Rice Var Research Articles

Foliar Fertilization on BRRI dhan28 To Reduce Soil Application of Nitrogenous Fertilizer

The experiment was conducted at the research farm of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during November 2019 to June 2020 to find out the effect of foliar fertilization on the performance of rice var. BRRI dhan28 and to estimate how much nitrogenous fertilizer can be saved by foliar fertilization without yield reduction. The experiment was laid out following split plot design with three replications. Four levels of foliar fertilization (F0 – No foliar fertilization, F1 – Foliar fertilization with 2% KNO3, F2 - Foliar fertilization with 2% DAP and F3 - Foliar fertilization with 1% American NPKS) were placed in the main plot treatments whereas three nitrogen fertilizer levels (N50 -50% of the recommended nitrogen fertilizer, N75 – 75% of the recommended nitrogen fertilizer and N100 – 100% of the recommended nitrogen fertilizer) were placed randomly in the sub-plots. Foliar fertilization with KNO3, DAP (Di-ammonium phosphate) and American NPKS significantly increased the grain yield (t ha−1) compare to control (F0) but KNO3 and American NPKS performed better than DAP. Foliar fertilization with KNO3 and American NPKS could save 25% of recommended nitrogen fertilizer but foliar fertilization with DAP could not save nitrogen fertilizer applied in soil for getting comparable grain yield found in F0N100. Foliar fertilization of KNO3 and American NPKS with recommended nitrogen fertilizer applied in soil could increase 11.8 and 12.5% grain yield, respectively compare to F0N100. Bangladesh Agron. J. 2024, 26(2): 77-85

Dissecting the molecular basis of the ultra-large grain formation in rice.

The shape of rice grains not only determines the thousand-grain weight but also correlates closely with the grain quality. Here we identified an ultra-large grain accession (ULG) with a thousand-grain weight exceeding 60 g. The integrated analysis of QTL, BSA, de novo genome assembled, transcription sequencing, and gene editing was conducted to dissect the molecular basis of the ULG formation. The ULG pyramided advantageous alleles from at least four known grain-shaping genes, OsLG3, OsMADS1, GS3, GL3.1, and one novel locus, qULG2-b, which encoded a leucine-rich repeat receptor-like kinase. The collective impacts of OsLG3, OsMADS1, GS3, and GL3.1 on grain size were confirmed in transgenic plants and near-isogenic lines. The transcriptome analysis identified 112 genes cooperatively regulated by these four genes that were prominently involved in photosynthesis and carbon metabolism. By leveraging the pleiotropy of these genes, we enhanced the grain yield, appearance, and stress tolerance of rice var. SN265. Beyond showcasing the pyramiding of multiple grain size regulation genes that can produce ULG, our study provides a theoretical framework and valuable genomic resources for improving rice variety by leveraging the pleiotropy of grain size regulated genes.

Assessment of Integrated Nutrients on Soil Health Parameters and Yield of Rice (Oryza sativa L.) var. Sarna

Assessment of Integrated Nutrients on Soil Health Parameters and Yield of Rice (Oryza sativa L.) var. Sarna

Influence of Various Nutrient Sources on Rice (Oryza sativa L.) Productivity and Quality under Organic Farming

The field investigation aimed to examine the impact of various organic nutrient sources on rice var. GNR-7 at the organic farm of ASPEE College of Horticulture, Navsari Agricultural University, Navsari, Gujarat during the kharif season of 2021. The experiment was structured using a Randomized Block Design with a factorial concept, incorporating two levels: soil application and foliar application. Total of twelve treatment i.e., S1: 100% RDN through NADEP compost, S2: 80% RDN through NADEP compost along with Azospirillium and PSB @ 2 l/ha each S3: 60% RDN through NADEP compost along with Azospirillium and PSB @ 2 l/ha each and S4: Ghan-jivamrut @ 500 kg/ha + Jivamrut @ 500 l/ha and that of foliar application were, F0: Control, F1: Novel organic liquid nutrient @ 1% and F2: moringa leaf extract @ 3%. The application of foliar spray was done thrice at 15, 30 and 45 days after sowing. were replicated thrice. The result revealed that S1 treatment significantly recorded the grain yield and S2 treatment significantly recorded the straw yield. While for foliar application, the treatment F2 significantly recorded the highest grain and straw yield but remained at par with F1 treatment. The mean data of quality parameters did not significantly change due to soil and foliar application of different organic nutrient sources. It can be determined that the soil application of 100 per cent RDN through NADEP compost and foliar application of either 3 per cent Moringa leaf extract or 1 per cent Novel organic liquid nutrient at 15, 30 and 45 DAS resulted in higher yield and also improved the quality parameters of rice under organic farm.

