Early Milk Stage Research Articles

Understanding the molecular regulation of flavonoid 3’-hydroxylase in anthocyanin synthesis: insights from purple qingke

BackgroundThe Flavonoid 3’-hydroxylase gene(F3’H) is an important structural gene in the anthocyanin synthesis pathway of plants, which has been proven to be involved in the color formation of organs such as leaves, flowers, and fruits in many plants. However, the mechanism and function in barley are still unclear.ResultsIn order to explore the molecular mechanism of the grain color formation of purple qingke, we used the cultivated qingke variety Nierumzha (purple grain) and the selected qingke variety Kunlun 10 (white grain) to conduct transcriptomic sequencing at the early milk, late milk and soft dough stage. Weighted Gene Co-expression Network Analysis (WGCNA) was used to construct weighted gene co-expression network related to grain color formation, and three key modules (brown, yellow, and turquoise modules) related to purple grain of qingke were selected. F3’H (HORVU1Hr1G094880) was selected from the hub gene of the module for the yeast library, yeast two-hybrid (Y2H), subcellular localization and other studies. It was found that in purple qingke, HvnF3’H mainly distributed in the cytoplasm and cell membrane and interacted with several stress proteins such as methyltransferase protein and zinc finger protein.ConclusionsThe results of this study provide reference for the regulation mechanism of anthocyanin-related genes in purple grain qingke.

Natural allelic variation confers diversity in the regulation of flag leaf traits in wheat

Flag leaf (FL) dimension has been reported as a key ecophysiological aspect for boosting grain yield in wheat. A worldwide winter wheat panel consisting of 261 accessions was tested to examine the phenotypical variation and identify quantitative trait nucleotides (QTNs) with candidate genes influencing FL morphology. To this end, four FL traits were evaluated during the early milk stage under two growing seasons at the Leibniz Institute of Plant Genetics and Crop Plant Research. The results showed that all leaf traits (Flag leaf length, width, area, and length/width ratio) were significantly influenced by the environments, genotypes, and environments × genotypes interactions. Then, a genome-wide association analysis was performed using 17,093 SNPs that showed 10 novel QTNs that potentially play a role in modulating FL morphology in at least two environments. Further analysis revealed 8 high-confidence candidate genes likely involved in these traits and showing high expression values from flag leaf expansion until its senescence and also during grain development. An important QTN (wsnp_RFL_Contig2177_1500201) was associated with FL width and located inside TraesCS3B02G047300 at chromosome 3B. This gene encodes a major facilitator, sugar transporter-like, and showed the highest expression values among the candidate genes reported, suggesting their positive role in controlling flag leaf and potentially being involved in photosynthetic assimilation. Our study suggests that the detection of novel marker-trait associations and the subsequent elucidation of the genetic mechanism influencing FL morphology would be of interest for improving plant architecture, light capture, and photosynthetic efficiency during grain development.

Zinc Biofortification through Biofertilizers, Foliar and Soil Application in Maize (Zea mays L.)

Aims: Here is clearly aim of study is to achieve the maximum grain yield and for improve the economic conditions of farmers. Study Design: The experiment was conducted in a split-plot design. Place and duration of study: The field experiment was conducted to study the effect of biofertilizers, foliar and soil application of zinc fertilizers in maize (Zea mays L.) at the research farm of the Khalsa College, Amritsar, Punjab (India) (31o63' N latitude, 74o83' E longitude and 234 m above sea level) during rainy seasons of 2018 and 2019. Methodology: The four levels of biofertilizers and foliar application as main plot [recommended dose of fertilizer (RDF: 150 kg nitrogen: 27.3 kg phosphorus: 25 kg K ha-1), RDF + Zn solubilizing bacteria (ZnSB), RDF + ZnSB + vesicular-arbuscular mycorrhiza (VAM) + 0.5% foliar ZnSO4.7H2O) at silking and early milk stage] and four subplot treatment of soil application of ZnSO4.7H2O @ 12, 25 and 50 kg/ha at the time of sowing along with no soil Zn control were evaluated in three replications. Results: Foliar application of zinc in addition to biofertilizers (ZnSB + VAM) produced significantly higher growth, yield and quality over control treatment. Soil application of zinc sulphate (50 kg ha-1) significantly improved growth, grain yield and Zn harvest index, Zn mobilization efficiency index and recovery efficiency over no Zn control treatment. The grain zinc content, zinc uptake and zinc use efficiencies were significantly maximum with the application of VAM + ZnSB along with 0.5% zinc sulphate foliar at silking and early milk stage than ZnSB, VAM and control treatment. Conclusion: Zn application of soil and foliar improved the growth, yield and quality parameters of maize.

