Shahid Khan

The study focused on assessing the stability of 55 F5:8 bread wheat genotypes across multiple locations in Khyber Pakhtunkhwa, Pakistan. Using an alpha lattice design over two years during 2014 and 2015, researchers analyzed the genotype × environment (GE) interaction and its impact on grain yield. Results from the additive main effect and multiplicative interaction (AMMI) analysis highlighted significant GE interactions influencing grain yield variability. Genotypes, environments, and their interaction contributed 9.0 %, 35.1 %, and 28.9 %, respectively, to total explainable phenotypic variation, respectively. Certain genotypes, such as G17, G45, and G40 showed average yield at well across different environments, while G58, G53 and G1 excelled in specific environments. GGE biplot analysis identified stable genotypes (e.g., G51, G36, and G53) and grouped environments into mega-environments based on yield performance. The AMMI and GGE biplot analyses explained similar proportions of the genotype × environment interaction (56.1 % and 55.5 %, respectively). Because the two methods have complementary objectives, AMMI was used to investigate GE interaction patterns, whereas GGE biplot facilitated genotype evaluation, mega-environment identification, and visualization of genotype performance, the two methods should be regarded as complementary rather than competing tools for evaluating genotype performance across environments.

Herbicide selectivity in cassava is essential for effective pre-emergence weed management. However, the limited number of registered products restricts available options. This study aimed to evaluate the efficacy and selectivity of pre-emergence herbicides applied using the plant-and-apply system for weed control in cassava. A field experiment was conducted with the IPR Paraguainha variety in a randomized block design with four replications. Treatments included ametryn; clomazone; flumioxazin; s-metolachlor; pyroxasulfone; isoxaflutol; metribuzin; diuron; metribuzin + s-metolachlor; ametryn + clomazone; pyroxasulfone + flumioxazin; flumioxazin + s-metolachlor; sulfentrazone; and two controls (control and weeded control). Evaluations included crop phytotoxicity, plant height, stem diameter, chlorophyll content, and weed control. After ten months, yield, starch content, and root length and diameter were assessed. Sulfentrazone caused phytotoxicity above 20%. S-metolachlor alone provided only 30% weed control. Ametryn and ametryn + clomazone resulted in more than 80% and 90% weed control, respectively. For ametryn, root yield exceeded 28 t/ha. Among herbicides commonly used in soybean, metribuzin and flumioxazin + s-metolachlor showed effective weed suppression, demonstrating their potential as viable options for cassava production.

The pre-plant burndown of Conyza spp. is a fundamental practice to mitigate weed competition with soybean. However, in light of reports of biotypes resistant to 2,4-D, the search for new options of post-emergent herbicides becomes essential. The objective of the present study was to evaluate the effect of post-emergent herbicides on the leaf structure and chemical control of Conyza spp. with heights greater than 10 cm in soybean pre-plant desiccation. A field experiment was conducted following a randomized block design, with seven treatments and four replicates. For the control data, only mesotrione + atrazine and chlorimuron resulted in control percentages lower than 80%. Regarding scanning electron microscopy (SEM), trichomes were denser on the adaxial leaf surface, while stomata predominated on the abaxial side, though both were present on both surfaces. Their distribution showed tendencies of clustering and randomness, with no consistent pattern linked to the treatments. Slight, non-significant variations in trichome density occurred, especially with halauxifen + diclosulam. The control and halauxifen + diclosulam treatments exhibited higher trichome intensity and less structural damage, whereas fluroxypyr + clethodim, dicamba, and triclopyr resulted in lower intensity and trichome disruption. Consequently, fluroxypyr + clethodim, triclopyr, dicamba, and halauxifen + diclosulam were effective in desiccating Conyza spp., with the first two causing trichome damage via plasmolysis.

Despite the development of adapted popcorn cultivars such as UENF WS01, strategies such as bacterial inoculation are being explored to enhance plant resilience to abiotic stress. This study investigates the impact of drought stress on popcorn cultivation. Specifically, the aim was to identify the benefits of Bacillus cereus interaction with the drought-tolerant hybrid UENF WS01 for its morphophysiology and growth by comparing inoculated and non-inoculated plants under water-stressed (WS) and well-watered (WW) conditions. This evaluation was conducted using a randomized complete block design in a factorial arrangement. For WS with inoculation samples, there were significant increases in relative chlorophyll content, maximum fluorescence intensity, and agronomic water use efficiency. Chlorophyll content increased by an average of 50.39% for WS samples, compared to a modest increase of 2.40% for WW samples. Both leaf and stem biomass also significantly increased for WS relative to WW conditions. Overall, B. cereus inoculation mitigated the impact of water stress, significantly enhancing the expression of physiological and morphological traits, even when paired with a drought-tolerant hybrid.

