Normal Irrigation Conditions Research Articles

Dissection of genotype × environment interactions for mucilage and seed yield in Plantago species: Application of AMMI and GGE biplot analyses.

Genotype × environment interaction (GEI) is an important aspect of both plant breeding and the successful introduction of new cultivars. In the present study, additive main effects and multiplicative interactions (AMMI) and genotype (G) main effects and genotype (G) × environment (E) interaction (GGE) biplot analyses were used to identify stable genotypes and to dissect GEI in Plantago. In total, 10 managed field trials were considered as environments to analyze GEI in thirty genotypes belonging to eight Plantago species. Genotypes were evaluated in a drought stress treatment and in normal irrigation conditions at two locations in Shiraz (Bajgah) for three years (2013-2014- 2015) and Kooshkak (Marvdasht, Fars, Iran) for two years (2014–2015). Three traits, seed yield and mucilage yield and content, were measured at each experimental site and in natural Plantago habitats. AMMI2 biplot analyses identified genotypes from several species with higher stability for seed yield and other genotypes with stable mucilage content and yield. P. lanceolata (G26), P. officinalis (G10), P. ovata (G14), P. ampleexcaulis (G11) and P. major (G4) had higher stability for seed yield. For mucilage yield, G21, G18 and G20 (P. psyllium), G1, G2 and G4 (P. major), G9 and G10 (P. officinalis) and P. lanceolata were identified as stable. G13 (P. ovata), G5 and G6 (P. major) and G30 (P. lagopus) had higher stability for mucilage content. No one genotype was found to have high levels of stability for more than one trait but some species had more than one genotype exhibiting stable trait performance. Based on trait variation, GGE biplot analysis identified two representative environments, one for seed yield and one for mucilage yield and content, with good discriminating ability. The identification of stable genotypes and representative environments should assist the breeding of new Plantago cultivars.

Simultaneous Improvement and Genetic Dissection of Drought Tolerance Using Selected Breeding Populations of Rice.

Drought is the most important factor limiting rice yield in most rainfed areas of Asia and Africa. Four large BC2F2 populations consisted of 3,200 individuals, which were derived from crosses between an elite Geng variety, Jigeng88, and four donors from three different countries, were screened and progeny tested under severe drought stress, resulting in the development of 72 introgression lines (ILs) with significantly improved yield compared to the recurrent parent Jigeng88. These DT ILs plus four random populations (without drought selection population) from the same crosses were evaluated in replicated trials under both drought stress and non-stress conditions in two environments, and characterized with simple sequence repeat (SSR) markers to understand how directional selection was operating on the genetic variation of DT of rice. Thirteen DT QTLs of large effect were identified based on the significant allelic and genotypic frequency shits in the DT ILs by using the joint segregation distortion method. The 13 QTLs were validated by the genotypic differences at individual QTL in the random populations. Putative genetic networks consisting of 30 loci in 29 functional genetic units underlying DT were detected by X2 tests and non-random associations between or among DT loci in DT ILs from the four populations. Most large-effect DT QTLs were previously reported and located in the upstream of the genetic networks as putative regulators, and were either mapped to important regulatory genes for DT or drought responsiveness reported previously. In our study, five promising ILs with significantly improved yield were selected under both drought and normal irrigated conditions. The QTLs and their genetic networks underlying DT detected provided useful genetic information for further improving DT and yield using designed QTL pyramiding.

