Different Levels Of Water Stress Research Articles

Do winter and summer cohorts of the invasive weed Parthenium hysterophorus differ in seed germination and seedling growth?

AbstractThe highly invasive weed Parthenium hysterophorus flowers during both hot, humid summers and cold, dry winters in Nepal, yet it remains unknown if there are differences in seed germination and seedling growth during these contrasting seasons. We analysed seed germination and seedling growth of summer and winter cohorts of P. hysterophorus in Kathmandu Valley. Seeds were germinated at low (25/15°C) and high (30/20°C) temperatures, 12/12 h photoperiod and complete dark, and at different levels of water stress. Seedlings were grown in a greenhouse to determine biomass allocation and relative growth rate (RGR). Winter seeds had higher seed biomass than summer seeds, and both seed types germinated under complete dark and 12/12 h photoperiod. Summer seeds germinated at significantly lower rates and percentage than winter seeds at the low temperature, but this difference in germination was not present when summer and winter seeds were incubated at the high temperature. Winter seeds had higher germination (percentage and rate) and took a longer time to reach maximum germination than summer seeds at different levels of water stress. Seedling emergence of both seed types declined with increasing soil depth. Seedling RGRs were nearly equal (summer: 73 mg g−1 day−1, winter: 77 mg g−1 day−1). Biomass allocation to stem and leaves were similar in both cohorts but root biomass allocation was higher in the winter than in the summer cohort. Overall, the maternal environmental effect was moderate on seed germination, and weak on seedling growth. Lack of a pronounced difference in the germination and seedling growth of summer and winter cohorts of P. hysterophorus suggests a wide environmental tolerance of the species, and this could be one of the reasons for the species' ability to invade diverse climatic and geographic regions globally.

Exploring Physiological and Nonphysiological Responses of Sun-Induced Chlorophyll Fluorescence to Different Levels of Water Stress in Winter Wheat

Exploring Physiological and Nonphysiological Responses of Sun-Induced Chlorophyll Fluorescence to Different Levels of Water Stress in Winter Wheat

Impacts of water constraints on economic outputs and trade: A multi-regional input-output analysis in China

Water resource constraints pose significant challenges to sustainable development of economy, environment, and human society. This study addresses the existing gap in understanding the impacts of water resource constraints on economic outputs and inter-provincial trade in China. A water-use constrained multi-regional input-output (MRIO) model is developed to analyze the impacts on economic outputs resulting from different water constraints imposed on economic sectors. A series of scenarios are designed to represent different levels of sectoral water use restrictions based on short-term water policy and water stress alleviation targets. Results reveal that regions experience different levels of water stress displaying diverse economic impacts due to future water restrictions. Overall, national economic outputs will experience a 0.76–1.14% decrease compared to the baseline scenario, that is, the “business-as-usual” scenario. Provinces with lower levels of economic development tend to be less resilient to the economic losses arising from water constraints. As such, Ningxia and Shanxi show with the greatest relative economic impact, accounting for 7.09% and 4.21% of their respective provinces’ economic outputs under the baseline scenario. Furthermore, the direction of net bilateral trade, such as net trade between Henan and Shaanxi or between Henan and Hunan, would reverse under water constraint scenarios from the baseline scenario. This underscores the importance of considering the cascading effects of local water constraints on inter-provincial trade. Our study highlights the trade-offs between water conservation and economic development, emphasizing the need for region-specific water-saving measures.

Physiological Assessment of Temperature Stress Tolerance in Selectively Fertilzed Coconut Hybrids

In vitro pollen germination study is one of the important technologies for understanding the functions of pollens as well as in many areas of pollen biotechnology particularly in pollen selection. Ability to separate germinated and non-germinated pollen offers selective treatments and can be used for identifying stress tolerant and sensitive alleles carried by their pollen grains. The present study was carried out in Kerasree and Keraganga selectively fertilized (S.F) coconut hybrids produced through pollen selection. Pollens were subjected to germination in specific media maintained at different levels of water stress induced by PEG 6000 and the critical water potential for pollen germination was identified. The water stress tolerant pollen grains at critical level were selected and used for fertilization. Evaluation of temperature stress tolerance of these two selectively fertilized hybrids along with their normal hybrids and west coast tall (WCT) was carried out by assessing their critical temperature stress for pollen germination. Both Kerasree selectively fertilized and Keraganga selectively fertilized hybrids recorded highest critical temperature of 420C for pollen germination with germination percentage of 20.17 and 22.77 respectively compared to their normal hybrids (380C) and WCT (400C).

