Experiments in Niger assessed whether extreme environmental conditions including sunlight exposure affect the performance of triple-layer PICS bags in protecting cowpea grain against bruchids. Sets of PICS bags and woven polypropylene bags as controls containing 50 kg of naturally infested cowpea grain were held in the laboratory or outside with sun exposure for four and one-half months. PICS bags held either inside or outside exhibited no significant increase in insect damage and no loss in weight after 4.5 months of storage compared to the initial values. By contrast, woven bags stored inside or outside side by side with PICS bags showed several-fold increases in insects present in or on the grain and significant losses in grain weight. Grain stored inside in PICS bags showed no reduction in germination versus the initial value but there was a small but significant drop in germination of grain in PICS bags held outside (7.6%). Germination rates dropped substantially more in grain stored in woven bags inside (16.1%) and still more in woven bags stored outside (60%). PICS bags held inside and outside retained their ability to maintain internal reduced levels of oxygen and elevated levels of carbon dioxide. Exposure to extreme environmental conditions degraded the external polypropylene outer layer of the PICS triple-layer bag. Even so, the internal layers of polyethylene were more slowly degraded. The effects of exposure to sunlight, temperature and humidity variation within the sealed bags are described.

中文翻译：

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尼日尔萨赫勒地区极端条件下 PICS 袋的性能

在尼日尔进行的实验评估了包括阳光照射在内的极端环境条件是否会影响三层 PICS 袋在保护豇豆粒免受黑斑病方面的性能。将含有 50 公斤天然感染豇豆粒的 PICS 袋和聚丙烯编织袋作为对照，在实验室或室外放置四个半月的阳光照射。与初始值相比，放置在内部或外部的 PICS 袋在存放 4.5 个月后，昆虫损害没有显着增加，重量也没有损失。相比之下，与 PICS 袋并排存放在内部或外部的编织袋显示，谷物内部或谷物上的昆虫增加了几倍，并且谷物重量显着减少。与初始值相比，储存在 PICS 袋内的谷物发芽率没有降低，但在外面的 PICS 袋中谷物的发芽率有小幅但显着的下降（7.6%）。储存在内部编织袋中的谷物的发芽率大幅下降（16.1%），而储存在外部编织袋中的谷物发芽率下降幅度更大（60%）。内部和外部的 PICS 袋保持其内部氧气含量降低和二氧化碳含量升高的能力。暴露在极端环境条件下会降低 PICS 三层袋的外部聚丙烯外层。即便如此，聚乙烯的内层降解得更慢。描述了暴露在阳光下、密封袋内温度和湿度变化的影响。6%）。储存在内部编织袋中的谷物的发芽率大幅下降（16.1%），而储存在外部的编织袋中（60%）的发芽率下降更多。内部和外部的 PICS 袋保持其内部氧气含量降低和二氧化碳含量升高的能力。暴露在极端环境条件下会降低 PICS 三层袋的外部聚丙烯外层。即便如此，聚乙烯的内层降解得更慢。描述了暴露在阳光下、密封袋内温度和湿度变化的影响。6%）。储存在内部编织袋中的谷物的发芽率大幅下降（16.1%），而储存在外部编织袋中的谷物发芽率下降幅度更大（60%）。内部和外部的 PICS 袋保持其内部氧气含量降低和二氧化碳含量升高的能力。暴露在极端环境条件下会降低 PICS 三层袋的外部聚丙烯外层。即便如此，聚乙烯的内层降解得更慢。描述了暴露在阳光下、密封袋内温度和湿度变化的影响。内部和外部的 PICS 袋保持其内部氧气含量降低和二氧化碳含量升高的能力。暴露在极端环境条件下会降低 PICS 三层袋的外部聚丙烯外层。即便如此，聚乙烯的内层降解得更慢。描述了暴露在阳光下、密封袋内温度和湿度变化的影响。内部和外部的 PICS 袋保持其内部氧气含量降低和二氧化碳含量升高的能力。暴露在极端环境条件下会降低 PICS 三层袋的外部聚丙烯外层。即便如此，聚乙烯的内层降解得更慢。描述了暴露在阳光下、密封袋内温度和湿度变化的影响。