Micro-meteorological parameters, growth indices and productivity of barley (Hordeum vulgare) cultivars as influenced by clipping and zinc biofortification

A study was carried out during the winter (rabi) season of 2015–16 and 2016–17 at Punjab Agricultural University, Ludhiana, to assess the effect of different barley (Hordeum vulgare L.) cultivars (2- and 6-row) on micro-meteorological parameters, growth indices, photosynthetic parameters and productivity of barley (Hordeum vulgare L.) in relation to different clippings time along with Zn foliar application. The results indicated that cultivar ‘DWRUB 52’ intercepted more photosynthetically active radiation (PAR) than ‘PL 807’ and ‘PL 426’, whereas, normalized difference vegetative index (NDVI) values of ‘DWRUB 52’ and PL 807 were statistically similar and significantly better than ‘PL 426’. Cultivar ‘DWRUB 52’ showed the highest absolute growth rate (AGR) and crop-growth rate (CGR), followed by ‘PL 807’ and ‘PL 426’ during both the years of study. Cultivar ‘DWRUB 52’ gave 6.0 and 18.7% higher grain yield than ‘PL 807’ and ‘PL 426’ respectively. Foliar application of Zn at anthesis and early milk stages enhanced the PAR and NDVI, AGR, CGR and RGR at 90–120 days after sowing (DAS) and at 120 DAS to maturity. Foliar application of Zn with both clippings, i.e. 50 and 60 DAS resulted in the statistically similar transpiration rates and were significantly higher than the other treatments. There was an increase of 12.6% in grain yield when clipping was done at 50 DAS with foliar application of Zn and an increase of 8.9% in grain yield when clipping was done at 60 DAS with foliar application of Zn than control crop.

Yield enhancement and grain vis-à-vis malt quality of barley (Hordeum vulgare L.) genotypes as influenced by clipping and foliar application of zinc

Barley is mostly grown under rainfed condition on poor to marginal soils having deficit soil moisture and zinc (Zn) deficiency, which limits the barley productivity and grain quality. Zn spray could improve the productivity and grain quality in these soils. Therefore, this two-year field study was conducted to assess the influence of barley genotypes and clipping stages vis-à-vis Zn foliar application in barley productivity and grain quality. The experiment consisted of three barley genotypes; DWRUB 52, PL 807, and PL 426 and five clipping management; control, clipping at 50 d after sowing (DAS), clipping at 60 DAS, clipping at 50 DAS and ZnSO4 foliar spray @ 0.5% at anthesis + early milk stages and clipping at 60 DAS and ZnSO4 foliar spray @ 0.5% at anthesis + early milk stages. Barley genotype PL 426 showed in maximum lodging, protein content and yield, grain hardness, and husk content, while, DWRUB 52 gave the highest grain yield, Zn content, starch content, hectoliter weight, and bold grain proportions. Foliar spray of ZnSO4 @ 0.5% at anthesis + early milk stages significantly enhanced the grain yield of 12.5 and 12.7% with clipping at 50 DAS and 9.0 and 8.8% with clipping to 60 DAS than control crop during the first and second year, respectively. Zn content, protein content and yield, bold grains, and diastatic power were significantly improved over control with these treatments. Zn foliar application in combination with clipping may be opted to maximize the barley productivity, Zn concentration, and grains quality.

Alternative Furrow Irrigation Combined with Topdressing Nitrogen at Jointing Help Yield Formation and Water Use of Winter Wheat under No-Till Ridge Furrow Planting System in Semi-Humid Drought-Prone Areas of China

