanate methyl (0.1%) in sett treatment device should be made mandatory to suppress the disease development in young crop. This treatment takes care of infections from soil and sett borne infections of inocula; once disease development from these inoculum sources is arrested, we can prevent build-up of sources of inoculum for secondary spread. However, under epidemic situations secondary infections do occur in a healthy crop, hence prophylactic sprays of the same fungicide 2 to 3 times during May to July is suggested to protect the crop from infections and serious crop damages. 
• A robust and dedicated seed replacement programme has to be taken especially in the red rot affected areas and the farmers have to be educated adequately to use quality and healthy seed. Encouragement has to be given for the development of entrepreneurship in the production and distribution of disease free and healthy seed cane to the farmers with a proper monitoring system.
• Farmers may also be advised to have seed cane nurseries with a close monitoring by the sugar mill personnel, for their own use. A separate field or area may be earmarked for raising a seed crop. The seed cane crop preferably be raised using single bud sett of apparently healthy canes. The single bud sett should be treated with a systemic fungicide like Thiophanate methyl (0.1%) in Seed Treatment Device before planting. Further, the nursery crop may be raised with Trichoderma culture fortified organic manures or vermicompost.
• Unscientific practices like applying bleaching powder in the field should be discouraged.  

Source : ICAR-IISR, Lucknow