Panicle Weight Research Articles

Responses of Hybrid Rice (Oryza sativa L.) Plants to Different Application Modes of Nanosized Selenium

The application of selenium (Se) fertilizer not only promotes crop growth but also meets the human demand for Se by increasing the Se content in food. However, the application of nanosized selenium (nano-Se) in hybrid rice (Oryza sativa L.) production has not been reported. Therefore, the present study conducted a field experiment to investigate hybrid rice’s performance under the different application modes of nano-Se. The nano-Se solution was foliar-applied: once at the end of the tillering (S1), heading (S2), and grain-filling (S3) stages or twice at the end of the tillering stage and the heading stage (S4), and at the end of the tillering stage and the grain-filling stage (S5). The treatment without Se application was taken as the control (CK). The results showed that compared with CK, the S1, S2, S3, S4, and S5 treatments increased the grain yield by 27.83–40.60%, 16.06–25.95%, 14.78–40.86%, 20.94–43.79%, and 22.41–43.52%, respectively. The highest or equally highest grain yield was recorded in the S1 treatment. Yield-related traits including the effective panicle number, grain number per panicle, seed-setting rate, and 1000-grain weight significantly increased under nano-Se treatments. Compared with CK, nano-Se treatment increased the SPAD value (chlorophyll content), net photosynthetic rate, and dry matter accumulation by 3.82–32.83%, 2.85–59.55%, and 8.09–55.29%, respectively. An 11.51–572.85% higher grain Se content was recorded in nano-Se treatments than CK. Moreover, nano-Se application significantly enhanced the activity of superoxide dismutase and catalase. In conclusion, the foliar application of nano-Se enhanced the growth and yield formation of hybrid rice plants, and the S1 treatment was considered as the best application due to having the highest yield.

Phenotypic characterization of Echinochloa species in California rice

AbstractTwo independent greenhouse experiments were conducted in December 2020 and July 2021 in Davis, CA to characterize Echinochloa crus‐galli (L.) P. Beauv., Echinochloa colona (L.) Link, Echinochloa oryzicola (Vasinger) Vasinger and Echinochloa walteri (Pursh) A. Heller found in California rice systems based on their morphological traits. Phenotypic data was collected on 10 vegetative traits including plant height, number of tillers, flag leaf length, flag leaf width, flag leaf angle, the colour of leaf sheath, leaf blade colour, internode colour, node colour, growth habit and nine reproductive traits including number of days to heading, number of panicles, length of panicle, length of panicle branches, seeds per panicle, panicle weight, seed colour, awn length and awn pattern. High plasticity was observed in all species characterized in both experiments for both vegetative and reproductive traits, indicating potential inter‐specific hybridization. Awn length, days to heading, length of the panicle, length of the panicle branches, plant height, flag leaf angle, and growth habit were significantly higher in the fall experiment for all species indicating photoperiod could play a role in the expression of these traits. Also, high variation was observed for plant height, number of tillers, awn length, panicle weight, seeds/panicle, length of panicle branch, and number of panicles for all species in both experiments. The results from this study indicate morphological diversity currently present in Echinochloa species could contribute to their adaptation to selection pressure imposed by different management tools in California, emphasizing the need for a diversified management approach to effectively control this weed species.

Production of Sorghum Seed and Straw Biomass for Feed as Affected by Different Harvesting Ages

This study evaluated the sorghum “Samurai Two” production for feed harvested at different times after planting during the rainy season. A randomized block design was employed with five groups and five treatments representing different harvesting ages: 90, 95, 100, 105, and 110 days after planting. The variables measured included panicle length, weight, dry weight, seed dry weight per panicle, 1000-seed weight, number of seeds, dry seed production, total fresh and dry weight of panicles, moisture content, and total fresh and dry weight of straw biomass. Harvesting between 90 and 100 DAP resulted in a higher fresh and dry panicle weight, fresh and dry biomass, seed dry weight per panicle, 1000-seed weight, and dry seed production. The optimal seed production for “Samurai Two” occurred at 90 DAP during the rainy season. Conversely, harvesting at 95 DAP significantly increased straw biomass's total fresh and dry weight, with this age being optimal for straw biomass production.