Effect of Seed Priming on Germination, Seedling Emergence and Development of Spring Rice Var. Hardinath-1

Poor germination percentage and non-uniform seedling emergence and establishment are major causes of low rice yield in water-deficit arid ecosystems. A seed priming study with a low concentration of MoP, DAP, urea, vitamin C, ZnSO4, sucrose, NaCl, and hydro priming was conducted to assess the seed germination, seedling emergence, establishment, and seedling growth of the spring rice variety Hardinath-1. The experiment was conducted using a completely randomized design with three replications. Two test sets of experiments were carried out using blotting paper rolls and separate sand trays. Germination was observed at intervals of 24 hours up to 7 days, and germination and growth parameters were monitored. The results showed that germination (88.67%) and seedling emergence (88.67%) were high in vitamin C at 7 days after sowing (DAS). Germination energy (81%), germination speed (91.78%), and vigor index (91.78) were higher with seed priming of MoP. The lowest germination (56.44%) was observed with the priming of urea. At 30 DAS, the longest shoot length (19.93 cm) and longest root length (11.79 cm) were observed with the priming of ZnSO4. The highest seedling fresh weight (0.75 g) and dry weight (0.16 g), the highest number of leaves (3.57), and the longest leaf length (11.97 cm) were found with the priming of MoP, NaCl, and ZnSO4, respectively. However, the lowest seedling growth parameters were observed in the control priming. The overall results revealed that seed priming with MoP is an effective tool to enhance the germination percentage and seedling establishment of rice. SAARC J. Agric., 21(2): 81-93 (2023)

Acidity and nutrient management practices for enhancing soil nutrient availability, nutrient uptake and grain yield of rice in Vaikom kari soils in Kuttanad, Kerala

A field investigation was conducted during August to December 2015 and 2016 in farmers` fields in Thalayazham panchayat in Kottayam district. The experiment was laid out in randomized block design having 16 treatments in three replications with rice (Oryza sativa L.) var. Uma. The treatments were dolomite, lime + MgSO4 or RHA (rice husk ash) + MgSO4 along with 100% package of practice (POP) alone or with 100% POP + foliar spray of 13-0-45 N-P-K (KNO3) (1%) or borax (0.5%) or 13-0-45 + borax at PI (panicle initiation) stage. Lime + MgSO4 + 75% POP + 13-0-45 + borax as well as lime without MgSO4 + 100% POP combined with 13-0-45 or borax or both were also included as treatments. Higher grain yield of 5.42 and 5.57 t ha-1 during 2015 and 2016 respectively were produced by dolomite + POP + 13-0-45 followed by dolomite + POP + 13-0-45 + borax and lime + POP + MgSO4 + 13-0-45. The treatments involving dolomite and lime with or without MgSO4 produced taller plants, higher tiller number m-2 and higher Leaf Area Index during both the years. Dolomite + POP + 13-0-45 produced the highest number of panicles m-2. Higher test weight and lower percentage of unfilled grains were observed with dolomite + POP + 13-0-45 and dolomite + POP + 13-0-45 + borax. Lime and dolomite treatments were more effective in reducing soil acidity and improving dehydrogenase activity and nutrient availability in the soil than RHA treatments during both the years. However, the effect of liming materials applied as basal and at 30 DAS diminishes after the crop and this necessitates application of liming materials in every crop season. Availability of soil N improved by treatments involving lime + POP without MgSO4 at PI and harvest stages. The treatments involving dolomite + POP and lime + POP with or without MgSO4 recorded higher available P during PI stage. In general, higher status of available K was registered by the treatments involving dolomite or lime application and lower K status registered by the treatment with 75% POP fertilizer. All treatments involving lime or dolomite registered higher soil available Ca and those involving dolomite or lime + MgSO4 showed higher availability of Mg in the soil. The treatments involving dolomite registered lower status of soil available Fe and higher status of available B. Higher status of available Zn was registered by the treatments involving dolomite or lime + MgSO4. Soil pH was significantly and positively correlated with available P, Ca and Mg and significantly and negatively correlated with available Fe in the soil. In general, higher uptake of macronutrients was observed with dolomite or lime + MgSO4 treatments along with 100% POP during both the years. Foliar spray of 13-0-45 recorded higher N and K uptake. Significant and positive correlation of grain yield with uptake of macro nutrients was also observed.

