Seed Priming Influence on Early Crop Growth,Phenological Development and Yield Performance of Linola (Linum usitatissimum L.)

Reduced early crop growth and limited branching are amongst yield limiting factors of linola. Field response of seed priming treatments viz. 50 mmol L⁻¹ salicylic acid (SA), 2.2% CaCl₂ and 3.3% moringa leaf extract (MLE) including untreated dry and hydropriming controls was evaluated on early crop growth and yield performance of linola. Osmopriming with CaCl₂ reduced emergence time and produced the highest seedling fresh and dry weights including Chl. a contents. Osmopriming with CaCl₂ reduced crop branching and flowering and maturity times and had the maximum plant height, number of branches, tillers, pods and seeds per pod followed by MLE. Increase in seed weight, biological and seed yields was 9.30, 34.16 and 39.49%, harvest index (4.12%) and oil contents (13.39%) for CaCl₂ osmopriming. Positive relationship between emergence and seedling vigor traits, 100-seed weight, seed yield with maturity time, 100-seed weight and seed yield were found. The study concludes that seed osmopriming with CaCl₂ or MLE can play significant role to improve early crop growth and seed yields of linola.     

Feeding value of urea molasses-treated wheat straw ensiled with fresh cattle manure for growing crossbred cattle calves

The study was carried out to evaluate the influence of urea plus molasses-treated wheat straw (WS) ensiled with cattle manure (CM) on nutrients intake, their digestibilities, and growth performance of crossbred (Sahiwal × Holstein Friesian) cattle calves. The CM was mixed with ground WS in a ratio of 30:70 on dry matter (DM) basis. The WS–CM mixture treated with urea (4% DM) and molasses (4% DM) was allowed to ferment for 40 days in a cemented pit. Four iso-nitrogenous and iso-energetic fermented wheat straw (FWS)-based experimental diets were formulated. The FWS0, FWS20, FWS30, and FWS40 diets contained 0%, 20%, 30%, and 40% FWS, respectively. Twenty calves (9–10 months of age) were randomly allocated to four dietary treatments in a randomized complete block design, five in each group. Increasing trends for DM, organic matter, crude protein, and neutral detergent fiber intakes by calves were observed with increasing dietary FWS level. Weight gain was significantly different among calves fed different levels of FWS. The highest weight gain (491.8 g/day) was observed in calves fed FWS40 diet, while calves fed FWS0 and FWS20 diets gained 350.0 and 449.6 g/day, respectively. The results from this study imply that the FWS can be added up to 30% in the diet of growing crossbred calves without any detrimental effect on their performance.     

Seed priming improves growth of nursery seedlings and yield of transplanted rice

Abstract

An attempt to improve the performance of rice (Oryza sativa L.) nursery seedlings through seed priming and its effect on the yield after transplantation was made in a field trial. Priming tools employed during the investigation include pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl₂ (ψs-1.25 MPa) for 24 h, vitamin priming with 10 ppm ascorbic acid for 48 h and seed hardening for 24 h. All the priming techniques resulted in improved germination speed and spread, seedling fresh and dry weight, root and shoot length, number of secondary roots, seedling nitrogen, total sugars and α-amylase activity. Osmohardening with CaCl₂ resulted in the best performance as indicated by improved germination speed and spread, seedling vigour and starch metabolism, followed by hardening and osmohardening with KCl. However, improved starch metabolism in coarse rice was observed in osmohardening with KCl. Higher K and Ca contents were observed in seeds osmohardened with KCl and CaCl₂, respectively. Maximum straw and kernel yield and harvest index were recorded from osmohardening with CaCl₂ in fine and osmohardening with KCl in coarse rice. Increased number of secondary roots and α-amylase activity were accompanied with increased seedling nitrogen and reducing sugars, respectively.     

