Search Results

In India wheat is conventionally planted on flat-bed and irrigation is applied by flooding, which results in low water-use efficiency. Efficient use of irrigation water is a major researchable issue in most command areas for improving crop productivity. Resource conservation technologies aimed at improving productivity and water-use efficiency such as raised-bed planting have been found useful in wide row crops like maize, cotton, sunflower, sugarcane, etc. However, such information is not available for a relatively narrow row crop like wheat. A field experiment was conducted during 2002–04 at New Delhi on a sandy loam soil to evaluate the performance of wheat crop under resource conservation techniques (RCTs), viz. furrow-irrigated raised-bed (FIRB), broad-bed and furrow (BBF), raised-bed and sunken-bed (RBSB) and conventional flat-bed (FB) in main plots, and 4 irrigation regimes, viz. irrigation only at crown root initiation (CRI); irrigation at 0.9 and 1.2 IW/CPE (irrigation water/cumulative pan evaporation) ratio and irrigations at six critical physiological growth stages in subplots. Wheat performed equally well under all the RCTs with respect to grain yield. The maximum grain yield was recorded under 1.2 IW/CPE ratio, which was at par with 6 irrigations at critical growth stages, but significantly higher than 0.9 IW/CPE and one irrigation at CRI. Bed planting techniques involving FIRB and BBF recorded significantly lower consumptive use (CU) of water than RBSB and FB. There was saving of 18.2 to 19.5% irrigation water by adopting FIRB compared to FB with flood irrigation. Water-use efficiency under FIRB and BBF was 8.3–22.8 and 4.9–24.8% higher respectively over the FB with flooding.

Nitrogen (N) movement in the soil resulting from the long-term application of fertilizer N is an environmental concern when it reaches the groundwater. The distribution of N in the profile of an alkaline sandy loam soil (Typic Haplustept) and its relationship with N uptake by plants was studied after 22 years of continuous cultivation in an annual crop rotation involving maize (Zea mays L.) and wheat (Triticum aestivum L.). Soil samples were collected to a depth of 1.2 m from the 0-0.15, 0.15-0.30, 0.30-0.45, 0.45-0.60, 0.60-0.90 and 0.90-1.20 m layers and analysed for alkaline KMnO_4­-oxidisable N (available N) and mineral N (NH₄-N and NO₃-N). The continuous addition of increasing levels of N resulted in an increase in N content, whereas the combined application of N, P and K caused a decline in its availability. Mineral N (2 M KCl-extractable NH₄-N and NO₃-N) was the lowest in the N₁₂₀P₃₅K_33.2 treatment plot. The available N and NH₄-N decreased with increasing soil depth. However, variations in NO₃-N concentration due to differential rates of fertilizer application were observed only to a depth of 0.45 m. This effect was more pronounced in the N₁₈₀P_17.5K_33.2 plot. Regression equations were used to predict N uptake by wheat using the N status in different soil layers as independent variables. Multiple regression analysis indicated that the predictability of the relationship between N uptake and available N improved considerably when its status to a soil depth of 0.45 m was included. In the case of NH₄-N, a noticeable increase in the coefficient of determination (R²) occurred to a depth of 0.90 m. The R² value of NO₃-N with the N uptake by wheat was quite low in the top layers (to a depth of 0.30 m). However, an increase in the R² value was observed when lower depths (beyond 0.30 m) were included in the regression analysis, suggesting that the inclusion of subsoil N status is important to achieve better and profitable N supply systems in crop production.

High yielding, stable wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite wheat breeding lines developed by CIMMYT, to analyze their stability for grain yield across diverse environments, and to identify superior genotypes that could be valuable for varietal release. Genetically diverse 196 advanced breeding lines were evaluated across different sites in Afghanistan. Grain yield, days to heading and plant height were analyzed. Genotypic superiority for grain yield was determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed arrays of variation for grain yield in each year, with mean values ranging from 3908 to 7209 kg/ha. A set of 20 experimental genotypes superior to the check based on their high mean yield and stability across environments as assessed by the GGE rank was identified. The most stable high yielding genotypes were HD 2687; Elvia/5/Cndo/R143//Ente/Mexi75/3/AE. sq./4/2*Oci; Quaiu; Whear/Vivitsi//Whear; Kiritati/2*Trch; Waxwing; Munal#1; Whear//Inqalab 91*2/Tukuru and Snb//Cmh79A.955/3*Cno79/3/Attila/4/Chen/A.sq.(Taus)//Bcn/3/2*Kauz. These superior genotypes also had acceptable maturity and plant height. The findings of this study provides information on adaptation of the internationally important wheat genotypes, valuable for wheat improvement program in Afghanistan and its neighbouring countries in West, Central and South Asia.

