Academic literature on the topic 'Different mustard varieties'

The objective of our research is to screen and search for suitable plant species for phytoremediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds. Phytoremediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phytoextraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phytoextraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyperaccumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl2, and Hg(NO3)2, were used as contaminant sources. Different types of soil were examined and chosen for phytoremediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phytoremediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots (<65 mg/kg), even though root mercury accumulation is significant (maximum 2298 mg/kg). Consequently, this plant species may not be suitable for mercury phytoremediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phytoextraction. During one experiment, Chinese brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 parts-per-million (ppm) and 1000 ppm HgCl2 powder, respectively; no visual stress symptoms were observed. We also studied mercury phytoremediation using aged soils that contained HgS, HgCl2, or Hg(NO3)2. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in floodplain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties.

Organic farming aimed at obtaining environmentally friendly food of the highest quality category is still relatively rare in Russian agriculture. Such agriculture is characterized by minimal use (up to complete abandonment of the use) of various pesticides and other agrochemicals. Tillage with such a farming system is also reduced to a minimum. At the same time, the use of siderates is of great importance. The most famous of them is seradella. But this culture is most widespread in the southern regions. In Western Europe, it has already been used for this purpose for hundreds of years. Other crops are also used on the territory of our country and these are mainly forage plants: yellow lupin, narrow-leaved lupin, white lupin, cocksfoot, pasture ryegrass, white mustard, Sarepta mustard, spring rapeseed, winter rapeseed, spring vetch, winter shaggy vetch, meadow clover and many others. To create specialized varieties for these purposes, the main thing is to select plants that will be able to suppress the development of weeds to the maximum extent, increase soil fertility and make difficult-to-dissolve nutrients available. In our country, there is a huge amount of difference in soil and climatic features (temperature, precipitation and their distribution by season, etc.); therefore, the creation of one variety of each crop for the whole country is extremely difficult. The requirements for siderates and the normal use of plants of the same crop differ dramatically. For example, the presence of prussic acid, glucosinolates and other substances toxic to animals in forage plants is unacceptable, and their presence in sideral crops is usually not harmful, but often useful. There are also differences in the requirements for the sowing rate, the rate of development and durability of such varieties. Therefore, the standards for breeding varieties intended for sideral steam or cover crops differ significantly from the requirements for the variety for other purposes – such varieties should differ in rapid seed germination, rapid growth of green mass, such varieties may not differ in durability, since they are used during one season, often they do not need winter hardiness. Work in this direction has already begun, the first specialized varieties have appeared, but for many crops this work is just beginning.