Assessing the impact of site-specific spraying on control of <Emphasis Type="Italic">Eurygaster integriceps</Emphasis> (Hemiptera: Scutelleridae) damage and natural enemies

Sunn pest, Eurygaster integriceps Puton is a key pest of wheat and barley in Iran. In this study, the impact of site-specific spraying on control of sunn pest damage and densities of the natural enemies was compared with the whole-field spraying method in 2009 and 2010. Three plots were assigned to each spraying method and two others were left untreated as control. The plots were divided into 11 × 11 m grids. Adults of E. integriceps were sampled using the distance-walk method. Coccinellids, Chrysoperla carnea and nymphs of sunn pest were sampled using a sweep net. Spatial analysis of datasets was done using Geostatistical Analyst extension of ArcGIS 9.3. The spatial analysis indicated that the adults and nymphs of E. integriceps had aggregated distribution in space and that site-specific spraying was applicable. Whole-field spraying was carried out when the mean density of E. integriceps in plots exceeded the economic threshold. In the site-specific spraying method, decamethrin ([cyano-[3-(phenoxy) phenyl] methyl] 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropane-1-carboxylate) was applied to the grid cells with densities above the economic threshold. Site-specific application reduced the insecticide input by ca. 40–50%. The numbers of C. carnea and coccinellids were higher in site-specifically sprayed plots compared with whole-sprayed plots after treatment. The mean numbers of nymphs were not significantly different (P < 0.01) in whole-field and site-specifically sprayed plots. Percent damaged grain was below the economic damage threshold in all treated plots. It can be concluded that site-specific spraying has the potential to control E. integriceps at an acceptable level along with reducing the amount of insecticide used. It also conserved natural enemies in untreated refuges.     

Salinity effects on nitrogen metabolism in plants – focusing on the activities of nitrogen metabolizing enzymes: A review

Nitrogen (N) metabolism is of great economic importance because it provides proteins and nucleic acids which in turn control many cellular activities in plants. Salinity affects different steps of N metabolism including N uptake, NO₃^? reduction, and NH₄⁺ assimilation, leading to a severe decline in crop yield. Major mechanisms of salinity effects on N metabolism are salinity-induced reductions in water availability and absorption, disruption of root membrane integrity, an inhibition of NO₃^? uptake by Cl^?, low NO₃^? loading into root xylem, alteration in the activities of N assimilating enzymes, decrease in transpiration, and reduction in relative growth rate which results in a lower N demand. However, the effects of salinity on N metabolism are multifaceted and may vary depending on many plant and soil factors. The present review deals with salinity effects on N metabolism in plants, emphasizing on the activities of N metabolizing enzymes in a saline environment.     

Improving nodulation,growth and yield of Cicer arietinum L. through bacterial ACC-deaminase induced changes in root architecture

Bacteria containing ACC-deaminase in the vicinity of roots may influence plant growth by modifying root architecture through their potential to regulate ethylene synthesis in plant roots. Approximately 138 isolates capable of utilizing ACC as the sole source of N were isolated from the rhizosphere soil of chickpea (Cicer arietinum L.) plants. Under axenic conditions, some rhizobacterial isolates were highly effective in increasing root length (up to 2.08 fold), number (up to 3.7 fold) and length (up to 3.9 fold) of lateral roots, and root biomass (up to 83%) of chickpea as compared to uninoculated control. Serratia proteamaculans strain J119 was found to be the most effective plant growth promoting rhizobacterium (PGPR) in improving root and shoot growth, nodulation and grain yield of chickpea as compared to respective controls in growth pouches, pot and field trials. A highly significant direct correlation (r = 0.99) was observed between number of lateral roots under axenic conditions (jar trial) and number of nodules per plant in pot and field trials. Interestingly, S. proteamaculans J119 also exhibited highest ACC-deaminase activity in addition to root colonization compared to other tested strains. The results of this study demonstrated that changes in root growth and architecture (particularly lateral roots) as a result of inoculation with PGPR containing ACC-deaminase are crucial for improving growth, yield and nodulation of chickpea under field conditions.     

