Background: Waste-land weeds present around the fields exert their allelopathic influence on crops through their leaf leachates and rhizospheric soils. Objective: A study was conducted to investigate the phytotoxic action of four common waste-land weeds Parthenium hysterophorus L., Achyranthes aspera L., Lantana camara L. and Withania somnifera L. through their aqueous extracts and rhizospheric soils against winter crops Avena sativa L., Cicer arietinum L., Hordeum vulgare L. and Triticum aestivum L. Methods: Experiments were conducted in Agronomy laboratory in College of Agriculture at the University of Sargodha. In first experiment, 5% (w/v) water extract from entire plant of each weed was applied to germinating seeds of crops whereas in second experiment, crop seeds were subjected to the rhizospheric soil of each weed for germination test. Results: Results revealed that aqueous extracts of weeds were more phyto-inhibitory compared to their rhizospheric soils. Minimum germination percentage (42.5%), germination index (7.4), seedling vigor index (665.3), root length (3.27 cm), seedling length (14.15 cm) and seedling biomass (74.2 mg) of crops were recorded in response to aqueous extract of P. hysterophorus. Root growth of the crops was affected more compared to the shoot growth. Minimum germination percentage was observed in A. sativa (13.3) by the action of L. camara aqueous extract. Rhizospheric soil of L. camara and P. hysterophorus resulted in minimum germination percentages (57.5 and 58.3, respectively) and seedling vigor indices (1472.5 and 2008.4, respectively) of crops. The lowest germination (30%) and germination index (3.7) was observed for T. aestivum seeds germinated in the rhizospheric soil of W. somnifera. Among crops, A. sativa and C. arietinum were more susceptible to the aqueous extracts whereas T. aestivum to rhizospheric soils of weeds. Conclusions: It can be concluded that waste-land weeds especially P. hysterophorus and L. camara negatively affect the crops by their allelopathy.

To ensure energy security and greenhouse gas emission, the world has decided to look for more sustainable and renewable energy sources. Biogas production from agricultural biomass is a fast growing market in the world. Suitable energy crops include maize, clover grass, alfalfa, sorghum, sudangrass, miscanthus and many others. Management considerations of energy crops such as harvesting time and nitrogen (N) application considerably influenced the biomass yield, quality of crop along with bio-methane production. Therefore, field study was conducted to determine the impact of harvesting times (HT) and nitrogen rates on the biomass yield of maize and production of bio-methane from it. The variable NR and HT, had a substantial influence on morphological, and compositional traits and bio-methane production. The N application at 200 kg ha-1 produced the taller plants, with maximum leaves, leaf area, biomass yield, protein contents, acid detergent fiber (ADF), neutral detergent fiber (NDF), and lignin contents. In addition to that higher nitrogen rate (200 kg ha-1) produced higher methane production however, it remained the same with 150 kg N ha-1. Harvesting at 65 DAS produced the maximum taller plants with maximum leaf area, biomass yield and had maximum ADF and NDF which negatively affected the specific methane yield. Moreover, harvesting at 65 DAS produced maximum methane yield (MP) due to higher biomass yield (BY). It is concluded that N application @ 150 kg ha-1 and harvesting at 65 DAS can be suitable for getting the higher bio-methane production under semi-arid conditions of Pakistan.

A pot experiment was conducted to investigate the role of thiourea exogenous application (0 mg/L and 100 mg/L) on the morphological, physiological, and yield traits of two varieties of tomato (Naqeeb and Nadir) under different salt stress treatments (0, 60, and 120 mM) in completely randomized design (CRD). The imposition of salinity by rooting medium showed that salt stress reduced plant height by 20%, fresh shoot weight by 50%, dry shoot weight by 78%, fresh root weight by 43%, dry root weight by 84%, root length by 34%, shoot length by 32%, shoot K⁺ by 47%, Ca²⁺ by 70%, chlorophyll a by 30%, chlorophyll b by 67%, and the number of seeds per berry by 53%, while shoot Na⁺ ions were increased by 90% in comparison to those grown with control treatment. However, the exogenous application of thiourea significantly enhanced dry root weight by 25% and the number of seeds per berry by 20% in comparison to untreated plants with thiourea when grown under salt stress. Salt stress resulted in a reduction in the number of berries, weight per berry, number of seeds per berry, and seed weight in both varieties, while thiourea foliar application increased these yield parameters. On the other hand, the Nadir variety surpassed Naqeeb in plant height (+13%), root length (+31%) and shoot length (+11%), fresh shoot weight (+42%) and dry shoot weight (+11%), fresh root weight (+29%), dry root weight (+25%), area of leaf (+26%), chlorophyll a (+32%), and chlorophyll b (+24%). In conclusion, the exogenous application of thiourea can be used to mitigate salt stress in tomato plants since it can improve the growth, physiological, and yield traits of this strategic crop.