Benefiting from the high–farmland construction program in China, one–off irrigation can be guaranteed in most fields in semi–humid drought–prone areas in China. However, little information is available on water and nitrogen (N) management in wheat production under this condition. This study aimed to explore the effects of alternative furrow irrigation (AFI) and topdressing N fertilizer (TN) on wheat productivity under a no–till ridge–furrow planting system in semi–humid drought–prone areas. The experimental design was as follows: two furrow irrigation (FI) methods, namely, EFI (every furrow irrigation) and AFI (alternative furrow irrigation) with 75 mm at the jointing stage were set as the main treatments. Two topdressing N (TN) patterns, namely, NTN (0 kg ha−1 of N) and TN (60 kg ha−1 of N) along with irrigation were set as the secondary treatments. Moreover, a traditional planting practice with no irrigation and no topdressing N (NINTN) was set as control. In 2018–2020, a field experiment was carried out to investigate the effects on soil water, leaf chlorophyll relative content (SPAD) and net photosynthetic rate (Pn), aboveground dry matter assimilates, grain yield, water use efficiency (WUE) and economic benefit. We found that both FI methods and TN patterns significantly influenced soil water content. Compared with NINTN, the soil water content in each combination of the FI method and TN pattern was effectively improved at the booting and anthesis stages, leading to the significant increase in SPAD and Pn in leaves, post–anthesis dry matter accumulation (POA), grain yield, WUE and economic benefit of winter wheat. Compared with the EFI, averaged across years and TN patterns, the AFI technique increased the soil water storage at booting and anthesis stages and significantly improved the Pn at early milk (4.9%) and early dough (7.5%) stages, POA (40.6%) and its contribution to grain (CRPOA, 27.6%), the grain yield (10.2%), WUE (9.1%) and economic benefit (9.1%). In addition, compared with the NTN, the TN pattern significantly increased the water computation by wheat from booting to maturity, enhanced leaf Pn after anthesis and POA, and finally resulted in the increase in grain yield (14.7–21.9%) and WUE (9.6–21.1%). Thus, the greatest improvement in the leaf photosynthetic characteristics, aboveground dry matter assimilates, grain yield, WUE and economic benefit was achieved under AFITN treatment. Above all, it can be concluded that the AFITN with AFI of 75 mm and TN of 60 kg ha−1 at jointing was an alternative management strategy for optimizing yield formation and water use of winter wheat. This study provided new insights into improving wheat productivity in drought–prone areas where one–off irrigation can be guaranteed.

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

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

Combined use of foliar zinc fertilisation, thiamethoxam and propiconazole does not reduce their effectiveness for enriching zinc in wheat grains and controlling insects and disease

Agronomic biofortification is possible through foliar zinc fertilisation around the earing and early milk stage of wheat. Farmers can be encouraged to apply foliar zinc fertilisation if there is yield enhancement or if it is compatible with other pesticides which are used during these stages to control aphid and stripe rust. To investigate the effectiveness of tank-mix applications of fertiliser and pesticide for enriching grain zinc and controlling the spread of aphid and stripe rust, studies were conducted at Punjab Agricultural Univeristy, Ludhiana, India for 4 years (2017–18 to 2020–21). We tested tank-mixing of zinc (0.5% ZnSO4.7H2O) + thiamethoxam 25 WG (50 g/ha), zinc + propiconazole (500 mL/ha) and zinc + thiamethoxam + propiconazole with one foliar application at the milk stage and two foliar applications at the flag leaf and milk stages. We did not find any adverse effect of tank-mix application of zinc sulfate, thiamethoxam and propiconazole on zinc enrichment in grains, nor in aphid and stripe rust control. The grain zinc enhancement was 99.8–114.9, 100.2–112.1 and 98.0–115.5% with application of foliar Zn, foliar Zn + thiamethoxam and foliar Zn + thiamethoxam and propiconazole respectively. We also found 5.74% increased grain yield with foliar Zn + thiamethoxam and 7.24% increased grain yield in foliar Zn + thiamethoxam + propiconazole. Better net returns in combining Zn + thiamethoxam + propiconazole were also recorded. The results advocate for the tank-mix application of Zinc + thiamethoxam + propiconazole for pest management and Zn biofortification.

Gene Action Governing the Inheritance of Stomatal Conductance in Four Wheat Crosses Under High Temperature Stress Condition.

