Use of hydrogel in the irrigation management of white pitaya (Hylocereus undatus) seedlings: Biometrics and accumulation of organic and inorganic solutes

The initial development of pitayas may be limited by a few factors, among them, water deficit. Agricultural hydrogels can be used as an alternative to enhance the retention and availability of water and nutrients in the soil. Therefore, this study aimed to evaluate the influence of irrigation frequency and hydrogel doses on the development of white pitaya (Hylocereus undatus) seedlings to establish a time interval in days between irrigations that provides better seedling development and determine the hydrogel dose that provides a reduction of water consumption without damaging seedling development. The experimental design consisted of randomized blocks in a 4 x 4 factorial arrangement, in which the treatments corresponded to 4 hydrogel doses (0, 2, 4, and 6 g/plant of Biogel Hidro Plus) incorporated into the substrate and four irrigation frequencies (1, 3, 5, and 7 days of interval). The biometric characteristics, photosynthetic pigments, and organic and inorganic solutes of the plants were evaluated after 120 days. The use of daily irrigation negatively influenced the growth and biomass accumulation of the aerial part of the seedlings and, consequently, provided the lowest values of cladodes of the pitaya seedlings. Pitaya seedlings had greater development when using an irrigation frequency of around 3 days. The application of 6 g/plant of hydrogel provided the highest averages for accumulation of dry biomass, photosynthetic pigments, and organic and inorganic solutes at irrigation levels of 3.6, 4, and about 3.8 days of intervals, respectively. Hydrogel incorporation allowed increasing the interval between irrigations by 1 day without damages to the seedling development.

Effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean (Ricinus communis L.)

To study the effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean, an experiment was conducted at the East Azarbaijan Agricultural Research and Education Center, Tabriz, Iran in 2017-2019 cropping seasons. The experiment was laid out as a split-plot design based on a completely randomized block design with three replications. In the present study, main cluster length, number of branches, number of capsules per plant, number of seeds per capsule, 100-grain weight biological yield, grain yield, oil percent and oil yield were measured. Irrigation intervals (normal irrigation (irrigation after 60 mm), irrigation after 80 mm and 140 mm of evaporation) was established as main plots and the foliar applications of fertilizers (N, K, S, N + K, and N + S, K + S, N + K + S and control) input as sub-plots. The results showed that, except for the oil percentage, all the examined traits were decreased by water limitation. The highest values of the traits, other than the 100-grain weight, were obtained for foliar application of N + K + S. This treatment improved the grain yield per unit area under normal irrigation and moderate irrigation and severe stresses by 62.76%, 41.46% and 28.98% respectively. Thus, the foliar application of S (2000 ppm) + N (3000 ppm) + K (3000 ppm) fertilizer is the best treatment for mitigating some harmful effects of water deficit on castor bean.

Effects of Irrigation Levels on the Yield of Chickpea (Cicer Arietinum Linn) Due to Incidence of Helicoverpa Armigera

Effects of four different irrigation levels viz., One irrigation at 50 per cent flowering stage, one irrigation at grain filling/pod initiation stage, two irrigations (one at 50 per cent flowering + one at grain filling stage), control (without irrigation) on the incidence of gram pod borer, Helicoverpa armigera (Hubner) on chickpea were studied during Rabi, 2014-15 and 2015-16 at Research Farm, College of Agriculture, Bikaner (Rajasthan), India. Results revealed that the highest mean larval population (3.12 larvae per 5 plants) and maximum pod damage (33.24%) were recorded in the crop which was irrigated twice viz., one at 50 per cent flowering stage and second at grain filling stage. The lowest larval population (2.03 larvae per 5 plants) with minimum pod damage (8.34%) was recorded in the crop where irrigation was not given. The maximum seed yield (11.05 q/ha) was obtained from the crop which was irrigated two times and minimum seed yield (7.56 q/ha) was obtained in control. Bangladesh J. Bot. 50(4): 1203-1207, 2021 (December)

