Tamil Nadu Agricultural University is one of leading institutions in the world in developing simple mechanical devices to remove insects attaching stored grains at home, farm and warehouses.
Technologies for Urban grain storage:
In Urban India grains are stored mainly in smaller quantities ranging from 25-50kg of rice, wheat, etc., In some cases where Urban people used to get rice from their farm and store at home for consumption they may store rice/pulses(dhal) in one to two bags.
In all cases stored product insects cause damage in storage. Some insects which are common in storage such s flour beetle, Triboliumcastaneum, lesser grain borer, Rhyzoperthadominica, saw toothed beetle, Oryzaephilussurnamensis, etc.
In storage only very few insects are seen during the beginning of storage. Hence if these small numbers are removed, there will not be any build up to insects during storage.
TNAU has developed and popularizing two gadgets for urban grain storage.
1. Insect Probe trap: The use of trap is relatively a new method of detecting, trapping insects in stored grains. The basic component of a TNAU probe trap consists of three important parts: A main tube, insect trapping tube and a detachable cone at the bottom. Equispaced perforations of 2 mm diameter are made in the main tube.
Concept: Insects love “AIR” and move towards air. This behavior of the insect is exploited in this technology.
Method of working: The insect trap has to be kept in the grain like rice, wheat etc., vertically with the white plastic cone downside as shown the figure. The top red cap must be with the level of the grain. Insects will move towards air in the main tube and enter through the hole. Once the insect enters the hole it falls down into the detachable white cone at the bottom. Then there is no way to escape and the insects are trapped forever. The white detachable cone can be unscrewed once in a week and the insects can be destroyed.
Salient Features: No chemicals; No side effects and No maintenance cost.
Efficiency: TNAU Insect traps are excellent insect detection devices in food grains and more effective in the detection of stored grain insects namely Rhyzoperthadominica(F.), Sitophiluscryzae(L.) and Triboliumcastaneum(Herbst) in stored food grains both in terms of detection as well as number of insects caught than the standard normal sampling method (by spear sampling). The detection ratio (trap: normal sample) is higher in trap than of normal sampling method by factors ranging from 2:1 to 31:1. The insects catch is also higher in the probe trap than the normal sampling method by factors ranging from 20:1 to 121:1.
They are also good mass trapping devices when used at 2 – 3 numbers / 25 kg bin (28 cm dia and 39 cm length). They should be placed at top 6 inches of the grain, where the insect activity is seen during early period of storage. They can remove > 80% of the insects within 10 – 20 days.
2. TNAU Insect remover from bulk grain stored (Indian Patent No. 198434)
In many urban households people procure rice/dhal from villages and stored in houses up to a level of one / two bags (100-150kg). They use rice/dhal daily from the bag for cooking.
Heavy infestation of insects sometimes gets noticed under this situation. In such cases they can use TNAU insect remover (Patent No. 198434) to clean their product from TNAU licensed entrepreneurs and do this cleaning for a nominal cost.
This machine has the capacity of cleaning efficacy around 50 kg/hr and 200 kg/hr (1 HP motor) for hand and machine operated respectively. This machine can crush the eggs present in the grains, when the grains flow through the machine to a considerable extent so that further insect development can be prevented. Besides eggs this machine also effectively removes the adult weevils/ beetles present in the grains. Free living larvae of insects are also crushed.
Hand Operated Cleaning efficacy: 50 Kg/hr
Power Operated Cleaning efficacy: 200 Kg/hr