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Weed infestation is one of the most damaging biotic factors to limit crop production by competing with the crop for space, water, and nutrients. Different conventional approaches are being used to cope with weed infestation, including labor intensive manual removal and the use of soil-degrading, crop-damaging, and environment-deteriorating chemical herbicides. The use of chemicals for weed control has increased 2-fold after the green revolution and their non-judicious use is posing serious threats to mankind, animals, and biodiversity. The detrimental effects of these approaches have shifted the researchers' attention from the last two decades towards alternate, sustainable, and eco-friendly approaches to cope with weed infestation. The recent approaches of weed control, including plant and microbial allelopathy have gained popularity during last decade. Farmers still use conventional methods, but the majority of farmers are very passionate about organic agriculture and describe it as a slogan in the developed world. The effectiveness of these approaches lies in host specificity by selective bacteria and differential response towards weeds and crops. Moreover, the crop growth promoting effect of microorganisms (allelopathic bacteria) possessing various growth promoting traits, that is, mineral solubilization, phytohormone production, and beneficial enzymatic activity, provide additional benefits. The significance of this review lies in the provision of a comprehensive comparison of the conventional approaches along with their potential limitations with advanced/biological weed control approaches in sustainable production. In addition, the knowledge imparted about weed control will contribute to a better understanding of biological control methods. [ABSTRACT FROM AUTHOR]

Vegetable cultivation under sewage irrigation is a common practice mostly in developing countries due to a lack of freshwater. Long-term usage provokes heavy metals accumulation in soil and ultimately hinders the growth and physiology of crop plants and deteriorates the quality of food. A study was performed to investigate the role of brassinosteroid (BRs) and silicon (Si) on lettuce, spinach, and cabbage under lead (Pb) and cadmium (Cd) contaminated sewage water. The experiment comprises three treatments (control, BRs, and Si) applied under a completely randomized design (CRD) in a growth chamber. BRs and Si application resulted in the highest increase of growth, physiology, and antioxidant enzyme activities when applied under canal water followed by distilled water and sewage water. However, BRs and Si increased the above-determined attributes under the sewage water by reducing the Pb and Cd uptake as compared to the control. It's concluded that sewerage water adversely affected the growth and development of vegetables by increasing Pb and Cd, and foliar spray of Si and BRs could have great potential to mitigate the adverse effects of heavy metals and improve the growth. The long-term alleviating effect of BRs and Si will be evaluated in the field conditions at different ecological zones. Numerous studies evaluated the effect of Brassinosteroid (BRs) and Silicon (Si) to mitigate heavy metal stress in vegetables through soil application. However, research on the foliar application of both BRs and Si to improve vegetable growth under heavy metal stress is very limited. Moreover, most researchers used only a single source of irrigation water but in our study, three different water sources including distilled water (CW), canal water (CW), and sewage water (SW) were used to evaluate their impact on growth, physiology, and antioxidant activities of leafy vegetables. In this way, this study could be the first in terms of specific vegetable crops (lettuce, spinach, and cabbage) and evaluated for their growth and development performance and antioxidant activities under three different types of irrigation sources with foliar application of BRs and Si. Brassinosteroid and Silicon improved the growth of leafy vegetables. Sewage water hindered the growth and physiological parameters of lettuce, spinach, and cabbage. Brassinosteroid and Silicon mitigated the heavy metal-induced stress in leafy vegetables. [ABSTRACT FROM AUTHOR]

Weeds are one of the major limiting factors for wheat production. So, a study was conducted to integrate allelopathic bacteria with a reduced dose of chemical herbicide for sustainable wheat production in wild oat infestation. Cyanide-producing Pseudomonas strains were applied in 4 combinations with and without 2 chemical herbicides (Axial and Atlantis) at the 25% and 50% recommended doses under axenic conditions. Results showed that the C4 bacterial combination (combination of B11×T19×T24×T75 bacterial strains) significantly reduced the growth and development of wild oat under 50% Axial while increasing wheat growth. Subsequently, C4 combination and Axial herbicide were selected for field evaluation, where they reduced the weed density (82.1%), soil plant analysis development (SPAD) value (26.0%), grain yield (88.2%) under 75% Axial, relative wild oat density (70.9%), photosynthetic rate (26.6%), and transpiration rate (25.6%) under 50% Axial in wild oat. While the C4 combination improved SPAD value (26.9%), shoot length (10.1%), tillering (33.3%), biological yield (32.7%), straw yield (24.4%), grain yield (46.8%), transpiration rate (9.6%), and stomatal conductance (14.7%) in wheat under 75% Axial. The increase in growth and yield of wheat was found to be similar to C4 under 50% and 75% Axial. Thus, it is concluded that allelopathic bacteria could be used with 50% Axial for sustainable wheat production under wild oat. [ABSTRACT FROM AUTHOR]