Xanthium strumarium L. (Common cocklebur) is a noxious weed prevailing in different ecosystems around the world. It incurs significant yield and economic losses in different cropping systems globally. Successful management of any weed species depends on sound knowledge of seed germination biology. However, detailed knowledge on seed germination biology of the species is missing. Therefore, we investigated the impact of different environmental factors on seed germination and seed burial depths on seedling emergence of two X . strumarium populations. The impact of different sorghum mulch doses (0–10 t ha -1 ) on seedling emergence of the tested populations was also explored. Seed germination was evaluated under different photoperiods (0, 12 and 24), constant temperatures (0–50°C with 5°C stepwise rise), and different levels of pH (3–12), salinity (0–600 mM) and osmotic potential (0 to -1.6 MPa). Seedling emergence was observed for seeds buried at different depths (0–15 cm). Seeds of both populations proved non-photoblastic; however, higher germination was recorded under 12-hour photoperiod. The seeds germinated under a wide range of constant temperatures (10–45°C), pH (4–10), osmotic potentials (0 to -0.8 MPa) and salinity levels (0–400 mM NaCl). However, the highest germination was observed under 30–31°C temperature and neutral pH (7.51–7.52). Seeds were able to withstand 400 mM salinity and -1.00 MPa osmotic potential. Seedling emergence was initially improved with increasing burial depth and then a sharp decline was noted for the seeds buried >3 cm depth. Most of the seeds of both populations did not emerge from >8 cm depth. Different sorghum mulch doses linearly suppressed seedling emergence of tested populations, and 5.83–5.89 t ha -1 mulch application suppressed 50% of seedling emergence. Seedling emergence was completely retarded with 8 t ha -1 sorghum mulch. The tested populations germinated under diverse environmental circumstances indicating that the species can become troublesome in marginal habitats and cropped lands. Deep burial of seeds and application of sorghum mulches suppressed seedling emergence. Thus, deep burial followed by shallow tillage and application of sorghum mulches could be used as a successful strategy to manage the species in agricultural fields. Nonetheless, management strategies must be developed to control the species in other habitats.

Caffeic acid (CA) is known as an antioxidant to scavenge reactive oxygen species (ROS), but the underlying mechanism of mediation of plant salt tolerance against various abiotic stresses by caffeic acid is only partially understood. A field experiment (120 days duration) was conducted to investigate the protective role of caffeic acid under a high saline medium (EC 8.7 dS m-1 and textural class: sandy loam) in two wheat genotypes (FSD -08 and Zincol-16). Two levels of caffeic acid (50 μM and 100 μM) were applied exogenously in combination with the salinity stress and results revealed that salt alleviation is more prominent when caffeic acid was applied at the rate of 100 μM. Under saline conditions, wheat genotypes show poor fresh and dry matter accumulation, chlorophyll contents, relative water contents (RWC), membrane stability index (MSI) and activities of antioxidant enzymes and increased uptake of Na+ ions. However, wheat genotype FSD-08 eminently responded to caffeic acid application as compared to wheat genotype Zincol-16 as demonstrated by higher growth indicators, RWC, MSI, activities of antioxidant enzymes, accumulation of mineral ions in grain along with yield attributes. In addition, caffeic acid also mitigated salt-induced oxidative stress malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents as well as significantly reduced Na+ uptake. It can be concluded that caffeic acid-induced salinity tolerance in wheat is attributed to improved plant water relations, K+ uptake, yield contents and activities of antioxidant stress enzymes.

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Wheat ( Triticum aestivum L) is among the most important cereal crops widely cultivated in the world. Wild oat ( Avena fatua L.) competes with wheat for moisture, sunlight, space and nutrition. The successful management of weeds requires sound knowledge of their biology and response to different herbicides. This study inferred the impact of different constant temperature regimes and seed burial depths on seedling emergence and biomass production of wild oat. Moreover, the impact of different post-emergence herbicides applied at different growth stages on biomass production of wild oat was tested. The influence of different wild oat-wheat density (WWD) combinations on biomass production of wheat and wild oat was also inferred. Different constant temperature regimes significantly altered seed germination and biomass production of wild oat. The highest seed germination percentage and biomass production were noted under 15°C and 20°C, whereas the lowest values were recorded under 30°C. Similarly, days to start emergence, seedling emergence percentage and biomass production of wild oat was significantly affected by different seed burial depths. The lowest and the highest values of these parameters were observed under 4 and 10 cm depth, respectively. Different post-emergence herbicides and wild oat growth stages significantly altered biomass production. The highest reduction in fresh and dry biomass was recorded with herbicides’ application at 2–4 leaf stage compared with anthesis stage. Clodinofop resulted in higher reduction of fresh biomass, whereas higher reduction in dry biomass was noted with Sulfosulfuron. Seed germination of both species was not affected by different WWD combinations, except for the treatment where no seed was sown of both species. These results indicate that deep burial of seeds could prevent seedling emergence, whereas post-emergence herbicides must be applied at 2–4 leaf stage of wild oat for its effective management.

Mismanagement in foliar fertilizer application at different crop stages decreases the productivity of the crop. Likewise, higher application of phosphorus (P) beyond recommended application rates not only decrease zinc (Zn) uptake in rice but also increase fertilizer use cost. Inoculation of arbuscular mycorrhizae (AMF) may optimize the uptake of P and improve crops production via organic secretions. That’s why the current study was conducted to examine the individual and coordinated effects of 0.5% Zn (0.5Zn) foliar spray (tillering (T) and/or panicle (P) initiation stage) and AMF application. Application of foliar 0.5Zn at tillering+panicle stage remained significantly better for significant enhancement in plant height, spike length, gas exchange attributes and total chlorophyll contents than control. A significant decrease in electrolyte leakage Also validated the effectiveness of treatment 0.5ZnT+P compared to control. Compared to control, the maximum increase in N (14.5 and 25.7%), P (42.1 and 33.3%), K (22.2 and 30.0%) and Zn (19.3 and 27.8%) accumulation was also found in 0.5ZnT+P, with and without AMF, respectively. In conclusion, 0.5ZnT+P with AMF is a better approach than sole application of Zn at tillering or panicle initiation stages. Nevertheless, more investigations are suggested at field level under variable climatic zones to confirm the effectiveness of 0.5ZnT+P with AMF for improvement in rice growth and production.