Normal Irrigation Research Articles

Biochar and alternate partial root-zone irrigation greatly enhance the effectiveness of mulberry in remediating lead-contaminated soils

Abstract Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils. This study aims to examine the growth, lead resistance and lead accumulation of mulberry (Morus alba L.) seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation (APRI). Methods We conducted a three-factor greenhouse experiment with biochar (with vs. without biochar addition), irrigation method (APRI vs. normal irrigation) and four levels of soil lead (0, 50, 200 and 800 mg·kg−1). The performance of the seedlings under different treatments was evaluated by measuring growth traits, osmotic substances, antioxidant enzymes and lead accumulation and translocation. Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination, and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead. The seedlings were able to resist the severe soil lead contamination (800 mg·kg−1 Pb) by adjusting glutathione metabolism, and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity. Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil. Pb, biochar and ARPI interactively affected Pb concentrations in leaves and roots, translocation factor and bioconcentration. Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.

Assessment of physiological traits of common bean cultivars in response to water stress and molybdenum levels

Molybdenum is an essential micronutrient that regulates plant growth, development, and responses to abiotic environmental stresses. However, little is known about the joint effects of water stress, molybdenum, and cultivar on physiological traits of field-grown common bean. Therefore, a split-plot factorial design was used to determine the main and interaction effects of Water stress (3 levels: 55–60, 90–95 and 120–125 mm evaporation from class A pan), Molybdenum (2 levels: control and 80 g per ha), and Cultivar (2 levels: Akhtar and COS-16) on physiological traits and grain yield of common bean. The results indicated that leaf area index (LAI), chlorophyll index, relative water content (RWC) and grain yield decrease with increasing water stress. Spraying molybdenum to the plants increased LAI, RWC, and grain yield, but the extent of the increase varied with cultivar. The positive effect of molybdenum also varied with the magnitude of water stress, and it was higher in severe water stress condition compared to that in normal irrigation and moderate water stress conditions. Of the two cultivars, COS-16 gave significantly higher grain yield than Akhtar cultivar, but Akhtar was superior in terms of physiological traits. The study demonstrated that the application of Molybdenum under water stress may cause an increase in N uptake and the efficiency of its use, that consequently increases the chlorophyll index and grain yield of common bean cultivars.

Multiple traits selection in bread wheat under drought stress and normal irrigation

The genetic materials were F2, F3, F4 and F5 generations of the cross “Giza164/Sids4” of bread wheat. The experiments were conducted under drought stress and normal irrigation. Three cycles of single trait selection for grain yield/plant (GY/P) and five models of desired gain selection index (combinations from seven traits) were achieved in both environments separately. After the third cycle of selection, the selected families for the six types of selection under drought stress, and the selected families under normal irrigation were evaluated under both environments. The GCV in GY/P decreased from the F2 to the F5. The remained variability in GY/P for the five selection indices was higher after the three cycles of selection than the single trait selection for GY/P. Heritability estimates as calculated from regression of F5/F4 generations for the traits under selection pressure were higher under drought stress than under normal irrigation except few cases. The observed gain increased from index1 to index5, and all indices were better in improving GY/ P than direct selection for GY/P. It could be concluded that selection index was better in improving grain yield than single trait selection for GY/P. Furthermore, selection under drought stress (antagonistic selection) in these materials was better than selection under normal irrigation (synergistic selection) in improving GY/P either selection evaluated under drought stress or under normal irrigation. Selection index5 which involved GY/P, 100GW and NG/S was the best index in improving GY/P.

