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by
K.G. El-Rokiek |
Total Records (
3 ) for
K.G. El-Rokiek |
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K.G. El-Rokiek
,
T.A. El-Shahawy
and
L.K. Balbaa
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Two greenhouse experiments were conducted in this regard on barley cv. Giza 122 during the period of (2004-2006). α-tocopherol and grasp were used in different concentrations (50, 100, 150 and 250, 500, 1000 mg L-1, respectively), as a post-emergence application either alone or in combination at 3-4 leaf stage. Grasp was extremely effective for controlling grassy weeds rather than broad leaves. However, the associated phytotoxic effect against barley growth was disappointed. The bleaching effect was a distinctive feature throughout. Albeit not permanent, the effect was extended to catch yield and its attributes as compared with hand weeded control. α-tocopherol fairly increased barley growth and its productivity at the different rates of application. Increasing the competitive and allelopathic capabilities of crop plants at the expense of associated weeds could be the reasons behind this fact. Applying α-tocopherol in combination with grasp was more promising than the individual application of either of them. It caused weed growth decreased to a minimum. Barley growth and its productivity increased to their best values in this regard. The chemical analysis revealed on more superiority of the combined application treatments in increasing the photosynthetic pigments (chlorophyll a, b and carotenoids) and amino acids grain yield than the singlet or even hand weeded treatments. It has been suggested that using α-tocopherol in combination with grasp is an excellent tool for reducing the bad effect of the herbicide against growth and development of grassy crops e.g., barley. Such compensatory effect of α-tocopherol might be arise from its ability to quench herbicide's free radicals before they react with intercellular biological systems. Grasp at 500 mg L-1 plus α-tocopherol at 100 mg L-1 is highly recommendable for achieving the best result. |
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T.A. El-Shahawy
,
L.K. Balbaa
and
K.G. El-Rokiek
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A pot trial was conducted to study the potential effect of Glutathione (GSH) and Ascorbic acid (ASA) either applied alone or in combination at different rates of concentration (50-250 and 25-100 mg L-1, respectively) on controlling weeds and yield productivity of marjoram (Origanum majorana L.). The two compounds and their combinations were applied as a post-emergence application after 30 days from sowing. Applying the two compounds alone at different concentrations significantly inhibited the broad and narrow-leaved weeds by up to 56 and 60%, respectively. The combined effect of the two compounds was more efficient in this regard (up to 100% weed reduction) than the individual application. Marjoram growth and development was seriously affected (up to 63% growth induction) at all levels of studied criteria. The effect was more pronounced on increasing the elementary components of total sugar, total nitrogen and oil yield (up to 91%); irrespective of the rate and sort of application. The in vitro study of the allelopathic influence of marjoram oil extracts against seed germination (%) and seedling root and shoot length of certain broad and narrow-leaved weeds (e.g., Amaranthus cruentus and Echinochloa crus-galli) revealed of more superiority of the treated plants rather than the untreated one. GLC analysis also showed a significant increasing in the terpene (oxygen-containing monoterpenes in particular) and phenolic substances in the treated plants. It has been suggested that applying GSH or ASA either alone or in combination might have a direct and/or indirect impact on increasing the allelopathic capacity of marjoram plants by increasing their content of the terpene and phenolic substances, which could be the key factor of the allelopathic influence of marjoram plants in their vicinity. |
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F.A. Sharara
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T.A. El-Shahawy
and
K.G. El-Rokiek
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Field experiments were conducted in two successive seasons to investigate the effect of some novel herbicides and/or hand hoeing treatments on controlling weeds and increasing maize (Zea mays L.) productivity. One pre-emergence herbicide (Gesaprim) and two post-emergence herbicides (Bentazone and Fluroxypyr) were applied at different concentrations either alone or followed by hand hoeing once treatment. Applying the three herbicides alone at different concentrations substantially reduced the weeds associated with maize as compared with controls. Gesaprim at 0.5 and 0.75 kg/feddan was the most effective herbicide for controlling both narrow and broad-leaved weeds as compared with the other two herbicides, irrespective of rate of application. Applying the three herbicides at lower concentrations, followed by one hand hoeing treatment gave, to a large extent, similar results to those herbicides applied alone at the highest and moderate concentrations for controlling a wide range of weeds and significantly increased the maize yield (52-74%) as compared with control. However, hand hoeing twice treatment was the most effective treatment for controlling the weeds and increasing the maize productivity (86-88%), either compared with control or other chemical treatments. Some difference was found between applying the three herbicides either alone or in combination with hand hoeing for increasing protein content in maize grain as compared with control. It has been suggested that applying the herbicides and/or hand hoeing for controlling weeds in maize must be considered in relation to the costs and environmental impact. |
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