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Environmental contamination, herbicide resistance development among weeds and health concerns due to over and misuse of synthetic herbicides has led the researchers to focus on alternative weed management strategies. Allelochemicals extracted from various plant species can act as natural weed inhibitors. In this study, allelopathic extracts from four plant species sorghum [Sorghum bicolor (L.) Moench], mulberry (Morus alba L.), barnyard grass [Echinochloa crusgalli (L.) Beauv.], winter cherry [Withania somnifera (L.)] were tested for their potential to inhibit the most problematic wheat (Triticum aestivum L.) weeds wild oat (Avena fatua L.) and canary grass (Phalaris minor Ritz.). Data regarding time to start germination, time to 50% germination, mean germination time, final germination percentage, germination energy, root and shoot length, number of roots, number of leaves, and seedling fresh and dry weight was recorded for both the weeds, which showed that mulberry was the most inhibitory plant species while sorghum showed least allelopathic suppression against wild oat. Mulberry extracts resulted in a complete inhibition of the wild oat germination. The allelopathic potential for different plants against wild oat was in the order: mulberry > winter cherry > barnyard grass > sorghum. Mulberry, barnyard grass and winter cherry extracts resulted in a complete inhibition of canary grass. Sorghum however exhibited least suppressive or in some cases stimulatory effects on canary grass. Plants revealing strong allelopathic potential can be utilized to derive natural herbicides for weed control.
The infestation of aphids in wheat is becoming a serious problem nowadays and it might become a threat to the future wheat crop in Pakistan. With this problem in mind we did a study pertaining to aphid dynamics in relation to meteorological factors and various management practices in bread wheat. The study was carried out at the Wheat Research Institute, Faisalabad, Pakistan. The aim of this study was to investigate how meteorological factors play a role in the fluctuating aphid population and how different management practices could be effective in combating aphids. The results revealed that a peak aphid population was recorded during the beginning of the third week of March for both of the study year periods of 2007-2008 and 2008-2009. Aphid density was positively associated with maximum as well as minimum temperature while it showed a negative correlation with relative humidity. However aphid population was positively but not significantly affected by rainfall. Early sowing on 1st November produced the least aphid infestation hence early sowing was encouraged as a cultural practice for keeping aphids below damaging levels. The recently developed wheat varieties like: SHAFAQ-06, SEHER-06, FSD-08 and LASANI-08,revealed aphid resistance and performed better against aphids. On the other hand the genotypes V-05003, BARS-09 and 0BT006, revealed maximum vulnerability to aphids. Number of aphids per tiller was positive correlated with loss in grain yield. Application of insecticide significantly controlled the aphid population which suggested that a combination of host plant resistance with chemical control could restrain the aphid infestation in wheat.
Background. Understanding of oil deterioration during heating/frying process is important as oils are normally kept hot at commercial food outlets during intermittent frying cycles. An increased level of consumer awareness toward fat composition and its impact on human health could have an effect on selection of fats in the food industry. The rate of quality deterioration during heating depends on fatty acid composition and also the content and composition of minor components. Therefore, the use of more stable frying oils would be desirable. The present study compares the heat stability at frying temperature of regular sunflower oil (RSFO) with that of high-oleic acid sunflower oil (HSFO). Material and methods. Heating test was carried out at 185 ±5°C for the samples RSFO and HSFO using electric fryer for 8 h/day for 3 consecutive days. The samples were collected every 4 h. The changes in physicochemical properties of the samples were monitored by analytical and instrumental methods. Results. In this study, reffactive index, free fatty acid content, peroxide value, p-anisidine value, TOTOX value and polar compounds of the oils all increased, whereas Clg.2/C16.0 ratio decreased as heating progressed. The percentage of linoleic acid tended to decrease, whereas the percentages of palmitic, stearic and oleic acids increased. The sample HSFO exhibited better heating performance compared to RSFO. However, a higher amount of free fatty acids was found in HSFO compared to RSFO at the end of heating trial. Moreover, heating process decreased the total tocopherol content and higher reduction was detected in RSFO. Conclusion. In conclusion, the heating caused the formation of comparatively lower amounts of some degradative products in HSFO compared to RSFO indicating a lower extent of quality deterioration of HSFO.
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