INSECT PESTS IN FOOD GRAIN STORAGE

Insects belong to     Phyllum  :  ARTHROPODA
                              Class      :  INSECTA
                                                                   
             Having 3 pairs of legs and outer skin called cuticle,body divided into 3 parts head,thorax and abdomen.The head bears 1 pair of antennae,the thorax carries 3 pairs of legs,1 or 2 pairs of wings.The exo skeleton is chitinous.


            As per the pause committee report,the storage losses due to insect pests of stored grains are 2.55%.In addtion they are also responsible for the qualitative losses of food grains.
         
            The classification of primary and secondary insect pests is given below:

RICE WEEVIL :

Scientific name  :  Sitophilus oryzae

Nature of Damage :

Damage is done by adults and larvae.Grains are hallowed out.Kernals are reduced to mere powder ,Sitophilus oryzae ans S.zeamais are known to attack in fields too.Adults cut circular holes.Heating takes place during heavy infestation.which is known as  dry heating.

Identification :

• Size  3 m.m 
• Weevils are beetles having characteristic beak or snout.
• Antennae elbowed and slightly clubbed.hind wings present except in S.granarius.
• colour ranges from reddish brown chocolate to almost black.
• S.zeamais -largest among three species.

Commodities attacked :


   Wheat,Rice ,Maize ,Jowar and Paddy etc.,


Life history and habits : 

Female makes a cavity and lays translucent  white eggs  and then plugs the hole with gelatinous secretion.Eggs are laid singly.

Single female lays 150 to 250 eggs.The leg less,fleshly  and curved larva remains in the grain and pupates also inside the grain.larval stage lasts for about 20 days.Pupal period is for 3-6 days.When development is complete the adult comes out having a circular hole.Adult lives for 3-5 months.Grain having moisture less than 10 % is not attacked.The life cycle takes 26days at  30 degrees centigrade and 75% R.H.The optimum climatic conditions for developments range from 26 to 36 degrees centigrade.

CAP STORAGE

The acronym 'CAP' stands for "COVER AND PLINTH" ,which are the basic needs for this type of storage of food grains  in bags in the open area.

METHOD OF CAP STORAGE:

A)SELECTION OF PLACES:

CAP storage may be undertaken in places which do not have the severity of weather condition,especially heavy rainfall and high wind velocity.It should be avoided in cyclone and flood prone areas and areas with high humidity.It is recommended to be adopted in telangana region and as far as possible coastal area should be avoided.

B) SELECTION OF SITE:

The site selected should be at higher level as compared adjoining ground.adequate arrangements for draining off the accumulated water should should exist in case the site does not fulfill this condition.Abandoned air strips,space in between rows of godowns and a variety of other sites can be chosen for the purpose.

C)PREPARATION OF SITE:

The construction of 1 meter high raised platforms with cement concrete is preferable,to make it rodent proof and safe from flooding.All katcha sites should be made clear of weeds,shrubs etc.,Anti-termite treatment to dunnage material with dis infestation with chlorpyriphos 20% E.C.at 1% will be helpful.

D)DRAWING OF STACK PLAN:

The stack plans should be drawn in advance  and also stack no.s indicated where ever possible.The standard size of the stack is 30'*20'.

E)PROVISION OF DUNNAGE:

Adequate dunnage need to be provided to all the stacks.A variety of materials can be used as dunnage,such as wooden crates ,sleepers and 3 layers of casuarina poles.In the interest of environmental protection and prevention of felling of trees ,alternate materials like granite slabs,blocks made up of cement concrete etc., should be preferred.The soil condition and local availability of materials are the guiding factors.Use of [polythene films or mats alone is to be avoided to allow free movement of rain water and prevent soaking of bottom layer bags.Wooden dunnage should be in variably cleaned,dis infected and creosote painted before use.The no.of wooden crates required for each stack would be 40(for stack size of 30'*20')Over the wooden crates or the 3rd layer of casuarina poles,a layer of matting is provided(to prevent spillage of grain on the floor)and the same also gives a prophylactic treatment.

F)METHOD OF STACKING:

Only the criss-cross method of stacking is followed in CAP storage in view of its stability.Stack is built in such a way that its length-side does not face the wind direction.Each stack has broadly 2 distinct regions viz.,the lower base region and upper dome formation.