Evaluation of Durum Wheat Genotypes under Normal Irrigation and Drought Stress Conditions

Evaluation of Durum Wheat Genotypes under Normal Irrigation and Drought Stress Conditions

Effect of drought stress on qualitative characteristics of canola cultivars in winter cultivation

To determine the appropriate canola cultivars for winter cultivation under late-season drought stress conditions, a factorial split-plot test was conducted in a complete randomized blocks design with three replications for two cultivation years (2014–2016) in Karaj, Iran. In this work, cultivations at two levels included fall cultivation (Oct. 7) and winter cultivation (Feb. 4). The irrigation was conducted at three levels including routine irrigation (control), irrigation interruptions from flowering and pod formation stage in factorial status in main plots and five Brassica napus L. cultivars including Sarigol, Delgan, Jacomo, Jerumeh and Hyola 401 in subplots. The interaction effect of cultivation date × irrigation × cultivar on the features of palmitic acid, linolenic acid, linoleic acid, oleic acid, erucic acid, glucosinolate and oil yield was significant at the level of 1%. The results indicated that Delgan cultivar with the highest oil yield (1582 kg/ha) in the winter cultivation date and normal irrigation conditions as well as with standard levels of erucic acid and glucosinolate can be effective in canola cultivation in the new stage of winter cultivation. Moreover, in winter cultivation and in the late-season drought stress conditions, hybrids Hyola 401 with the highest seed yield, and standard oligosaccharide and glucosinolate can also be recommended in late-season drought stress conditions.

Genetic potential to improve seed and forage yield simultaneously in smooth bromegrass under water deficit conditions

This study was conducted to assess genetic potential of smooth bromegrass for water stress and to identify the association among different seed and forage production related traits. Thirty-six genotypes were clonally propagated and evaluated in the field under two moisture environments (normal irrigation and water stress) during 2013–2015. High variation was observed among genotypes for all of the measured traits. Water stress had negative effects on seed yield and its components and reduced genotypic variation of measured traits. On average, water stress reduced seed and forage yield by 38 and 14%, respectively. Genetic coefficient of variation for seed yield and its components was higher under stress, providing opportunities for a greater selection differential. The estimates of heritability were higher in normal condition than water stress condition for all of the evaluated traits, which is advantageous for successful selection. Moreover, the majority of seed yield components had higher heritability estimates than seed yield. The higher heritability estimates of some seed yield components, compared to SYP, suggests a potential for indirect selection. The results showed that selection for both forage and seed yield is possible simultaneously in normal irrigation as well as in water stress environment. Genotypes 7, 8, 26 and 27 had high forage yield, while genotypes 23 and 27 had high seed yield under both normal irrigation and water stress condition. Three genotypes ranked among the top three for both seed and forage yield and under both normal irrigation and water stress condition. They are promising parents for further use in developing improved cultivars by cross-breeding.

Response of Canola Advanced Lines to Delay Plantings upon Late Season Drought Stress

In order to evaluation of canola advanced lines response to delay plantings under late season drought stress conditions, an experiment was carried out in a factorial split-plot arrangement based on RCBD with three replications during two years (2012-2014) in Karaj of Iran. Treatments were; (1): Planting date in two levels (16 October and 1 November), (2): irrigation, in two levels (I1: normal irrigation as control and I2: restricted irrigation after pod formation stage) as main plots and (3): twelve oilseed rape genotypes as sub plots such as BAL2, BAL1, BAL3, BAL6, BAL8, BAL9, BAL11, BAL15, L72, R15, L109 and Okapi. The interaction effects of planting date, irrigation and genotype on pod number per plant, seed number per pod, 1000-seed weight, seed yield, and oil yield were significant at 1% level probability. The maximum seed yield under planting at the appropriate time (16 October), normal irrigation and drought stress conditions (restricted irrigation after pod formation stage) was observed in Okapi and L109, respectively). Among genotypes, R15 line under delay planting (1 November) and both normal irrigation and drought stress conditions (restricted irrigation after pod formation stage) showed the maximum seed yield.