Effect of Water Stress, Nitrogen and Potassium Fertilizers on Maize Yield Productivity

Two field experiments were carried out at the Farm of Agric. Res. and Exp. Center of Fac. of Agric. Moshtohor, Benha University, Toukh Directorate, Qalyubia Governorate, Egypt, during two successive summer growing seasons of 2015 and 2016 to study the effect of three water stress, i.e. normal irrigation, skipping the second irrigation (skipping one irrigation during vegetative growth stage) and skipping the fifth irrigation (skipping one irrigation during kernels filling stage) and four nitrogen fertilizer rates, i.e. 0, 50, 100 and 150kg N/fed as well as three potassium fertilizer rates, i.e. 0, 24 and 48 kg K2O/fed on growth, yield and its components as well as some kernels chemical properties of maize (white single cross hybrid 2031 for Misr hytech Seed Int.,). Results of combined analysis of the two seasons showed that kernels filling stage was the most sensitive to water deficit stress and preventing irrigation at this stage (skipping the 5th irrigation) caused marked decrease in mean values of allmost maize yield and its components, while, full irrigation treatment appeared to be the best irrigation treatment sine it enhanced all maize traits under study. Planting maize under water stress by skipping the 2nd irrigation and skipping the 5th irrigation significantly decreased mean values of grain yield/fed (kg) by 25.49 and 41.04 % respectively, compared to mean values of grain yield/fed (kg) of maize under normal irrigation. Planting maize when received 150 kg N/fed caused significant increase in all mean values of maize traits under study such as plant height (cm), ear height (cm), No. of ears/fed, ear diameter (cm), ear length (cm), No. of rows/ear, No. of kernels/row, No. of kernels/ear, ear weight (g), kernels weight/ear (g), kernels shelling (%), 100-kernel weight (g), ear yield/fed (kg), grain yield/fed (kg), stover yield/fed (kg), biological yield/fed (kg), harvest index (%), kernels nitrogen content (%), kernels crude protein (%), nitrogen uptake/fed (kg) and protein yield/fed (kg) Meanwhile, the highest mean values of potassium use efficiency (KUE) which were recorded from growing maize when received 100 kg N/fed. Growing maize under the higher potassium rate (48 kg K2O/fed) was produced the maximum mean values of plant height (cm), No. of ears/fed, ear length (cm), No. of kernels/row, No. of kernels/ear, ear weight (g), kernels weight/ear (g), 100-kernel weight (g), kernels shelling (%), ear yield/fed (kg), grain yield/fed (kg), stover yield/fed (kg), biological yield/fed (kg), harvest index (%), kernels potassium content (%), nitrogen uptake/fed (kg) and protein yield/fed (kg) while, the highest mean values of KUE which were recorded from growing maize when received 24 kg K2O/fed. The first order interactions between (normal irrigation X 150 Kg N/fed), (normal irrigation X 48 kg K2O/fed) and (150 Kg N/fed X 48 kg K2O/fed) as well as the second order interaction between normal irrigation X 150 Kg N/fed X 48 kg K2O/fed) were significantly recorded the greatest mean values of maize yield and its components as compared with the others interactions. It could be summarized that grown maize under full irrigation and fertilization by 150 Kg N + 48 kg K2O/fed in order to maximizing its productivity.

Fertigation of Ajwain (Trachyspermum ammi L.) with Fe-Glutamate Confers Better Plant Performance and Drought Tolerance in Comparison with FeSO4

Shortage of fresh water limits crop yield. Different ways including the use of chemicals are being employed for the improvement in yield through induction of plant performance. In the present study, ajwain plants grown under water stress and normal irrigation conditions were fertigated with Fe-chelated glutamate (Fe-Glu), as a foliar spray for the induction of plant performance in comparison with FeSO4. Water shortage adversely affected the plant growth and seed yield, associated with decreased uptake of water and nutrients, along with perturbations in different physio-biochemical attributes. On the other hand, Fe-Glu and FeSO4 fertigation improved plant performance under water stress and normal irrigation conditions. Fe-Glu and FeSO4 fertigation ameliorated the adverse effects of water stress on biomass and seed production, improved water and nutrients uptake, increased the accumulation of essential amino acids, leaf chlorophyll and carotenoids, and reduced the lipid peroxidation due to the induction of antioxidative mechanisms. Fertigation of Fe-Glu and FeSO4 also improved Fe uptake and conferred better mobility and availability of Fe for plants when applied in chelated form. Overall, a significant improvement in ajwain performance under water stress and normal irrigation conditions was recorded due to the fertigation of Fe-Glu as compared with FeSO4.