 

PROCEDURE FOR CLASSIFICATION OF PADDY /RICE VARIETIES FOR CENTRAL POOL PROCUREMENT

The central grain analysis laboratory (CGAL) of the department of food and public distribution obtains authentical samples of  the paddy/rice varieties of commercial importance from the state government and Food corporation of India.The classification is accorded as per the existing norms for criteria of classification i.e., length and breadth ratio varieties having length and breadth ratio below 2.5 is classified as common.and those having  length and breadth ration of 2.5 and above is classified as  grade 'A' by following the under mentioned procedure.

1) An authenticated representative sample of paddy /brown rice,which should contain at least 90% kernels of the principal variety being considered for classification is obtained.

2) Samples of brown rice is mixed thoroughly and is spread in a circular layer of about 12mm thickness.

3) From this spread sample a quantity if 20 gms  is scooped out from center ,sides and different points for the purpose of analysis /classification.

4) Out of 20 grams of sample ,kernels of grade A and common groups are picked out as per the classification norms on length and breadth ratio basis.

5) Kernels so separated are counted and the % of each group i.e., grade A and common is worked out ignoring other physical components i.e., foreign matter, brokens ,damaged and discolored grains etc., on count basis.

6) Kernels which are majority are considered for classification/ notification.

7) Out of these kernels which are majority i.e., dominating variety 100 kernels are picked out for determination of length and breadth ratios.

8) The overall length and breadth  worked out and length and breadth ratio is ascertained (i.e., average length/average breadh

9) On the basis of the length and breadth ratio so obtained the variety is classified/notified.

PREVENTION OF FOOD ADULTRATION ACT

Quality requirements are as follows under the act:

Food grains meant for human consumption shall confirm to the following standards.

1.GENERAL:

Food grains shall be free from deleterious material including artificial coloring matter.The pesticide residue ,if any, shall not exceed the prescribed permissible limit.

2.FOREIGN MATTER :

Foreign matter means any extraneous matter other than food grains and will compromise inorganic and organic matter. Inorganic matter includes sand , gravel,dirt ,pebbles,stone ,lumps of earth,clay and mud  shall not exceed 1%  where as, in case of paddy ,it shall not exceed 3% by weight.Organic matter which includes chaff,straw,weed seeds,edible grain ,oil seed and other non-poisonous seeds shall not exceed 3% by weight.

3.DAMAGED GRAIN:

It means grain damaged by fungus,moisture,heating and where in the damage is not superficial but the grain is affected internally.It shall not exceed 5% by weight.

4.INSECT DAMAGE:

The amount of weeviled grains (by count)shall not be more than 10 % or uric acid content arising as a result of insect damage shall not exceed 10 mg/100 gms,which ever is lower.

5.RODENT HAIR OR EXCRETA:

Should not exceed 2 pieces / kg of the sample.

6.MOISTURE:

The loss in weight by heating the pulverised food grains at 130 - 133 degrees centigrade for 2 hrs shall not exceed 16%.

7.INSECT INFESTATION:

  A) A total of 8 insects either live or dead per kg in primary food.

  B) A total of 4 insects either live or dead in processed food like Rice,wheat products etc.,

BASIS OF CLASSIFICATION OF STOCKS IN STORAGE

Quantity of sample : 1 kilogram

CLEAR :  when the sample drawn from the stack is completely from live infestation of either major or minor 

pests.

FEW : When the sample drawn from the stack contain living infestation up to 2 minor and or major pests.

HEAVY : When the sample drawn from the stck contain more than 2 minor and or major pests.

    

Note : Stacks classified as FEW  and HEAVY should be fumigated immediately to arrest the infestation.

CATEGORIZATION OF PADDY

The basis of categorization is the same as the case of wheat except for incorporating the designation to indicate the intensity of slightly damaged  discolored kernels.Designation will be represented by adding 1.2.3.4 to the category as below.The categorization is to be done by the volumetric method in respect of above commodities except for maize here it is by count method.

Designation	Percentage of slightly damaged/discolored besides touched/damaged and discolored grains
1	Up to 5
2	Above 5 and up to 10
3	Above 10 and up to 15
4	Above 15 and up to 20

     The following illustration will elucidate how grains are to be  categorized and  designated :

A 1 : 

 Grains with 1% of weeviled and 3% of slightly damaged /discolored and damaged/discolored grains .

 B 3 :

  Grains with 4% of weeviled and 12% of slightly damaged /discolored and  damaged/discolored grains .

C 2 :

 Grains with 7% of weeviled and 7% of slightly damaged /discolored and  damaged/discolored grains . 

D 4 :

 Grains with 10% of weeviled and 17% of slightly damaged /discolored and  damaged/discolored grains . 

The designation should be done at the time of receipt and process repeated at least once in three months.