Genetic Analysis of Yield and Its Attributes in Wheat ( Triticum aestivum L.) Under Normal Irrigation and Drought Stress Conditions

CLIMATE change and global warming cause an increase of drought effects on wheat production all over the world. Therefore developing wheat drought tolerant genotypes is essential, especially, under current water shortage. The present study was performed at the Experimental Farm, Faculty of Agriculture, Zagazig University, Egypt over winter seasons 2014/2015 and 2015/2016. Five diverse parental wheat genotypes (Misr 1, Gemmeiza 9, Gemmeiza 11, Line 1 and Line 2) were involved in a half diallel cross fashion under normal irrigation and drought stress conditions to investigate the effect of drought stress on yield and related contributing traits through mean performance, combining ability and gene action. The results showed significant differences among parental wheat genotypes and their F1 crosses as well as highly significant mean squares of general and specific combining ability for all studied traits under both conditions. For days to heading, Line 1 exhibited good level of earliness reflected in the performance of their F1 crosses (Line 1 x Misr 1) and (Line 1 x Line 2) under both conditions. The local wheat cultivars Misr 1 and Gemmeiza 9 as well as their F1 cross (Misr 1 X Gemmeiza 9) had high mean values for yield and its components under both conditions, reinforcing their importance in applied breeding programs. The parental wheat cultivar Gemmeiza 11 and F1 crosses (Line 1 x Gemmeiza 11), (Misr 1 x Line 2) and (Gemmeiza 9 x Gemmeiza 11) showed drought sensitivity index (DSI) values less than unity. Thus, these genotypes were considered as more tolerant to drought stress as regards to their grain yield/plant. The magnitude of additive (D) genetic component was higher as compared to their corresponding dominance (H1 and H2) ones, for days to heading both conditions and number of grains/spike under drought stress one, resulting (H1/D)0.5 less than unity. While, the dominance components was more than the corresponding additive one for flag leaf area, chlorophyll content, number of spikelets/spike, spike length, spike density, number of spikes/plant, 1000-grain weight and grain yield /plant under both conditions as well as number of grains/spike under normal irrigation only. The average degree of dominance was more than unity, confirming the importance of over-dominance in the genetic of these traits. under both conditions, the regression lines cut Wr axis above point of origin for days to heading, showing that partial dominance mode of inheritance for this character through additive gene action. On the other hand, it cuts Wr axis below origin for grain yield/plant, demonstrating that over-dominance gene effects are the prevailed type.

Participatory evaluation of advanced potato (Solanum tuberosum) clones for water stress tolerance

An attempt was made to introduce potato (Solanum tuberosum L.) in hot arid water scarce zone of Western Rajasthan, India. Eight CIP-bred potato clones were evaluated along with two controls, viz. Kufri Pukhraj and Kufri Surya on farmer’s field at Jodhpur, Rajasthan under normal and moderate water stress regime during three winter crop seasons (2012-15). Pooled analysis revealed that CIP clone 397006.18 (34.0 tonnes/ha) out yielded Kufri Pukhraj (26.8 tonnes/ha) and Kufri Surya (20.2 tonnes/ha) for marketable tuber yield. This clone maintained yield under normal and deficit irrigation and attained 26.9% higher marketable yield under normal irrigations, which further improved by 31.3% under deficit water stress regime over the best control Kufri Pukhraj. This clone recorded highest tuber dry matter content (22.7%), statistically superior to both control Kufri Pukhraj (17.9%) and Kufri Surya (21.4%). Clone 397006.18 had highest mean drought tolerance index value (1.16) and least total weight loss under normal irrigation (4.9%) and water stress conditions (8.6%) up to 60 days of storage. Preference yield analysis by potato growers showed that they liked this clone most and its overall acceptability was fairly better for all organoleptic traits. Results of field study and participatory varietal selection indicated that clone 397006.18 performed better for tuber productivity under deficit water management, exhibited drought tolerance traits and achieved overall acceptance by the farmers in Western Rajasthan.