Performance of Ber (Zizyphus mauritiana lamk.) Varieties under Two Irrigation Scheduling of Saline Water in Central Gujarat Conditions in India

The field experimentation was carried out at Instructional Farm, BAIF Development Research Foundation, Nanodara of Ahmadabad district during 2014 to 2018 with an objective to evaluate the response of the two ber varieties (Seb and Gola) to number of irrigations on the growth and yield of ber crop. It was also intended to understand effect of saline irrigation water on soil status as irrigation water of the study location is slightly saline in nature. The study was conducted in Split Plot Design with six replications. Treatments consisted of two irrigation schedule; normal irrigation at 15 days interval and life saving irrigation at 30 days interval and two varieties (Seb and Gola). Soil and irrigation water of the study location was analyzed using standard procedures for initial and yearly status, respectively. Two ways ANOVA was carried out using R Studio Statistics Rx 64 software. Significance levels were tested at p≤0.05. The highest plant height (326.87 cm), girth size (60.75 cm), number of secondary branches per plant (7.24), dry leaf biomass per plant (3.96 kg), dry shoot weight per plant (16.65) as well as fruits per plant (337.58), fruit weight (56.96 g), fruit yield per plant (19.43 kg) and fruit yield per ha (5400 kg) were increased significantly with normal irrigation treatment (irrigations at 15 days interval) which was significantly superior over life saving irrigation. In case of varieties, all the parameters of the growth and yield of the crop were maximum for Gola variety compared to Seb. The pH, EC and SAR were comparatively lower in soil under life saving than normal irrigation.

Drought Stress Alleviation by ACC Deaminase Producing Achromobacter xylosoxidans and Enterobacter cloacae, with and without Timber Waste Biochar in Maize

The high consumption of water in industries, domestic areas and increasing earth temperature are major hurdles for the optimization of maize yield. Being the third most widely cultivated cereal crop, improvement in maize yield is a big challenge under the limited availability of irrigation. As the water requirement for maize cultivation is high, it is time to introduce technologies that can mitigate drought stress and are environmentally friendly. The inoculation of rhizobacteria with ‘1-aminocyclopropane-1-carboxylate deaminase’ (ACCD) can play an imperative role in that regard by decreasing stress ethylene in plants. Biochar (BC) can also alleviate drought stress. Therefore, a field study was conducted, to examine the single and combined application of drought-tolerant plant-growth-promoting rhizobacteria (PGPRs) Achromobacter xylosoxidans and Enterobacter cloacae, with 15 Mg ha−1 of timber waste biochar (TWBC) at normal irrigation = 16 irrigations, mild drought = 14 irrigations and severe drought = 12 irrigation for maize cultivation. A significant improvement in shoot dry weight (28%), 1000-grains weight (19%), grain yield (27%), concentrations of N (43%), P (92%) and K (71%) in grains, rate of photosynthesis (33%), transpiration rate (55%), stomatal conductance (104%), chlorophyll A (33%), chlorophyll B (62%) and total chlorophyll (45%) of maize was noted under drought stress where E. cloacae + TWBC was applied. Likewise, the application of A. xylosoxidans + TWBC also significantly enhanced the plant height (24%) and cob length (9%) of maize under drought stress. In conclusion, E. cloacae is more effective than A. xylosoxidans, with 15 Mg ha−1 TWBC to increase maize yield under drought stress, due to the potential of higher ‘1-aminocyclopropane-1-carboxylate’ (ACC)-deaminase synthesis, better nutrient solubilization and indole acetic acid (IAA) production.