BASIS OF CATEGORIZATION OF WHEAT

The basis of categorization is by volume cum count method.From out of the sieved sample 20 cc of representative sample may be measured out with the help of a measuring cylinder.This quantity shall then be analyzed on a sample plate for  categorization of the stock.The weeviled grains as well as the the touched germ eater grains shall be picked out and measured separately.If the % of theweeevild grains aloone by the volume goes beyond 3.5% then the % of weeviled grains should be determined by count.

Category	% of weeviled grains
A	Up to 1%
B	Above 1% and up to 4%
C	Above 4% and up to 7%
D	Above 7% and up to 10%

BASIS OF CATEGORIZATION OF RICE DURING STORAGE

     
             
     

Category	Damaged grain	Discolored grain
A	Upto 3%	Upto 3%
B	above  3%  up to 4%	above  3%  up to 4%
C	above  4%  up to 5%	above  4%  up to 5%

 

D         lot showing appreciable quantity of loose bran (more than 0.5%) or giving unpleasant smell.D category rice should be issued after **** where necessary.

BASIS OF CATEGORIZATION OF PULSES DURING STORAGE

1.PULSES WHOLE :
 
CATEGORY               PERCENTAGE OF WEEVILED AND DAMAGED/DISCOLORED GRAINS

      A                                  Upto 1 by count
      B                                  Above 1 and up to 2
      C                                  Above 2 and up to 5
      D                                  Above 5 and up to 10

2.PULSES SPLIT :

Categorization is done by volumetric  method,measuring out 20 cc out of the seived sample.Tribolium  is a major pest in dals.

CATEGORY               PERCENTAGE OF WEEVILED AND DAMAGED/DISCOLORED GRAINS


      A                                  Upto 2 by volume
      B                                  Above 2 and up to 4
      C                                  Above 4 and up to 6
      D                                  Above 6 and up to 10

NON ISSUABLE STOCKS

The stocks of rice containing damaged grains above 5% shall be treated as non issuable stocks,unfit for human consumption.These stocks shall be further categorized as:

S.No	Particulars of rice	Grade	% of sound grain other than foreign matter and damaged food grains	Remarks
1	Feed	I	i)85%to less than 95%
			ii)weeviled grains alone exceeding 10%
			iii)Uric acid content alone found exceeding 100 ppm
2	Feed	II	70%to less than 80%
3	Feed	III	55% to less than 70%
4	Industrial use		i)30% to less than 55%
			ii)contaminated with poisonous chemicals and fertilizers
5	mannure use		10% to less than 30%
6	Dumping		less than 10%	To be offered as manure once before dumping.

GUIDE LINES FOR ISSUE/DISPOSAL OF RICE

All the rice stocks being stored by FCI in the central pool will be categorized under two heads:

1)Issuable stocks i.e., fit for human consumption and with in PFA standards.
2)Non-issuable stocks i.e., unfit for human consumption

ISSUABLE STOCKS:These stocks shall be further categorized as:
A)Ready stocks i.e., rice  stocks falling ith in A,B,C categories confirming to PFA standards and free  from insect  infestation.These stocks may be issued under the PDS and other welfare schemes of the Govt., of India,providd the refractions are upto 20% in excess of the uniform specifications of the relevant marketing season in respect of broken grains,discoloured grains,chalky grains,red grains,dehusked grains and the incidence of foreign matter does not exceed 1% including rice bran.However,inorganic matter should not exceed 0.5% and the impurities of animal origin not more than 0.1%.
An illustration of maximum permissable parameters of issuable stocks of rice based on single grade specifications for the  marketing season 2011-2012 is as under

S.No	Refraction	max.limits as per uniform specifications		max limits in excess of 20% existing limits rounded off to nearest one
		Gr.'A'	common	Gr.'A'	common
1	Brokens	25	25	30	30
2	Chalky	5	5	6	6
3	Reds	3	3	4	4
4	Dehusked	12	12	14	14

Note:
1.Damaged grains / moisture content as per specified limits of PFA.
2.No change is proposed in the percentage of admixture of inferior groups.

B) up gradable stocks i.e., the stock of rice having foreign matter exceeding 1% including bran,inorganic foriegn matter within 0.5%  and other  re fractions beyond the maximum limit of refractions prescribed in para 2(A) above but containing damaged grains with in PFA standards and fit for human consumption.
i)These stocks of rice should where ever possible be upgraded by cleaning, polishing,reconditioning etc.,
ii)In case, further up gradation of these stocks is not found economically feasible,after due certification from the committee,it may be disposed off by calling tenders,at rate not belo the common issues price for APL families.