Seleksi dan Karakter Sekunder Jagung Inbrida Toleran Cekaman Kekeringan

The availability of drought-tolerant maize inbred materials are useful to develop a hybrid or synthetic drought tolerant maize varieties. This research was aimed to select drought tolerant and determine secondary traits for selection of inbred maize. Selection of 31 maize inbred lines was conducted in nested experimental design in which the replicate was nested into the drought stress selection condition and normal irrigation. Drought stress treatment was applied during flowering to milk phase. In the normal irrigation condition the water was supplied every 10 days. The results showed that the medium tolerant to tolerant to drought stress inbred lines were 1044-30, DTPYC9-F46-3-9-1-1-B, CML161 / NEI9008, DTPYC9-F46-1-2-1-2- B, and Mr14. The yield declined of tolerant/medium tolerant inbred lines of about 17.0-38.3% was lower than sensitive inbred lines of about 42.8-70.7% under stress condition. The tolerant/medium tolerant inbred lines can be used for developing drought tolerant or synthetic varieties. The secondary traits effective for selection of drought tolerant inbred lines were shelling percentage, leaf chlorophyll, leaf rolling scores, number of tassel, the female flowering dates, and anthesis silking interval (ASI). The traits were more effected by genetic factors than the environmental factors and correlated to yield under drought stress conditions.<br /><br />Keywords: anthesis silking interval, environmental condition, inbred lines, tassel number, yield<br /><br />

EVALUATION OF TEN BARLEY GENOTYPES UNDER NORMAL IRRIGATION AND WATER STRESS CONDITIONS

This research was conducted in order to identify the best barley genotypes that can be grown under water stress conditions. This experiment was conducted in a split plot design with three replications at Experi­mental Farm of Sakha Agricultural Research Station, (ARC), Egypt, during the two successive seasons 2014/15 and 2015/16. Ten barley genotypes (Giza 123, Giza 126, Giza 129, Giza 130, Giza 131, Giza 132, Giza 133, Giza 134, Giza 135 and Giza 136) were evaluated for drought tolerance by measuring yield performance under normal irrigation and water stress conditions. The results indicated that, all the studied characters were significantly affected by stress in both growing seasons, except for total chlorophyll, spike length, no of grains/spike and harvest index, in both seasons. Stress reduced grain yield (ardab/fad.) by reducing the number of spikes/m2 and 1000-kernel weight. This study showed that, the best genotypes of barley for all parameters studied under stress condition were Giza 133 followed by Giza 134 in both seasons.

Selection Efficiency for Grain Yield Under Normal Irrigation and Water Stress Conditions in Bread Wheat

Selection Efficiency for Grain Yield Under Normal Irrigation and Water Stress Conditions in Bread Wheat

Physiological and Fluorescence Reaction of Four Rice Genotypes to Exogenous Application of IAA and Kinetin under Drought Stress

To assess the effects of IAA and Kinetin plant growth regulators in order to improve the drought tolerance in rice seedlings (Oryza sativa L.), a factorial experiment was carried out based on complete randomized design with three replications. The experimental factors included different rice genotypes [‘Gharib’, ‘Khazar’, ‘Sepidrood’ and ‘IR83750 -131-1’ (‘IR83750’ )], drought stress from 1 to 4 code of the Vergara coding system and control (normal irrigation) and growth regulators in three levels (IAA and Kinetin through foliar spraying and non-application as control). The results indicated, under normal irrigation condition together with IAA application, ‘IR83750’ rice had the highest number of tillers and leaf greenness, with mean of 18.27 and 49.46, respectively. The highest amount of leaf relative water content) 95.11 percent) was related to ‘Sepidrood’. Under drought stress condition, the highest electrolyte leakage (36.59 percent) was observed in ‘Gharib’. In drought condition, the highest leaf drying score was related to ‘Gharib’ in both years, but the highest score of leaf rolling index (9) was observed in ‘Gharib’ and ‘Khazar’. The present findings showed that drought stress had harmful effects in all examined genotypes and the impact in susceptible genotypes (‘Gharib’ and ‘Khazar’) was more than ‘IR83750’ and ‘Sepidrood’. Application of growth regulators (IAA and Kin) improved conditions for the growth of all genotypes. Therefore, using the tolerant genotypes along with growth regulators can improve the rice growth traits.