Effects of nano-fertilizers on physiological and yield characteristics of pinto bean cultivars under water deficit stress

In order to evaluate the effects of water deficit stress and foliar application of zinc (Zn) and iron (Fe) nanoparticles on physiological characters and seed yield of pinto bean, an experiment was designed as a split factorial design based on randomized complete blocks with three replications in two growing seasons (2016–2017 and 2017–2018). Treatments were included water deficit stress (normal irrigation and water deficit stress in 50% flowering), foliar application of nano-fertilizers (control, nano-Zn (1.5 g L−1), nano-Fe (2 g L−1) and combination of nano-Zn and nano-Fe) and four cultivars of pinto bean (Sadri, Coosha, Cos16, and Ghaffar). The results showed that the soluble sugars and proline content was increased under water deficit. Water deficit stress through decreasing chlorophyll and relative water content of leaves as well as the iron and zinc content of seeds, decreased seed yield and quality. The application of nano-fertilizers of zinc and iron enhanced antioxidant enzymes activity, proline and soluble sugars content as well as leaf area. Also applied nano-fertilizers improved seed quality in terms of protein content. According to obtained results the effect of foliar spray of nano-fertilizers on iron and zinc content of seeds regards to bean cultivars was different. It was concluded that the foliar application of iron combined zinc nano-fertilizers can be useful in pinto bean cultivars under water deficit stress. In both normal and water deficit Cos16 cultivar showed the better amount of studied characteristics compared to other cultivars. The results of cluster analysis of these cultivars confirmed the superiority of Cos16 cultivar.

Effects of sub-low temperature and drought stress on water transport and morphological anatomy of tomato plant

We explored the effects of sub-low temperature and drought on water transport in tomato seedlings under normal temperature (25 ℃ day/18 ℃ night) and sub-low temperature (15 ℃ day/8 ℃ night) within the artificial climate chamber, and under normal irrigation (75%-85% field water holding capacity) and drought treatment (55%-65% field water holding capacity). We analyzed the effects of temperature and soil moisture on water transport, stomata and xylem vessel morpholo-gical and anatomical structure of tomato plants. The results showed that compared with condition of normal temperature + normal irrigation, drought treatment significantly reduced leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, sap flow rate, stomatal length, and diameter of leaf, stem and root conduit, and thus thickened the cell wall and enhanced the anti-embolism ability of conduit in leaf, stem and root. Leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, and conduit diameter in leaf, stem and root were significantly reduced by sub-low temperature treatment, but the stomata became larger, cell wall was thickened and the anti-embolism ability was enhanced in leaf, stem and root conduit. Under sub-low temperature condition, soil moisture did not affect leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, stomatal morphology, conduit structure of leaf and root. In conclusion, under drought treatment, the homeostasis in water relationship was obtained by the coordination of leaf, stem and root structure. Under sub-low temperature treatment, the regulation of water relationship was mainly dependent on the changes of conduit structure in leaf and root, which was less affected by soil moisture.

Estimation of percent wound area reduction over a period of four weeks among diabetic foot ulcers

Foot ulcers are the most commonly experienced,fearful complications of diabetes which can frequently be life or limb-threatening.Several factors can lead to the occurrence of foot ulcers in diabetics.Prevention and proper management of DFUs are the prime most important in the care of patients with diabetes. It is essential to predictthe wound healingtime in managing the diabetic foot ulcers.The main objective of the study is to examine the reduction in wound area over four weeks in achieving more than 50 % Percentage Area Reduction (PAR) as a clinical outcome.Twowound irrigation methods were used for irrigating the wounds. Assessment of the wound area was done and comparedon achieving more than 50 % reduction in ulcer area at the end of four weeks. The studyused a descriptive comparative design with a control group. DiabeticFoot ulcerpatients (N = 160) from a private hospital were randomly allocated into 80 in each group (Neem solutionirrigation and Normal saline irrigation groups). In both groupsSurface area of the wound was measured using a disposable wound ruler with standard calibrations at baseline and then at the end of each week till four weeks are completed. Data were analyzed in SPSS20 software while considering p< .05 as statistically significant.The mean Wound surface area of the Normal saline group was 18.41 at the end of the first week and 14.04 after four weeks verses 19.84. The above-quoted scores in the Neem solution irrigation group were 14.68 and 6.92, respectively, against 17.13(p < .05).At the end of 4 weeks, the mean per cent reduction in area from baseline of DFUs irrigated with Neem solution was 72.4 % and with Normal saline was 48.7 %. Ulcers irrigated with neem solution had a 28.7 % greater mean reduction in area from baseline when compared with the normal saline control group at the end four weeks (p<.05).