TERMINOLOGY AND DEFINITIONS OF VARIOUS REFRACTIONS FOUND FOOD GRAINS

FOOD GRAINS:

Food grains shall include edible cereals, millets and pulses free from any deleterious admixture hazardous to human health
                                                                                                                                                      REFRACTIONS:
The term applies to all components of grains which differ from sound grains. The following items shall constitute the refractions.

 FOREIGN MATTER:
 Includes organic and inorganic matter. The inorganic matter shall include sand, gravel, dirt, pebbles, stones, lumps of earth, clay and mud. The organic matter shall include chaff, straw, weed seeds and other inedible grains. In case of rice, paddy shall also considered as foreign matter.
 
OTHER FOODGRAINS:
Any food grains other than the grain concerned.

VARIETAL ADMIXTURE:
The presence of variety of the same grain other than the variety under consideration shall constitute the varietal admixture.

IMMATURE:
Kernals or pieces of grain kernals that are not fully devoloped.

BROKENS:
Pieces of kernals that are less than three-fourths of the size of the full kernals.In  case of dals,pieces that are less than the size of three-fourths of the split pulse shall be considered as brokens.
  A) BIG BROKENS:
      Those pieces of rice kernals hich are equal to or smaller than three-fourths but bigger than one half of the average length of the unbroken kernal.
  B) MEDIUM BROKENS:
       Those pieces of rice kernals  which are equal to or smaller than one-half but bigger than one-quarter the average length of the unbroken kernal.
  C) SMALL BROKENS:
       Those pieces of rice kernals which donot exceed one-fourth of the average length of unbroken kernal,retained on 1.10mm IS sieve.

DAMAGED:
Kernals or pieces of kernals that are sprouted or internally damaged as a result of heat,microbes,moisture or weather.

SLIGHTLY DAMAGED OR TOUCHED:
Kernals or pieces of kernals that are damaged or discolored superficially so as not to affect the quality of the material.

DISCOLORED:
Kernals or pieces of kernals that have changed the colour in the process of handling.

INSECT DAMAGED:
Kernals that are partially or wholly bored.

CHALKY:
Kernals or pieces of kernals of which atleast half of the portion is opaque,milky hite in colour and brittle in nature.

RED GRAINS:
Kernals or pieces of kernals having more than one-fourth of the surface covered with red cuticle.

FRAGMENTS:
Pieces of kernals that are one-eighth of the size of the full kernals.

DE HUSKED GRAINS:
Kernals,whole or broken which have more than one-fourth of the surface area of the kernal covered ith bran.

FRAGMENTS IN SPLIT PULSES:
Pieces of kernals taht are one-fourth or less than the full size of the split pulse.

MOISTURE:
The loss in mass caused as a result of heating for to hours at 130 degree centigrade to 133 degree centigrade under specified conditions and expressed as percentage.

STACK HEIGHT

The following factors decide the stack height :

A) load bearing capacity of the floor

B)Nature of the commodity

C)Strength of the container to stand the weight of the stack

D)Space required above the stack for operational purpose

E)Height of the gas proof cover.

High stacks undoubtedly utilize space but there is much resentment by the labour etc., who are entrusted with building of the stack.

CALCULATIONS OF CAPACITY

1.CAPACITY IN M.T :

(Total Area-alley ways)*height in no of layers  of the bags/Area occupied by each bag*weight of one bag /1000
  
= (100-20) 5m*100/2m*1000
= 80*5*100/1000
= 40/2
= 20 M.T.

NOTE:Provision for all ways is 20% of the total area.

2.CAPACITY IN NO. OF BAGS :(100 Kg)

(Total Area-alley ways)*no.of layers of bags/area occupied by one bag/area occupied by one bag=(100-20)*5m/2m

=80*5/2

=400/2

=200 bags.

Area of the stack:(Sq.M.) = 2H(L+B)+(L*B)

                                          = 2*3.6(5.4+3)+(5.4*3)

                                          = 2*3.6(8.4)+16.2
                                          =60.48+16.20
                                          =76.68 sq.m
where L=Length in meters ; B=Breadth in meters ;H=Height in meters.

BAG ARRANGEMENT

All bags in the stack should be of uniform size and weight.The stack should be uniform and neat.The stitched mouth of the bags should not face the peripheral side of the stack.In the case of hand stitching the mouth of the bag is rolled over and stitched in 2 rows with 14 stitches in each row.In the machine stitching 3 *** thread should be used and there should be about 5 stitches about 2.5 cms.