Glutathione Induced Antioxidant Protection Against Salinity Stress in Chickpea (Cicer arietinum L.) Plant

A POT experiment was conducted to evaluate the possible role of foliar treatment of glutathione in enhancing the antioxidant defense system of chickpea plant. Different concentrations (0, 50, 100 and 150 mg/L) of glutathione were used; namely GHS0, GHS1, GHS2 & GHS3, respectively under different levels of seawater salinity (0.23, 3.13 and 6.25 dS/m namely S0, S1 & S2, respectively). Seawater levels, S1& S2 caused obvious increases in proline, free amino acids and total soluble sugar contents. Moreover, foliar application of glutathione caused more significant increases in the above mentioned osmoprotectant contents of chickpea plants, as compared with those of corresponding controls. In addition, irrigation of chickpea plant with different levels of diluted seawater significantly increased hydrogen peroxide and lipid peroxidation, as compared with the tap water irrigated plants. Meanwhile, treating chickpea plants with different concentrations of glutathione resulted in significant decreases in hydrogen peroxide contents and lipid peroxidation levels in the control and salinity stressed plants. The applied concentrations of glutathione also resulted in marked increases of the antioxidant enzymes ascorbate peroxidase, glutathione reductase, peroxidase and superoxide dismutase. Maximum increases in the activities of antioxidant enzymes were observed on treating plants with glutathione at 100 mg/L either under normal irrigation or salinity stressed conditions. It could be concluded that foliar spray of glutathione was effective in improving chickpea performance by reducing hydrogen peroxide free radical and by enhancing compatible osmolytes, membrane stability and antioxidant enzyme activities.

Perusing biochemical antioxidant enzymes as selection criteria under drought stress in wheat varieties

ABSTRACTIn regard to important roles of enzymatic antioxidant in abiotic stresses, and their practical use as stress indices, the current research was implemented to peruse antioxidant enzymatic activities of different wheat varieties and to find the susceptible and the tolerant varieties based on these indices. The experiment was carried out in the greenhouse of Islamic Azad University, Sanandaj, Iran in 2015. A factorial experiment based on completely randomized design (CRD) with three replications were used to evaluate the effects of different water regimes, including 100% and 50% field capacity (FC) on 25 wheat cultivars. Antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbic peroxidase (APX), and grain yield of the wheat varieties were measured. The results showed that under normal irrigation condition, the relationships between grain yield and antioxidant were inversed, but under stressful condition the relationships between wheat grain yield and some important antioxidants such as CAT and SOD were positive. Among antioxidant enzymes, SOD activity showed a higher variation among wheat varieties of this study, indicating that this enzyme is an important trait to be used in the breeding programs. Based on the results of different statistical techniques and comparing relationships among traits for normal irrigation and stress condition, enzymatic antioxidant could be used as practical criteria for screening tolerant genotypes of wheat. On the other side, SOD and CAT resulted in being the most important criteria for achieving higher tolerant genotypes through indirect selection.

شناسایی ژنوتیپ های جو (Hordeum vulgare L.) متحمل به خشکی با استفاده از شاخصهای تحمل تنش