Spectral response to early detection of stressed oil palm seedlings using near-infrared reflectance spectra at region 900-1000 nm

A method was developed based on spectral analysis and classification models for early detection of water stress level in the leaves of oil palm seedlings. The healthy (well-watered: D0) and water-stressed (subjected to water stress for five days: D1-D5) leaves of oil palm seedlings were investigated to identify and classify the stress levels. The stress levels were grouped as light, moderate, and severe. The region 900–1000 nm was selected because it is highly correlated with water content, particularly in terms of first and second derivatives. The measured reflectance spectra at 900–1000 nm were pre-processed using smoothing, standard normal variate (SNV), and first and second Savitzky-Golay (SG) derivatives. Principal component analysis (PCA) was performed on several transformed datasets to reduce the reflectance spectral dimension and derive the principal components (PCs). Support vector machine (SVM) and linear discriminant analysis (LDA) classification models were employed to the scores of PCs to achieve six classification levels of water stress. Classification accuracy was assessed using the overall accuracy and confusion matrix of testing datasets. The SVM and PCA-LDA classification models predicted the water stress levels with high average overall classification accuracy of 92 % and 94 % using the smoothed + SNV + first derivative and smoothed + SNV spectral dataset, respectively. The findings confirmed the potential of 900–1000 nm region to distinguish the different levels of water stress in oil palm seedlings.

Water stress significantly affects the diurnal variation of solar-induced chlorophyll fluorescence (SIF): A case study for winter wheat

Remote sensing of Solar-induced chlorophyll fluorescence (SIF) has been widely used in estimating Gross Primary Productivity (GPP) and detecting stress in terrestrial ecosystems. Water stress adversely impacts the growth, development, and productivity of a plant. Recently, the characterizing and understanding of the diurnal cycling of plant functioning and ecosystem processes has been explored using SIF. However, the diurnal response of SIF to different levels of water stress remains unclear. This study conducted field experiments on winter wheat by subjecting it to different levels of water stress including well-watered (CK) and, mild, moderate, and severe water stress (D1, D2, D3), and collected the spectral data using an automated SIF measurement system. The results observed the strong SIF-PAR (photosynthetically active radiation) correlations and that these relationships gradually decoupled with increasing water stress, which further decreased the accuracy of temporal upscaling of far-red SIF from an instantaneous to daily scale. To quantify the characteristics of diurnal far-red SIF, five indices including peak time, peak value, curve opening coefficient (leading coefficient of the parabola), and left/right slopes of the peak were proposed. The results demonstrated that diurnal far-red SIF was characterized by an earlier peak time, decreasing peak value, wider curve opening, and flattening right slope from the CK plot to the D3 plot. There were certain mechanisms linking the different indices, for example, between peak size and opening coefficient. Furthermore, the response of far-red SIF to water stress was most pronounced at noon. SIF/PAR exhibited a more significant response to varying water stress compared to far-red SIF, which mitigated the negative influence of PAR variations on diurnal SIF. These findings contribute to the monitoring of plant water dynamics at fine temporal scales.

Determination of Yield and Quality Parameters in Pickling Hot Peppers Grown under Different Water Stress Conditions

Plants are exposed to various adverse environmental conditions throughout their growth period. In recent years, drought, which has occurred and necessitated different measures, ranks among these adverse conditions. At the same time, plants synthesize certain biochemical compounds in response to the adverse conditions they will encounter. These compounds not only strengthen the immune system but also provide resistance against various diseases, and they tend to increase under adverse environmental conditions that plants will face during cultivation. This study was conducted to determine the changes in yield and some biochemical components in pickling hot peppers (Capsicum Annuum L.) grown under different water stress conditions. Two different levels of water stress (%70 and %30 irrigation) were applied in addition to full irrigation (%100 irrigation). At the end of the research, while a yield of 269.42 g per plant was obtained in the control group (%100 irrigation), 150.14 g and 93.33 g of pickling hot peppers were harvested in each water stress treatment, respectively. Total phenolic compound levels increased with water stress; it was determined to be 0.827 mg-1g in the trial irrigated with full irrigation water, 1.170 mg-1g in plants exposed to mild water stress, and up to 1.536 mg-1g in the trial subjected to severe water stress. In addition, total flavonoids and antioxidant compound levels also increased with increasing water stress. The amounts of flavonoid compounds obtained from the trial groups were 0.146, 0.373, and 0.412 mg-1g, respectively, while the antioxidant levels determined by the DPPH method increased in quantity with increasing water stress, similar to other biochemical compounds. According to these results, it was determined that the yield of pickling hot peppers decreased in the case of water shortage that the plants would face in cultivation, but there was an increase in some biochemical compounds.