Introduction of the best criterion for evaluation of tolerance to drought stress in sorghum’s genotypes

<p class="042abstractstekst">Sorghum (<em>Sorghum bicolor</em> (L.) Moench) is the fifth important cereal considered a drought-tolerant crop. However, its reduction of grain yield considerably occurs in a shortage of water. In the current study, 10 sorghum genotypes were assessed for their grain yield under normal irrigation and water deficit irrigation. As well, the efficacy of several drought indices was evaluated for the selection of high-yield and drought-tolerant genotypes. The experiment was conducted as a split-plot considering three irrigation levels as main-plot and 10 genotypes as sub-plot. Correlation among the indices, clustering of the genotypes along with principal component analysis was employed. Yield production was significantly and positively correlated with indices MP (mean productivity), STI (stress tolerance index), GMP (geometric productivity), HM (harmonic mean), and YI (yield index) in all the irrigation levels. Therefore, these indices are more effective in the selection of high-yielding genotypes under different water conditions. Rank means of stress indices for each genotype revealed that genotype TN-04-79 in mild deficit irrigation and genotypes KGS23 and TN-04-79 in severe deficit irrigation were the most tolerant.</p>

Water Footprint for Garlic under Irrigation Levels and Agrispon Application

Field experiment was conducted in Giza, Egypt, during two growing seasons of 2017-2018 and 2018-2019 on garlic crop, with the objective of investigating the effect of different irrigation levels (60, 80 and 100 % of water requirements and their combination with the foliar spraying applications of agrispon (with 0.5 and 1.0 ml/ liter) on growth and yield. The results indicated that increased irrigation level up to 100% led to increased vegetative characters of garlic and that the lowest growth and productivity was obtained by 60% irrigation level. When considering spray application of agrispon; with 1.0 ml/L increased growth and productivity followed by 0.5 ml/L; while control treatment gave the lowest productivity during the both seasons. Interaction effect between irrigation level and agrispon treatments indicated that 100% irrigation level combined with 1.0 ml/L spray application of agrispon gave the highest garlic productivity followed by 100% irrigation level combined with 0.5 ml/L spray application. The chemical analysis showed that the highest NPK was obtained by 100% irrigation level combined with 1.0 ml/L agrispon application during the both seasons. Regarding water footprint, the highest irrigation water footprint was obtained by 80% irrigation level followed by 60% irrigation level, while the lowest footprint was obtained by 100% irrigation level due to high garlic productivity under 100% irrigation level. The estimate water footprint for garlic was 525 m3/ton. The blue water footprint for garlic was 422 m3/ton about 80% form total water footprint, while gray water percentage about 20% with value of 103 m3/ton.

Response of CERES-wheat and CROPGRO-urd model (DSSAT model v 4.5) for tarai region of Uttarakhand

The study aimed response of CERES-wheat and CROPGRO-urd model for tarai region of Uttarakhand. Field experiments were conducted at N. E. Borlaug, Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during rabi and kharif seasons 2007 and 2008. CERES-wheat and CROPGRO-urd models version v 4.5 were used in this study. Cultivar specific genotypic coefficients were derived for wheat and urd during calibration. Model validation based on several independent sets of growth and yield data, including different nitrogen and irrigation levels. For all parameters t-test was found non-significant (‘t’ calculated values were smaller than t tabulated values at 5% level of significance), indicating that there were least differences between observed and predicted values. The result obtained with the model demonstrated satisfactorily prediction of phenology, growth and yield and thus it can be used for the prediction of wheat and urd growth as well as yield in this region

Biofertilizer Application Enhances Drought Stress Tolerance and Alters the Antioxidant Enzymes in Medicinal Pumpkin (Cucurbita pepo convar. pepo var. Styriaca)