تنش خشکی انتهای فصل از مهم‌ترین عوامل محدودکننده تولید محصولات کشاورزی است. به‌منظور شناسایی ارقام متحمل به خشکی جو از بین 79 رقم خارجی و یک رقم شاهد ایرانی و نیز تعیین ارتباط بین اجزای عملکرد با شاخص‌های تحمل به تنش، آزمایشی تحت شرایط آبیاری نرمال و تنش آبی در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه شیراز انجام شد. از بین شاخص‌های مختلف تحمل به خشکی،MP، HMP، GMPو STIبیشترین همبستگی مثبت و معنی‌دار را با عملکرد در هردو شرایط آبیاری نرمال و تنش آبی نشان دادند و به‌عنوان بهترین معیارهای تعیین ارقام متحمل تعیین گردیدند. بعلاوه، عملکرد بیولوژیک، تعداد سنبله و وزن صد دانه در هر دو شرایط همبستگی مثبت و معنی‌داری را با شاخص‌های تحمل نشان دادند. با توجه به نتایج تجزیه به مؤلفه‌های اصلی، دو مؤلفه اول توانستند درمجموع 97 درصد از تغییرات را توجیه نمایند که مؤلفه اول به‌عنوان مؤلفه مقاومت و پایداری عملکرد و مؤلفه دوم به‌عنوان مؤلفه حساسیت معرفی شدند. با توجه به آنالیزهای آماری مختلف انجام‌شده ارقام 88 و 145 به‌عنوان متحمل‌ترین ارقام شناسایی شدند. تجزیه خوشه‌ای بر اساس شاخص‌های تحمل تنش و عملکرد در هر دو شرایط تنش و بدون تنش 80 رقم موردبررسی را در چهار گروه مجزا قرارداد. نتایج این تحقیق منبع مناسبی برای استفاده در برنامه‌های اصلاحی ارقام جو پاییزه برای افزایش تنوع ژنتیکی ژرم پلاسم ایرانی و نیز تولید ارقام متحمل به خشکی فراهم می‌آورد.

Exogenous application of chitosan on biochemical and physiological characteristics, phenolic content and antioxidant activity of two species of basil (Ocimum ciliatum and Ocimum basilicum) under reduced irrigation

Chitosan is a biopolymer with various industrial, medicinal, pharmaceutical, and agricultural applications. Effects of exogenous application of chitosan, a marine polysaccharide with unique bioactive properties, under normal irrigation and stressed conditions on morphology, physiology and biochemical characteristics of two species of sweet basil, including Ocimum ciliatum and O. basilicum in a pot experimental at semiarid and cold climate, southwestern Iran were investigated. Treatments comprised control, 0.0, 0.2, and 0.4g/L chitosan applied to plants under normal irrigation, slight and mild drought stress conditions. Results indicated that drought stress had significant effects on some morphology, physiology and biochemical characteristics. In both species of basil, drought stress decreased the content of photosynthetic pigments and growth parameters. Exogenousapplication of chitosan (in particular 0.4g/L) increased plant growth parameters in both species of basil under stressed or non-stressed conditions as compared to untreated plants. In addition, results indicated that the different levels of chitosan had significant effects on total phenol content and antioxidant activity of the extracts of two species. In conclusion, it is suggested that chitosan could be a promising material used to reduce the harmful effect of water stress on the growth parameters of basil plants and as a whole, treatment with chitosan partly could alleviate the effect of drought stress.

Evaluation of selection indices for drought tolerance in some bread wheat genotypes

This study was undertaken to evaluate various selection indices of moisture stress and their applicability in identifying drought stress tolerant wheat genotypes which can acclimatize to various moisture stressed environments in different wheat growing agro climatic zones of Gujarat. Advance lines of wheat genotypes were tested under moisture stress condition of different irrigation regimes. Two sets of irrigation regime i.e one set as irrigated and second as limited irrigation. Ten wheat advance lines along with five check varieties were tested for water stress tolerance at two locations representing North Gujarat and Saurashtra region. Stress intensity at both the locations was markedly differed which indicates differences in soil type, properties and environmental conditions. On the basis of this study, it can be concluded that along with SI, the use of stress indices follows the order of DSI, STI, MP and GMP for selection of drought tolerant genotypes under stress conditions and they may be used to screen wheat varieties tolerant to moisture stress conditions. On the basis of findings of these indices wheat varieties GW 487, GW 488 anf GW 173 were found having higher stress tolerance and with better yield potential under both normal and restricted irrigation conditions. The irrigation criteria under stress condition at Junaghadh location may be revised.