Germination ecology and seedling growth of invasive Ageratum species and allied native Adenostemma lavenia

AbstractThe success of invasive plants can be better understood by comparing their traits with closely related native species. This study compared germination ecology and seedling growth of invasive Ageratum houstonianum and Ageratum conyzoides with co‐occurring and allied native Adenostemma lavenia. Seeds were germinated under a different light (12 h photoperiod/complete dark), temperatures (low: 25°C/15°C day/night, and high: 30°C/20°C), and different levels of water stress (−0.1, −0.25, −0.5, −0.75, and −1 MPa). Seedlings were grown to determine biomass allocation, relative growth rate (RGR), plant height, and number of leaves. The seed mass and size of native A. lavenia were higher than those of invasive species. Seeds of all species were positively photoblastic. At low temperature and in all levels of water stress, all measured parameters except mean germination time were the highest in A. houstonianum. However, at high temperature, there was no significant difference in germination percentage between A. houstonianum and A. lavenia. No germination of A. conyzoides and A. lavenia was recorded beyond −0.5 MPa water potential, but seeds of A. houstonianum germinated up to −0.75 MPa. A. houstonianum had higher root mass fraction, root‐to‐shoot ratio, and number of leaves than the other two species. Stem mass fraction and the height of seedling were highest in A. conyzoides. The RGR was 1.6 times higher in invasive Ageratum species than the native species; it was slightly higher in A. houstonianum than in A. conyzoides. Overall, the results suggest that germination traits and seedling growth performance can be used as predictors of a species' invasiveness.

The Role of Regular and Nano-Chitosan in some Indicators of Vegetative and Root Growth of Tecoma stans (L.) Seedlings Under Different Levels of Water Stress

A factorial experiment was conducted with three factors, the first using three levels of water stress (50, 75 and 100%) of the field capacity value, the second spraying seedlings of Tecoma stans (L.) Juss. ex Kunth with regular chitosan in three concentrations (0, 150 and 300 mg.L-1), and the third spraying seedlingsat with nano-chitosan in three concentrations (0 and 150 and 300 mg.L-1). arithmetic mean of the coefficients was compared. Statistically according to Duncan’s Multiple Range Test. The results of the single effect of water stress showed the superiority of the seedlings that were treated with light water stress treatment by (100%) of the field capacity value, as well as the single effect of the regular and nano-chitosan biofertilizer, the superiority of the seedlings that were treated with a concentration of (300 mg.L-1) in the increase in the height of the seedlings, the increase in the diameter of the main stem of the seedling, main root length and root volume in the increase in the height of the seedlings, the increase in the diameter of the main stem of the seedling, main root length and root volume.

Yield and Yield Attributes of Aus Rice Genotypes as Influenced by Different Levels of Water Stress

Yield and Yield Attributes of Aus Rice Genotypes as Influenced by Different Levels of Water Stress

Automating reference temperature measurements for crop water stress index calculations: A case study on grapevines

The use of temperature as an indicator of water stress is gaining attention in agriculture. However, the need for reference temperature measurements in the field (Twet and Tdry) for normalization purposes (calculation of the crop water stress index - CWSI) inhibits the practical implementation of this technique. Therefore, in this study, two new models namely the heat transfer (HT) model and the empirical (EMP) model, are presented and compared with the standard method of physical reference temperature measurements and leaf energy balance calculation as an exploratory case study on grapevines. The HT model is a novel method, based on physical heat transfer principles and uses only input data obtained from a conventional weather station to determine reference temperatures. The EMP model is a simple method based on wet- and dry-bulb temperatures, calculated from ambient temperature and relative humidity measurements. To develop and evaluate the new models, physical measurements of the reference temperatures were taken in a commercial vineyard cv. Cabernet Sauvignon under different levels of water stress at two times during the day on seven days over the growing season. These physical measurements were used to optimize unknown parameters in the new methods by using the particle swarm optimization procedure. Input data for the model was collected by a conventional weather station located nearby the experimental vineyard block. In the validation process, it was found that the HT model can accurately predict the reference temperatures to within 0.5 °C and 1.0 °C for Twet and Tdry, respectively, reacting to environmental conditions as expected. The EMP model, requiring even less meteorological information, can accurately predict the reference temperatures to within 0.8 °C and 1.4 °C for Twet and Tdry, respectively. These proposed methods can provide reference temperatures that do not require physical measurements which can make the use of CWSI more practical and easier to implement for determining plant water stress in vineyards.