Morphological and metabolic profiling of a tropical-adapted potato association panel subjected to water recovery treatment reveals new insights into plant vigor.

SUMMARYPotato (Solanum tuberosum L.) is one of the world's most important crops, but it is facing major challenges due to climatic changes. To investigate the effects of intermittent drought on the natural variability of plant morphology and tuber metabolism in a novel potato association panel comprising 258 varieties we performed an augmented block design field study under normal irrigation and under water‐deficit and recovery conditions in Ica, Peru. All potato genotypes were profiled for 45 morphological traits and 42 central metabolites via nuclear magnetic resonance. Statistical tests and norm of reaction analysis revealed that the observed variations were trait specific, that is, genotypic versus environmental. Principal component analysis showed a separation of samples as a result of conditional changes. To explore the relational ties between morphological traits and metabolites, correlation‐based network analysis was employed, constructing one network for normal irrigation and one network for water‐recovery samples. Community detection and difference network analysis highlighted the differences between the two networks, revealing a significant correlational link between fumarate and plant vigor. A genome‐wide association study was performed for each metabolic trait. Eleven single nucleotide polymorphism (SNP) markers were associated with fumarate. Gene Ontology analysis of quantitative trait loci regions associated with fumarate revealed an enrichment of genes regulating metabolic processes. Three of the 11 SNPs were located within genes, coding for a protein of unknown function, a RING domain protein and a zinc finger protein ZAT2. Our findings have important implications for future potato breeding regimes, especially in countries suffering from climate change.

Generation Mean Analysis for Three Bread Wheat Crosses under Normal and Water Stress Treatments

The objective of this study was to identify tolerant and susceptible genotypes of bread wheat under different irrigation treatments and determine the type of gene action and some genetic parameters in three bread wheat crosses; (Line 1 × Line 2), (Line1 × Giza 171) and (Misr 2 × Line 3) under normal irrigation and water stress treatments. Genetic materials included six populations (P1, P2, F1, F2, BC1 and BC2) for each cross. Positive and high significant values for heterotic effects relative to the mid- parent of grain yield were found for the second (Line1 × Giza 171) and third cross (Misr 2 × Line 3) under both irrigation treatments, while positive values heterosis for better parent detected for the third cross under both irrigation treatments. Non-allelic interaction was found for all studied characters in all the crosses under both irrigation treatments. Dominance effects were greater than the additive gene effect. Dominance × dominance gene interaction was higher in magnitude than additive × additive and additive × dominance for most characters under both irrigation treatments, indicating that these characters greatly affected by dominance and non-allelic interactions. Heritability in the broad sense was high for all the studied characters in three crosses under both irrigation treatments, while narrow sense heritability estimates were moderate to high for all the studied characters under both irrigation treatments. In general, the highest values of grain yield/plant were in the third cross (Misr2 × Line 3) under both irrigation treatments, based on tolerance index (Line 1) and (Line 2) are the most tolerant for water stress and the first cross (Line1 × Line2) was the most one for water stress tolerant, so this cross is recommended under water stress conditions.

