This book gives a review about the grain quality of wheat under the post harvest storage system. It has been observed that very high percentage of wheat kernels has been lost under post harvest storage. The work done on the biotic stresses of post harvest stored wheat grains is scanty. Therefore, it became very much necessary to estimate the quality of wheat grains under storage. This may help to minimize the spoilage of stored grains as the wheat crop is playing a vital role in the Indian economy which is contributing around 32% of total food grain basket of the country.The biotic and abiotic factors influence the various physical and chemical properties of wheat grains under post harvest storage. The various physical, microbial and biochemical analyses of post harvest storage wheat grain is an essential component to evaluate the grain quality in various Indian wheat varieties and also important for facilitating the minimal post harvest food grain loss. Readers are encouraged to use the unbiased information provided in this book to formulate rational opinions about the wheat. It is also hoped that readers will appreciate the wonder of nature and the creative ways.
Pakistan annually produces about 25 million tons of wheat & 6 million tons of rice. Storage of these grain is undertaken for various domestic and commercial reasons. During storage heavy quantitative and qualitative losses are known to occur that reduce the food availability and render monitory losses. Major shortcomings in this regard are poor sanitary conditions, leaky and poorly maintained warehouses and ill trained storage officials. Storage losses are not only a problem in wheat and rice but also effect the other stored grains. During storage, insect pests are known to cause considerable damage and weight loss to these commodities. In this study seven (7) methods of loss assessment were examined to investigate the actual losses in stored IRRI-6 and Basmati varieties of rice and wheat stored in public sector godowns. Studies have concluded that during one year storage 1-2% average loss on dry basis was recorded depending upon various factors. Study also pin pointed the areas of future research.
Wheat crop is relatively safe from insects in field but the grains suffer considerably high losses during storage. Rhizopertha dominica, the most commonest species, commonly known as lesser grain borer has an important position among the stored grain pests and caused considerable damage to wheat in storage. The losses during storage by the pests are not only in terms of quantity, but also in quality of the food grains. The qualitative losses are attributed to changes in chemical components of grains. It was found that grain with over 0.5% kernel infestation was unfit for milling, and that wheat flour containing over 10 mg uric acid/100 g from insect contamination was unacceptable to consumers. Therefore, investigation carried out on growth and development of Rhizopertha dominica Fabr. on different wheat varieties to find out relative degree of resistance in relation to their physical and chemical traits and to evaluate the efficacy of indigenous plant products as grain protectants.
The newly enhanced diatomaceous earth formulation and Metarhizium anisopliae was evaluated for its insecticidal efficacy against stored grain pests. For this validation 1 kg lot of all grains were treated with three dose rates 50, 100 and 150 ppm of DE. Samples were taken at the day of 1st storage and each 45 d until the end of a 180 day era of storage. Mortality of adults after 14 days of disclosure was >80% on wheat at the beginning of storage than rice, maize and sorghum. During the first 90 days, adult mortality was increased and progeny emergence was less in the beginning of storage. Mixture of new enhanced DE Gain-Guard and Metarhizium anisopliae against stored grain pests was applied at the application rate of 1.7?104 conidia alone or in combination of enhanced DE with two dose rates 25 and 50 ppm on wheat. New enhanced DE was more effective than fungal conidia alone. The new insecticide based DE in the fungal conidia at the highest dose rate provided antagonistic interactions while with low dose rate additive interactions. The cadavers offered maximum percentage of mycosis and sporulation when fungi were tested alone while low was observed in mixture of both.
Effect of different grades of black pointed seeds on leaf blight severity and healthy seed production of wheat was conducted in field conditions. The grades were; 0= apparently healthy looking seeds (Free from infection), 1= only embryo blackish, 2= embryo and its adjacent area slightly infected, 3= embryo and less than ? of grains are discolored, 4= embryo and ? of grains are infected and 5= grains are shriveled, almost completely discolored or more than ? of grains are discolored. Seedling emergence and vigor index were significantly decreased with the increase of severity grades of black pointed seed. Significantly highest and lowest leaf blight severity was recorded on the plants raised from grade 5 seeds and grade 0 seeds respectively. The highest 1000 seed weight and grain yield was recorded from the plots where apparently healthy seeds were sown. The apparently healthy seeds (grade 0) increased 29.69% grain yield over grade 5 seeds. Findings of the present study emphasized the sowing of physically sorted apparently healthy looking seeds to minimize leaf blight severity and increasing quality yield of wheat.