Muhammad Naeem Akhtar

| Seed dormancy impacts seed germination success and seedling health. Ethylene plays a crucial role in facilitating the breaking of seed dormancy by initiating essential biochemical and physiological changes that are necessary for successful seed growth and development. It was hypothesized that acetylene (C 2 H 2 ) from calcium carbide (CaC 2 ) has the potential to induce an ethylene response in seed for breaking seed dormancy and better seedling growth. A study was conducted to evaluate the impacts of C 2 H 2 released from ten CaC 2 concentrations, i.e., 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20 mg petri-plate -1 , on seed dormancy and seedling growth in sweet pepper. Results indicated that CaC 2 significantly induced 100% early seed germination, with significant improvements in post-germination variables. CaC 2 applied at 14 mg petri-plate -1 was found to be an optimum dose for regulating seed dormancy and post-germination growth positively. However, CaC 2 >16 mg petri-plate -1 proved lethal and suppressed the germination or growth of the seedlings. Compared to control treatment, improvements in seed sermination and growth variables, i.e., 8 to 37% in seed germination, 5 to 22% in seedling biomass, 5 to 46% in shoot length, and 3 to 37% in root length, suggest that calcium carbide, easily available on the market, can be used for seed dormancy breakage and better crop stand.

Pakistan’s agriculture sector faces a 50% water shortage, impacting crops like cotton and the textile industry, thus affecting the economy. K-efficient cotton cultivars, which withstand dry conditions through morphological and biochemical traits, can conserve moisture. K-efficient cotton cultivars can be used as donors of key K acquisition traits in breeding programs to develop promising cotton varieties with enhanced yields for the low K environments and can also be recommended for general cultivation to improve cotton production on a sustainable basis. This chapter aims to contribute to enhance water use efficiency (WUE) on the physiological basis to develop strategies for K-efficient cotton cultivars for improvement. Strategies involve regulating transcription factors to improve K-uptake efficiency, increasing root volume through lateral roots and root hairs, and enhancing K-uptake via channels and transporters, ultimately boosting WUE. Molecular breeding programs can leverage K+-associated QTLs to develop high K+ use efficiency cultivars. Physiological processes affecting WUE are discussed alongside factors influencing their contributions, acknowledging the complexity across crops, environments, and nutrients.

| Gradual climate changes has delayed wheat harvesting and monsoon arrival in Pakistan and thus, cotton sowing in Pakistan particularly in Southern Punjab cannot be completed in time. Late sown cotton faces problem of heat stress at reproductive growth stages which results in significant reduction of yield with poor fiber quality. Additionally, soil health of Pakistani soils is very poor due to low soil organic matter, non-judicial use of fertilizers and high cropping intensity with mono-cropping pattern. The integrated and judicial use of organic and synthetic fertilizers boosts the soil and plant health and mitigates the deteriorative effects of heat stress on plants. Based on past studies, the objective of the study was to integrate pre-tested compost, SA, Zn-Fe-B consortia and foliar K with conventional fertilizers for ameliorating detrimental effects of heat stress on morphological and fiber characteristics of cotton. During study, salicylic acid based Fe, Zn, B consortia (S-N consortia), foliar potassium (K) and compost were used in different combinations along with conventionally used fertilizers. Nutrient Results reveal that integrated use of compost and S-N consortia improved yield attributes particularly fruit set percentage, flower to fruit conversion percentage, square boll size and weight, opening of square bolls and seed-cotton yield compared to conventional approach. Compare to farmer practice, foliar K application showed a significant increase in fiber quality parameters such as fiber length, fiber strength, MIC, micronaire and ginning out turn (GOT). Results advocate compost, micronutrients and K essential element of cotton production whenever cotton is under heat stress.