SBIEC 14006 – A HIGH BIOMASS ENERGYCANE FOR POWER, ALCOHOL AND PAPER INDUSTRIES

Six energycanes viz., SBIEC 14001, SBIEC 14002, SBIEC 14003, SBIEC 14004, SBIEC 14005 and SBIEC 14006 developed at ICAR-Sugarcane Breeding Institute were evaluated along with a registered genetic stock SBIEC 11002 for biomass production under suboptimal management condition with limited irrigation and fertigation during 2013-14 and 2014-15 and under normal irrigation during 2015-16 (Plant crop) and 2016-17 (Ratoon crop). Among the six clones evaluated, SBIEC 14006, a selection from open pollinated fluff of Erianthus arundinaceus clone IK 76-75 was identified as promising clone based on high harvestable biomass and fibre content in cane. This clone recorded the highest mean harvestable biomass of 265.28 t/ha compared to the SBIEC 11002 (219.22) across four environments and showed 21.01 % improvement. The mean harvestable biomass yield under limited irrigation condition was 241.47 t/ha while under normal irrigation condition the yield was 289.08 t/ha. For fibre % cane also SBIEC 14006 recorded the highest value of 27.54 % compared to SBIEC 11002 (20.90 %). The clone recorded an average of 8.94 % juice brix and 4.72 % juice sucrose. It also recorded 2.18 cm cane diameter and 1.24 kg of single cane weight. Tall and non-lodging nature of canes makes the clone amenable for mechanical harvesting. This clone can be ratooned for at least 7-8 years hence no need for replanting every year. This promising clone is identified as an ideal energycane due to more biomass yield per unit area and requires low input, low production cost and low nutrient requirement which are the characteristics of energycanes.

WATER STRESS ON DIFFERENT GROWING STAGES FOR QUINOA (Chenopodium quinoa willd) AND ITS INFLEUNCE ON WATER REQUIRIMENTS AND YIELD

A factorial experiment was conducted within split-split plot design with three replicates. Four genotypes seeds (Regalona, Q-37, KVL-SR2, and Q21) were planted in the sub plots while six water treatments distributed in the main plots. They were ordinary river irrigation (S0), stress at emergence (S1), branching (S2), at ear formation (S3), at flowering (S4), and at maturity (S5). Irrigation water was applied in the normal irrigation when 50-60% of the available water was depleted and one irrigation was omitted from the water stress treatments. Reference and actual evapotranspiration, pan evaporation, yield, crop coefficient, and water use efficiency were calculated. Mean irrigation requirement for the four genotypes based on irrigation scheduling was 230.8 mm, decreased by 14 and 17% under stress conditions of the drought tolerant stages. Grain yield ranged between 3.1 and 5 Mg ha-1 for water stress treatments compared to 5.6 and 4.2 mg. ha-1 for normal irrigation treatments. Genotype Q21 gave the highest yield and differed significantly from others. Field water use efficiency ranged between 1.6 to 1.1 kg m-3 and crop water use efficiency 1.38 to 2.22 kg m-3. KVL-SR2 and Q21 showed the highest efficiency (1.87 kg m-3). Results indicated that the stage of ear formation and flowering are the most tolerant to water stress. On the other hand, the branching, and maturity were critical stages with high reduction in yield under stress conditions.

Drought stress improves the composition of secondary metabolites in safflower flower at the expense of reduction in seed yield and oil content

Abiotic stresses like drought may modulate the synthesis of plants' secondary metabolites, with various pharmacological effects. In this study, the influence of water deficit was determined on safflower (Carthamus tinctorius L.) seed yield and oil content as well as antioxidant activity and phenolic and flavonoid compounds of both seed and flower for their industrial application. Eight safflower genotypes were planted in the field in two separate experiments under normal and water deficit conditions in a randomized complete block design. Agronomic traits of the genotypes were measured and their polyphenolic compounds were evaluated using liquid chromatography analysis. Results indicated that averaged over all genotypes and under normal irrigation conditions, seed yield and antioxidant capacity of seed extracts were 74% higher and 2.32 times of those under drought stress conditions, respectively. In contrast, under water stress, flower extracts had 2-fold antioxidant capacity at the expense of a significant decrease in seed yield, seed oil content, and antioxidant capacity of the seeds. The most abundant polyphenolic components in flowers of most genotypes which accumulated due to water stress were vanillic and caffeic acids. While in seeds, rutin and quercetin were more accumulated under normal irrigation regime. Interestingly, three components of apigenin, luteolin, and ferulic acid were not detected in flower extract of any genotypes in both irrigation regimes. The contrasting status of seeds vs. flowers under two environmental conditions were depicted by multivariate data analysis. Based on the principal component analysis, under normal irrigation regime, the higher antioxidant activity of the seeds (seed preferability) was correlated with total content and compounds of flavonoids. In contrast, in water deficit condition, the higher antioxidant activity of the flowers (flower preferability) was correlated with total phenolic content and vanillic, caffeic, and p-coumaric acids. Finally, one breeding line may be introduced with high seed yield and quality under both irrigation regimes, which its higher drought tolerance is possibly due to the induced synthesis of caffeic acid and quercetin.

