110 TECHNOLOGY OF CEREALS a minty smell and hairs from the animals bodies however, have several advantageous features can cause skin and lung disorders in workers Thus underground stores provide protection from handling infected flour. Silk from the larvae of temperature fluctuations, the most successful the Mediterranean four moth webs together simple ones being found in hot dry regions. They causing agglomeration of grains and blockages in are filled, to leave little air space, and sealed , to handling and processing equipment. In tropical approach the concept of hermetic storage under countries termites can weaken the structure of a which insects and moulds rapidly use up oxygen store, leading to its collapse giving rise to high CO2 content of the intergrain atmosphere. In more humid regions ventilation Vertebrate pests is de ble as the crop may have to be stored before reaching a safe moisture level. Such a The principal vertebrate pests in cereal stores system is suited to cob maize rather than threshed are rodents and birds. In many countries the three grains, as adequate space for air movement within main rodent species involved are: the store is essential. Clearly the requirements Rattus norvegicus -the Norway, common of ventilation and exclusion of insects are not immediately compatible and hence careful design Ratus rattus is essential Mus musculus the roof, ships or black rat; Storage of maize as cobs is practised now largely by small scale growers producing for the apart from consuming grains, particularly the requirements of the local community. It was at embryo of maize, rodents cause spoilage through one time adopted more widely even in highly their excretions which contain micro-organisms commercial practice, much as small grain cereals pathogenic to man. These include salmonellosis, were stored unthrashed in ricks murine typhus, rat-bite fever and Weils disease In the commercial context stores are needed Rodents also damage stores'structural elements, for three purposes containers, water pipes and electric cables In well-managed stores access by rodents 1. Holding stocks on the farm prior to sa denied and good housekeeping practice, such 2. Centralization before distribution or processing as removal of grain spillages, maintenance of during the year following harve uncluttered surroundings and regular inspec- 3. Storage of annual surpluses over a longer tions, prevent problems. The same is true of birds. These are serious pests only when access Farm stores may consist of any available space is easy, as for example in hot countries where that will keep out the elements. The facilities for grain may be left to dry in the sun. Damage to protection against mould and pests are very drains and blockage of pipes by nests can variable Stores range from small wooden enclos give rise to secondary storage problems through ures in the barn, to round steel bins holding 25- promoting local dampness in some stores 80 tonnes, to silos of larger capacities. Good on farm storage facilities allow farmers to choose the Design of storage facilities time to sell, to receive the best prices The degree of centralization depends upon the The requirements of long term safe storage are marketing regime within the country of produc protection against dampness caused by weather tion. In North America, Country elevators and or other sources, micro-organisms, destructively Terminal elevators with storage capacity up to high temperature, insects, rodents and birds, 500,000 tonnes exist. The country elevators provide objectionable odours and contaminants and un- a local staging en route to terminal elevators which authorized disturbance. Clearly the simplest stores include high-capacity equipment for cleaning such as piles on the ground, unprotected are suit- drying and conditioning of grain. The term able for short periods only. Other simple stores, 'elevator'is applied to the entire facility although110 TECHNOLOGY OF CEREALS a minty smell and hairs from the animals’ bodies however, have several advantageous features. can cause skin and lung disorders in workers Thus underground stores provide protection from handling infected flour. Silk from the larvae of temperature fluctuations, the most successful the Mediterranean flour moth webs together simple ones being found in hot dry regions. They causing agglomeration of grains and blockages in are filled, to leave little air space, and sealed, to handling and processing equipment. In tropical approach the concept of hermetic storage under countries termites can weaken the structure of a which insects and moulds rapidly use up oxygen, store, leading to its collapse. giving rise to high C02 content of the intergrain atmosphere. In more humid regions ventilation is desirable as the crop may have to be stored before reaching a safe moisture level. Such a Vertebrate pests The principal vertebrate pests in cereal stores system is suited to cob maize rather than threshed are rodents and birds. In many countries the three grains, as adequate space for air movement within main rodent species involved are: the store is essential. Clearly the requirements of ventilation and exclusion of insects are not immediately compatible and hence careful design Rattus nomegzcus - the Norway, common or brown rat; is essential. Rattus rattus -the roof, ships or black rat; Storage of maize as cobs is practised now largely by small scale growers producing for the Mus musculus - the house mouse. Apart from consuming grains, particularly the requirements of the local community. It was at embryo of maize, rodents cause spoilage through one time adopted more widely even in highly their excretions which contain micro-organisms commercial practice, much as small grain cereals pathogenic to man. These include salmonellosis, were stored unthrashed in ricks. murine typhus, rat-bite fever and Weil’s disease. In the commercial context stores are needed Rodents also damage stores’ structural elements, for three purposes: 1. Holding stocks on the farm prior to sale. containers, water pipes and electric cables. 2. Centralization before distribution or processing In well-managed stores access by rodents is denied and good housekeeping practice, such during the year following harvest. as removal of grain spillages, maintenance of 3. Storage of annual surpluses over a longer uncluttered surroundings and regular inspec- period. tions, prevent problems. The same is true of birds. These are serious pests only when access Farm stores may consist of any available space is easy, as for example in hot countries where that will keep out the elements. The facilities for grain may be left to dry in the sun. Damage to protection against mould and pests are very drains and blockage of pipes by nests can variable. Stores range from small wooden enclos￾give rise to secondary storage problems through ures in the barn, to round steel bins holding 25- promoting local dampness in some stores. 80 tonnes, to silos of larger capacities. Good on￾farm storage facilities allow farmers to choose the time to sell, to receive the best prices. The degree of centralization depends upon the Design of storage facilities The requirements of long term safe storage are marketing regime within the country of produc￾protection against dampness caused by weather tion. In North America, Country elevators and or other sources, micro-organisms, destructively Terminal elevators with storage capacity up to high temperature, insects, rodents and birds, 500,000 tonnes exist. The country elevators provide objectionable odours and contaminants and un- a local staging en route to terminal elevators which authorized disturbance. Clearly the simplest stores include high-capacity equipment for cleaning, such as piles on the ground, unprotected, are suit- drying and conditioning of grain. The term able for short periods only. Other simple stores, ‘elevator’ is applied to the entire facility although