各類農(nóng)產(chǎn)品貯藏技術(shù)課程介紹(完整版)
【正文】 the effects of sun, wind and rain.n The logic of this is inescapable。 that is from, say, 150 to 15 days.mouldsn Mould growth is also regulated by the proportions of oxygen, nitrogen and carbon dioxide in the intergranular atmosphere. n Many moulds will grow at very low oxygen concentrations。t use a spreader and periodically remove fines that accumulate in the bin center during filling (Figure 1). n Figure 1. Removing fines during bin filling. Use Aeration to Cool Grain n Keeping grain cool reduces mold and insect activity. Activity slows at temperatures below 60 degrees F and almost ceases below 40 degrees F. Because daytime temperatures are usually greater than 60 degrees F in late summer and early fall, it might be necessary to operate fans at night to start the cooling process. Don39。 sawtooth grain beetle (Oryzaephilus surinamensis)。C. However, the same maize stored at 30176。C will be substantially damaged by moulds within three months.mouldsn Insects and mites (arthropods) can, of course, make a significant contribution towards the biodeterioration of grain, through the physical damage and nutrient losses caused by their activity. n They are also important, however, because of their plex interaction with moulds and, consequently, their influence on mould colonisation.mouldsinsectsn In general, grain is not infested by insects below a temperature of 17176。 and confused flour beetle (Tribolium confusum).n 常見的貯糧害蟲有米黑蟲、黃粉蟲、玉米象、豌豆象、蠶豆象、綠豆象、麥蛾、谷蠹、螨類等 Temperature and moisturen Notwithstanding the storage facility, two factors are critical to the retention of grain quality for a long period of time: the temperature and moisture content of grain.n Seeds in a single head do not ripen uniformly but over a period of about 3 to 10 days. At this stage, the average moisture content of the seed is about 25 to 30%. This moisture is too high for bin storage. n For storage in winter, the grain moisture should be more than 14% in most case. n In the Coastal Plains and Gulf Coast, a lower moisture content of 11 to 12% is remended. n Lower percent of moisture (1% lower on the average) is required in the summer months. n A bination of high moisture (13% or greater) and high temperature (70℉,or ℃ ) promotes infestation by microanisms and insects that leads to spoilage. n Under such conditions, the grain respires, producing heat, carbon dioxide, and water.n This additional water further increases grain moisture content. n The respiratory activities of the anism raise the heat in the grain bin, sometimes to 90176。t be cleaned. n After the bin and equipment are cleaned, consider spraying the bin with an approved, residualtype insecticide. Make Sure Grain is Dry Enough n Insects and molds are less active in dry grain, so make sure wheat is 14% moisture or less for 9 months storage and 13% moisture or less for more than 9 months storage. n Barley should be about percentage points drier than these values. Insecticide Treatment n If grain will be stored into next summer or if you often have problems with insects, consider applying a grain protectant as the crop is moved into storage. Contact your county extension office for the latest information on approved protectants. Contact potential buyers to see if they will accept treated grain—some will not. Rusty Grain Beetle on Wheat Red Flour Beetle on Wheat Mites on Wheat AspergillusManage Fines n Fines tend to congregate in pockets in storage bins, they restrict airflow, and they are more susceptible to attack by molds and insects. Try to limit the amount of fines in storage by setting bines for minimum grain damage and maximum cleaning, operate grain augers slowly and full of grain to reduce kernel breakage, and consider cleaning grain before storage to r
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