SCREENING RICE (Oryza sativa L.) GENOTYPES FOR RESISTANCE AGAINST DROUGHT

Drought is regarded as one of the limiting factors in rice production nationally and globally. The present study was conducted to study morpho-physiological and biochemical responses of rice genotypes to drought stress, to identify potential traits for use as a selection criterion in breeding drought-tolerant rice at seedling stage and finally to identify rice genotype resistant to drought stress for use as parents in future breeding. The experimental design used was a split-plot design with three replications, with drought stress as the main plot and rice genotypes as the sub-plot. The main plots consisted of control (normal irrigation) and drought stress. The sub-plots consisted of twelve rice genotypes namely Apami (V1), Boewani (V2), Basmati 370 (V3), Cica- 4 (V4), Dular (V5), Jarom mas (V6), Kalarata (V7), Biris (V8), Haiboq (V9), Moroberekan (V10), MR 297 (V11) and Aerob 1 (V12). Results showed that drought stress led to a decrease in plant height, leaves size, root length, total dry weight, and number of leaves but an increment in proline content. The genotype Apami and Kalarata were found to accumulate higher proline content indicating potential resistant ability towards drought stress. Dular and Aerob1, along with tolerant control genotype, Moroberekan, on the other hand, recorded a lower SES score. Leave size, root length, and plant height could also be used as a selection criterion in breeding drought-tolerant rice due to high values of broad-sense heritability and genetic advance by percentage of mean (GAM). Nevertheless, further study on the genetics and physiological basis of tolerant ability at reproductive growth stages are necessary in order to assess grain yield potential of the potentially tolerant genotype reported in this study.

Effect of Drought and Irrigation Management on Two Rice Mutants of Bangladesh

Drought stress is a major constraint to the sustainable production of of crops. Rice (Oryza sativa L.) is considered as a drought-sensitive crop species. The experiment was carried out to investigate the response of two rice mutants to drought condition and to develop appropriate irrigation management. Experiment was conducted at mini-lysimeter (1.5 m x 1.0 m x 0.28 m, having drainage outlet and rain-shed) at BINA, Mymensingh in Aman season (August to October, 2017) and Aus season (March to June, 2018) consecutively. The mutants used were N4/250/P-1(2) and N4/250/P-2(6)-26. The mutants were tested against four levels of drought stress. The imposed treatments were: Normal irrigation (3 days AWD), supplemental irrigation (ASM drops below 85%, throughout the growing season), irrigation at 0.85 ASM (up to booting stage) then irrigation at 0.60 PASM, irrigation at 0.85 ASM (throughout the growing season). Treatments were imposed after 3 weeks from transplanting. Experiment was laid out according to random complete block design (RCBD) with split-plot arrangements and three replications. The results showed that the mutants produced reasonable yield under stress condition compared to normal irrigation condition, which indicates their tolerance capacity under drought condition. Rice drought tolerance could help the country deal with the shortages in water that are facing Bangladesh farmers already.

Wheat Productivity In Relation To Salicylic Acid Under Water Stress

The present study was carried out at Abess, Alexandria, Egypt, during the two seasons of 2018/2019 and 2019/2020 to study the effect of water stress and foilar application of salicylic rates on yield and quality of wheat. This experiment was laid out in a split plot system with three replications in both seasons. The main plots were water stress treatments (normal irrigation, skipping the first irrigation at the age of 50 days, skipping the second irrigation at the age of 70 days, and skipping the third irrigation at the age of 90 days from sowing), while salicylic acid (SA) concentration (water = control, 1 mM; 2 mM and 3 mM) distributed in a sub plot in both seasons. The obtained results showed that sowing wheat cultivar namely Shandaweel- 1 with foliar application of salicylic acid (SA) twice at 50 and 70 days after sowing (DAS) at the rate of 2 mM/l under normal irrigation or skipping one irrigation at the first or the second irrigation achieved the highest mean value of yield, yield components and protein (%) in grain under study conditions at Abess, Alexandria Governorate, Egypt.

