A Controlled Room in Bastar Cut Graft Mortality by More Than a Quarter

Most of the attention in Indian horticulture goes to what happens in the field. A large share of the outcome, though, is decided before a plant ever reaches one — in the nursery, during the days after a graft is made and the union either takes or fails.

Graft healing in India is conventionally done inside a polyhouse, and a polyhouse is only as good as the weather it is buffering. When conditions inside drift outside the narrow band a fresh graft union needs, three things follow together: mortality rises, the plants that do survive are of poorer quality, and results stop being consistent from batch to batch.

That inconsistency is the part growers rarely see and always pay for. A nursery prices its plants to cover the ones that died, so mortality upstream shows up as the cost and availability of grafted planting material downstream — for tomato and brinjal growers, and for anyone buying fruit saplings.

A graft healing facility in the Bastar–Jagdalpur belt of Chhattisgarh has moved that step out of the polyhouse and into a fully controlled room. The unit is operated by SKF, MKF and RKF Nurseries, and it is a purpose-built installation rather than a retrofit — high automation, and environmental control across several parameters at once. The commercial enquiry behind it came in May 2026, and the facility has only recently begun operating.

The early comparison against conventional polyhouse grafting at the same operation is striking: more than a 25% reduction in mortality, with better plant quality.

Two caveats belong with that number, and they are the operator's own framing rather than a criticism. It is initial feedback from a facility in its first months, not a season-long dataset, and it is a comparison between one operation's old method and its new one rather than a controlled trial. What makes it worth reporting is the size of the gap, not its precision.

The obvious reading of a controlled-environment room — that it swaps sunlight for LEDs — is the wrong one, and it is the misreading that has slowed adoption. Light is one input in a set that has to hold together.

The parameter set this facility runs to:

• Temperature: 28°C day, 25°C night
• Relative humidity: around 90%
• Light intensity: about 100 PPFD
• Light spectrum: Nx4.1
• Photoperiod: 14 hours
• Wind velocity: about 30 cm per second
• CO₂: around 600 ppm, treated as optional and variable

Read as a group rather than a list, those numbers describe a room kept deliberately warm, close to saturated, gently moving and dimly lit — conditions aimed at keeping a cut union from drying out while it knits, rather than at driving photosynthesis. A polyhouse can hit some of these on a good day. Holding all of them, every day, is the thing that is hard to do without control.

Nursery mortality is an unusually leveraged cost. Every graft that fails has already absorbed the rootstock, the scion, the skilled labour of making the union and the weeks of space and energy spent trying to heal it. The loss lands at the end of the process, when the plant is at its most expensive.

Cutting that loss by a quarter therefore does more than trim a line item: it changes the cost per surviving plant, which is the only number a nursery actually sells on. It also changes capacity, because the same floor area yields more saleable plants per cycle.

The wider context is that India's horticulture area keeps expanding — the sector's production and area data show a crop base that has grown for years — and every hectare added needs planting material from somewhere. Nursery capacity, not field area, is frequently the constraint on how fast a high-value crop can scale.

One well-run installation is an existence proof, not a trend. The questions that would turn this into one are specific, and they are answerable within a year.

Does the mortality gap hold across a full season and across species, or is the early result partly the attention a new facility gets? Does the cost per surviving plant beat the polyhouse once capital and running energy are counted, not just the mortality rate? And does the parameter set transfer, or does each crop and each rootstock–scion combination need its own recipe?

For nurseries weighing the same investment, the useful move is to ask the operators of a running facility for their numbers rather than a supplier for a specification. The evidence that matters here is operational, and it is starting to exist in India rather than only in journals.