If gaps in a ratoon crop are above 20%, the yield is badly affected. There are three ways to fill gaps: 1 to 3 bud setts, 35 to 40 day old settling raised in polybags, or moving clumps from crowded spots. Prepare the settling before harvest.
Why do gaps appear in ratoon?
According to an ICAR-SBI, Coimbatore study, the causes of poor sprouting are weather, a weak plant crop, fungal disease and pests. According to an Indian Farming article, labour moving through the field at harvest also causes gaps. In the same SBI study, only about 40% of farmers filled gaps, because the work needs a lot of labour. But if gaps go above 20%, there can be noticeable loss.
First cut the stubble evenly
With a sharp knife, cut the stubble down to soil level. This removes the old buds and encourages new buds to sprout. Take care that the clump does not shift, especially in shallow planting; otherwise the plant count may fall. Only after this, decide where the gaps are.
Three ways to fill gaps
- Setts: Place healthy 1, 2 or 3 bud setts directly in the gap.
- Polybag settling: Plant ready-grown settling in the gap. Because the plant is already grown, it establishes more easily with this method.
- Moving clumps: Take clumps from where the sugarcane is crowded and place them in the gap. Before using clumps from the same field, make sure they have no disease.
In an SBI study of 32 farmers, 46.87% used bud chip settling, 43.75% used polybag settling and 40.63% split clumps. If labour is short, you can start with clumps from crowded spots, and if settling is ready, plant that first.
Preparing polybag settling
- Place the bud facing upward in the bag.
- Keep the bags in shade.
- Buds sprout in about 10 to 12 days.
- Settling 35 to 40 days old is used for planting.
- Before planting, cut the bag from one side so that the soil does not break.
What did the Lucknow trial find?
In the multi-ratooning trial in the Indian Farming article, the average ratoon yield was:
- Stubble cutting + trash mulch + gap filling: 63.4 tonnes / hectare
- Stubble cutting + trash mulch, without gap filling: 55.7 tonnes / hectare
- Control: 45.0 tonnes / hectare
These are figures from one trial, not a promise. In your field it can be different depending on soil, water and variety.
Water after gap filling
According to the SBI study, ratoon roots are shallow, so the ratoon feels water shortage quickly, especially early on. Newly planted settling also needs moisture, so give irrigation on time after filling gaps.
Questions and answers
When should gaps in ratoon be filled?
The sources we saw do not give an exact day. Settling is ready in 35 to 40 days, so raise the nursery before harvest and fill the gaps after harvest, once the stubble is cut.
How many gaps make filling necessary?
According to an SBI study, gaps above 20% cause noticeable loss. Even when gaps are fewer, filling them keeps up the plant count.
Sources: Rana et al.: Multi-ratooning in sugarcane, Indian Farming 71(05), 2021 · Shanthy et al.: Constraints and opportunities in sugarcane ratoon management, Journal of Sugarcane Research 2014 · TNAU Expert System for Sugarcane: Ratoon management
*Farmers' results are their own experience, not a guarantee. Results change with soil, water, weather and care.
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