The knowledge pertaining to gene action and interactions involved in the inheritance of a character in different generations is crucial for determining the breeding strategies in crop improvement program. In the present study, the gene action of stomatal conductance was determined in four wheat populations under high elevated temperatures coupled with late sowing at experimental farm, ICAR-Indian Agricultural Research Institute, New Delhi, India. Steady-state SC-1 leaf porometer was used to record stomatal conductance on adaxial and abaxial leaf surface at late boot (Z 49–50), early milk (Z 73), and late milk (Z 77) growth stages. Evidence for nuclear genetic control of stomatal conductance was strong, with large and repeatable genetic difference observed for parents and progeny across all the four crosses. Mean stomatal conductance for genotypes, GW 322 and GW 366, was consistently low at late boot, early milk, and late milk under timely sown, late sown, and very late sown condition, whereas the converse was true for the high-conducting parents, KAUZ/AA//KAUZ and RAC 875. Additive and additive x additive epistatic effects were large and reasonably consistent at three stages and in all crosses. Detection of epistasis and evidence of transgressive segregation suggested that variation for stomatal conductance was under oligo or polygenic control. Thus, it is conceivable that independent alleles at two or more loci could be pyramided into a single family for increased or decreased stomatal conductance. Additive-based gene action also facilitates with simple selection at early generation to improve stomatal conductance in expected direction. This is the first report on estimates of gene action for stomatal conductance of flag leaf under heat stress condition during reproductive and grain filling stage.

Responses of Purple Rice Genotypes to Nitrogen and Zinc Fertilizer Application on Grain Yield, Nitrogen, Zinc, and Anthocyanin Concentration.

Purple rice is recognized as a staple food for humans and as a source of anthocyanins and micronutrients such as zinc (Zn). This study examined how nitrogen (N) and Zn fertilizers affected grain yield and grain N, Zn, and anthocyanin concentration among purple rice genotypes. Six purple rice genotypes (PIZ, KAK, KS, KH-CMU, KDK, and HN) were grown under two levels of N, the optimum N60 (60 kg/ha) and high N180 (180 kg/ha) rates, along with three Zn application methods (no Zn application (Zn0), soil Zn application (ZnS; 50 kg ZnSO4/ha), and foliar Zn spray (ZnF; 0.5% ZnSO4 at the rate of 900 L/ha three times at heading, flowering, and early milk stages). Grain yield of the five purple rice landraces increased by 21–40% when increasing N from N60 to N180, although no response was found with HN. The higher N rate increased grain N concentration by 10–50% among the genotypes, while anthocyanin concentration increased by 100–110% in KAK and KS, and grain Zn was increased in KS. Applying ZnS increased grain yield by 16–94% but decreased anthocyanin and N concentrations compared to the control Zn0. Applying ZnF effectively increased grain Zn concentration by 40–140% in the genotypes without adversely impacting grain anthocyanin or N concentration. This study demonstrated that the appropriate management of N and Zn fertilizers for specific purple rice genotypes would be one way to increase productivity and grain N, Zn, and anthocyanin concentration.

High-Resolution Airborne Hyperspectral Imagery for Assessing Yield, Biomass, Grain N Concentration, and N Output in Spring Wheat

Remote sensing allows fast assessment of crop monitoring over large areas; however, questions regarding uncertainty in crop parameter prediction and application to nitrogen (N) fertilization remain open. The objective of this study was to optimize of remote sensing spectral information for its application to grain yield (GY), biomass, grain N concentration (GNC), and N output assessment, and decision making on spring wheat fertilization. Spring wheat (Triticum turgidum L.) field experiments testing two tillage treatments, two irrigation levels and six N treatments were conducted in Northwest Mexico over four consecutive years. Hyperspectral images were acquired through 27 airborne flight campaigns. At harvest, GY, biomass, GNC and N output were determined. Spectral exploratory analysis was used to identify the best wavelength combinations, the most suitable vegetation indices (VIs) and the best growth stages to assess the agronomic variables. The relationship between the spectral information and the agronomic measurements was evaluated by the coefficient of determination (R2) and the root mean square error (RMSE). The ability of the indices to guide fertilizer recommendation was assessed through an error analysis based on the N sufficiency index. GY was better assessed from the end of flowering to the early milk stage by VIs based on the combination of bands from near infrared radiation/visible and from near infrared radiation/red-edge regions (R2 > 0.6; RMSE < 700 kg ha−1). N output was efficiently assessed by a combination of bands from near infrared radiation/red-edge at booting (R2 > 0.7; RMSE < 9 kg N ha−1). The GNC was better estimated by VIs combining bands in near infrared radiation/red-edge at early milk, but with great variability among the years studied. Some VIs were promising for guiding fertilizer recommendation for increasing GNC, but there was not a single index providing reliable recommendations every year. This study highlights the potential of remote sensing imagery to assess GY and N output in spring wheat, but the identification of GNC responsive sites needs to be improved.