Variability of Agronomic Traits of Wheat (Triticum aestivum L.) Lines in Two Agroecosystems in Indonesia

Wheat is an important agricultural commodity in Indonesia, yet the country remains heavily reliant on imports to meet domestic demand. The diverse agroclimatic conditions in the highlands and lowlands pose significant challenges for national wheat production. This study aimed to evaluate the performance of wheat lines in two distinct altitude environments: Cipanas (1120 m above sea level) and Cisarua (600 m above sea level). An augmented randomized complete block design (RCBD) assessed 50 F6 wheat lines derived from the HP1744/”Selayar” cross. The results revealed significant variability in agronomic traits attributable to altitude differences. However, genotype-by-environment (GxE) interactions were found to be non-significant for all evaluated characters. Broad-sense heritability was classified as medium for the grain-filling period in Cipanas and seed weight of the main panicle in Cisarua, while all other traits exhibited low heritability. Based on the stress sensitivity index (SSI), 14 lines (28%) were identified as tolerant to higher temperatures in the medium-altitude environment, particularly in terms of seed weight of the main panicle. These findings are of utmost importance as they underscore the need to consider genetic and environmental factors in developing wheat cultivars suitable for Indonesia’s diverse agro-climatic conditions.

Impact of supplemental irrigation and organic manure on growth and yield performance of rice variety BRRI dhan103 under terminal drought condition in Aman season

BRRI dhan103 is a transplanting Aman (T. Aman) rice variety that demands sufficient organic manure and supplemental irrigation to ensure successful production. Seven treatments, viz., T1= rainfed control; T2= one supplemental irrigation at 80 days after transplanting (DAT); T3= two supplemental irrigations at 70 and 80 DAT; T4= additional 5 t ha-1 poultry compost under rainfed condition; T5= additional 10 t ha-1 poultry compost under rainfed condition; T6= additional 2.5 t ha-1 biochar under rainfed condition; and T7= additional 5 t ha-1 biochar under rainfed condition, were evaluated against BRRI dhan103 to assess the impact of supplemental irrigation and manuring under terminal drought conditions. It was revealed that supplemental irrigation and manuring significantly improved all growth parameters and yield attributes compared to the rainfed control. Notably, T5 treatment provided its greatest performance statistically in respect of SPAD value (36.13), root dry weight (12.43 g), number of tillers hill-1 (13.22), panicle length (28.87 cm), panicles hill-1 at harvest (9.13), total spikelet (194.53), spikelet panicle-1 (197.63), filled spikelet panicle-1 (197.63), thousand grain weight (33.78 g), grain weight panicle-1 (28.70 g), grain yield hill-1 (31.97 g), and above-ground biological yield (3043.35 g m-2). The highest tiller hill-1 at harvest (9.53) was achieved when an additional 10 t ha-1 of poultry compost was applied under rainfed conditions. This study suggested that additional 10 t ha-1 poultry compost under rainfed conditions performed best to enhance the growth and yield of BRRI dhan103.

Optimization of sowing dates for enhanced rice yield: insights from field experiments in the middle and lower reaches of the Yangtze River, China

An efficacious strategy to adapt to climate change involves optimizing the planting season, a technique that has been extensively utilized to enhance the use of solar radiation and temperature resources in rice cultivation. Field experiments were executed in the middle and lower reaches of the Yangtze River, China, employing three distinct rice cultivars and seven disparate sowing periods spanning 2019 to 2021. The objective of assessing the impact of sowing date on apparent radiation use efficiency (RUEA), accumulated temperature use efficiencies (TUE), and overall rice yield. Subsequent to the delay of sowing dates, the duration of the comprehensive growth period initially exhibited a declining trajectory before subsequently escalating, with the reduction predominantly ascribed to a decrease in the number of days preceding heading. Furthermore, there was a tendency for both the mean daily and effective cumulative solar radiation to decline over the course of the growing period. The yield of the three rice varieties demonstrated an initial surge, which was then followed by a subsequent decline in reaction to the delay of sowing dates. A correlation analysis disclosed that solar radiation and effective cumulative temperature (EAT) were the predominant elements impacting grain yield. The outcomes of the path analysis indicate that EAT exerts the most substantial influence on yield, succeeded by cumulative total solar radiation (TSR), while photothermal quotient (PTQ) demonstrates the least impact on yield. There was a significant positive correlation between EAT and cumulative TSR with spikelets per panicle (0.237** and 0.218**), grain filling (0.753** and 0.576**), and grain weight (0.339** and 0.359**), respectively. The findings of this study indicate that an increase in yield is facilitated when the EAT after heading exceeds 594.9 ℃, the EAT surpasses 2016.7 ℃, the cumulative TSR before heading is above 1548.7 MJ m− 2, the cumulative TSR after heading is over 603.0 MJ m− 2, and the cumulative total radiation throughout the entire growth period is more than 2151.8 MJ m− 2. Furthermore, the most optimal sowing date, as identified by this study, is June 6. This study provides key insights into boosting rice productivity in the middle and lower reaches of the Yangtze River, China by analyzing the impact of temperature and solar radiation on yield and identifying optimal growth conditions.Clinical trial number Not applicable.