CaO Nanoparticles Seed Invigoration on Germination and Seedling Growth of Rice var. TRY 3

Rice (Oryza sativa L.), a vital cereal and staple food crop in South East Asia. It faces significant challenges in cultivation worldwide, due to soil salinity. Seed enhancement techniques like priming have shown resilience against salt stress. In this study, the potential of nano-priming with calcium oxide nanoparticles (CaO NPs) to enhance rice seed germination and growth was investigated. CaO NPs were synthesized from organic waste (eggshells) using a sol-gel technique and characterized using Raman and UV-Vis spectroscopy. Paddy seeds were primed with varying concentrations of CaO NPs, and their germination and seedling growth were assessed. The results showed that nano-priming with 40 ppm of CaO NPs significantly improved germination, root and shoot length, dry matter production, and seedling vigour as compared to the control. However, higher concentrations of CaO NPs had a detrimental effect on germination. The study suggests that CaO NP seed priming has the potential to enhance rice germination and seedling development.

Hormones and the antioxidant transduction pathway and gene expression, mediated by Serratia marcescens DB1, lessen the lethality of heavy metals (As, Ni, and Cr) in Oryza sativa L.

Microorganisms have recently gained recognition as efficient biological tool for reducing heavy metal toxicity in crops. In this experiment, we isolated a potent heavy metal (As, Ni, and Cr) resistant rhizobacterium Serratia marcescens DB1 and detected its plant growth promoting traits such as phosphate solubilization, gibberellin synthesis, organic acid production and amino acid regulation. Based on these findings, DB1 was further investigated for application in a rice var. Hwayeongbyeo subjected to 1 mM As, 4 mM Ni, and 4 mM Cr stress. The rice plants treated with Cr and Ni appeared healthy but were lethal, indicating unfitness for consumption due to toxic metal deposition, whereas the plants treated with > 1 mM As instantaneously died. Our results showed that DB1 inoculation significantly decreased metal accumulation in the rice shoots. Particularly, Cr uptake dropped by 16.55% and 22.12% in (Cr + DB1) and (Cr + As + Ni + DB1), respectively, As dropped by 48.90% and 35.82% in (As + DB1) and (Cr + As + Ni + DB1), respectively, and Ni dropped by 7.95% and 19.56% in (Ni + DB1) and (Cr + As + Ni + DB1), respectively. These findings were further validated by gene expression analysis results, which showed that DB1 inoculation significantly decreased the expression of OsPCS1 (a phytochelatin synthase gene), OsMTP1 (a metal transporting gene), and OsMTP5 (a gene for the expulsion of excess metal). Moreover, DB1 inoculation considerably enhanced the morphological growth of rice through modulation of endogenous phytohormones (abscisic acid, salicylic acid, and jasmonic acid) and uptake of essential elements such as K and P. These findings indicate that DB1 is an effective biofertilizer that can mitigate heavy metal toxicity in rice crops.