DUNNAGE

In newly constructed godowns wooden crates are in use.These are wooden structures of 1.53 m * 0.92 m of rectangular shape.In the older godown  where the problem of seepage from the floor does not pose any damage,polythene sheet of 300 gauge sand witched between to bamboo mats is used.

TYPES OF STACKS

Proper stacking of commodities is necessary for preservation , physical verification,and accounting of stocks.An ideal stock when complete should be straight ,perfectly cuboid in shape having all bags in plane without the face of the stack bulging outward or inward at any point.Hence due care and attention should be given while building stacks.The stitched  end of the bags should always be kept inside the stacks to avoid spillage of bags on the floor due to bursting of bags.The top of the stack shall be built to form a dome in the shape of an inverted 'U' to facilitate easy flow of rain water and prevent accumilation of water on the top in case of CAP storage.The common types of stacking are as under
1.SIMPLE STACKING:
In this case the bags are placed one above the above in horizontal position.The stack cannot be more than 10 bags.This is generally done as temporary stacking in case of emergency and at the time of loading in to and unloading from wagons.
2.BLOCK TYPE:
In this type one bag is layed length wise and the other breadth wise in the same layer and the process is repeated alternately.This type of stacking is commonly in use and the advantage is that required no. of bags from a block can be removed without affecting the stability of the stack.
3.CRISS CROSS:
In this case the bags for the first layer are placed length wise and the second layer breadth wise and so on.This type of stack is very stable and desirable in case of  long storage but it is not generally in practice in food grain godowns on account of demerit that the entire stack is to be broken even if few bags are required to be taken out.

STACK PLANS

Stack plans are necessary for ordinary storage.The floor should be divided  in to uniform sized rectangles each forming a stack base.The sstandard size for a stack is 9.144m * 6.090m(30' * 20' ).There should be a minimum of 75cms (2.5')wide space between stacks and walls and between two stacks to serve as alley ways for moving about for inspection and dis infestation and also for facilitating movement of bags.In addition,depending on the dimensions of the godown ****alleyways of the door points (120cms i.e., 4' )should be provided for operational purposes.the total space left for alley ways etc., should be a minimum of 20% and maximum of 27%of the total floor area of the godown.Stack plans should be prepared in such a manner that the stacks do not obstruct light  and free flow of air into the godown.The standard sizes of fumigation covers should also be kept in views while drawing the stack plans. 

SPACE UTILISATION

The prime objective of ware house planning is maximum utilisation of space.Space planning ,therefore involves using not only length and breadth of the godown but also its height.Infact space utilisation in warehouses should provide full utilisation of cubic area of the godown as far as possible.

TYPES AND METHODS OF STACKING,MERITS AND DEMERITS,STACK CARDS &ANALYSIS SLIP

Maintenance of Food grains in good conditions,while in storage needs effective and efficient management.It calls for coordinated action both by godown and quality control staff and a constant vigil over a number of points.With the view to ensure proper and efficient handling and a storage of food grains,it becomes a       necesssary to equip each storage depot with the minimum required equipment.A list of equipment required for a storage depot is given in the chapter equiping storage depot.

OPERATIONS IN GODOWNS

The godowns mainly witness three handling operations of food grains i.e.,
1.Reciept
2.Storage and
3.Issues/Despatches
storage of grains in the godown requires precautions,which are to be carried out before actual reciept of the grain in the godown

UTILISATION OF THE SPACE:
The capacity depends upon length,breadth and height of the godown.However sometimes there are pillars and other structure which do not permit proper and regular stacking.This area has nto be deducted from the total area of the godown.
         Provision of the alley ways are also necessary for scientific storage,inspection,aeration and disinfection of stocks which reduce the space available for storage,operational storage and alleyways should not exceed 27%of the total space.

VARIOUS TYPES OF GODOWN STRUCTURES

1.CONVENTIONAL STORAGE :

               Consists of godowns with brick masonry walls and A.C sheet roofing on tublar trusses.The flooring consists of cement concrete.These godowns were constructed in three spans of 9.15 m each with vally guttem.Subsequently  godowns were contructed with 13.72 m spam that would accomodate 2 stacks of 6.09 m * 9.15 m each.a typical 5000 MT godown has 3 compartments each of 41.85 m length.In each compartment four rolling shutters are provided.Rail side platform is 3.05 m wide .The platform should not be less than 57cm on railway side.The height should not exceed 90cm. above the ground level.The storage unit should have ancillary structures.

1.Office block.

2.Isolation shed.

3.Laboratory room.

4.Canteen.

5.Chowkidars quarters.

6.weigh bridge.