Growth-related changes in wheat (Triticum aestivum L.) genotypes grown under salinity stress

The sensitivity of crop genotypes determines the level of growth reduction by salinity. Effect of salinity levels (7.5 and 15 dihydrate m^?1) using completely randomized design (CRD) with four replications per treatment were compared on germination, chlorophyll content, water potential, ionic sodium and potassium (Na⁺, K⁺) balance, and other growth-related parameters of six wheat genotypes for varietal differences under long-term salinity stress. Chlorophyll contents at flowering stage and yield aspects at maturity of all the wheat genotypes decreased with increasing salinity. The maximum Na⁺ concentration was observed at 7.5 and 15 dS m^?1 in Bhakhar and Saher-2000, respectively, while minimum Na⁺ concentration was observed for 9476. However, the maximum K⁺ concentration and water potential was noticed in 9476 at 7.5 dS m^?1. Careful selection of salt-tolerant genotypes for field crops is an important perspective especially in the developing countries facing salinity problem. Our results revealed that the wheat genotype 9476 performed best regarding growth and physiological parameters compared to other wheat genotypes.     

Sodium exclusion is a reliable trait for the improvement of salinity tolerance in bread wheat

Identification of novel wheat (Triticum aestivum L.) germplasm is imperative to develop salt tolerant varieties. In the first phase, 400 accessions were screened against high salt stress (200 mM NaCl) on the basis of Na⁺ accumulation in leaf blade, and 40 genotypes with contrast reaction to salinity were selected. Salt tolerant group (25 genotypes) had higher leaf K⁺/Na⁺ ratio, maximum root and shoot lengths, leaf fresh/dry weights and chlorophyll content as compared to the salt sensitive group (15 genotypes). In second phase, physiologically based screening was performed on selected genotypes against varying salinity levels (0, 100 and 200 mM NaCl). GGE biplot analysis indicates that genotypes TURACO, V-03094, V0005, V-04178, Kharchia 65 and V-05121 were the most salt-tolerant and declared winners as depicted by more gaseous exchange relations and growth potential which was strongly correlated with proper Na⁺, K⁺ discrimination in leaf and root tissues. Genotypes PBW343*2, NING MAI 50, PGO, PFAU, V-04181, PUNJAB 85, KIRITATI, TAM200/TUI and TAM200 were poor performer due to more Na⁺ accumulation in leaf ultimately retarded growth. In conclusion, low Na⁺ accumulation in leaf can be used as the best screening criteria, employing a large set of genotypes in a breeding program.     

Co-inoculation integrated with P-enriched compost improved nodulation and growth of Chickpea (Cicer arietinum L.) under irrigated and rainfed farming systems

The present study was designed with the objective of improving the nodulation and growth of chickpea (Cicer arietinum L.) by integrating co-inoculation of Rhizobium sp. (Mesorhizobium ciceri) and plant growth promoting rhizobacteria (PGPR) carrying ACC (1-aminocyclopropane-1-carboxylate) deaminase activity with P-enriched compost (PEC) under irrigated and rainfed farming systems. PEC was prepared from fruit and vegetable waste and enriched with single super phosphate. The results demonstrated that co-inoculation significantly (P?<?0.05) increased the number of nodules per plant, nodule dry weight, pods per plant, grain yield, protein content, and total chlorophyll content under irrigated and rainfed conditions compared to inoculation with rhizobium alone. Integrating PEC with co-inoculation showed an additive effect on the nodulation and growth of chickpea under both farming systems. Analysis of leaves showed a significantly (P?<?0.05) higher photosynthetic rate and transpiration rate in comparison with inoculation with Rhizobium. Compared to irrigated farming system, co-inoculation with PEC under rainfed conditions was more beneficial in improving growth and nodulation of chickpea. Post-harvest soil analysis revealed that the integrated use of bioresources and compost enhanced microbial biomass C, available N content, dehydrogenase, and phosphomonoesterase activities.