Effect of Different Organic and Inorganic Fertilizers on Spring Rice Var. (Hardinath 1) Production in Rural Gorkha, Nepal

The effect of different organic and inorganic fertilizers had a significant effect on the yield of spring rice. A field experiment was carried out to determine the effects of different organic and inorganic fertilizers on the yield of spring rice var Hardinath-1 at Siranchowk rural municipality-4, Gorkha during the spring season of 2021 with four replications and five treatments: T1[Recommended inorganic fertilizer Nitrogen, Phosphorous, and Potassium (@100:30:30 kg/ha)], T2[75% recommended inorganic fertilizer + 25% recommended organic fertilizer: i.e. (Farm Yard Manure (6 ton /ha)], T3(50% recommended inorganic fertilizer + 50% recommended organic fertilizer), T4(25% recommended inorganic fertilizer + 75% recommended organic fertilizer ), and T5 (Recommended organic fertilizer) using simple Randomized Complete Block Design with 3*3 m of individual plot size. A biometrical observation like plant height (95.33 cm), and the number of tillers (340.75/ m2) were found significantly highest on T2. Similarly, yield attributing characteristics like the number of effective tillers (315.75/m2), several filled grains per panicle (150.25), and highest panicle length (25.06 cm) were also significantly highest on T2. The highest grain yield (8.27 ton/ha), straw yield (12.14 ton/ha), and harvest index (0.40) were also observed on T2. Total net return was found highest on T2: 287330 Nepalese Rupees(NPR) incurring the cost of fertilizer Rs NPR 18940 per hectare returning the gross return of NPR 268390 per hectare. In conclusion, T2 was the best combination of other biofertilizer combinations. So, the spring rice productivity can be enhanced via the adoption of 75% recommended inorganic fertilizer + 25% recommended organic fertilizer in fertilizer management practice at Chorkate, Gorkha.

Comparative analysis of the three nutrient management decision support tools for irrigated lowland rice (Oryza sativa L.) var. NSIC Rc176H in Cantilan, Surigao del Sur, Philippines

Comparative analysis of the three nutrient management decision support tools for irrigated lowland rice (Oryza sativa L.) var. NSIC Rc176H in Cantilan, Surigao del Sur, Philippines

Effects of fungicides and antagonistic marine-derived fungi on rice seedling promotion and rice sheath blight control

Fourteen fungicides and three marine-derived fungi were tested for their activities in the promotion of rice seedling development and their efficacy in controlling rice sheath blight disease in two rice varieties, RD43 and KMDL105, under greenhouse conditions. The results showed that the rice seeds treated with carbendazim 50%SC and azoxystrobin 25%SC displayed the best promotion of rice growth in root length and shoot height at seven and 14 days in rice var. RD43. Rice seeds from var. KMDL105 treated with thiophanate-methyl 70%WP exhibited significant stimulation of rice seedling growth resulting in the greatest increase in root length and shoot height at seven and 14 days. In pot experiments with rice var. RD43, spraying with triforine 19%EC, propiconazole 25%EC, trifloxystrobin 50%WG, and validamycin 3%SL showed a high level of fungicidal activity in controlling sheath blight disease, with this evidenced by significant suppression of the disease severity by 71–75% and 61–73% at seven and 14 days after inoculation, respectively. The treatment of rice var. KMDL105 with validamycin 3%SL exhibited the best activity in controlling sheath blight disease by reducing disease severity by up to 62% and 64% at seven and 14 days, respectively. The antagonistic marine fungi tested in this study displayed low activity against sheath blight disease and low effects on rice seedling promotion compared to fungicides. Specifically, Trichoderma harzianum KUFA 0689 and T. asperellum KUFA 0677 reduced sheath blight disease severity by 42–46% and 27–37% at seven and 14 days, respectively.

