Action of Photosynthetic Diuron Herbicide on Cell Organelles and Biochemical Constituents of the Leaves of Two Soybean Cultivars

The effects of the herbicide methabenzthiazuron (175 and 220 g ha-1) on vegetative and reproductive growth, nodulation and nitrogenase activity of Vicia faba were studied in the field under Mediterranean conditions. Nitrogenase activity of excised nodules was estimated using the acetylene reduction assay four times during the developmental period. Leaf area index, dry weight and nitrogen content of the different parts of the plants were measured. Methabenzthiazuron-treated plants showed an increase in nodulation, nitrogenase activity and vegetative growth at early pod fill. Methabenzthiazuron also caused an increase in leaf N content and fruits. These were transient effects found during early and mid pot fill. Nevertheless, plants treated with these sublethal doses of herbicide improved seed production and nitrogen content of seeds at harvest time. The stimulatory effect of methabenzthiazuron on N2 fixation and vegetative growth seems not be related with the transient stimulatory effect on photosynthetic capacity, also caused by the herbicide, since the stimulatory effect on N2 fixation was apparent during pod fill, when photosynthetic capacity declined and was not modified by methabenzthiazuron.

Effect of methabenzthiazuron on growth and nitrogenase activity in Vicia faba

Literature data on structure of coordination sphere of selected monoatomic cations in aqueous and methanol solutions have been reviewed and compared. The following structural parameters have been considered: coordination number, interparticle distances, the second coordination sphere features, and ionic association type. It has been revealed that for doubly charged ions the parameters of the first coordination sphere are similar in the both solvents. The second coordination sphere of the same cation consists of fewer solvating molecules located farther from the ion in the case of methanol as compared to water.

Comparative review of structural parameters of the nearest surrounding of monoatomic cations in water and methanol media

https://jesj.journals.ekb.eg/article_192105_ccc86de6e7ab2bc4705c20e5d64dfb79.pdf

Alteration in protein contents and polypeptides of peanut plants due to herbicides and salicylic acid treatments

Comprehensive research and studies are going on to find out effect and degree of toxicity of pesticides and alternative approaches to minimize the toxic effects of pesticides. The present experiment was hence conducted to study the toxicity of pesticide malathion on growth and metabolic activities of an important pulse crop moong (Phaseolus radiatus) and role of micronutrients iron and zinc on this toxicity. Root length, Shoot length and Germination percentage of moong plants were found to be decreased with increasing doses of pesticide. Decrease in root growth and shoot growth were upto 41% and 79% respectively and germination percentage was recorded as low as 59% at 5% dose of pesticide. When micronutrients, 5.6ppm Fe or 15ppm Zn, were supplied with 2% malathion on moong plants they both showed resistance to the ill effects of pesticides. Decrease in root growth was as low as 1.84% when Fe was supplied along with 2% malathion, while germination percentage was increased when moong seeds were soaked in combined dose of 2% pesticide with Zn. Chlorophyll, protein content and catalase activity decreased while peroxidase activity increased significantly with increasing doses of malathion. Protein content at higher doses viz. 2% and 5% was 49.11 mg./gm.f.wt. and 21.78 mg./gm.f.wt. as compared to 115.65 mg./gm.f.wt. in control. Both Fe and Zn supplemented with 2% basal dose negated the ill effects of pesticide on protein content significantly. Supplementation of Fe also enhanced the chlorophyll content significantly. Catalase and peroxidase activities were found to increased due to supplementation of Fe whereas decrease in these parameters were observed due to supplementation of Zn with 2% pesticide. Thus it can be inferred that higher dose of malathion can be applied on moong plants if supplemented with 5.6ppm Fe without compromising the plant growth and its antioxidant potential.

Role of Iron and Zinc in Mitigating Phytotoxic Effects of Pesticide Malathion on Moong Plants ( Phaseolus radiatus )

We have studied the effect of three herbicides viz., triazole, pyrazon and metribuzin on total chlorophyll, carotenoids and cell protein in leaves, and PS II and PS I activity in the chloroplasts isolated from control and herbicide treated pea plants. Pyrazon and metribuzin at 10μм concentration affect these parameters resulting in the chlorosis of the leaves.

K. N. Singh

Papers

Interaction of herbicides with pea chloroplasts