Mısır bitkisinde sulamayı sonlandırma zamanının tane verimi, hasatta tane nemi ve bazı tarımsal özellikler üzerine etkileri

This study was conducted to investigate the effects of different irrigation termination dates on maize grain yield, kernel moisture at harvest and some other agronomic traits. The relationships between irrigation termination dates and investigated traits were visually assessed through biplot analysis. Experiments were conducted for two years (2016 and 2017) with three replications. Irrigations were terminated at eight different dates (S1: R2 blister stage; S2: R3 early milk stage; S3: R3 milk stage; S4: R3 late milk stage; S5: R4 dough stage; S6: R5 early dent stage; S7: R5 dented stage; S8: R5 late dent stage). Despite low kernel harvest moisture levels, early irrigation termination dates had low yield levels (S1:10460 kg ha-1 grain yield; 11.7% moisture). However, despite high yield levels, late irrigation termination dates had high kernel harvest moisture levels (S7:16100 kg ha-1 grain yield; and 18.8% moisture; S8:16240 kg ha-1 grain yield and 19.6% moisture). In terms of grain yield and harvest moisture, S4 (14050 kg ha-1 grain yield and 14.2% harvest moisture), S5 (14170 kg/ha grain yield and 15.0% moisture) and S6 (14880 kg ha-1 grain yield and 16.1% moisture) treatments had similar values and were considered to be as the most appropriate irrigation termination dates. Kernel weight per ear varied between 150.6 (S1) and 238.7 g (S7); number of kernels per ear varied between 677 (S1) and 741 kernels (S5), ear lengths varied between 16.7 (S1) - 24.1 cm (S4), thousand-kernel weights varied between 271 g (S1) and 381 g (S8), hectoliter weights varied between 74.3 (S1) and 78.1 kg (S4) and number of days to physiological maturity varied between 112.5 (S1) and 124.5 days (S8).

Composition and Predominance of Fusarium Species Causing Fusarium Head Blight in Winter Wheat Grain Depending on Cultivar Susceptibility and Meteorological Factors.

Fusarium head blight (FHB) is one of the most important diseases of wheat, causing yield losses and mycotoxin contamination of harvested grain. A complex of different toxigenic Fusarium species is responsible for FHB and the composition and predominance of species within the FHB complex are determined by meteorological and agronomic factors. In this study, grain of three different susceptible winter wheat cultivars from seven locations in northern Germany were analysed within a five-year survey from 2013 to 2017 by quantifying DNA amounts of different species within the Fusarium community as well as deoxynivalenol (DON) and zearalenone (ZEA) concentrations. Several Fusarium species co-occur in wheat grain samples in all years and cultivars. F. graminearum was the most prevalent species, followed by F. culmorum, F. avenaceum and F. poae, while F. tricinctum and F. langsethiae played only a subordinate role in the FHB complex in terms of DNA amounts. In all cultivars, a comparable year-specific quantitative occurrence of the six detected species and mycotoxin concentrations were found, but with decreased DNA amounts and mycotoxin concentrations in the more tolerant cultivars, especially in years with higher disease pressure. In all years, similar percentages of DNA amounts of the six species to the total Fusarium DNA amount of all detected species were found between the three cultivars for each species, with F. graminearum being the most dominant species. Differences in DNA amounts and DON and ZEA concentrations between growing seasons depended mainly on moisture factors during flowering of wheat, while high precipitation and relative humidity were the crucial meteorological factors for infection of wheat grain by Fusarium. Highly positive correlations were found between the meteorological variables precipitation and relative humidity and DNA amounts of F. graminearum, DON and ZEA concentrations during flowering, whereas the corresponding correlations were much weaker several days before (heading) and after flowering (early and late milk stage).

Effect of Exogenous Application of Methyl Jasmonate on the Lipid and Carbohydrate Content and Composition of Winter Triticale ( Triticosecale Wittm.) Grain and the Severity of Fungal Infections in Triticale Plants and Grain.