Impact of Plant Growth-Promoting Rhizobacteria Inoculation on the Physiological Response and Productivity Traits of Field-Grown Tomatoes in Hungary

Drought-tolerant plant growth-promoting rhizobacteria (PGPR) may promote plant development under limited water supply conditions, when plant’s water demand is not completely satisfied under rain-fed conditions or when irrigation water availability is limited. The aim of this study was to examine the effects of two inoculation treatments (B2: Alcaligenes sp. 3573, Bacillus sp. BAR16, and Bacillus sp. PAR11 strains and B3: Pseudomonas sp. MUS04, Rhodococcus sp. BAR03, and Variovorax sp. BAR04 strains) and compare those to a control (B0) without artificial inoculation on chlorophyll fluorescence, leaf chlorophyll content (SPAD value), canopy temperature, and the yield of the processing tomato cultivar H-1015 F1 grown under field conditions. The young seedlings of the hybrid tomato variety H-1015 F1 were immersed in 1% of B2 or B3 products (BAY-BIO, Szeged Hungary) for 5 min. Inoculated and untreated seedlings were grown under three irrigation treatments [regular irrigation (RI), deficit irrigation (DI), and no irrigation (I0)], to reveal the effect of PGPR under different levels of water stress. In the dry year (2018), higher canopy temperature and chlorophyll fluorescence (Fv/Fm) were measured during flowering in plants treated with bacteria than in untreated plants. In the stage of flowering and fruit setting, the B3 treatment led to a significant decrease in the Fv/Fm value, canopy temperature remained high, and the SPAD value was statistically the same in all treatments. Under limited water supply, in most cases, PGPR led to a significantly greater total yield but more unripe green berries compared to untreated plants. Under moderate water shortage (dry year + deficit irrigation), the B3 treatment resulted in 26% more ripe, marketable fruit and 49% less unripe fruit compared to the B2 treatment. On the other hand, in the wet year (2020), the bacterial treatments generally did not affect physiological properties, though the B2 treatment produced a higher marketable yield while the amount of green and diseased fruits did not differ statistically, compared to the B3 treatment under deficit irrigation. Based on our study, we recommend the application of the B3 PGPR product as it positively affected key physiological processes, leading to a higher marketable yield particularly under water shortage.

Screening of Oil Sunflower Cultivars Grown in the Iraq Conditions Under Different Levels of Water Stress

The experiment was carried out in the experimental field of the College of Agriculture, Al-Qasim Green University, during the spring season of 2021, to study the effect of water stress in some traits of growth and yield and yield component in three sunflower cultivars. A factorial arrangement in randomized complete block design with three replications was used, first factor was included cultivars of sunflower (C1 : ESHAKI, C2 : AQMAR and C3 : SAKHA), the Second factor was included water stress levels : (I1 : 100%, I2 : 75% and I3 : 50%) from field capacity. The C2 cultivar was excelled in all characteristics at 100, 75 and 50% irrigation level on the other cultivars. The results of C2 cultivar in 50% irrigation did not significantly differ on 75 and 100% irrigation level in all study traits except leaf area.

Characterisation and Effects of Different Levels of Water Stress at Different Growth Stages in Malt Barley under Water-Limited Conditions.

Malt barley is typically grown in dryland conditions in South Africa. It is an important grain after wheat, but little is known about its water requirements and, most importantly, how it responds to water stress. Determining when water stress sets in and how malt barley responds to water deficit during its growing season is crucial for improved management of crop water requirements. The objectives of this study were to evaluate the response of transpiration (T), stomatal conductance (SC), and leaf water potential (LWP) to water stress for different growth stages of malt barley and to characterise water stress to different levels (mild, moderate, and severe). This was achieved by monitoring the water stress indicators (soil- and plant based) under greenhouse conditions in well-watered and water-stressed lysimeters over two seasons. Water stress was characterised into different levels with the aid of soil water content ‘breaking points’ procedure. During the first season, at the end of tillering, flag leaf, and milk/dough growth stages, which represent severe water stress, plant available water (PAW) was below 35%, 56%, 14%, and 36%, respectively. LWP responded in accordance to depletion of soil water during the growing season, with the lowest recorded value to −5.5 MPa at the end of the milk/dough growth stage in the first season. Results also show that inducing water stress resulted in high variability of T and SC for both seasons. In the second season, plants severely stressed during the anthesis growth stage recorded the least total grains per pot (TGPP), with 29.86 g of grains. The study suggests that malt barley should be prevented from experiencing severe water stress during the anthesis and milk/dough stages for optimum malt barley production. Quantification of stress into different levels will enable the evaluation of the impact of different levels of stress on the development, growth, and yield of barley.

