Different Growth Stages Of Wheat Research Articles

Impact of Skipping Irrigation at Different Growth Stages of Wheat on Crop Water Productivity in North Nile Delta 1- Vegetative Growth and Water Relationships

Impact of Skipping Irrigation at Different Growth Stages of Wheat on Crop Water Productivity in North Nile Delta 1- Vegetative Growth and Water Relationships

Phthalate ester (PAEs) accumulation in wheat tissues and dynamic changes of rhizosphere microorganisms in the field with plastic-film residue

Phthalates acid esters (PAEs) have accumulated in soil and crops like wheat as a result of the widespread usage of plastic films. It is yet unclear, nevertheless, how these dynamic variations in PAE accumulation in wheat tissues relate to rhizosphere bacteria in the field. In this work, a field root-bag experiment was conducted to examine the changes of PAEs accumulation in the rhizosphere soil and wheat tissues under film residue conditions at four different growth stages of wheat, and to clarify the roles played by the microbial community in the alterations. Results showed that the plastic film residues significantly increased the concentrations of PAEs in soils, wheat roots, straw and grains. The maximum ΣPAEs concentration in soils and different wheat tissues appeared at the maturity, with the ΣPAEs concentration of 1.57 mg kg−1, 4.77 mg kg−1, 5.21 mg kg−1, 1.81 mg kg−1 for rhizosphere soils, wheat roots, straw and grains, respectively. The plastic film residues significantly changed the functions and components of the bacterial community, increased the stochastic processes of the bacterial community assembly, and reduced the complexity and stability of the bacterial network. In addition, the present study identified some bacteria associated with plastic film residues and PAEs degradation in key-stone taxa, and their relative abundances were positive related to the ΣPAEs concentration in soils. The PAEs content and key-stone taxa in rhizosphere soil play a crucial role in the formation of rhizosphere soil bacterial communities. This field study provides valuable information for better understanding the role of microorganisms in the complex system consisting of film residue, soil and crops.

Impacts of Long-term Application of Fertilizer and Manures on Physico-chemical Properties, Phosphorus Uptake and Crop Yield at Different Growth Stages of Wheat

A field experiment was conducted on wheat in a sandy loam soil (Typic Haplustept) at IARI farm, New Delhi during 2018-19 in a long-term fertilizer experiment to study the physico-chemical properties of soil, crop yield, phosphorus uptake and phosphorus availability. The experiment was designed with seven different treatments, replicated thrice in a randomized complete block design. The treatments details were T1: Control, T2: 100%N, T3: 100%NP, T4: 100%NPK, T5: 150% NPK, T6: 100%NPK+5t FYM and T7: 100% NPK+ Zn-5 kgha-1. The results revealed that pH and electrical conductivity were highest under control and lowest recorded under 100% NPK+FYM. Available phosphorus content at all four stages was wheat significantly greater under NPK+FYM followed by 150% NPK treatment and lowest under nitrogen alone (100% N) and unfertilized treatment (control). Initially available phosphorus in soil ranged from 13.5 to 39.8 and 15.4 to 37.9 kg ha-1 at 0-15 cm and 15-30 cm depth, respectively. At the tillering stage, available P was 20.7 to 43.7 and 16.5 to 38.1 kg ha-1 at 0-15 cm and 15-30 cm depth, respectively. At panicle emergence, it was 24.1 to 48.4 kg ha-1 and 18.6 to 42.3 at 0-15 cm and 15-30 cm depth. At harvest of wheat crop, available P ranged from 20.5 to 41.8 and 16.5 to 39.1 kg ha-1 at 0-15 cm and 15-30 cm depth, respectively. Total phosphorus uptake and crop yield significantly increased under 150% NPK treatment followed by 100% NPK+FYM.