Grain, Yield and Quality of Transplant Aman Rice and Soil Nutrients Status with Application of Fertilizers and Green Manures

A field experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka during 2014 on transplant aman rice var. BR11 (Mukta) under different levels of chemical fertilizers and green manures to evaluate its grain yield, grain quality and soil fertility status with incorporation of green manures. The experiment was carried out in a split- plot design with three replications. The level of fertilizers (0, 100, 75, 50% of recommended dose, RFD) was placed in main -plot and levels of green manures management (0, 5 and 10 t ha-1 each Mimosa invisa (Lajjaboti) and Sesbania spp. (Dhaincha) in sub-plot. Recommended dose of fertilizers of 83N, 21P, 37K, 11S and 1.5 Zn kg ha-1, were applied in the form of urea, triple super phosphate (TSP), muriate of potash (MoP), gypsum and zinc sulfate, respectively. Sixty-day old Mimosa invisa and Sesbania spp. were in - vitro incorporated before aman transplantation. Combined application of 75% RFD along with Mimosa invisa @ 10 t ha-1 was proved to be the best management in producing higher grain yield (7.25 t ha-1) and that was at par with treatment 50% RFD plus Mimosa invisa @ 10 t ha-1. Quality of grain was increased markedly in respect of amylose, carbohydrate, and protein as well. Furthermore, the treatment improved soil nutrient status in respect of organic matter, nitrogen, sulfur and Zn over no incorporations of green manures. So, addition of green manure like Mimosa invisa could cut fertilizer cost by 25-50%.
 Bangladesh Agron. J. 2022, 25(2): 67-72

UHPLC-Q-Orbitrap HRMS-Based Metabolomic Reveal Biological Pathways Involved in Rice (Oryza sativa L.) under Fe Toxicity Stress

The iron (Fe) toxicity stress is still a serious problem in rice cultivation, especially on land with high Fe content. The Fe toxicity stress affects various complex physiological aspects of plants. The metabolomic analysis using LC-MS is expected to provide information about rice's metabolism regulation under Fe toxicity stress. The objective of this study was to show the biological pathway signature in rice after exposure to Fe toxicity stress using UHPLC-Q-Orbitrap HRMS-based metabolomic analysis. The two rice varieties, i.e., IR64 (Fe-sensitive) and Pokkali (Fe-tolerant) were analyzed their metabolites using UHPLC-Q-Orbitrap HRMS. The metabolite profiles of both varieties were analyzed using MetaboAnalyst 5.0 software. The results showed that Fe toxicity stress affected the metabolite profile in both root and shoot tissues of two rice varieties. A number of 102 metabolites were detected in root and shoot tissues of rice. The comprehensive univariate and multivariate analyses showed that 1-aminocyclopropane-1-carboxylate (ACC) in shoot tissues and galactose in root tissues was suggested as metabolite markers for Fe tolerance character of rice var. Pokkali. The genes encoded the enzymes involved in biosynthetic pathway of both metabolite markers could be a target to be explored for Fe toxicity tolerance in rice.

Effects of tree leaf biomass on the yield and its yield contributing characters of hybrid rice

A field experiment was conducted in the Agroforestry Field Laboratory of Bangladesh Agricultural University, Mymensingh during the period from November 2016 to April 2017 to find out the effects of Sadakoroi (Albizia procera), Kalokoroi (Albizia lebbeck) and Akashmoni (Acacia auriculiformis), leaves biomass with different fertilizers dose applications on the yield and yield contributing characters of Chinese Hybrid Rice. There were 10 treatments : T1 = Sadakoroi (leaf biomass 2 kg /plot ) + 15% RFD (Recommended fertilizer dose), T2= Sadakoroi (leaf biomass 2 kg /plot )+ 30% RFD, T3 = Sadakoroi (leaf biomass 2 kg /plot )+ 45% RFD, T4 = Kalokoroi (leaf biomass 2 kg /plot) + 15% RFD, T5 = Kalokoroi (leaf biomass 2 kg /plot) + 30% RFD, T6 = Kalokoroi (leaf biomass 2 kg /plot) + 45% RFD, T7 = Akashmoni (leaf biomass 2 kg /plot) + 15% RFD, T8 = Akashmoni (leaf biomass 2 kg /plot) + 30% RFD, T9 = Akashmoni (leaf biomass 2 kg /plot) + 45% RFD and T10= Control ( 100% RFD). The boro hybrid rice var. SQR6 was used as a test crop. The experiment was conducted in a Randomized Complete Block Design (RCBD) with three replications. The result showed that green leaf biomass had a significant effect on the yield contributing characters. The panicle length varied from 21.0 to 25.5 cm. The number of leaves on hill-1 varied from 40.2-25.9. The number of effective tillers on hill-1 varied from 12.27-10.63. The highest grain yield of 8.87 t ha-1was obtained from treatment T10 followed by 8.77 tha-1 noted with T3 where Sadakoroi leaf biomass was applied. Therefore, this study suggests that the green leaf biomass of Sadakoroi and Kalokoroi can be applied to the improvement of yield and yield contributing characters of rice. Bangladesh J. Agri. 2022, 47(2): 44-52