The present study reports the effects of pre-treatment with ferulic acid (FA) on antioxidant response of wheat seedlings. In comparison to hydropriming, 100 and 150 ppm of FA significantly enhanced seedling growth of wheat at 6th day after germination (DAG). However, 1000 ppm of FA led to reduction in seedling growth. Roots and shoots of wheat seedlings pre-treated with 100 ppm of FA showed significant upregulation of peroxidase (POX), ascorbate peroxidase (APX) activities. Although catalase (CAT) remained unaffected in the roots, but showed about 2-fold increase in the shoots. Despite of low glutathione reductase (GR) and high polyphenol oxidase (PPO) activities in the shoots and roots, respectively, ascorbic acid and total phenolic contents also increased at 6th DAG which may be due to the activation of their biosynthetic pathways in seedlings pre-treated with 100 ppm of FA. Proline content of wheat seedlings pre-treated with 100 ppm of FA remained unaffected. Results signify the role of FA pre-treatment in augmenting the antioxidant response of wheat and thereby suggest that at lower concentrations, it can be used for improving performance of wheat under various environmental constraints.

Field experiments were conducted over two years under low input conditions to know the influence of bio-inoculants, namely arbuscular mycorrhiza fungi (AMF, Glomus fasciculatum ) and Azotobacter chroococcum (Azc) on the performance and gene effects for important root and plant characters in three crosses of wheat (WH147×WH157, WH147×PBW175 and WH147×WH542). Six generations representing P ₁ , P ₂ , F ₁ , F ₂ , BC ₁ and BC ₂ populations of each cross were grown in randomized block design with three replications. The estimate of means (m) indicated that bio-inoculants enhanced the mean performance of most of the characters and root length density and grain yield in some crosses only. Crop season also showed considerable effect on impact of bio-inoculants. The joint scaling test revealed adequacy of additive-dominance model of gene effects for root biomass, root length density, flag leaf area, tillers/plant, grain weight and grain yield in all the crosses and bio-inoculants treatments in both years. The AMF treatment brought about changes in the magnitude and significance of additive component for root biomass, plant height, flag leaf area in all the three crosses. Both additive (d) and dominance (h) components were affected with respect to grain yield in WH147×WH157 and WH147×WH542. The dominant component was important for tillers/plant, grain yield, root length in control, as well as bio-inoculants treated populations of WH147×PBW175 but treatment of AMF and AMF+ Azc reduced the magnitude of h and increased the magnitude of d. Digenic interactions were prominent for grains/spike in WH147×WH157. Magnitude of digenic interactions was higher under bio-inoculation. Simple pedigree and bulk pedigree methods are suggested to capitalize on adequate additive gene effects for developing bio-inoculants responsive wheat genotypes.

Maize cultivars (4 composites, 14 inbreds and 7 hybrids) cultivated in Punjab were characterized using a set of 70 Simple Sequence Repeat (SSR) markers with a total of 199 alleles. Out of these, 67 markers produced polymorphic profiles, 3 were monomorphic. Eight SSR primers detected eight unique alleles in three genotypes. These unique SSR alleles provide an opportunity for unambiguous differentiation of the respective genotypes. SSR profiles were analyzed by using computer softwares NTSYS-pc and DARwin 5.0. Both of them classified the genotypes in four distinct groups.

Effects of salinity on correlation, path and stress indices, yield and its components were studied in a set of 34 promising rice genotypes collected from various national and international organizations. These genotypes were evaluated in a randomized complete block design with three replications during the wet seasons (kharif) of 2009 and 2010 in normal (EC_iw ∼ 1.2 dS/m) and salinity stress (EC_iw ∼ 10 dS/m) environments in micro plots at Central Soil Salinity Research Institute (CSSRI), Karnal, India. Grain yield per plant showed positive significant association with plant height, total tillers, productive tillers, panicle length, and biological yield per plant and harvest index under normal environment, whereas grain yield showed positive significant association with biological yield and harvest index under salinity stress. These results clearly indicate that selection of high yielding genotypes would be entirely different under normal and saline environments. The stress susceptibility index (SSI) values for grain yield ranged from 0.35 (HKR 127) to 1.55 (TR-2000-008), whereas the stress tolerance index (STI) values for grain yield ranged from 0.07 (PR 118) to 1.09 (HKR 120). The genotypes HKR 120, HKR 47 and CSR-RIL-197 exhibited higher values of stress tolerance index (STI) in salinity. Under salinity, negative and significant association was shown by SSI and grain yield in contrast to positive and significant association shown by STI and grain yield. These associations could be useful in identifying salt tolerant and sensitive high yielding genotypes. The stress susceptible and stress tolerance indices suggest that the genotypes developed for salinity tolerance could exhibit higher tolerance, adaptability and suitability. Harvest index and biological yield traits emerged as the ideal traits for improvement through selection and could be used to increase the rice productivity under saline stress environments.