Kernels of winter triticale ( Triticosecale Wittm. cv. Dinaro) were analyzed. In the autumn of 2015, the effect of methyl jasmonate (MJ) on the germination of triticale kernels and the development of triticale seedlings was analyzed in a laboratory before kernels were sown in experimental plots. Kernels harvested from plots in August 2016 were analyzed to determine their lipid and carbohydrate content and composition and the severity of fungal infections. Triticale grain was harvested at full maturity. The plots were sprayed with MJ at concentrations of 10-6 to 10-3 M in the stem elongation stage (200 L/ha) and in the early milk stage (300 L/ha). Other preventive treatments, fungicides, pesticides, or foliar fertilizers were not applied. Lipids of triticale kernels contained 20 fatty acids (FAs) with the highest proportion of linoleic acid. Methyl jasmonate did not exert a significant effect on the FA composition of kernel lipids treated with the plant hormone during the growing season. Statistical analysis did not reveal significant ( p < 0.05) differences in the total content of soluble carbohydrates in control kernels and in the kernels collected from triticale plants treated with MJ. Methyl jasmonate applied at a concentration of 10-3 M in BBCH stages 54 and 73 reduced the prevalence of stem base, leaf, and spike diseases. However, the severity of grain infections caused by mycotoxin-producing fungi increased in treatments where MJ was applied at a concentration of 10-5 M relative to the control treatment. The study describes the results noted in naturally infected plants and provides valuable inputs for agricultural practice, but further research is required to validate the presented findings.

Effects of Foliar Application of Zinc on Grain Yield and Zinc Concentration of Rice in Farmers’ Fields

Three field experiments were conducted on farms in Chiang Mai, Thailand in 2015 to evaluate the effects of: (i) foliar application of Zn on the grain yield and grain Zn concentration of rice and (ii) using Zn-enriched seeds in the next cropping on growth and yield. Zn was applied by foliar spraying 0.5% ZnSO 4 at three different growth stages: booting, flowering, and early milk stages. Foliar spraying of Zn improved the grain Zn concentration by 41% in one field, and an average of 30% across the three fields. The foliar- sprayed Zn did not, however, affect the grain yield in any of the fields. The Zn-enriched seeds also did not affect the grain yield of the plants in the farmers’ fields in the next cropping, probably because of the high amount of soluble Zn already in the experimental fields. Clearly, the foliar application of Zn significantly increased grain Zn concentration, but had no effect on grain yield

Hyperspectral measurements of yellow rust and fusarium head blight in cereal crops: Part 1: Laboratory study

This paper assesses the potential use of a hyperspectral camera for measurement of yellow rust and fusarium head blight in wheat and barley canopy under laboratory conditions. Scanning of crop canopy in trays occurred between anthesis growth stage 60, and hard dough growth stage 87. Visual assessment was made at four levels, namely, at the head, at the flag leaves, at 2nd and 3rd leaves, and at the lower canopy. Partial least squares regression (PLSR) analyses were implemented separately on data captured at four growing stages to establish separate calibration models to predict the percentage coverage of yellow rust and fusarium head blight infection. Results showed that the standard deviation between 500 and 650 nm and the squared difference between 650 and 700 nm wavelengths were found to be significantly different between healthy and infected canopy particularly for yellow rust in both crops, whereas the effect of water-stress was generally found to be unimportant. The PLSR yellow rust models were of good prediction capability for 6 out of 8 growing stages, a very good prediction at early milk stage in wheat and a moderate prediction at the late milk development stage in barley. For fusarium, predictions were very good for seven growing stages and of good performance for anthesis growing stage in wheat, with best performing for the milk development stages. However, the root mean square error of predictions for yellow rust were almost half of those for fusarium, suggesting higher prediction accuracies for yellow rust measurement under laboratory conditions.