Agronomic Evaluation and Yield Potentials of Grafting of Piper nigrum and Piper colobrinum

Foot rot disease (Phytophthora capsica) is Indonesia's primary challenge in cultivating pepper (Piper nigrum). Grafting to another Piper species, Piper coclobrinum, or melada (the local name), is a potential solution to increase resistance to this disease. The use of melada as rootstock has shown promising results during the seedling phase, but it has not been thoroughly evaluated during the production phase. The study was conducted in the pepper grower’s location in Puput and Simpang Katis Villages, Central Bangka, Bangka Belitung Islands Province. The study used kapok (Ceiba petandra) as the standard; plant morphology, leaf area, leaf thickness, and crown diameter for grafted melada and non-grafted pepper were recorded. Harvest variables included panicle length, panicle weight, the number of fruits per panicle, and fruit diameter, measured in three different areas of the canopy: the lower area (0-1 meter above the ground surface), the middle area (1-2 meters above the ground surface), and the top area (more than 2 meters above the ground surface). Physiological variables measured included rates of photosynthesis, stomatal conductance, transpiration rate, intercellular CO2, and CO2 conductance. The study demonstrated that the grafted pepper plants had a larger leaf area than the non-grafted pepper plants; the panicle weight and the number of fruits per panicle were higher. Panicles located in the middle zone of the plant canopy tended to be longer for grafted and non-grafted peppers. Panicle weight, fruit size, and the number of fruits per panicle were generally more significant at the top of the plant canopy. In all parts of the canopy, grafted peppers exhibited larger fruit size, greater panicle weight, and a higher number of fruits per panicle than non-grafted “Nyelungkup” peppers, highlighting the potential of melada as a rootstock for pepper plants.

Effect of Nano Urea and Nano DAP on Growth, Yield and Nutrient Uptake of Transplanted Rice (Oryza sativa L.)

Foliar nutrition is aimed to eliminate the problems of fixation and immobilization of nutrients. Hence, foliar nutrition is being recognized as a significant way of fertilizing modern agriculture, especially under rainfed conditions. Nano fertilizers because of smaller size and higher surface area are efficient as compared to conventional and produce better results when used in combined form. The experiment was laid out in Randomized complete block design with three replications. A field experiment was conducted in black clayey at Agricultural Research Station, Dhadesugur, during Kharif 2023. There were eight treatment combinations, consisting of different levels of conventional and nano fertilizers. RDF - 150:75:75 kg N:P2O5:K2O ha-1 and 50 % of N, entire P and K were applied as basal and remaining 50 % of N was top dressed at tillering and panicle initiation stage. RNR- 15048 variety of transplanted rice. Application of 50 % Rec. N with soil application + 50 % Rec. N through nano urea with two applications (at tillering and panicle initiation stage) + Rec. P & K with soil application recorded significantly higher number of green leaves, leaf area and leaf area index at harvest (52.7, 954.8 cm2 plant-1 and 4.77, respectively). It also produced higher panicle length (20.1 cm), number of grains panicle-1 (242.3), panicle weight (3.73 g plant-1), test weight (19.1 g) and grain yield (5578 kg ha-1). Nutrient content and uptake also showed higher values for the same treatment. Combined application of conventional and nano fertilizers helped to increase growth, growth attributes like number of leaves, leaf area, leaf area index, yield attributes, yield, nutrient content and nutrient uptake of transplanted rice.

Study about Correlation and Path Analysis in Grain Amaranth (Amaranthus hypochondriacus L.)