Unrevalling phenotypic diversity of root system architecture in ancient wheat species versus modern wheat cultivars

Understanding the phenotypic variability in root system architecture and root-shoot relationships across different growth stages of wheat is of utmost importance for the improvement of genotypes with enhanced nutrient uptake and resource-use efficiency. This study focused on identifying variations and relationships in the root and shoot characteristics of seven modern cultivars and twelve ancient wheat accessions of different species, including T. monococcum, T. turanicum, T. polonicum, T. mirabile, T. durum, and T. aestivum, during the early vegetative growth and stem elongation stages. The results demonstrated significant phenotypic variation among the genotypes for shoot traits, root biomass, rooting depth, R/S ratio, and seminal and nodal root numbers. When considering both growth stages, the dry land-adapted cultivar ‘Taner’ and ancient wheat species, such as T. turanicum (2) and T. monococcum (1) accessions, exhibited deeper roots, which can enhance access to water in drought-prone areas. Furthermore, it was observed that modern wheat cultivars and T. turanicum accessions exhibited increased root biomass, suggesting a higher allocation of resources towards root growth, which could potentially enhance nutrient uptake. Conversely, T. monococcum accessions and T. mirabile revealed lower root biomass compared to other ancient species and modern cultivars. Additionally, the unrooted cluster analysis based on root biomass, rooting depth, and root to shoot ratio at both growth stages indicated a distinct separation of T. monococcum accessions and T. mirabile from other genotypes. Overall, these findings underscore the importance of phenotypic diversity in root traits for crop improvement and adaptation to varying environments. Identifying genotypes with desirable root characteristics can enhance nutrient and water uptake efficiencies, leading to increased crop productivity and sustainability.

Molecular diagnostic assay for pre-harvest detection of Tilletia indica infection in wheat plants.

The current study describes a new diagnostic method for the rapid and accurate detection of Tilletia indica, the pathogen accountable for causing Karnal bunt (KB) disease in wheat. This method uses quantitative real-time polymerase chain reaction (qPCR) and a primer set derived from glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene of T. indica to identify the presence of the pathogen. The qPCR assay using this primer set was found highly sensitive, with a limit of detection (LOD) value of 4 pg of T. indica DNA. This level of sensitivity allows for the detection of the pathogen even in cases of different growth stages of wheat, where no visible symptoms of infection on the wheat plants can be seen by naked eyes. The study also validated the qPCR assay on ten different wheat cultivars. Overall, this study presents a valuable molecular tool for rapid, specific and sensitive detection of KB fungus in wheat host. This method has practical applications in disease management, screening of wheat genotypes against KB and can aid in the development of strategies to mitigate the impact of Karnal bunt disease on wheat production.

Exploring Drought Tolerance in Wheat: Insights from Biochemical, Morphological, and Physiological Responses

This review paper delves into the intricate biochemical foundations underlying drought tolerance mechanisms in wheat plants. This exploration encompasses multifaceted aspects, ranging from physiological adaptations to gene expression modulation. Plants like wheat employ repertoire of biochemical strategies to bolster their resilience against drought stress. It involves coordinating antioxidant enzymes, osmotic regulators, polyamines, and hormones to combat drought stress. The antioxidant system is crucial, countering reactive oxygen species produced during drought. Enzymes like SOD, CAT, and POD are activated to protect cells. Osmolytes like sugars and polyamines maintain cell integrity and water retention, while hormones like ABA control stomatal closure and water conservation. Gene expression highlights the plant's drought adaptability. AP2/ERF factors boost drought tolerance when overexpressed. Gene repression uses motifs like EAR to reduce expression for environmental adaptation. Gene expression shows the plant's drought adaptability. Overexpressed AP2/ERF factors enhance tolerance. Repression, like the EAR motif, aids variation. The morphological basis study examines how water scarcity affects different growth stages of wheat, such as germination, tillering, flowering, and grain filling. It identifies physio-morphological traits that could serve as the indicators of drought resilience, providing a new way to breed stress resistance. Furthermore, this article also explains plant characteristics important for adapting to drought, including photosynthesis, water relations, nutrient uptake, oxidative state, osmotic balance, and hormonal consequences. Each facet contributes to the intricate web of physiological adaptations that allow wheat plants to withstand and thrive under drought conditions. Comprehending these mechanisms aids breeding for drought-tolerant wheat, ensuring food security amid climate change.

Responce of European Wheat to Weed Competitiveness as Affected by Potassium Fertilizer Levels