Влияние на биовъглен върху добив от царевица и микробиална активност при Алувиално- ливадна почва

A three-year field experiment with maize was carried out on fluvisol. The aim of the present study was to evaluate the impact of biochar on maize yield at different levels of water stress and its effect on the amount of soil microorganisms. The following variants were studied: control with no biochar addition, and variants with biochar. Biochar was applied in 2 t/ha in 2016, produced by pyrolysis of rice straw, then in 3 t/ha in 2017 and 10 t/ha in 2018, both obtained by pyrolysis of oak bark. These variants were divided into three more depending on the irrigation regime: i.e. non-irrigated, irrigation at dT>0 °C, and irrigation at dT<-1 °C. Under non-irrigated conditions, the effect of biochar on maize yield was not pronounced over three years. Under irrigation conditions with water added according to crop water stress, higher yields of maize were obtained in the third year when biochar application to the soil was highest (10 t/ha). Also, yield was higher when faster (at lower water stress dT<-1 °C) irrigation rates were applied. Soil moisture changed slowly in the biochar variants and the best values of the temperature differences were obtained for irrigation at dT<-1 °C in 2018. These results showed that the influence of biochar on soil microbiota was significantly greater, and the most stimulating effect of biochar was obtained for bacterial populations.

The Responses of Physiological Characteristics and Flowering Related Gene to the Different Water Stress Levels of Red-Flesh Pummelo Cultivars (Citrus grandis (L.) Osbeck) Own-Rooted by Air Layering Propagation under Two Growing Conditions

One of the major problems in the fruit production of citrus, including pummelo (Citrus grandis) is controlling flowering induction. Water stress is known to be related to flowering induction via physiological responses related to the flowering gene. However, reports on the mechanisms underlying floral induction by water stress in pummelo are limited. Thus, this study aimed to determine the physiological characteristics and the expression of genes related to flowering induction, CiFT (Citrus Flowering locus T), in pummelo at different levels of water stress. Experiments were conducted under two growing conditions: field and container conditions, each using a 2 × 5 factorial experiment in a randomized complete block. Factor A consisted of two red-flesh pummelo cultivars while factor B consisted of five levels of water stress based on the leaf rolling index. Among the seven characteristics studied, only the data of total nitrogen, CiFT, and flower number were combined for analysis due to their results in a homogeneity test. Although a consistent tendency was not observed for the interaction among environments, genotypes, and water stress levels of all characteristics, ‘KKU-105’ grew more flowers under higher water stress conditions (225 flowers). This result may imply that decreases in total nitrogen (1.48%), stomatal conductance (50.53 m−2s−1), chlorophyll fluorescence (0.30 Fv/Fm), and upregulation of CiFT mRNA level (13.95) may induce flowering in the pummelo cultivar ‘KKU-105’.

Yield response of a mature hedgerow oil olive orchard to different levels of water stress during pit hardening

Drought sensitivity in olive trees varies throughout the season. The yield response to drought needs to consider the final use of the fruits and harvest date. In Mediterranean climates, the oil accumulation tends to occur in a period of low evaporative demand and during the rainy period. The aim of this work was to evaluate the effect of water stress during pit hardening on the yield components of oil olive trees. The experiment was conducted during three seasons (2017–2019) in a mature hedgerow olive orchard (11 years-old, Arbequina cv). The experiment design was a randomized completed block with 4 repetitions of 4 different irrigation treatments. Treatments were: Control, no water stress throughout the season; Regulated deficit irrigation (RDI)-1, moderate water stress during pit hardening and total recovery after the last week of August; RDI-2, same as RDI-1 but with severe water stress and partial recovery; and sustained deficit irrigation (SDI), constant applied water rate and the same seasonal water than RDI-2. The irrigation scheduling in RDIs were based on the frequencies of the trunk growth rate. No significant differences were found in fruit and oil yield between treatments. There were a significant relationship between water status measurements and fruit and oil yield. Part of the decrease in fruit yield with midday stem water potential (SWP) was related to fruit moisture, as no significant fruit drop was found. Only conditions of water stress in 2017, before the end of endocarp size, were related to a great reduction of fruit volume and, consequently, with fruit and oil yield. The relationship between the percentage of oil in dry weight and SWP was quadratic in different phases. Such relationships could help quantify the water stress level in these periods to maximize oil accumulation.

