Abiotic and Biotic Stress Factors Affecting Storage of Legumes in Tropics

Abstract

Tropical regions such as South Asia (SA) and Sub-Saharan (SSA) do have storage environment that may impose abiotic and/or biotic stress or. This book chapter aims to broaden current knowledge on the ‘Abiotic and Biotic Stress Factors Affecting Storage of Legumes in Tropics’. This book chapter is prepared by including all relevant studies and detailed literatures using various scholastic search approaches. Typically, published papers and abstracts are identified by a computerized search of electronic data bases that include PubMed, Science Direct, Scirus, ISI Web of Knowledge, Google Scholar and CENTRAL (Cochrane Central Register of Controlled Trials). Thus, diseases, insects, etc…, are biological factors that cause biotic stress in plants while abiotic stress is caused by either physical or chemical factors. Biotic and abiotic stresses create adverse effects on multiple procedures of morphology, biochemistry and physiology that are directly connected with growth and yield of legume grains. It is, therefore, clear that the most important factors of food grains loss are moisture, temperature, metabolic activity and respiration, insects, mites, micro-organisms, rodents, birds and storage structures. Initial grain condition or quality of the seed for storage can indirectly be affected by abiotic stresses like water scarcity, high salinity, extreme temperatures, and mineral deficiencies or metal toxicities which reduce the crop’s productivity. For maintenance of storage of initial grain’s quality, grain must be dried and cooled prior to storage, the store must be constructed for blocking rodents and birds, enabling protection from sun and light entrance, allowing aeration to keep the temperature uniform in the store. Also, bringing the temperature of the grain down to below 12°C is necessary, since this temperature is a threshold at which microorganisms’ reproductive activity is inhibited. Storage spaces with higher relative humidity (95%) and a temperature of 35°C, are detrimental for storage of legume grains. In general, legume grains should be attaining a temperature of about ≤ 10 °C before placing them in store. For storage safety, it is preferable to place the grain in the storage at moisture content of 13%, or less than 14% on wet basis. Also, combining drying and storage facilities in one and the same structure is economical, and allows further conditioning at later stages if required. In order to reduce postharvest loss from customs of traditional storage by farmers in tropics, governments should mobilize and integrate multidisciplinary management system of storage loss, and monitor precautionary measures of the stored grain throughout the storage period. They should be facilitating the selection and promotion of alternative, cost-effective and appropriate storage structures considering suitability to local conditions and sustainability.