The effects of mycorrhiza, Thiobacillus and Nitroxin (Azotobacter and Azospirillum sp.) biofertilizers under drought stress conditions with four levels of field capacity (FC) (control(100%), 85%, 70%, and 50%) on the antioxidant enzyme activities of medicinal pumpkin (Cucurbita pepo convar. pepo var. Styriaca) were evaluated during the years 2018–2019. Irrigation levels exhibited significant effects on all studied variables, except for the catalase (CAT) enzyme. A significant correlation was observed between the effects of irrigation levels and biofertilizers on antioxidant enzymes, soluble protein content, and grain yield. The highest activity of catalase and ascorbate peroxidase (APX) enzymes was achieved using mycorrhiza in 50% FC. Increasing drought intensity and mycorrhiza stimulated glutathione reductase (GR) and guaiacol peroxidase (GPX) activities by 32% and 66%, while Nitroxin increased them by 16% and 43%, respectively. Under severe drought stress conditions, only mycorrhiza exhibited a positive effect on GR and GPX enzymes. Under moderate and severe drought stress conditions, Nitroxin increased grain yield by 13% and 12.6%, respectively. The irrigation regimes and bio-fertilizers had a significant effect on β-sitosterol percentage. The highest amount was observed at the highest level of drought stress. Among the various bio-fertilizers treatments, the application of Thiobacillus yielded the highest percentage of β-sitosterol. The results of the present study demonstrate that the application of biofertilizers is beneficial in coping with drought stress.

Influence of Different Drip Irrigation and Fertigation Levels on Yield and Economics of High-density Cotton

An experiment was conducted to study the effect of different drip irrigation and fertigation levels on yield and economics of high-density cotton at College of Agriculture, Professor Jayashankar Telangana State Agricultural University, Hyderabad, during kharif 2019 and 2020. The experiment consisted of twelve treatments laid out in Factorial randomised block design (FRBD) replicated thrice. Three irrigation levels (irrigation scheduled at 0.6 [I1], 0.8 [I2] and 1.0 [I3] Epan throughout the crop growth period) and four fertigation levels (application of 100% RDNK in differential dosage as per recommendation [F1], application of 100% RDNK in differential dosage as per crop coefficient curve [F2], application of 125% RDNK in differential dosage as per recommendation [F3], and application of 125% RDNK in differential dosage as per crop coefficient curve [F4],) were included as treatments in this study. Irrigation levels did not show any significant influence on yield and economics during 2020 and 2021. While among the four fertigation levels, application of 125% RDNK in differential dosage as per crop coefficient curve (F4) recorded significantly higher gross returns, net returns and B:C ratio which were on par with application of 125% RDNK in differential dosage as per recommendation (F3). Lower gross returns, net returns and B:C ratio were obtained with the application of 100% RDNK in differential dosage as per recommendation (F1) which were on par with application of 100% RDNK in differential dosage as per crop coefficient curve during both the seasons (F2). Further the gross returns and net returns produced under F3 was also on par with F2.

Detection of drought tolerance-related QTL in the Plainsman V./Cappelle Desprez doubled haploid wheat population

Drought stress is one of the major abiotic factors that significantly reduces wheat grain yield. Improving drought tolerance is a challenge that plant breeders are facing nowadays. In this study, our goal was to identify quantitative trait loci (QTL) in the Plainsman V./Cappelle Desprez doubled haploid (DH) population under drought induced as decreased irrigation (ds) and well-watered (ww) conditions in glasshouse. In total, 54 QTL were detected across the three years in two water regimes linked to 10 drought tolerance-related agronomic traits. Out of the detected QTL regions several have been previously reported. The QTL on chromosome 1A (wPt-744613-wPt-8016) related to thousand grain weight was detected in both ds and ww conditions, explaining the 12.7–17.4% of the phenotypic variance. QTL for grain yield was detected on chromosomes 1A, and 6B in the ds treatment. Numerous QTL was identified under both irrigation levels.