Iodine biofortification of wheat, rice and maize through fertilizer strategy

Iodine (I) deficiency is distinct from other micronutrient deficiencies in human populations in having a high endemic prevalence both in well-developed and in developing countries. The very low concentration of iodine in agricultural soils and cereal-based foods is widely believed to be the main reason of iodine deficiency in humans, especially in developing countries. In the present study, the possibility of using iodine containing fertilizers for agronomic biofortification of cereal grains with iodine was studied. The aim was to establish the best application method (to the soil or as foliar spray), the best form of iodine (potassium iodate or potassium iodide) and the optimal dose of iodine. Additionally, experiments were conducted to study transport of iodine in plants and localization of iodine within the grains. Experiments were conducted both under greenhouse conditions and in the field on wheat (Triticum aestivum) grown in Turkey and Pakistan, on rice (Oryza sativa) grown in Brazil, Thailand and Turkey and on maize (Zea mays) grown in Turkey. The iodine concentration in the grain, localization of iodine in different grain fractions of wheat (i.e., endosperm, bran and embryo) and iodine concentration of both brown rice and polished rice was analyzed. In short-term experiments, the translocation of iodine from older into younger leaves was also studied. Inductively coupled plasma mass spectrometry (ICP-MS) was used for analysis of iodine in plant and soil samples. In greenhouse experiments on wheat, soil-applied potassium iodide (KI) and potassium iodate (KIO3) at increasing rates (i.e., 0, 0.1, 0.25, 1, 2.5, 5, 10 and 20 mg I kg−1 soil) both iodine forms substantially increased iodine concentration in the shoot, with the highest shoot iodine resulting from the KI treatments. However, these soil treatments did not affect iodine concentrations in the wheat grain, with the exception of the highest iodine rates (i. e., 10 and 20 mg I kg−1 soil) which also depressed the grain yield. In contrast to the soil applications, foliar spray of KI and KIO3 at increasing rates during heading and early milk stages did enhance grain iodine concentrations up to 5- to 10-fold without affecting grain yield. Including KNO3 or a surfactant to the iodine containing foliar spray further increased the grain iodine concentration. In a short-term experiment using young wheat plants, it was found that iodine is translocated from older into younger leaves after immersion of the older leaves in solutions containing KI or KIO3. Adding KNO3 or a surfactant in the immersion solution also promoted leaf absorption and translocation of iodine into younger leaves. Field experiments conducted in different countries confirmed that foliar application with increasing rates of iodine significantly increased grain iodine concentrations in wheat, brown rice and maize. This increase was also found in the iodine concentration of the endosperm part of wheat grains and in polished rice. The results of the present study clearly show that foliar application of iodine containing fertilizers is highly effective in increasing grain iodine concentrations in wheat, rice and maize. Presented results suggest that iodine is translocated from shoot to grain by transport in the phloem. Spraying KIO3 up to the rate of 0.05% w/v is suggested as the optimal form and rate to be used in agronomic biofortification with iodine. The substantial increase in grain iodine concentrations could contribute to the prevention of iodine deficiency in human populations with low dietary iodine intake. The reasons behind the higher effectiveness of foliar-applications compared to the soil applications of iodine fertilizers in improving grain iodine concentration are discussed.

Cover Crop Termination Timing is Critical in Organic Rotational No‐Till Systems

Core Ideas Hairy vetch–triticale biomass peaked at early hairy vetch flowering but mechanical control was highest at late flowering to early pod set. Cereal rye biomass peaked at late dough stage but optimal mechanical control was obtained between 50% anthesis and early milk stages. Volunteer hairy vetch was problematic in Delaware and Maryland whereas volunteer cereal rye was problematic in Pennsylvania. Volunteer cover crops resulting from incomplete termination with mechanical rolling can be problematic in subsequent crops and may impact the benefits of organic rotational no‐till. Cover crop‐based rotational no‐till enables organic farmers to reduce labor and build soil health. In these systems, cover crops are terminated with a roller‐crimper and cash crops are direct‐seeded into the resulting mulch. A systems experiment was conducted at three Mid‐Atlantic locations to test how cover crop termination timing affects cover crop biomass production, control, and volunteers in subsequent crops during the transition to organic production. The annual crop rotation was hairy vetch (Vicia villosa Roth) plus triticale (x Triticosecale Wittm.)–corn (Zea mays L.)–cereal rye (Secale cereale L.)–soybean [(Glycine max (L.) Merr.]–winter wheat (Triticum aestivum L.) using a full‐entry design. Cover crops were terminated based on growth stages designated Early, Intermediate, or Late. Hairy vetch–triticale and cereal rye biomass production exceeded 5000 kg ha−1 by Late termination in all site‐ years. Although hairy vetch–triticale biomass production peaked at early flowering of hairy vetch, control increased as termination was delayed. Hairy vetch regrowth and volunteer hairy vetch in subsequent soybean and winter wheat crops was lower in Late compared to Early termination treatments. Cereal rye biomass increased as termination was delayed but optimal control was achieved with Intermediate termination. Rolling cereal rye Early resulted in tillering and seed production whereas rolling Late allowed kernels to mature. Wheat grain contamination by volunteer hairy vetch ranged from 11 to 29% and by volunteer cereal rye from 3 to 11% at Maryland and Pennsylvania, respectively, demonstrating that minimizing cover crop seed production with strategic termination is critical in rotational no‐till.