Evaluation of Combining Ability and Heterosis for Yield and Its Components Traits of Rice under Normal Irrigation and Drought Stress Conditions تقییم القدرة على التآلف وقوة الهجین للمحصول ومکوناته فی الأرز تحت ظروف الری الطبیعی والجفاف

During 2010 and 2011seasons, two field experiments of rice experimental farm of Sakha, Kafr El-Sheikh, Egypt, were performed through a 6 x 6 diallel system analysis to investigation the combining ability and heterosis and their component features of rice under normal irrigation and drought stress conditions.A broad range of genetic variation among research genotypes was indicated by the routine analysis of variance. As for all the features of normal irrigation and drought stress conditionsThe significance of non-additive genetic variation in the heritage of grain yield / plant has been established by GCA / SCA ratios. While the selection based on the accumulation of the additive effect will boost yield and assign it successfully. According to drought susceptibility index (DSI), four parents and six crosses were the lowest genotypes affected by drought.GCA shows all parental lines are intrinsically performing with a strong index of their overall ability to blend. The combinations of IR7887-176-B-2-B X IR80508-B-194-1-B to boost the output of grain per plant was the best possible cross, as reported by SCA.Under drought, the highest values significant for heterosis from better parent, five crosses for panicle length and seven crosses for number of branches / panicles and grain yield characters. In the general sense, higher heritability levels emerged in normal irrigation; genotypic variances played a major part in phonotypical yield variances and their components.Lower and moderate heritage tests for all yields and their components showed that selection for these characteristics would be successful in late generations.

Seed biopriming mitigates terminal drought stress at reproductive stage of maize by enhancing gas exchange attributes and nutrient uptake

Maize Zea mays L. is an important cereal crop around the globe. Scarcity of water is one of the major abiotic factors reducing yields in this crop. The development of maize varieties with stress-tolerant traits is time-consuming and laborious work. There is a strong need to develop techniques that could have the effect of reducing irrigation requirements and mitigating waterstress conditions. Biopriming seed priming with bacterial inoculation is a newly emerging, simple, and easily adaptable strategy to mitigate drought stress for enhanced crop production. The current trial was executed using a randomized complete block design with factorial arrangements during the spring seasons of 2016 and 2017 at the research area of the Department of Agronomy, Bahauddin Zakariya University, Multan, Pakistan. The experiment consisted of two irrigation levels normal irrigation and terminal drought stress at reproductive stage and three seed priming techniques control, hydropriming, and biopriming . Hybrid maize variety HC9091 was used as a test species. For hydropriming, seeds were soaked in distilled water ratio 1:5 for 12 h. For biopriming, the hydroprimed seeds were inoculated with bacteria culture Rhizobium phaseoli-RS-1 + Pseudomonas spp. at the ratio of 1:5. Seeds were sown on ridges, maintaining a 75-cm row-to-row and 22.5-cm plant-to-plant distance. The results indicated an overall decline in agronomic and physiological attributes of the plants under terminal drought stress. However, seed biopriming considerably ameliorated the droughtinduced deterioration in agronomic plant height, cobs per plant, cob length, cob weight, grain yield, biological yield, and harvest index as well as physiological photosynthesis, transpiration rate, intrinsic water use efficiency, stomatal conductance, relative water content, and nutrient uptake parameters of plants. It is concluded that seed biopriming is an easy, commercially feasible, cost-effective technique and an ecofriendly way to cope with drought stress at the reproductive growth stage of maize in order to enhance crop productivity.