Performance Assessment of Submergence tolerance Rice variety in Flood prone areas of Dibrugarh, Assam, India

A three years field demonstration was conducted under Krishi Vigyan Kendra, Dibrugarh during 2020, 2021 and 2022 in flood prone situation to increase the present low yield of traditional rice variety through adoption of submergence tolerant high yielding rice variety with improved package of practices. The results revealed that rice var. Ranjit Sub 1 yielded maximum average 50.24 qt ha-1 after submergence period of 7 days followed by Jalashree (38.50 qt ha-1), Jalkuwari (38.70 qt ha-1) where as 29.62 qt ha-1 received from traditional rice variety after same submergence period. The variation was also obtained in net income received from Ranjit sub -1 Rs. 21,398/- ha-1 was more as compared to Jalkuwari (Rs.11,060/- ha-1), Jalashree (Rs. 10,850/- ha-1)and traditional rice variety that provides Rs.1,620 ha-1 only. Rice variety Ranjit Sub -1 showed 5.46 qt ha-1, 20.92 qt ha-1 and 9.76% Technology gap, Extension gap and Technology index respectively where as rice variety Jalashree and Jalkuwari showed 6.50 qt ha-1 and 6.30 qt ha-1 and 8.88 qt ha-1 and 9.08qtha-1 and 14.44 % and 14.00% Technology gap, Extension gap and Technology index respectively. From the experiment all the submergence tolerant high yielding rice variety performed better as compared to traditional rice variety and can be the alternative for the rice growers in flood prone areas of the district to decrease their production loss due to flood situation.

Effect of in situ soil moisture conservation practices on maize and its crop residue incorporation on yield and economics of succeeding transplanted rice Var. ADT 46

Crop residue incorporation is a key component of sustainable cropping systems. It reduces the adverse effects of residue burning and enhances soil fertility. Effective usage of crop residue in the field and proper management are required. With this background, a field experiment was conducted during 2020 – 21 in the maize-rice cropping sequence at Annamalai University Experimental Farm, Department of Agronomy, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Tamil Nadu to find out the residual effect of different mulching practices adopted in preceding maize crop and maize stubble incorporation on the growth, yield and economics of transplanted rice Var. ADT 46. The field experiment was conducted in Factorial Randomized Block Design with three replications. In factor I, soil moisture conservation in preceding maize crop viz., mulching of sugarcane trash, water hyacinth, hydrogel and control were allotted. In factor II, different levels of maize crop stubble incorporation on rice viz., 0, 33, 66 and 100% were provided. Water hyacinth mulched plot (M3) to the preceding crop registered significantly (þ <0.05) higher yield parameters, yield and economic returns of succeeding rice. The lower values were observed in unmulched (M1) plot. With respect to maize crop stubble incorporation on rice crop, the incorporation of 66% (SI3) of maize stubble registered higher yield parameters, yield and economic returns. In the interaction effects, mulching with water hyacinth to preceding maize + maize crop stubble incorporation at 66% in rice crop (M3SI3) recorded significantly (þ <0.05) higher yield parameters, yield and economic returns than other treatments. The lowest values were recorded with an unmulched + 100% crop residue incorporated (M1SI4) plot. Mulching the preceding maize crop with water hyacinth at a rate of 12 t ha-1 and incorporating 66% maize stubble into the transplanted rice (M3SI3) had a remarkable yield advantage and financial rewards.