Mitigating zinc deficiency through integration of agronomic biofortification for achieving high zinc wheat grain in northern states of India

Twenty-five field experiments on wheat as test crop were conducted across four northern states of India viz., Uttar Pradesh, Punjab, Haryana and Himachal Pradesh during 2014–15 and 2015–16 to investigate the effect of soil and foliar applications of zinc (Zn) on wheat grain yield and grain Zn concentration. Experimental design was complete randomized block design with three replicates. Wheat crop was grown under three different Zn application rates as follows: (i) Control (no Zn application), (ii) Soil Zn application, and (iii) Foliar Zn application. The soil Zn treatment consisted of 50 kg ZnSO4.7H2O ha applied to the soil before sowing of wheat. The foliar Zn treatment, a 0.5% (w/v) aqueous solution of ZnSO4.7H2O was realized two times i. e. first at anthesis or heading and the second one at early milk stage of wheat crop. Results showed that the application of Zn fertilizer in soil increased grain yield of wheat significantly over control at 23 locations during both the years. However, the effect of foliar Zn fertilizer on grain yield was quite less effective. The foliar Zn application resulted in significant increment in grain Zn concentration over control at all locations. In particular, soil Zn application markedly increased grain yield and slightly less content of grain Zn over foliar Zn application. However, foliar application of Zn at specific stages was an important agronomic practice for the farmers to enhance wheat grains with zinc to mitigate hidden hunger. In conclusion, agronomic biofortification was found to be most suitable for both optimum grain yield and grain biofortification of wheat to combat Zn deficiency.

Differences in grain zinc are not correlated with root uptake and grain translocation of zinc in wild emmer and durum wheat genotypes

Cereal-based foods fall short of providing adequate dietary zinc (Zn) to human beings. Developing new genotypes with high genetic capacity for root uptake and grain deposition of Zn is an important challenge. There is a large genetic variation for grain Zn concentration among and between wheat species, especially within wild emmer wheat (Triticum turgidum ssp. dicoccoides) that can be exploited in order to understand the physiological mechanisms contributing to grain Zn accumulation. Eight different wild emmer genotypes and two durum wheat (Triticum durum) cultivars were used to investigate root uptake, root-to-shoot translocation and remobilization (i.e., retranslocation) from flag leaves into grains of 65ZnSO4-treated plants. The initial seed Zn concentrations of wild emmer wheat and durum genotypes used in the experiments were different, ranging from 45 to 73 mg kg−1 and from 35 to 40 mg kg−1, respectively. Plants were grown in nutrient solution for the experiments investigating root uptake and shoot transport of Zn by using 65Zn labeled ZnSO4 and in soil medium for the experiments studying shoot and grain Zn concentrations and 65Zn translocation from flag leaves into grains. The treatment of flag leaves with 65Zn was realized by immersion of flag leaves into 65ZnSO4 solution for 15 seconds and for 5 times during the anthesis and early milk stages. Wild emmer and durum wheat genotypes expressed highly significant differences in root uptake and root-to-shoot translocation of 65Zn and translocation of 65Zn from flag leaves into grains. However, none of these parameters showed a significant correlation either with the initial seed Zn concentrations at sowing or the grain Zn concentrations at harvest. The durum wheat cultivars with higher grain yield had lower concentration of Zn both in seeds at sowing or in grains at harvest, while wild emmer genotypes with lower grain yield capacity had higher concentration of Zn both in seeds at sowing or in grains at harvest. The concentration or content (total amount) of Zn in shoot during the early growth stage also did not correlate with the initial seed Zn concentrations. Differences in grain Zn concentration of wild emmer and cultivated wheats could not be explained by root Zn uptake and Zn translocation from flag leaf into grains during seedling and reproductive growth stages, respectively. It seems that there are additional key factors affecting the expression of genetic variation for grain Zn accumulation.