Large amounts of nitrogen (N) fertilizers applied to maize cropping systems support high yields but cause adverse environmental impacts. The development of cultivars with higher N use efficiency is essential to maintain sustainable production. Thus, the present study aimed to select popcorn inbred lines efficient and responsive to N fertilization expressing high popping expansion. Fifty-one popcorn inbred lines from different origins were evaluated in the field under low and high N availability, arranged in a randomized complete block design with three replications. The two main traits of economic interest in the crop were evaluated: grain yield (GY) and popping expansion (PE). A joint analysis of variance was performed and a scatter plot was generated to classify the inbred lines regarding the response to the N use, focusing on GY. For PE, a Scott-Knott grouping of means was conducted. Within the panel of evaluated popcorn inbred lines, it was possible to identify sources of favorable alleles for nitrogen use efficiency and popcorn expansion, highlighting the inbred lines L205, L206, L217, and L395. These genotypes emerge as potential parents to be included in mating blocks for the development of hybrids and/or breeding populations with high nitrogen use efficiency and popping expansion.

Microbial interactions with plant roots play an imperial role in tomato plant growth and defense against the Rhizoctonia solani. This study performed a field experiment with two antagonistic bacteria (Pseudomonas and Bacillus) inoculated in healthy and Rhizoctonia solani treated soil in tomato rhizosphere to understand the metabolic pattern and microbial function during plant disease suppression. In the present study, we assessed soil and microbial enzymes, bacterial and fungal cell forming unit (CFU), and carbon utilization profiling through Bio-Eco plates of rhizoplane samples. Antagonist bacteria and pathogen interaction significantly (p < 0.05) influenced the bacterial count, soil enzymes (chitinase and glucanase), and bacterial function (siderophore and chitinase production). These results indicated that these variables had an imperial role in disease suppression during plant development. Furthermore, the metabolic profiling showed that carbon source utilization enhanced under fruit development and ripening stages. These results suggested that carbon sources were essential in plant/pathogen/antagonist interaction. Substrates like β-methyl-D-glucoside, D-mannitol, D-galacturonic acid, N-acetyl-D-glucosamine, and phenylethylamine strongly connect with the suppuration of root rot disease. These carbon sources may help to propagate a healthy microbial community to reduce the pathogen invasion in the plant root system, and these carbon sources can be stimulators of antagonists against pathogens in the future.

We investigated the proteomic profiles of two popcorn inbred lines, P2 (N-efficient and N-responsive) and L80 (N-inefficient and nonresponsive to N), under low (10% of N supply) and high (100% of N supply) nitrogen environments, associated with agronomic- and physiological-related traits to NUE. The comparative proteomic analysis allowed the identification of 79 differentially accumulated proteins (DAPs) in the comparison of high/low N for P2 and 96 DAPs in the comparison of high/low N for L80. The NUE and N uptake efficiency (NUpE) presented high means in P2 in comparison to L80 at both N levels, but the NUE, NUpE, and N utilization efficiency (NUtE) rates decreased in P2 under a high N supply. DAPs involved in energy and carbohydrate metabolism suggested that N regulates enzymes of alternative pathways to adapt to energy shortages and that fructose-bisphosphate aldolase may act as one of the key primary nitrate responsive proteins in P2. Proteins related to ascorbate biosynthesis and nitrogen metabolism increased their regulation in P2, and the interaction of l-ascorbate peroxidase and Fd-NiR may play an important role in the NUE trait. Taken together, our results provide new insights into the proteomic changes taking place in contrasting inbred lines, providing useful information on the genetic improvement of NUE in popcorn.

Salinity stress is a barrier to crop production, quality yield, and sustainable agriculture. The current study investigated the plant growth promotion, biochemical and molecular characterization of bacterial strain Enterobacter cloacae PM23 under salinity stress (i.e., 0, 300, 600, and 900 mM). E. cloacae PM23 showed tolerance of up to 3 M NaCl when subjected to salinity stress. Antibiotic-resistant Iturin C (ItuC) and bio-surfactant-producing genes (sfp and srfAA) were amplified in E. cloacae PM23, indicating its multi-stress resistance potential under biotic and abiotic stresses. Moreover, the upregulation of stress-related genes (APX and SOD) helped to mitigate salinity stress and improved plant growth. Inoculation of E. cloacae PM23 enhanced plant growth, biomass, and photosynthetic pigments under salinity stress. Bacterial strain E. cloacae PM23 showed distinctive salinity tolerance and plant growth-promoting traits such as indole-3-acetic acid (IAA), siderophore, ACC deaminase, and exopolysaccharides production under salinity stress. To alleviate salinity stress, E. cloacae PM23 inoculation enhanced radical scavenging capacity, relative water content, soluble sugars, proteins, total phenolic, and flavonoid content in maize compared to uninoculated (control) plants. Moreover, elevated levels of antioxidant enzymes and osmoprotectants (Free amino acids, glycine betaine, and proline) were noticed in E. cloacae PM23 inoculated plants compared to control plants. The inoculation of E. cloacae PM23 significantly reduced oxidative stress markers under salinity stress. These findings suggest that multi-stress tolerant E. cloacae PM23 could enhance plant growth by mitigating salt stress and provide a baseline and ecofriendly approach to address salinity stress for sustainable agriculture.