Variety with good ratooning potential and good plant crop are the essential prerequisites for good ratoons. This has to be combined with basic ratooning operations, viz. stubble shaving, off-barring and gap filling, and proper crop management practices like early manuring, control of chlorosis and management of pests and diseases to get higher ratoon yields.
Variety
Sugarcane varieties differ in their ratooning ability. The success of a variety depends on its ability to give better ratoons since varietal adoption by most farmers depends on this factor, besides plant crop yields. Most of the present day sugarcane varieties have the good ratooning ability. Early maturing varieties are poor ratooners than mid-late or late varieties. Thin or medium thin varieties give better ratoons than thick varieties. Varieties giving high yields as plant crops give better ratoon yields in most cases.
However, this is not always true. Some varieties give higher ratoon yields than plant crops. Co 6304 variety that was once grown widely in Tamil Nadu is a good ratooner while another popular variety CoC 671 a poor ratooner. However, CoC 671 was found to give good ratoon yields in some parts of Northern Karnataka, Maharashtra and Gujarat.
Thus the ratooning ability of a variety differs from region to region also. Co 740 the variety of Maharashtra & Co 1148, a variety of the subtropics are excellent ratooners. Co 7314, Co 8013, Co 8018, Co 8021, Co 8121, Co 8122, Co 8134, Co 8145, Co 8208, Co 8362, Co 86010 and Co 86011 Co 2001 – 13, Co 2001 – 15 etc. released from the Sugarcane Breeding Institute have been found to possess excellent ratooning potential.
Plant crop and its harvest
Good ratoons result from healthy plant crop. The plant crop should be raised under optimum input levels, particularly nutrients and irrigation. Poorly grown plant crops due to reasons like moisture stress, lack of sufficient nutrients or due to certain pests, cannot give satisfactory ratoons. Plant population in the ratoons can be maintained if there were adequate stubbles in the field. Thus for my reason, if the plant crop has too low cane population at harvest, it is desirable to avoid ratooning. Pest and disease infected plant crops also should not be ratooned, particularly if there is the danger of such disease or pest being carried forward through stubbles to the ratoon crops.
Time of harvest
Harvesting the plant crop when weather conditions are conducive for stubble sprouting is important. Low as well as high temperatures are harmful. The optimum temperature for
sprouting ranges between 25 and 30oC. When the crop is harvested in winter, as usually
happens in the northern part of our country, bud sprouting does not occur because of low
temperature. When the cane harvesting is done in the hot summer months, again, sprouting
is affected due to drying up of the buds and stubbles.Sprouted buds also die.Thus plant population becomes inadequate.
The incidence of certain pests like shoot borer becomes heavy. Both these extremes of weather conditions require special management to obtain better ratoon crops. As extremes of climatic conditions are not much in the southern tropical states, harvesting of cane any time excepting sweltering summer months (April-June) would result in satisfactory ratoons. However, December to February harvested crops would give best ratoons in the tropical states. In general, early harvested crops always give better ratoons.
Autumn planted (early planted during October-November) Sugarcane in the tropical states when harvested early in the crushing season would give better ratoons since the weather conditions are quite favourable for better sprouting and early growth. Besides, the ratoons would have grown up sufficiently by the time hot summer and moisture stress is felt and thus would be able to overcome the ill-effects of moisture stress. Autumn planting also helps in overcoming certain insect pests like the early shoot borers both in the plant and ratoon crops.
Duration of harvest
For ensuring uniformity of the sprouts and further to promote uniform growth of the ratoon crop, it is essential that the period of harvesting of a field is not extended beyond a week. Jaggery farmers and some registered growers harvest in piece meal and then ratoon which leads to heterogeneous ratoon population. This should be avoided as far as possible.
Method of harvest
Harvesting the plant crop close to the ground level is very important not only to add a few more tonnes to the yield but also to get a better ratoon crop. This is particularly important in places where stubble shaving operation cannot be carried out due to either labour scarcity or unfavourable soil conditions like either excess moisture or lack of it.
Trash disposal
Trash disposal is an important task soon after the harvest of the plant crop before any other ratooning operations could be taken up. Green tops are mostly removed for feeding cattle, and some are used for tying the cane bundles. Still as much as 8-10 t of trash per hectare is left in the field which must be disposed of.
Most of the farmers burn the trash. Scientifically, trash must be conserved and returned
to the soil since it contributes towards organic matter and nutrient status of the soil, Average
Nutrient content in the sugarcane trash has been estimated to be around 0.35 % N, 0.13 % P205
moreover, 0.65 % K20. When incorporated with soil, trash helps in improving the soil physical
conditions.
Source-
- Sugarcane Breeding Institute, Coimbatore-641 007
