Issue |
Agron. Sustain. Dev.
Volume 25, Number 4, October-December 2005
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Page(s) | 497 - 504 | |
DOI | https://doi.org/10.1051/agro:2005050 |
DOI: 10.1051/agro:2005050
Effect of herbicides on growth, nodulation and nitrogen content of greengram
Almas Zaidia, Md. Saghir Khana and Pervez Qamar Rizviba Department of Agricultural Microbiology, Institute of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
b Department of Plant Protection, Institute of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
(Accepted 10 June 2005)
Abstract - We studied the effects of glyphosate, metribuzin, fluchloralin and 2,4-dichlorophenoxy-acetic acid (2,4-D) on plant vigor, nodulation, photosynthetic pigments, N content, seed yield and protein content in seeds, in greengram inoculated with Bradyrhizobium sp. (vigna). The pre-emergence application of the four herbicides, at 2 mg a.i. g-1 of soil, adversely affected the parameters. The average maximum increase of 12.5% in seed yield occurred at 0.5 mg a.i. g-1 of glyphosate, while metribuzin at 0.5 and 1 mg a.i. g-1 decreased the seed yield by 33.3 and 55.5%, respectively. The average maximum chlorophyll content of 3.41 mg/g was obtained at 0.5 mg a.i. g-1 (fluchloralin), which declined consistently for all herbicides and increasing dose rates. Glyphosate at 0.5 mg a.i. g-1 increased the number of nodules formed per plant by 12.5% and 14.3% at 35 and 60 days after seeding the greengram. In contrast, metibuzin (0.5 and 1 mg a.i. g-1) and the higher rates of 2 mg a.i. g-1 of glyphosate, fluchloralin and 2,4-D significantly reduced the nodulation (nodule number and dry mass). The average maximum grain protein of 24% was obtained for glyphosate at 0.5 mg a.i. g-1 while minimum grain protein was obtained at 0.5 (10%) and 1 mg a.i. g-1 (8%) of metribuzin application. Nitrogen content in whole plants decreased gradually with herbicide rates both at 35 and 50 days after seeding. Among the herbicides tested, metribuzin showed a large degree of phytotoxicity to the crop, inhibiting its vegetative growth, and was thus incompatible with greengram.
Key words: greengram / herbicides / nodulation / seed protein
Corresponding author: Md. Saghir Khan khanms17@rediffmail.com
© INRA, EDP Sciences 2005