Breaking Potato tuber Dormancy or Pagpapatubo
Planting of sprouted seed tubers result in early and uniform emergence. The dormancy of potato seed tubers may be broken by various methods:
- Use fluctuating temperature. Bring tubers to a warmer area for a short period before returning them to the farm or storage room. This could be done by holding tubers above the cooking areas.
- Use chemicals such as calcium carbide (CaC2) and gibberellic acid (GA3).
How to use calcium carbide
Calcium carbride or carburo is a good sprout stimulator. It generates acetylene that produces ethylene-like effect necessary for sprouting. It makes seed potatoes sprout faster.
Treat only healthy tubers that have been stored for month in DLS.
Treat tubers with small pieces of carburo wrapped in paper. Three to five kilograms of carburo treats 1 ton (1000 kgs) of seed tubers.
In using drums or plastic cellophane, distribute the wrapped CaC2 alternately to equal sides for uniform sprout stimulation. When tubers are in red or mesh bags pile red bags inside a drum or spread on the floor.
Cover the drum or the pile tightly with a canvas tolda or plastic sheet. Spread pieces of paper on top of the pile prior to covering with the canvas.
For treating larger volume of seeds, use cemented floors. Place carburo under crisscrossed or slatted wood or an available platform. Cover it with plastic or canvass sheet and seal the sides.
Remove the canvas or plastic sheet after 10 days and store the sprouted tubers further in diffused light. Longer period causes rotting of tubers. Unsprouted tubers must be displayed further in dark store to enhance sprout length.
Use of Gibberellic Acid (Progibb 4%)
Select healthy tubers. Cure for five to seven days.
Tubers dipped in 1 tsp per liter of Progibb 4% for 10 minutes sprout faster than those untreated tubers. When tubers are stored for one month in the DLS, they become sensitive to lower concentration of Progibb. This treatment can be done to newly harvested and cured tubers.
Large seeds may be cut when seed tubers are limited. Cutting of seedpieces, however, poses danger because microorganisms may enter through the cuts and dry up the potato.
When cutting the seed, use sharp knives that have been disinfected with either sodium hypochlorite (chlorox) , Lysol or a powder detergent.
Cut seeds under the shade or inside a room. Seedpieces should have at least one to two sprouts. Each seedpiece should weight at least 40 grams.
Cure or allow the wound to heal by covering cut seedpieces with clean and moist jute sack for four days. If possible, treat with dust containing at least 15% carbonate to reduce seed-piece decay.