Twenty six genotypes of grain amaranth were evaluated during rabi 2017-18 for assessing the correlation and path coefficient analysis for grain yield and its components. The grain yield per plant was found to be positively and significantly associated with plant height, panicle length, dry weight of leaves, dry weight of panicles, biological yield/plant and harvest index. Dry weight of panicles had highest path towards grain yield per plant, dry weight of leaves directly associated with days to maturity and plant height. This indicates that these characters played an important role in higher grain yield in grain amaranth.

The effect of the Fitostemin-WP® biostimulator on yield and quality characteristics of rice (Oryza sativa L.)

In order to avoid yield and quality reduction of rice, it is essential to provide nutrition rice plants require. Therefore, a field experiment was conducted at the research area of the Institute of Agriculture - Skopje, Department of Field Crops, Ss. Cyril and Methodius University in Skopje, Republic of Macedonia, in Kochani, a rice production region. The experiment was set up to determine the effects of the Fitostemin-WP® biostimulator on some yield and quality properties of an Italian rice variety Opale during the vegetative seasons in 2020 and 2021. Standard agrotechnical methods for crop production were applied. Fitostemin-WP® is an herbal product in the form of powder and it consists of herbal extracts and minerals. It is used for increasing crop yield. The field experiment was arranged in a Zade method with a Fitostemin-WP® treatment and a control one in 3 replications. Only basic fertilizers (350kg/ha NPK and 200kg/ha Urea (46% N)) were applied on the control plot, while the treatment plot, besides basic fertilization, was also treated with Fitostemin-WP® with 100 g/ha dosage once during the vegetation period (tillering stage). The following parameters were examined in this study, namely the biological, grain and straw yield, the number of productive tillers/m2, panicle weight, and milling fractions. Results were analyzed with the ANOVA and LSD test. According to the results from this study, statistically significant differences were not found in these two years of field experiments for the examined parameters. However, the values for the brokens have shown some significant differences between the years, but not between the treatment and the control. This can result from the environmental impact during the vegetative period. More frequent usage of Fitostemin-WP® during the vegetation period of the rice plant may show more significant results.

Optimizing rice (Oryza sativa) growth, productivity, profitability and nutrient uptake with coated urea and organic manure in the new alluvial zone of West Bengal

A two-year field experiment was carried out at experimental farm of BCKV, Nadia, West Bengal during kharif seasons of 2019–20 and 2020–21 to study the effect of combined application of coated urea and organic manure on performance of rice. The experiment was laid-out in a randomized complete block design with four replications and treatment comprised 5 treatment combinations, such as T1 , control plot (without N); T2 , 100% recommended dose of nitrogen (RDN) through neem-coated urea (NCU); T3 , 75% RDN through NCU + 25% RDN through FYM (farm yard manure); T4, 100% RDN through polymer sulphur coated urea (PSCU); T5, 75% RDN through PSCU+25% RDN through FYM. The results showed that 75% RDN through PSCU+25% RDN through FYM re- sulted in maximum growth attributes, viz. plant height (110.8 cm), maximum number of effective tillers per square meter (416/m2 ), highest dry-matter accumulation (DMA) (740 g/m2 ), leaf area index (LAI) (4.47) and crop growth rate (CGR) (6.56 g/m2 /day), highest yield components like panicle length (23.5 cm), panicle weight (9.95 g), num- ber of filled grains/panicle (113), test-weight (21.3 g) and maximum grain yield (4.79 t/ha) and straw yield (5.53 t/ ha). Similarly, maximum amount of total nutrient uptake by crop (99.7, 40.1 and 208 kg/ha NPK), protein yield (418 kg/ha), gross returns (` 71.8 × 103 /ha), net return (` 52 × 103 /ha) and B: C ratio (2.73) were noticed under T5 treat- ment. Therefore, it is advisable to implement a comprehensive nutrient management strategy T5 (75% RDN through PSCU + 25% RDN through FYM) in rice cultivation. This approach enhances growth, yield, nutrient absorption, and quality, ultimately boosting agricultural productivity, profitability, and sustainability.

Influence of Iron and Zinc Biofortification on Growth and Yield of Drilled Rice (Oryza Sativa L.)