Purpose: The significance of potassium has been well documented as one of the major macronutrients for many crops, particularly wheat. Herbicide resistance in weeds and other environmental issues in the wheat crop has encouraged researchers to find alternative methods for weed management.Research methods: A field experiment was conducted during the winter season 2021-2022 at a private farm in North Samawah city, Iraq to examine the competitive ability of two European wheat cultivars against weeds as affected by potassium (K) levels. Treatments included two wheat cultivars (Milano and Pick-row), and three K fertiliser levels (0, 200 and 400 Kg K2O/ha).Findings: The results showed that Pick-row was a superior cultivar in terms of crop competitive ability with weeds compared with Milano. Pick-row was taller, produced the largest number of spikes, had the greatest grain yield, greatest crop biomass and least weed biomass about 61.5 cm, 70 spike/m2, 0.66 t/ha, 2.29 t/ha, and 52.5 g/m2 respectively. The increased K fertiliser level has a positive effect on crop production and weed biomass reduction, especially with Pick-row cultivar.Originality/ Value: It is implicated that Pick-row can be useful as a competitive cultivar under Al-Muthanna Province environments. Potassium K fertiliser is better to be increased and split into a number of equal doses and applied at different growth stages of wheat to avoid critical competitive timing risks.

Effects of nitrogen application rate on the accumulation of 13C assimilates after flowering and water-nitrogen use efficiency of wheat under supplemental irrigation based on soil moisture.

This study aimed to explore nitrogen fertilizer management measures to synergistically improve wheat yields and water and nitrogen use efficiency under supplemental irrigation based on soil moisture in the Huang Huai winter wheat area. Wheat variety "Yannong 1212" was used as the test material. There were three nitrogen application levels, 150 kg·hm-2 (N1), 210 kg·hm-2 (N2), and 270 kg·hm-2 (the conventional nitrogen application rate in the Huang Huai winter wheat area, N3), with the relative soil water content of 0-40 cm of each treatment was supplemented to 70% at the jointing and flowering stages. We investigated the effects of nitrogen rates on photosynthetic characteristics of flag leaves after flowering, 13C assimilate accumulation and transport, and water and nitrogen use efficiency after flowering of wheat. The results showed that photosynthetic capacity of flag leaves in the N2 and N3 was significantly higher than that in N1 14-35 days after flowering, and that there was no significant diffe-rence between N2 and N3 treatments. The 13C isotope tracing results showed that the translocation amount of 13C assimilates in vegetative organs in N2 was 12.1% and 7.1% higher than that in N1 and N3, respectively. The distribution amount of 13C assimilates in grains at maturity was 10.1% and 5.3% higher than that of N1 and N3, respectively. The amount of nitrogen fertilizer affected water consumption, water consumption proportion, and total water consumption in different growth stages of wheat. Water consumption during the whole growth period showed no difference between N2 and N3 treatments, but both were significantly higher than that for N1. Water consumption and water consumption proportion of N2 were higher from the jointing to maturity stages, water use efficiency of N2 was 7.5% and 4.8%, and grain yield was 4.7% and 10.9% higher than that of N3 and N1 treatments, respectively. The partial productivity of nitrogen fertilizer was 34.6% higher in the N2 than that of N3. Considering wheat grain yield and water and nitrogen use efficiency, 210 kg·hm-2 nitrogen application was the best rate under water-saving condition of supplementary irrigation after soil moisture measurement in the study area.

Physio-biochemical characterization of wheat genotypes under temperature stress.

Thermal stress is a major abiotic stress in wheat and ishighly complex in mechanism. A large area in northwestern plain zones (NWPZ), which is the wheat bowl of India is affected by heat stress. Climate change also causes anabrupt increase in temperature at different growth stages of wheat. Thus, wiser selection of stress tolerant varieties is an important strategy to combat the climate change effect. The present study aims for physiological and biochemical screening of timely sown NWPZ wheat varieties (WB2, HD3086, DBW88, DPW621-50, DBW17, HD2967 and PBW550) of India for their thermal stress tolerance along with heat tolerant (RAJ3765) and susceptible checks (RAJ4014) at seedling stage. The experiment was conducted in completely randomized design under controlled laboratory condition and heat stress was induced at 37°C at seedling stage. Later different physio-biochemical traits were studied in both control and stress seedlings. All traits exhibited significant variations among genotypes under heat stress condition. Root and shoot weight, relative water content, chlorophyll content index and chlorophyll fluorescence reduced significantly, whereas membrane leakage, osmotic potential, catalase, ascorbate peroxidase, guaiacol peroxidase, malondialdehyde content and proline content were increased in stress plants. A tolerance matrix was prepared based on stress response of the genotypes for each trait and a final tolerance score was given to each genotype. Based on this tolerance matrix, DBW88 and PBW550 were identified as tolerant, DPW621-50, DBW17 and HD2967 as moderately susceptible and HD3086 and WB2 as susceptible to heat stress. Earlier studies parade that seedling level stress tolerance has high correlation with adult level stress tolerance under field condition in wheat. Hence, this study helps in wiser selection of varieties for sowing in NWPZ based on weather forecast of the location for creating varietal mosaic in context of climate change.