Enhancement of yield through marker-assisted pyramiding of yield contributing genes in rice (Oryza sativa L.) var. BPT5204

Enhancement of yield through marker-assisted pyramiding of yield contributing genes in rice (Oryza sativa L.) var. BPT5204

Weed seed bank and weed population as influenced by weed management practices in rice var Co 54

Weed seed bank in soil serves as the reservoir of weed seeds which emerge whenever conditions become conducive and affects crop growth. In the present study, a field experiment was performed at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, India, during Kharif 2021 and Rabi 2022 to determine weed seed bank present in soil by direct seed extraction using the sieving method at discrete depths of 0-5 cm, 5-10 cm and 10-15 cm after rice harvest with reference to different weed management practices imposed and its effect on weed population in succeeding crop. The average proportion of weeds that emerged in the field ranged from 9 to 38 % of the total weed seed bank. Weed management practices followed during the preceding crop greatly influenced weed seed germination. The higher weed seed reserve (1384 m-2) and consequent weed population (528 no’s m-2) were found at a depth of 0-5 cm in unweeded plots. The lower weed seed density (536 m-2) and weed population (94 no’s m-2) were found in pre emergence application of Pyrazosulfuron + Pretilachlor and early post emergence application of Bispyripac sodium. The results from the present study confirmed that herbicide treatment considerably minimized the weed seed density and population, which will assist in predicting weed infestation and appropriate timing of weed control.

Assessment of rice (Co 51) seed ageing through volatile organic compound analysis using Headspace-Solid Phase Micro Extraction/ Gas Chromatography-Mass Spectrometry (HS-SPME/GCMS)

Seed ageing is an inevitable process that reduces seed quality during storage. When seeds deteriorate as a result of the lipid peroxidation process, it leads to produce toxic volatile organic compounds. These volatiles served as an indicator for the viability of stored seeds. With this background, the study was conducted to profile the volatile organic compounds emitted from rice seeds during storage. Volatile profiling of stored rice var. Co 51 seeds was done through Headspace-Solid phase microextraction/ Gas chromatography-mass spectrometry (HS-SPME/GCMS). The study clearly demonstrated that the significant decrease in physiological and biochemical quality attributes was noted due to an increase in the strength of volatiles released during ageing. When the release of total volatile strength reached more than 40%, a significant reduction in physiological attributes such as germination, root and shoot length, dry matter production and vigour index were observed. With respect to biochemical properties, a significant increase in electrical conductivity of seed leachate, lipid peroxidation and lipoxygenase activity, and decrease in dehydrogenase, catalase and peroxidase activities were observed. However, the highest reduction in all these properties were recorded when the total volatile strength reached to 54.90%. Finally, the study concluded that, among all the volatiles, 1-hexanol, 1-butanol, ethanol, hexanal, acetic acid, hexanoic acid and methyl ester were the most closely associated volatiles with seed deterioration. It indicates that these components could be considered the signature components for assessing the seed quality in rice during storage.

Effect of Fermentation on Bacteriological and Physicochemical Properties of ‘Ofada” Rice

Rice (Oryza sativa) is an important annual crop in Nigeria. It is one of the major staples, which can provide a nation’s population with the required food security of 2,400 calories per person per day. In Nigeria rice is one of the few food items whose consumption has no cultural, religious, ethnic or geographical boundary. Fermented rice is used to produce rice wine, spaghetti and noodles. Work was then carried out on the Nigerian rice var. ITA 150 (ofada) to determine the bacteriological and physicochemical activities during fermentation. Standard microbiological and chemical methods were used. Six microorganisms were isolated which include; Bacillus cereus, Micrococcus luteus Lactobacillus plantarum, Staphylococcus aureus, Leuconcostoc mesenteroides, and Bacillus licheniformis. It was observed that the microbial loads increased till the 72nd hours of fermentation except Staphylococcus aureus and Micrococcus luteus that their loads decreased after the 72nd hours. There was an increase in the moisture, fibre, fat and protein contents, while carbohydrate, ash and anti-nutrients contents decreased. It was evident that fermentation process contributes to the bacteriological and physicochemical properties of the fermented rice in the production of another consumable product like rice wine, kunnu –zaki, spaghetti and the noodles.