A field experiment was conducted during kharif 2022 and 2023 to study the effect of iron and zinc biofortification on the growth and yield of drilled rice (Oryza sativa L.) at Krushi Vigyan Kendra, Navsari Agricultural University, Dediapada, Gujarat. The experiment was laid out in a randomized block design with ten treatments. Based on pooled analysis, almost all the growth attributes (periodical plant height, number of tillers plant-1, leaf area, leaf area index and dry matter accumulation plant-1), yield attributes (productive tillers m-2, number of filled grains panicle-1, panicle length, weight of panicle and 1000 grain weight), grain yield (3035 kg ha-1) and straw yield (5336 kg ha-1) were recorded significantly higher under treatment T10 (soil ZnSO4 + FeSO4 each @ 25 kg ha-1 and foliar ZnSO4 + FeSO4 each @ 0.5% at 30 & 60 DAS). Based on the results, it concluded that for achieving higher growth and yield in drilled rice, the crop should be fertilized with soil ZnSO4 + FeSO4 each @ 25 kg ha-1 and foliar ZnSO4 + FeSO4 each @ 0.5% at 30 & 60 DAS along with RDF and soil ZnSO4 + FeSO4 each @ 25 kg ha-1 along with RDF.

Evaluation of new sorghum varieties for grain production cultivated in mineral soil

Sorghum bicolor L. (Sorghum) has been recognized as the fifth largest cereal crop in the world, following maize, wheat, rice, and barley, with a mean annual production of more than 5.89 million tons over the past five years. Grain sorghum is one of the cultivated varieties of the sorghum genus. It is primarily used as human food and animal feed due to the beneficial effects of bioactive compounds in the grain. Sorghum is less popular and unrecognizable in Malaysia, as it was not included in the reports by the Agriculture Department regarding plantation areas. In Malaysia, sorghum is limited because this crop is considered new, and no studies were conducted on the adaptability of its varieties to Malaysian soil and local climatic conditions. Crop production practices such as variety selection, planting density and fertilization will affect yield production. Therefore, a study on grain sorghum varieties (Brachy Sorgho, Jumbo Super, India and Pacific Seed 99) was conducted to evaluate the growth and yield performance of sorghum. Jumbo Super had a significantly higher value for plant height, followed by Brachy Sorgho, India and Pacific Seed 99. India showed the highest value of leaf fresh and dry weight, but no significant difference compared with Brachy Sorgho. Brachy Sorgho recorded the highest value of stem fresh and dry weight, while the least was recorded for Pacific Seed 99. Brachy Sorgho and India showed significantly higher grain yields than Jumbo Super and Pacific Seed 99 in terms of panicle length, panicle weight without grain, grain weight without panicle per plant, number of grains per panicle, and 100-grain weight. The highest gross weight of grain sorghum is Brachy Sorgho (140.00 g/plant), which showed no significant difference compared to the India variety (131.13 g/plant). Meanwhile, Jumbo Super and Pacific Seed 99 varieties showed the lowest grain weight, 77.27 g/plant and 80.16 g/plant, respectively. Overall, all four varieties are adaptable in mineral soil and are considered potential alternative crops for grain production. Bachy Sorgho and India varieties showed the best performance on grain yield compared to Jumbo Super and Pacific Seed 99 varieties. Thus, Brachy Sorgho and India varieties can be recommended for future grain production in mineral soil.

EFFECT OF RABBIT MANURE AND ROW ARRANGEMENT ON CROP YIELD UNDER FINGER MILLET AND GROUNDNUT INTERCROPPING SYSTEMS IN A SEMI-ARID NIGERIA

Field trials were conducted at the Research and Training farm of the Centre for Dryland Agriculture, Bayero University Kano (Latitude 11º 58' N and Longitude 8º26' E and 475 m above sea level) and at community-based demonstration farm, Dawakin Kudu (Latitude 11º 84 N and Longitude 8º 59” E) Kano State, Nigeria during the 2019 rainy season, to investigate the effects of rabbit manure (RM) and row arrangement (RA) on finger millet and groundnut intercropping system. The treatments consisted of six row arrangements (1:1, 1:2, 2:1, 2:2, 2:4, and alternate stand) and four levels of rabbit manure (0, 1.5, 2.5, and 3.5 t ha-1) and one level of NPK fertilizer. The treatments were laid out in a split-plot design, with row arrangement (RA) occupying the main plot and rabbit manure (RM) occupying the sub plot, which were replicated three times. Findings revealed that Rabbit manure application significantly (P < 0.05) affected most finger millet and groundnut yield parameters, except for row arrangement which had minimal impact. The optimal rate of rabbit manure application depended on the specific parameter, location, and crop. For finger millet, application of RM increased spike weight, panicle weight, 1000-grain weight, and total grain yield at Dawakin Kudu but only affected spike weight at BUK. For groundnut, RM application increased the number of pods per plant, mean pod weight, and 100-kernel weight at Dawakin Kudu, while only affecting the number of pods per plant at BUK. Intercropping was generally more productive than sole cropping, with the most productive combinations varying by location. Therefore, it could be recommended for farmers in the Sudan savanna to consider the possible adoption of the application of rabbit manure at a rate of 2.5–3.5 t ha-1 to increase finger millet and groundnut yields.

