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Nitrate reductase and dehydrogenase activities of Cowpea nodules as affected by ammonium sulphate and urea fertilizers
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Abstract: Cowpea seeds , vartiey Giza I , were planted in Nile silt soil . The seeds were inoculated with cowpea rizobia . Tow weeks after planting , the plant were fertilized at the rate 5,10,20 and 40 kg N/fedanin the from of ammonium sulphate and urea . After 8weeks , the plants were uprooted and assayed for fresh weight of nodules , dry weight of tops , total nitrogen , and total amino nitrogen . Samples of fresh leaves were assayed for nitrate reductase and dehydrogenase activities and phenol content .The dry weight of tops, fresh weight of nodules and total nitrogen increased progressively with the increase of the rate of fertilizers up to the rate of 20 kg N / fedan . The rate of 40 kg N / feddan caused a great decline in these inices . The response to urea was higher than to ammonium sulphate .
A significant and positive correlation existed between nitrogen fixed and total dry weight, amino and total nitrogen of tops and fresh weight of nodules . A negative correlation , but not significant , was observed between nitrogen fixed and total phenols in plants fertilized with ammonium sulphate . With urea , this trend was not clear .
Nitrate reductase activity in leaves was of positive and significant correlation with the total nitrogen of plants , receiving all rates of urea fertilizers . with Ammonium Sulphate, however , no significant correlation was found . Nitrate reductase activity in nodule homogenate was not correlated with nitrogen fixation . The dehydrogenase activity in the nodule homogenate was negatively – but non-significantly correlated with nitrogen fixation. The highest level of dehydrogenase activity in the presence of urea was obtained at the rate of 5 kg N/feddan, then started to decrease up to the rate of 20 kg N/feddan, wereupon a slight increase in activity was noted at 40 kg N/feddan. With ammonium sulphate ac appreciable increase in activity occurred with the application of 5 and 10 kg N/feddan, followed by a drop at 20 kg N/feddan. A sharp increase at the rate of 40 kg N/feddan was observed.
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| Publication year |
1978
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| Pages |
400-407
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| Organization Name |
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| City |
القاهرة
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| serial title |
Zbl, Bakt. ΙΙ. Abt., Bd
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| Author(s) from ARC |
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| Agris Categories |
Weeds and weed control
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AGROVOC
TERMS |
Nitrate reductase.
Vigna.
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| Proposed Agrovoc |
dehydrogenase activ;Urea fertilizers;Urea fertilizers;
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| Publication Type |
Journal
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