Reducing and Delaying Nitrogen Recommended by Leaf Critical SPAD Value Was More Suitable for Nitrogen Utilization of Spring Wheat under a New Type of Drip-Irrigated System

Timely and accurate judgment of the nitrogen nutritional status of crops is the key to develop an optimal nitrogen application strategy. However, the evaluation criteria of nitrogen nutrition and nitrogen application strategies at each growth stage of wheat are not clear for the new type of drip-irrigated spring wheat system, TR6S (where one drip tube serves six rows of wheat, with a row spacing (RS) of 10 cm, inter-block space (IBS) of 25 cm and the lateral spacing (LS) of 80 cm, which achieved a lower drip-tube input and higher profit compared with the traditional planting system in Xinjiang). Therefore, we studied the recommendation mechanism of nitrogen fertilizer in different growth stages of wheat based on the critical SPAD values of leaves under TR6S. We set four nitrogen treatments (N1 (300 kg ha−1), N2 (270 kg ha−1), N3 (240 kg ha−1) and N4 (0 kg ha−1)) during two spring wheat growth seasons. The results revealed that the correlation coefficient (r2) between SPAD (soil plant analysis development) value and plant nitrogen content in the middle of first top leaf (L1-M) of wheat was higher than that in other leaf types and leaf positions under TR6S. A quadratic function relationship existed between a SPAD value of L1-M and grain yield. The critical SPAD values at the jointing, booting, anthesis, early milk, and late milk stages were 37.34, 39.40, 42.25, 45.57, and 35.91, respectively. In addition, through the establishment of the nitrogen application recommendation model for various wheat growth stages based on the critical SPAD value, the recommended optimal nitrogen application rates at jointing, booting, anthesis, early milk, and late milk stages were observed to be 69.4, 80.0, 90.8, 44.0, and 6.0 kg ha−1, respectively. This recommended nitrogen application strategy exhibited a better parallel relationship with the nitrogen nutrition index (NNI) of each growth period than the conventional nitrogen application strategy. Therefore, it was more in line with the actual absorption and utilization of nitrogen in wheat of TR6S. In conclusion, the SPAD values of L1-M could be relatively more accurate to evaluate the nitrogen nutrition status of wheat. Compared to traditional nitrogen application strategy, reducing and delaying nitrogen application, recommended based on the leaf SPAD model, was more suitable for nitrogen utilization under TR6S. The results can be applied in other arid and semiarid regions.

Ground Hyper-Spectral Remote-Sensing Monitoring of Wheat Water Stress during Different Growing Stages

Monitoring agricultural drought via ground hyper-spectral remote sensing has always been a hot topic in the fields of agriculture and meteorology. In this study, a greenhouse experiment was conducted on wheat subjected to water stress during its different growth stages, namely tillering, jointing, and milk maturity. An instrument (HOBO ware PRO) used to continuously measure soil moisture was employed to measure the soil water content (SWC). An analytical spectral device (ASD) was utilized to obtain the spectral curve of wheat subject to different water treatment methods. The canopy temperature was obtained using thermal infrared sensors (METER SI-400). The relationships between the SWC, wheat drought stage, canopy temperature, and spectral response characteristics were elucidated. The results showed that the significant differences in spectral characteristics were due to water stress during the different growth stages of wheat. Red-edge parameters of red-valley position (RVP) and red-edge position (REP) both changed by 21 nm for the tillering-stage drought and the jointing-stage drought; however, the RVP and REP values for the milk maturity stage drought and the treatment under no water stress changed by 2 nm. Further, it was proved that the red-edge blue-shift phenomenon was affected not only by the different wheat growth processes, but also by the water stress at different growth stages. Red-edge reflectance clearly reflects wheat water stress at different growth stages. From SWC and canopy temperature analysis results, SWC and canopy temperature had a significant difference between wheat drought at different growth stages, and the canopy temperature at the jointing stage drought had the strongest change. The water index (WI) based on eleven vegetation water indexes exhibited a good performance for distinguishing wheat water stress at different growth stages. In conclusion, ground-based hyperspectral remote sensing can provide a large amount of high temporal and spectral resolution data on vegetation and its surrounding environment, making it an important technical tool for wheat drought monitoring, which has a great significance on the monitoring and early warning of wheat drought, reducing drought-related yield losses, and ensuring food security.

