Influence of meteorological parameters on wheat yield under different sowing conditions

Field experiments were conducted on the research farm of IARI, New Delhi during Rabi 2016-17 and 2017-18. Three varieties of wheat (PBW-723, HD-2967 and HD-3086) were sown on three different dates for generating different weather condition during various phenological stages of crop. Results showed that during early crop growth stages soil moisture had higher value and soil temperature had lower value and with progress of crop growth stage, the moisture in the upper layer decreased and soil temperature increased significantly as compared to the bottom layers. During tillering and jointing stage, air temperature within canopy was more and relative humidity was less while during flowering and grain filling stage, air temperature within canopy was less and relative humidity was more in timely sown crop as compared to late and very late sown crop. Radiation use efficiency and relative leaf water content had significantly higher value while leaf water potential had lower value in timely sown crop followed by late and very late sown crop. Yield had higher value in HD-3086 followed by HD-2967 and PBW-723 in all weather conditions. Canopy air temperature difference had positive value in very late sown crop particularly during flowering and grain-filling stages. This reflects in the yield. Yield was more in timely sown crop as compared to late and very late sown crop.

FAO AquaCrop model for determining optimum wheat sowing date in Tarai region of Uttarakhand

The ideal sowing period is critical for maximizing the crop's yield potential under specific agroclimatic conditions (Nain, 2016; Patra et al., 2017). It influences the phenological stages of the crop's development and, as a result, the efficient conversion of biomass into economic yield. During rabi 2013-14, a field research was done at GBPUA&T's Borlaug Crop Research Centre to determine the best sowing dates for wheat crops employing Aquacrop model. Aquacrop model has been calibrated against vegetative and economic yield forthree sowing dates, viz., 3rd December, 18th December and 3rd January (Pareek et al., 2017). After calibrating the Aquacrop model, a set of conservative variables was obtained (Pareek et al., 2017). Afterward, the calibrated Aquacrop model was used to validate wheat yield and biomass for three years in a row, namely 2010-11, 2011-12 and 2012-13. The model subsequently used to simulate yield under different sowing dates. For all of the tested years, the simulation findings of the Aquacrop model reflected the observed crop yields and biomass of wheat. The model was used to simulate the optimum sowing week based on varying sowing dates and produced grain yield for a period of 10 years (Malik et al., 2013). The average and assured yield of wheat was worked out based on probability analysis (60, 75 and 90%). The optimum sowing time for Tarai region of Uttarakhand was suggested as first week of November followed by second week of November (Nain, 2016). In no case wheat should be sown during third week of November and beyond due to poor assured yield and average yield (Nain, 2016). The finding of the studies will help to increase productivity and production of wheat crop in Tarai region of Uttarakhand.

Genome-wide association mapping for high temperature tolerance in wheat through 90k SNP array using physiological and yield traits

Dissecting the genetic basis of physiological and yield traits against tolerance to heat stress is an essential in wheat breeding programs to boost up the wheat yield for sustainable food security. Herein, a genome-wide association study (GWAS) was performed to reveal the genetic basis of heat tolerance using high-density Illumina 90K Infinium SNPs array through physiological and yield indices. These indices were phenotyped on a diverse panel of foreign and domestic genotypes of Pakistan, grown in normal and heat-stressed environments. Based on STRUCTURE analysis, the studied germplasm clustered into four sub-population. Highly significant variations with a range of moderate (58.3%) to high (77.8%) heritability was observed under both conditions. Strong positive correlation existed among physiological and yield related attributes. A total of 320 significant (-log10 P ≥ 3) marker-trait associations (MTAs) were identified for the observed characters. Out of them 169 and 151 MTAs were recorded in normal and heat stress environments, respectively. Among the MTA loci, three (RAC875_c103017_302, Tdurum_contig42087_1199, and Tdurum_contig46877_488 on chromosomes 4B, 6B, and 7B respectively), two (BobWhite_c836_422 and BS00010616_51) and three (Kukri_rep_c87210_361, D_GA8KES401BNLTU_253 and Tdurum_contig1015_131) on chromosomes 5A, 1B, and 3D at the positions 243.59cM, 77.82cM and 292.51cM) showed pleiotropic effects in studied traits under normal, heat-stressed and both conditions respectively. The present study not only authenticated the numerous previously reported MTAs for examined attributes but also revealed novel MTAs under heat-stressed conditions. Identified SNPs will be beneficial in determining the novel genes in wheat to develop the heat tolerant and best yielded genotypes to fulfill the wheat requirement for the growing population.

GGE Biplot Analysis to Explore the Adaption Potential of Italian Common Wheat Genotypes

Given the substantial variation in global wheat yield, insufficient research in cultivar selection for climate change, and the lack of suitable germplasm in sustainable agroecosystems, there is a requisite for soft wheat genotypes, with stable grain yield as well as quality parameters. The present study was aimed at genotype evaluation (GGE biplot for “mean performance versus stability”) not only for yield, but also for technological, phytosanitary and functional quality parameters of 24 Triticum aestivum L. genotypes (eight landraces, old and modern varieties, respectively) within a single organic farm location (Argelato, Emilia-Romagna, Italy) over three consecutive years. Overall, high yield stability was shown for the landraces and old varieties. In particular, the landraces Piave and Gamba di Ferro, as well as the old variety Verna, showed high stability with above-average means for numerous quality parameters of interest. Additionally, relative stability combined with above-average mean for quality parameters was also demonstrated for the high-yielding Gentil Bianco and Guà 113. Aside from Verna, these “unrecognized” resilient genotypes were also shown to meet the requisites for suitable germplasm in sustainable agroecosystems. Future potential utilization of these more stable landraces in addressing climate change would also ultimately facilitate the survival of valuable genetic resources.

