Water-related soil erosion is a major environmental concern for catchments with barren topography in arid and semi-arid regions. With the growing interest in irrigation infrastructure development in arid regions, the current study investigates the runoff and sediment yield for the Gomal River catchment, Pakistan. Data from a precipitation gauge and gridded products (i.e., GPCC, CFSR, and TRMM) were used as input for the SWAT model to simulate runoff and sediment yield. TRMM shows a good agreement with the data of the precipitation gauge (≈1%) during the study period, i.e., 2004–2009. However, model simulations show that the GPCC data predicts runoff better than the other gridded precipitation datasets. Similarly, sediment yield predicted with the GPCC precipitation data was in good agreement with the computed one at the gauging site (only 3% overestimated) for the study period. Moreover, GPCC overestimated the sediment yield during some years despite the underestimation of flows from the catchment. The relationship of sediment yields predicted at the sub-basin level using the gauge and GPCC precipitation datasets revealed a good correlation (R² = 0.65) and helped identify locations for precipitation gauging sites in the catchment area. The results at the sub-basin level showed that the sub-basin located downstream of the dam site contributes three (3) times more sediment yield (i.e., 4.1%) at the barrage than its corresponding area. The findings of the study show the potential usefulness of the GPCC precipitation data for the computation of sediment yield and its spatial distribution over data-scarce catchments. The computations of sediment yield at a spatial scale provide valuable information for deciding watershed management strategies at the sub-basin level.

A method to estimate the sensible heat flux (H) for unstable atmospheric condition requiring measurements taken in half-hourly basis as input and involving the land surface temperature (LST), H_LST, was tested over a tall and dense aspen stand. The method avoids the need to estimate the zero-plane displacement and the roughness length for momentum. The net radiation (Rn) and the latent heat flux (λE) dominated the surface energy balance (SEB). Therefore, λE was estimated applying the residual method using H_LST as input, λE_R-LST. The sum of H and λE determined with the eddy covariance (EC) method led to a surface energy imbalance of 20% Rn. Thus, the reference taken for the comparisons were determined forcing the SEB using the EC Bowen ratio (BREB method). For clear sky days, H_LST performed close to H_BREB. Therefore, it showed potential in the framework of remote sensing because the input requirements are similar to current methods widely used. For cloudy days, H_LST scattered H_BREB and nearly matched the accumulated sensible hear flux. Regardless of the time basis and cloudiness, λE_R-LST was close to λE_BREB. For all the data, both H_LST and λE_R-LST were not biased and showed, respectively, a mean absolute relative error of 24.5% and 12.5% and an index of agreement of 68.5% and 80%.

The onion (Allium cepa L.) belongs to the family Alliaceae and has paramount importance among vegetable crops around the globe. Salinity stress and the soil-borne fungus Fusarium oxysporum f. sp. Cepa (FOC), which is the cause of basal rot, are potentially hazardous factors related to the yield of onion crops. The present study was conducted in CRD using three replicates in in vitro conditions and in a greenhouse to investigate the impact of stress factors (salinity levels and FOC) (T₁ = Negative control; T₂ = Positive control (FOC); T₃ = EC 2.5 dS m⁻¹; T₄ = EC 3.5 dS m⁻¹; T₅ = EC 4.5 dS m⁻¹; T₆ = EC 2.5 dS m⁻¹ + FOC; T₇ = EC 3.5 dS m⁻¹ + FOC; and T₈ = EC 4.5 dS m⁻¹ + FOC) on the morphological, physiological, and yield parameters of onions. Fungal biomass, in the in vitro condition, increased at a salinity level of 2–8 dS m⁻¹. In the greenhouse, the application of salinity levels, viz. 2.5, 3.5, and 4.5 dS m⁻¹, and fungal pathogens exhibited a more severe impact on the severity of the disease, onion growth, and bulb compared to sole stress. Overall, the decreased levels of osmotic potential, total chlorophyll content, membrane stability index, and total protein were assessed in onion leaves, whereas total phenolics were enhanced in the mentioned stress conditions. Sugar contents were reduced due to the sole application of pathogens, whereas they were enhanced in the sole application of salinity stress and increased due to a combination of FOC and salinity level applications. Polyphenol oxidase (PPO) activity was not altered as a result of pathogen infection, while peroxidase (PO) and phenylalanine ammonia-lyase (PAL) contents were enhanced, and the activity of catalase (CAT) was reduced. Sole stress along with the combined application of salinity levels with fungal pathogens exhibited enhanced PO and PPO activity; in contrast, CAT and PAL activity decreased. In summary, onion crop cultivation in saline soil conditions increases the disease’s severity, which is caused by FOC. Furthermore, it is crucial to carry out field trials while considering these outcomes in order to support a strong strategy for reducing the tested stresses within a wider range of environmental conditions.

During 21^st century, abiotic stress has adversely affected the agriculture crop production around the globe. Keeping in view the food requirement under water shortage condition, a study was planned to investigate the effect of thiamine application on radish crop under drought stress conditions on plant. For study purpose, two varieties of locally available radish (‘Early-Milo’ and ‘Laal-Pari’) were grown with normal water application as well as thiamine (100 mg L^-1) application while maintaining a stress condition (60% field capacity). Increasing water deficit stress linearly reduced plant growth, yield and biomass in both varieties by reducing water use efficiency, while significantly enhanced these attributes with thiamine application. Thiamine application under drought stress exerted significant impacts on physiological attributes in both varieties, including enhanced osmolytic attribute in drought conditions and improvements in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), H₂O₂, and malondialdehyde (MDA) activities in plant leaves. Antioxidant and osmoprotectant upregulation positively linked to radish crop's drought tolerance. Moreover, PCA and heatmap analysis revealed a significant interdependence among various traits and interconnected in determining the crop's capacity to sustain growth under conditions of drought stress. In crux, thiamine application conclusively enhances radish growth, yield, biomass, physio-chemical and osmolytic attributes, ionic composition and enzymatic antioxidant potential. Therefore, it is recommended to consider the application of thiamine in commercial agriculture practices to mitigate the negative effects of drought stress on radish crop production.