Background: Under K deficiency the uptake and distribution pattern in plant cells is mediated through different transport proteins and channels which were controlled by specific gene family. Therefore, a hydroponic experiment was conducted under control condition for testing the gene expression pattern of the K transporter under adequate and low K supply levels. After that, a 2-year field experiment was conducted to evaluate five selected cotton cultivars (four K-efficient cultivars, viz., CIM-554, CYTO-124, FH-142, IUB-2013, and one K non-efficient, BH-212) screened from the initial hydroponics culture experiment and two levels of potassium (0 K₂O kg·ha⁻¹ and 50 K₂O kg·ha⁻¹) were tested under reduced irrigation (50% available water content; 50 AWC) and normal irrigation conditions (100% available water content; 100 AWC). Result: Results revealed that the transcript levels of GhHAK5aD in roots were significantly higher in K⁺ efficient cultivars than that in K⁺ non-efficient cultivars. The GhHAK5aD expression upon K⁺ deficiency was higher in roots but lower in shoots, indicating that GhHAK5aD could have a role in K⁺ uptake in roots, instead of transport of K⁺ from root to shoot. Similarly, under field conditions the cultivar FH-142 showed an increase of 22.3%, 4.9%, 2.4%, and 1.4% as compared with BH-212, IUB-2013, CYTO-124, and CIM-554, respectively, in seed cotton yield (SCY) with K application under reduced irrigation conditions. With applied K, the FH-142 showed an increase in net photosynthetic rate by 57.3% as compared with the rest of the cultivars under reduced irrigation over K control. However, the overall performance indicators of K-efficient cultivars like FH-142, CYTO-124, CIM-554, and IUB-2013 were better than BH-212 (K in-efficient) under reduced irrigation conditions with applied K at 50 kg·ha⁻¹. Fiber quality trait improved significantly with K application under water deficit. The increase in micronaire was 3.6%, 4.7%, 7.8%, 3.4%, and 6.7% in BH-212, IUB-2013, CIM-554, CYTO-124, and FH-142, respectively, with K application at 50 kg·ha⁻¹ over without K application under reduced irrigation conditions during the cotton growing season. Similarly, the cultivars FH-142 increased by 12% with K application under reduced irrigation as compared with other cultivars. The performance of K-efficient cultivars under reduced irrigation conditions was 30% better in SCY and quality traits with the application of K at 50 kg·ha⁻¹ as compared with K-non-efficient cultivars. Similarly, water use efficiency (WUE) (40.1%) and potassium use efficiency (KUE) (20.2%) were also noted higher in case of FH-142 as compared with other cultivar with K application under reduced conditions. Conclusion: Higher expression of GhHAK5aD gene was observed in K-efficient cultivars as compared with K-non-efficient cultivars in roots indicates that GhHAK5aD may be contributing to genotypic differences for K⁺ efficiency in cotton. K-efficient cotton cultivars can be used for the low-K environments and can also be recommended for general cultivars.

| Pulse beetle (Callosbruchuschinesis) causes serious damage to the seed of chickpea, and other pulses during storage. Seed viability and other quality parameters are affected by its infestation. This pest is controlled by phosphine fumigation and synthetic insecticides. Unfortunately, this pest has developed resistance against these pesticides. Moreover, with application of these pesticides, chemical residues may cause severe damage to non-target organisms. Host plant resistance against insect pests is considered best ecological approach to pest management. Keeping this in consideration, the current research activity is planned to screen out available germplasm of chickpea against dhora beetle (Callosobruchuschinisensis) . For this purpose, 8 genotypes of chickpea genotypes were taken from Ayub Agricultural Research Institute, Faisalabad. 1 kg of each genotype was taken in plastic jars. There were three replications of each genotype for each insect. Twenty adults of dhora beetle were discharged in each container which were enclosed with muslin cloth with rubber bands. The Jars were placed at room temperature. Data of egg laying were observed after five days of release of insects. Data of emergence F1 adults were observed after 30 days of storage. At this time percent weight loss and Seed viability was also analyzed. The Same data were observed after two- and three-month storage period. The results revealed that all the varieties/lines differed significantly from one another for percent weight loss and viability. On the basis of percent weight loss, the variety Bittal-2016 was found to be the most susceptible. Whereas the variety Niab-CH-2016 was also found to be the least susceptible. The current research found that none of the chickpea cultivars were totally resistant to C.chinensis , however their vulnerability varied significantly. Finally, the acquired data will be statistically examined for the study of variance via statistical software. Means of significant treatments will be examined at = 5% using the HSD-Tuckey test.

Low nitrogen-use efficiency (NUE) is a serious issue for cotton production and environmental sustainability in arid climates. A pot study was conducted to evaluate the effect of K nutrition on NUE and performance of low- and high-K-efficiency cotton cultivars under two moisture regimes. Treatments included two soil moisture levels—i.e., normal irrigation, 100% available water content (AWC); reduced irrigation, 50% AWC—three levels of nitrogen (N)—i.e., 0, 375, and 750 mg N pot⁻¹—and two K levels, i.e., 0 and 208 mg K pot⁻¹. Results reveal that 208 mg K pot⁻¹ application with nitrogen significantly enhanced the N-use efficiency, growth, and yield attributes of both cotton cultivars compared with sole N fertilization. Similarly, the combined application of NK @ 375 N + 208 K mg pot⁻¹ caused up to 83% increase in NUE under AWC_50% and AWC_100%, as compared with NK control (0 N + 0 K). Compared with the control, imposed low-moisture stress caused a decrease of 13.9% in stomatal conductance (g_s), 2.5% in transpiration rate (E), and 6.5% in net photosynthetic rate (P_N), respectively_. The physiological water use efficiency (P_N/E) decreased by 13.2% under AWC_50%. Applied NK @ 375 N:208 K, mg pot⁻¹ caused 27.39 and 27.56% improvement in the P_N/E in HKE and LKE cultivars under AWC_50%, respectively. The HKE cultivar, i.e., CIM-554, maintained the highest g_s and P_N than FH-901, that was low-K-efficiency cultivar. The study suggests that varietal selection and adequate K fertilization have the prospects to improve NUE and save considerable quantities of fertilizer and irrigation water in cotton production under arid environments.