Phytosanitary condition and yield of winter wheat in crop rotations of the forest-steppe zone of the Volga region

In the conditions of the forest-steppe zone of the Volga region, winter wheat occupies the largest area among grain crops, which is associated with its relatively high productivity, economic efficiency and the ability to unload the peaks of field work in the spring. Winter wheat makes fuller use of the bioclimatic potential of productivity, especially in the arid conditions of the region. Despite the fact that the adaptive-integrated approach to the joint use of agricultural techniques and chemicalization means when growing grain crops provides significant and stable yield increases, they require regular study to adjust agricultural technologies. The article presents the results of 3-year studies in a stationary field experiment to assess the influence of predecessors, methods of basic soil cultivation and plant protection on the spread of diseases and weeds, as well as on the yield of winter wheat. Studies have shown that the placement of winter wheat after clean fallow helps to reduce the infestation of crops, and after cruciferous predecessors (white mustard, spring rape)— the spread of root rot (Bipolaris sorokiniana (Helmintosporium sativum)) and leaf rust (Puccinia recondita). Winter wheat yield after different predecessors varied from 5.16 t/ha for pure fallow to 3.77–4.04 t/ha after nonfallow predecessors with a significant increase in adaptive-integrated plant protection by 0.37 t/ha (9.2%) and insignificant — for combined tillage in crop rotation — by 0.19 t/ha (4.6%).

Impact of Safe Rock® Minerals, Mineral Fertilizers, and Manure on the Quantity and Quality of the Wheat Yield in the Rice–Wheat Cropping System

Rice–wheat (RW) rotation is the largest agriculture production system in South Asia with a multifaceted role in maintaining the livelihood of people. The customary practices and indiscriminate use of synthetic fertilizers have culminated in the decline of its productivity and profitability during the past two decades, thus affecting the sustainability of wheat. Safe Rock® Minerals (SRM) is a multi-nutrient rich natural rock mineral with great potential to manage soil degradation, reducing the input of fertilizers, improving soil fertility, and plant health. Thus, a field trial was conducted at the research farm of ICAR—Indian Agricultural Research Institute, New Delhi from 2016 to 2018 to evaluate the impact of Safe Rock® Minerals (SRM) on biometric parameters, productivity, quality, and nutrient uptake by conventional wheat and System of Wheat Intensification (SWI) in the wheat–rice cropping system. The results indicate that SWI performed better in terms of growth, yield, and quality parameters than conventional wheat. Among nutrient management practices; the highest growth, yield, and yield attributes of wheat were achieved with the use of SRM application 250 kg ha−1 + 100% Recommended Dose of Fertilizer (RDF). SRM application also increased grain protein content significantly. In conclusion, the integrated use of SRM with organic manures can serve as an eco-friendly approach for sustainable wheat production.

A Major Quantitative Trait Loci Cluster Controlling Three Components of Yield and Plant Height Identified on Chromosome 4B of Common Wheat

Wheat yield is not only affected by three components of yield, but also affected by plant height (PH). Identification and utilization of the quantitative trait loci (QTL) controlling these four traits is vitally important for breeding high-yielding wheat varieties. In this work, we conducted a QTL analysis using the recombinant inbred lines (RILs) derived from a cross between two winter wheat varieties of China, “Nongda981” (ND981) and “Nongda3097” (ND3097), exhibiting significant differences in spike number per unit area (SN), grain number per spike (GNS), thousand grain weight (TGW), and PH. A total of 11 environmentally stable QTL for these four traits were detected. Among them, four major and stable QTLs (QSn.cau-4B-1.1, QGns.cau-4B-1, QTgw.cau-4B-1.1, and QPh.cau-4B-1.2) explaining the highest phenotypic variance for SN, GNS, TGW, and PH, respectively, were mapped on the same genomic region of chromosome 4B and were considered a QTL cluster. The QTL cluster spanned a genetic distance of about 12.3 cM, corresponding to a physical distance of about 8.7 Mb. Then, the residual heterozygous line (RHL) was used for fine mapping of the QTL cluster. Finally, QSn.cau-4B-1.1, QGns.cau-4B-1, and QPh.cau-4B-1.2 were colocated to the physical interval of about 1.4 Mb containing 31 annotated high confidence genes. QTgw.cau-4B-1.1 was divided into two linked QTL with opposite effects. The elite NILs of the QTL cluster increased SN and PH by 55.71–74.82% and 14.73–23.54%, respectively, and increased GNS and TGW by 29.72–37.26% and 5.81–11.24% in two environments. Collectively, the QTL cluster for SN, GNS, TGW, and PH provides a theoretical basis for improving wheat yield, and the fine-mapping result will be beneficial for marker-assisted selection and candidate genes cloning.