Effect of boron on cadmium uptake and expression of Cd transport genes at different growth stages of wheat (Triticum aestivum L.)

Boron (B) is an essential microelement for plant growth and has been shown to reduce cadmium (Cd) toxicity in wheat through modulating gene expression. However, there is not enough information about the effects of different applications of B fertilizer on the accumulation of Cd, particularly throughout the wheat growth period. This experiment employed two different B fertilization methods. The soil application method utilized 1.5 mg B kg−1 soil (Cd+B) and foliar application utilized 0.1% (F0.1%), 0.3% (F0.3%), and 0.6% (F0.6%) B concentrations along with 4 mg kg−1 Cd. The results showed that B application in the soil reduced Cd concentrations per plant by 43.9% at the seedling stage, 74.59% in the roots, and 52.11% in the shoots at the elongation stage. At the same time, Cd concentrations in the roots were higher by B application at the anthesis and maturity stages, suggesting that B retains more Cd in the roots. The gray correlation analysis showed that the gray relational coefficients followed the following order: F0.3% > F0.1% > Cd+B > F0.6%. According to quantitative real-time PCR analysis, the six Cd transporters were mostly expressed in the roots at the seedling stage and anthesis stage. In addition, the expression of TCONS1113, TRIAE1060, and TRIAE5370 showed a negative correlation relationship with Cd concentration at the seedling stage, both in roots and shoots. At the anthesis stage, the expression of TCONS1113 and TRIAE5370 in roots was higher in Cd-treated plants compared to B-treated plants, and a similar tendency was noted for the expression of TRIAE5770 and TRIAE1060 in shoots as well. These results suggest that B application could significantly inhibit Cd uptake and translocation by regulating the expression of Cd transporter genes, especially at the seedling stage and the elongation phase in wheat.

Night warming at the vegetative stage improves pre-anthesis photosynthesis and plant productivity involved in grain yield of winter wheat

We conducted pot experiments during the 2018–2020 growing seasons to study the effects of night warming at different growth stages of wheat on the photosynthetic performance; accumulation, transportation, and distribution of dry matter; and grain yield of winter wheat. Night warming at all the different growth stages resulted in an elevation of wheat yield by increasing the 1000-grain weight and the number of grains per ear. Night warming during the period from jointing to booting stage resulted in the greatest increase in wheat yield. It also increased the amount of overall dry matter and transferrable amount of dry matter in plants and increased the distribution of dry matter to grains to increase grain weight. Night warming treatments at three different growth stages enhanced pre-anthesis photosynthetic capacity by increasing flag leaf net photosynthetic rate, chlorophyll content, and photochemical efficiency of winter wheat at the early stage of grain filling, especially in the night warming treatment from jointing to booting stage. Night warming not only increased the stomatal density and stomatal index of wheat leaves but also increased stomatal conductance and transpiration rate in the early stage of grain filling, thus being conducive to the smooth progress of photosynthesis. In conclusion, night warming treatment at different growth stages increased the photosynthesis of flag leaves at the early stage of grain filling, and promoted the accumulation of dry matter in plants after anthesis, which was conducive to the grain yield of winter wheat.

Phosphate solubilizing bacteria inoculated low-grade rock phosphate can supplement P fertilizer to grow wheat in sub-tropical inceptisol

