Post harvest Management of Horticultural Crops (2+1)

Methods of sprout suppression

Methods of sprout suppression
A. Physicals method

Refrigeration and controlled atmosphere reduces sprouting and rooting rates but because of their costs, chemical inhibition is preferred.
Sprouting of potatoes is suppressed at and below 50C and enhanced at higher temperature storage, and in yam no sprouting was observed during 5 month storage at 130C, but tubers sprouted during that period at 150C.

B. Chemicals methods

Sprouting can be suppressed by application of growth regulators on the crop. In bulbs, such as onion, this is not possible because the meristamatic region where sprouting occurs is deep inside the bulb and difficult to treat with post harvest chemicals. Therefore, chemicals like Maleic Hydrazide (MH) is applied to the leaves of the crop at least 2 weeks before harvesting, so that chemical can be translocated deep into the middle of the bulb in the meristamatic tissue where sprouting is initiated.

Potatoes - commercially CIPC (3-chloro –iso-propyl-N phenylcarbamate is also called chloropropham) is applied prior to storage as dust, immersion, vapor or other forms of application as sprout suppressant. CIPC inhibits sprout development by interfering with spindle formation during cell division. However, cell division is extremely important during wound healing or curing period after potatoes have been placed onto storage. Wound healing requires production of 2-5 new cell layers by cell division. CIPC should be applied after wound healing process/suberisation is complete, but before periderm formation. Hence, it must be applied after curing is completed.



Care must be taken not treat seed potato with CIPC and also avoid storing same in place where, already CIPC treated potato has been stored. CIPC is mainly used for the potato stored for processing purpose.

C. Ionization methods

Sprout suppression can also be achieved by irradiating onion bulb, potato and yam tubers.