Physiological and Molecular Responses of 'Dusa' Avocado Rootstock to Water Stress: Insights for Drought Adaptation.

Avocado consumption is increasing year by year, and its cultivation has spread to many countries with low water availability, which threatens the sustainability and profitability of avocado orchards. However, to date, there is not much information on the behavior of commercial avocado rootstocks against drought. The aim of this research was to evaluate the physiological and molecular responses of ‘Dusa’ avocado rootstock to different levels of water stress. Plants were deficit irrigated until soil water content reached 50% (mild-WS) and 25% (severe-WS) of field capacity. Leaf water potential (Ψw), net CO2 assimilation rates (AN), transpiration rate (E), stomatal conductance (gs), and plant transpiration rates significantly decreased under both WS treatments, reaching significantly lower values in severe-WS plants. After rewatering, mild- and severe-WS plants showed a fast recovery in most physiological parameters measured. To analyze root response to different levels of drought stress, a cDNA avocado stress microarray was carried out. Plants showed a wide transcriptome response linked to the higher degree of water stress, and functional enrichment of differentially expressed genes (DEGs) revealed abundance of common sequences associated with water stress, as well as specific categories for mild-WS and severe-WS. DEGs previously linked to drought tolerance showed overexpression under both water stress levels, i.e., several transcription factors, genes related to abscisic acid (ABA) response, redox homeostasis, osmoprotection, and cell-wall organization. Taken altogether, physiological and molecular data highlight the good performance of ‘Dusa’ rootstock under low-water-availability conditions, although further water stress experiments must be carried out under field conditions.

Antecedent Drought Condition Affects Responses of Plant Physiology and Growth to Drought and Post-drought Recovery

Antecedent environmental conditions may have a substantial impact on plant response to drought and recovery dynamics. Saplings of Eucalyptus camaldulensis were exposed to a range of long-term water deficit pre-treatments (antecedent conditions) designed to reduce carbon assimilation to approximately 50 (A50) and 10% (A10) of maximum photosynthesis of well-watered plants (A100). Thereafter, water was withheld from all plants to generate three different levels of water stress before re-watering. Our objective was to assess the role of antecedent water limitations in plant physiology and growth recovery from mild to severe drought stress. Antecedent water limitations led to increased soluble sugar content and depletion of starch in leaves of A50 and A10 trees, but there was no significant change in total non-structural carbohydrate concentration (NSC; soluble sugar and starch), relative to A100 plants. Following re-watering, A50 and A10 trees exhibited faster recovery of physiological processes (e.g., photosynthesis and stomatal conductance) than A100 plants. Nonetheless, trees exposed to the greatest water stress (−5.0 MPa) were slowest to fully recover photosynthesis (Amax) and stomatal conductance (gs). Moreover, post-drought recovery of photosynthesis was primarily limited by gs, but was facilitated by biochemistry (Vcmax and Jmax). During recovery, slow regrowth rates in A50 and A10 trees may result from insufficient carbon reserves as well as impaired hydraulic transport induced by the antecedent water limitations, which was dependent on the intensity of drought stress. Therefore, our findings suggest that antecedent water stress conditions, as well as drought severity, are important determinants of physiological recovery following drought release.

Calibration and validation of InfoCrop model for phenology, LAI, dry matter and yield of wheat

Present experiment was conducted (2015-16 and 2016-17) comprising different levels of water stress and environmental conditions for the model parametrization and validation of Info Crop-wheat v2.1 model. The model was calibrated and validated for popular wheat variety HD-2967 under semi-arid environmental conditions. The important genetic coefficients were generated and model fine-tuned for simulating phenology, leaf area index (LAI), dry matter and yield of wheat crop. The result showed that the model simulated the phenology in terms of days to 50% anthesis and days to physiological maturity very accurately with root mean squared error of 2.26 and 1.36 days, respectively. The model could also able to simulate temporal course of LAI and biomass very satisfactorily. The errors in simulating final biomass and yield were also within the acceptable limit of 10%. We conclude that InfoCrop model is reasonably suitable to simulate the developmental stages, leaf area expansion, dry matter and yield of wheat crop in semi-arid environment hence it can be utilized for undertaking various crop management applications.