Soil phosphorus (P) despite being an important element for plant growth, its high reactivity and low solubility has challenged the farming community for its efficient utilization. P fertilizers are produced from high grade rock phosphates. Reserve of this non-renewable resource is getting exhausted very rapidly. That establishes the need of using non-conventional P sources to grow crops. In this study, low grade rock phosphates (LGRP) were used as alternate P source to grow wheat in Inceptisol. Different quantities of phosphate solubilizing bacteria (PSB) inoculated LGRP were applied in incubation and pot experiments and were compared with a commercial P fertilizer. It was hypothesized that PSB inoculation would increase P solubility from LGRP and reduce P fixation in soil, thus improve supply parameter and increase P availability to the crop. Short term P dynamics at three different growth stages of wheat, enzyme activities, P-fixation and adsorption chemistry were studied. Incubation experiment established that PSB inoculated LGRP can supply significantly higher amount of P as compared to untreated LGRP. It also proved the potentiality of PSB inoculated LGRP treatment to maintain better supply of P in soil for long term. Pot experiment revealed that combined application of PSB inoculated LGRP + di-ammonium phosphate (DAP) can supplement 50% P fertilizer and maintain similar yield and P uptake as compared to DAP treatment. Applied PSB solubilized P from LGRP and soil, also prevented P fixation in soil by producing organic acids, siderophores, phosphatase enzymes. Thereby, application of PSB inoculated LGRP provided steady supply of available and saloid P for wheat throughout the growth stages and synchronised P supply with its demand. Application of PSB inoculated LGRP reduced the value of P adsorption maxima by ∼18% and bonding energy related constant of P-fixation by ∼11%; while value of P supply parameter enhanced by ∼14% over no PSB application. The PSB inoculated LGRP application enhanced inherent microbial activities by 10–24%, slashed P-fixation capacity by altering P adsorption chemistry and optimised P supply parameter. Thus, application of PSB inoculated LGRP could be recommended to crops to save ∼50% of the commercial P-fertilizer without affecting crop yields.

Radiation use efficiency and instantaneous photosynthesis at different growth stages of wheat (Triticum aestivum L.) in semi arid ecosystem of Central Punjab, India

The instantaneous canopy net photosynthetic rate (Ac) and photosynthetic radiation use efficiency (PhRUE) were investigated diurnally at different growth stages of wheat during two seasons 2009-2010 and 2010-11. Diurnal changes in Ac were synchronized with changes in incident photosynthetic photon flux density (PPFDo) throughout the experimental period during both the seasons. Regardless of growth stages, high Ac values were always observed around noon, when there was a high photosynthetic photon flux density (PPFD). In addition, the highest AC values were noticed at heading stage, when compared to other growth and development stages of wheat. With respect to PhRUE, the highest values occurred in the active tillering stage and decreased gradually upto soft dough stage during both the seasons. PhRUE was lowest after heading stage for wheat crop in both seasons, corresponding to decrease in photosynthetically active leaf area, another explanation for the decrease in RUE is a decrease in crop growth rate. Regarding diurnal changes in PhRUE, study revealed that it was always higher during early morning and evening time of the day at all the stages of the crop. The seasonal PhRUE of wheat was observed to be 1.21 g MJ-1 and 1.27 g MJ-1, respectively during two seasons.

Response of dry matter partition and yield components to waterlogging and sunlight shortage in different growth stages of wheat

Response of dry matter partition and yield components to waterlogging and sunlight shortage in different growth stages of wheat

Influence of Organic Manures on Drought Stress at Different Growth Stages of Wheat

A pot experiment was conducted in the net house of the Agronomy department, Sher-e-Bangla Agricultural University, Dhaka during the period from November, 2018 to March, 2019 to evaluate the suitable organic source to mitigate the drought stress impact on wheat. The experiment comprised two factors viz. factor A: Three levels of organic manures, i) O0 = Control (Without organic manure), ii) O1 = Cowdung (10 t/ha), iii) O2 = Poultry litter (5 t/ha), and factor B: four levels of drought i) D0 = Control (without drought), ii) D1 = Crown root initiation stage (at 20-29 DAS), iii) D2 = Booting stage (at 45-54 DAS), iv) D3 = Anthesis stage (at 55-64 DAS). The experiment was laid out in a completely randomized design (factorial) with three replications. Organic manure showed positive impact on yield and cowdung (O1) gave the highest grain yield (4.06 g plant-1). This may be attributed to the highest number of effective tillers plant-1 (3.21), spike length (9.53 cm), spikelet spike-1 (17.31), grains spikelet-1 (2.31) and 1000-grain weight (44.61 g) of wheat in this treatment. In respect of drought imposition treatments, grain yield was found higher in control treatment (without imposition of drought) which was statistically similar with drought imposition at booting stage treatment (D2). These two treatments also showed highest number of effective tillers plant-1, spikelets spike-1, grains spike-1 and 1000-grain weight. Regarding the interaction of organic manure and drought, cowdung without drought imposition (O1D0) and cowdung with drought imposition at booting stage (O1D2) were highest yielder among the other interactions which was attributed to higher 1000-seed weight, number of effective tillers plant-1, spikelets spike-1 and grains spike-1. Results revealed that application of organic manure could reduce the impact of drought on wheat irrespective of growth stages. However, application of cowdung (10 t ha-1) was found more effective to combat drought impact at booting stage of wheat compared to other growth stages.
 Bangladesh Agron. J. 2020, 23(2): 81-86