Soil salinity is one of the major environmental constraints in increasing agricultural crop production, especially wheat production in India. Screening of diverse germplasm in representative growing conditions is prerequisite for exploring traits with stable expression imparting salinity tolerance. A study was undertaken during 2011–2012 for characterizing wheat germplasm in three environments representing growing conditions of crop in Northern parts of India, estimating inter-relationship among traits and evaluating stability of trait conferring salinity tolerance. Significant value of mean square for observed trait across the environments signified presence of large variability in genotypes. Significant yield reduction was recorded in almost all genotypes in saline environment compared to non-saline condition. Ratio of potassium and sodium ion in leaf tissue (KNA); a key salt tolerance traits was found to be significantly correlated with biomass, SPAD value and plant height. Due to the presence of significant genotype × environment interaction (G × E) for KNA, additive main effect and multiplicative interaction (AMMI) model was utilized to study stability of KNA among genotypes and environments. IPCA1 and IPCA2 were found to be significant and explained more than 99 per cent of variation due to G × E. KRICHAUFF was having maximum trait value with specific adaptation while DUCULA 4 and KRL 19 were having general adaptability. AMMI2 biplot revealed high stability of Kharchia 65 and KRL 99 across environments. E₁ (timely sown, non-saline soil) recorded maximum site mean while E₂ (timely sown, sodic soil) was having minimum interaction with genotypes (AMMI1 = 1.383). Thus, our studies suggest that AMMI model is also useful for estimating adaptability of traits other than yield utilized for breeding salt tolerant wheat varieties.

Abstract

In the modern era, nutraceutical properties of horticultural crops are indispensable to determine their adaptability to different agro-ecological regions. The present study exploits the potential of mulches (P: plastic mulch; S: straw mulch; N: No mulch) in relation to drip irrigation (I₁: 100%, I₂: 80%, I₃: 60% of crop evapotranspiration (Etc)), and fertigation (F₁: 100%, F₂: 80%, F₃: 60% of recommended dose of fertilizer (RDF): 125 kg N, 62.5 Kg P₂O₅, 62.5 kg K₂O per ha) on Pak choi at three maturity stages in the North West region of India. Plant fresh weight was the highest at 55 days after transplanting (DAT); however, maximum soil plant analysis development (SPAD) values were registered at 45 DAT. Antioxidant activity, FRAP, DPPH, phenols, flavanols, total sugars, ascorbic acid, free amino acids, and irrigation water use efficiency were observed significantly higher in plants grown on plastic mulch at different levels of irrigation and fertigation. It is envisioned that Pak choi plants had the highest nutritional value at 45 DAT from plots mulched with silver-black, irrigated at 80% Etc, and fertigated at 100% RDF. The nutrient enriched plants are used for green salad and as ingredients for the preparation of many recipes in the semi-arid and sub-tropic areas of India.

Combining ability analysis in spring wheat (Triticum aestivum L. em. Thell) involving 10 diverse parents and their 45 F₁ and F₂ progenies indicated significant differences between the parents for GCA and between the crosses for SCA for all the characters studied. The GCA and SCA components of variance were significant for all the traits. However, the GCA component of variance was predominant, indicating the predominance of additive gene effects for the traits studied. Among the parents HD 2329, Raj 1972, HD 2285 and HD 2428 were the best general combiners for grain yield and average to high combiners for other important traits. The best specific crosses for grain yield were CPAN 3004 × Durgapura 65, Sonalika × HD 2329, Raj 3077 × CPAN 3004, Raj 3077 × HD 2428 and HD 2428 × WH 157.The parent Raj 1972 was the best general combiner for grain yield and protein content, while Raj 3077 and Lok-1 were the best general combiners for protein content. The most suitable specific crosses for protein content were HD 2329 x HD 2285, HD 2428 × Raj 1972 and CPAN 3004 × WH 157. Most of the specific crosses for grain yield and protein content involved high × average, average × average or average × poor general combiners. To ensure a further increase in grain yield along with high protein, combinations of desirable yield components are advocated. The exploitation of additive and non-additive gene actions through bi-parental mating and/or diallel selective mating systems are suggested for a tangible advance in grain yield coupled with high protein in spring wheat.