Combining Ability Estimation and Gene Action in Maize (Zea mays L.), Using Line X Tester Method under Normal Irrigation and Water Stress Conditions

A line x tester analysis involving 28 top-crosses generated by crossing seven elites maize inbred lines (yellow) with four testers (yellow single crosses) was conducted for different some traits during 2015 cropping season at the Experimental Farm of Agricultural Faculty, Mansoura University, Egypt. The experimental design was the Randomized Complete Block Design (RCBD), with three replications. The objectives of this study were to estimate of general and specific combining ability effects of the parents (the inbred lines and the testers) and to evaluate the top-crosses performance of the hybrids for flowering, vegetative and ears yield plant-1 traits. The GCA/SCA ratio was found to be less than unity in all studied traits under both conditions, except ear height under stress condition, revealing that non-additive gene effects were more important than additive gene effects in the expression of these traits. Results showed that line (1), line (2), line (6), tester (1) and tester (2) were the best general combiners among the parents for ears yield per plant. Top-crosses no. 3, 4, 7, 9, 13, 20 and 26 under both conditions, 10, 19, 21, 22, 27 and 28 under water stress condition and 14, 23, 24 and 25 under normal irrigation condition showed negative and highly significant specific combining ability estimates for tasseling date. Top-Crosses no. 3, 4, 7, 9, 10, 13, 20 and 26 under both conditions, 19, 21, 22 and 28 under water stress condition and 6, 8, 23, 24 and 25 under normal irrigation condition showed negative and highly significant specific combining ability estimates for silking date. Negative and significant or highly significant specific combining ability estimates were detected for top-crosses no. 1, 11, 16, 19 and 26 under stress condition for ear height. Significant or highly significant and negative specific combining ability estimates were detected for top-crosses no. 1, 6, 9, 16 and 20 under stress water condition and 7, 12 and 13 under normal watering condition for plant height. Highly significant and positive specific combining ability estimates were detected for top-crosses no. 3, 4, 10, 13, 17 and 24 under stress water condition, 1, 2, 9, 16 and 20 under normal water condition and 5, 8, 11, 15, 18, 22, 25 and 26 under both water conditions for ears yield per plant.

Evaluation of proline, chlorophyll, soluble sugar content and uptake of nutrients in the German chamomile (Matricaria chamomilla L.) under drought stress and organic fertilizer treatments

ObjectiveTo investigate the effect of drought stress and organic fertilizer on German chamomile (Matricaria chamomilla) nutrient uptake, leaf chlorophyll content and osmotic adjustment under field conditions. MethodsThis experiment was carried out through a randomized complete block design with a split factorial arrangement of treatments in three replications. The main plots were subjected to the following irrigation treatments: irrigation after 60, 90, 120, 150 and 180 mm evaporation from Class A pan. The sub-plots were treated with three vermicompost doses (0, 5 and 10 t/ha). ResultsAlthough drought stress reduced the nutrient percentages in the shoots, application of vermicompost enhanced the nutrient percentages, particularly when the plants were subjected to moderate to severe drought stress conditions. Moreover, the results of this study showed that the interaction between irrigation treatments and vermicompost rates on leaf chlorophyll content was significant. Comparison between the combined treatments indicated that under normal irrigation and moderate drought stress conditions chamomile plants received 5 and 10 t/ha vermicompost showed significantly higher leaf chlorophyll content comparing to the control treatment. ConclusionsTotally, organic fertilization by vermicompost could partly alleviate the effect of drought stress on chamomile by increasing N, P and K uptake and leaf soluble sugar, especially in stressed treatments.

Roles of compost fertilizer on nitrogen fixation in soybean (Glycine max L.) under water deficit conditions

Presently, increasing nitrogen fixation in soybean is critical because of widespread increase in soil degradation in Egypt. Therefore, a greenhouse research was conducted at the laboratory of Plant Nutritional Physiology, Hiroshima University, Japan for assessing the impact of compost in alleviating the adverse effects of water stress on soybean. The nitrogen-fixing activity was estimated by using gas chromatograph. The results showed that water deficit stress reduced biological nitrogen fixation and specific nodule activity than normal irrigation conditions. Application of compost increased the biological nitrogen fixation and specific nodule activity under water stress conditions. As the results indicate that compost application could help in improving nitrogen fixation in soybean.