Physiological differences at different growth stages of wheat and their effect on yield and yield attributing traits

India being the second largest wheat producer in the world provides 13% of global wheat supply. Traditional breeding approaches are limited by the low genetic variability, complexity of stress tolerance traits and yield components and the lack of efficient selection techniques under stress conditions. Although the physiological tolerance indices are not directly related to yield but their use might prove increasingly useful. Integration of physiological traits complimented with efficient breeding methodologies will drive the present research to the required wheat yields. A set of twelve wheat lines were used to study the effect of different physiological parameters on the overall yield and its component traits. Progressive increase in NDVI values was noticed during the vegetative phase and a definite decline in values was observed during milk development to ripening stages in the genotypes. In high yielding genotypes a sharp decline of NDVI values was observed from anthesis to milk development stage. This set of genotypes generally showed a slower increase in NDVI values from seedling growth stage to inflorescence emergence stage and faster decline from inflorescence stage to ripening stage. The grain filling occurs in high temperatures and genotypes showing faster utilization of green matter showed higher yield.

Impact of high night temperature stress on different growth stages of wheat

Increasing temperature especially the High night temperature (HNT) is a major constriction for sustaining global food production under changing climate scenario. Recent climate change has resulted into events of abrupt night temperature rise either throughout the crop period or at specific growth stage. Historical temperature observations and model projections have predicted a more pronounced increase in night temperature [minimum temperature (Tmin.)] compared to that of day temperatures [maximum temperature (Tmax.)]. Hence, the present study was carried out to identify the most critical growth stage affected by HNT and their effects on physiological, growth and yield traits of wheat. A unique field-based movable temperature controlling system was designed to enhance the night temperature by 5 °C than ambient temperature. The three critical phenological stages of wheat i.e. at GS 15 (before tillering initiation), GS 45 (booting) and GS 75 (grain filling) of Zadok’s scale were separately subjected to HNT treatment. The results reveals that GS 75 (grain filling) was the most sensitive stage affected by HNT, which has recorded remarkable reduction in grain yield (GY), Harvest Index (HI), Thousand grain weight (TGW) and grain weight per spike (GWPS) compared to control treatment. Pearson correlation analysis showed that breeders can choose lines with higher TGW, GWPS and grain number per spike (GNPS) for obtaining better GY under HNT conditions and vegetative/booting stage HNT in field condition may not attribute for any significant yield loss.

Influence of Crop Establishment Techniques, Fertilization and Microbial Consortia on Potassium Nutrition of Wheat

A field experiment was conducted for 2 years (2013-14 and 2014-15) during winter (Rabi) season at Research Farm of ICAR-Indian Agricultural Research Institute, New Delhi, India with an objective to study the significance of two microbial consortia inoculations, zinc (Zn) fertilization (5 kg Zn ha-1 through ZnSO4∙7H2O soil application in each crop at sowing) and three rates of nitrogen (N) and phosphorus (P) fertilization on potassium (K) concentration, uptake and as well as ammonium acetate (NH4OAC)-extractable K content in soil at different growth stages in wheat. The microbial consortia used were Anabaena sp. (CR1) + Providencia sp. (PR3) and Anabaena-Pseudomonas biofilmed bio-fertilizer; while rate of fertilization were 0, 75% and 100% of recommended rate of nutrients (RDN) (120 kg N ha-1 and 25.8 kg P ha-1). The concentration and uptake of K was significantly higher in zero tillage wheat (ZTW) than conventional drill-sown wheat (CDW) and system of wheat intensification (SWI) at all observations except at 30 days after sowing. The application of 100% RDN and Zn fertilization have significant and positive effect on K uptake. The microbial consortia increase K concentration and uptake by 0.09-0.12 mg kg-1 and 9.9-12.7 kg ha-1 in straw and 0.08-0.11 mg kg-1 and 3.8-5.6 kg ha-1 in grain. The soil ammonium acetate (NH4OAC)-extractable K decreased by 87-108 kg ha-1 and 19-44 kg ha-1 in first and second year, respectively over initial soil K even after application of recommended rate of K (49.8 kg ha-1). Our study concludes the significant increase in K uptake due to ZTW and use of microbial consortia and there is the need for redeciding K fertilization in wheat for sustained productivity.