Enhancing growth and yield attributes through bio priming approach in direct seeded rice

Sowing pregerminated and primed rice seeds was found to be advantageous in shortening the numbers of emergence, heading, and maturity days. Reduction in the maturity period of rice by 14.1 days is a significant phonological achievement. Therefore, to ensure the benefits of seed enhancing techniques on seed yield and yield components of rice (Oryza sativa L.),field experiment was conducted in Split Plot Design with four replications using PMK(R)4 with fourteen different seed biopriming liquid microbial cultures and its combinations. The results showed that the seeds soaked in equal volume of liquid microbial cultures Azospirillum+ Phosphobacteria 20% for 18hrs recorded maximum plant height at 45(29.2cm), 90DAS(105.2 cm) and harvest stages (113.3 cm). The leaf area index(10), number of productive tillers, panicle length(36.3 cm), number of spikelets per panicle (106) and panicle weight were maximum in co-inoculated priming treatment Azospirillum + Phosphobacteria and Azospirillum+ Phosphobacteria+ Silicate Solublizing Bacteria followed by Azosprillium 20% for 18hrs and minimum with non-primed seeds. Combined application of Azospirillum + Phosphobacteria was found to be most effective treatment in improving seed yield per plot(6.6g), seed yield per hectare and 1000 seed weight (24.72 g) over non-primed seeds.

Influence of Nitrogen Levels and Microbial Inoculation on Growth, Yield and Straw of Direct Seeded Basmati Rice (Oryza sativa L.)

Background: Rice, a staple cereal, serves as the primary food for almost 50% of the world¢s population. Nitrogen is the predominant mineral element found in crops and serves as the primary constraint on Rice production. Direct-seeded rice cultivation has emerged as a potential alternative to traditional transplanting method. The goal is to provide insights that may be used to build sustainable agricultural methods that are specifically designed for Basmati rice production. Methods: This study aim to evaluate the effect of different N application levels (M1: 0 kg ha-1, M2: 40 kg ha-1 and M3: 60 kg ha-1) options as first factor with four microbial inoculation treatments (S1-Control, S2-Azosprillum (618g/ha) + Streptomyces’s (618g/ha), S3- Consortium (1235 g/ha) and S4-AMF (1235 g/ha). The experiment was conducted using a split-plot design (SPD) with three replications. Result: The study revealed that the maximum yield and yield attributes viz. plant height (116.47 cm), effective tillers ( 354.13 m2),leaf area index (2.64), no. of grains per panicle(84.17), length of panicle (24.66 cm), no. of filled grains per panicle (125.0), grain yield (54.30 q ha-1), straw yield ( 80.42 q ha-1), biological yield (134.72 q ha-1) and 1000-grain weight (24.64 g), maximum protein content (%) in grains (8.73%), straw (5.78%) was recorded in M3S2 i.e. 60 kg N ha-1 with azosprillum (618 g/ha) + streptomyces's (618 g/ha) significantly highest compared to other nitrogen levels and microbial inoculation treatments. Hence, the application of N @ 60 kg ha-1 along with azosprillum (618 g/ha)+Streptomyces¢s (618 g/ha) can be suggested to achieve higher rice grain yield, yield attributes and nitrogen content in grain and straw in DSR.

Unraveling Promising Genetic Variability Associated with Strong Culm and Yield Parameters in Inter Sub-Specific Cross Derived Recombinant Inbred Lines in Rice (Oryza sativa L.)

Strengthening the rice culm through genetic improvement has been an important target in breeding to abate the lodging problem in rice. The present investigation was attempted to study the variability, genetic parameters and trait association in recombinant inbred lines (RILs) derived from inter sub-specific cross of elite indica mega variety ‘Swarna’ and Tropical japonica strong culm accession ‘IRGC 39111’. Analysis of Variance (ANOVA) displayed significant variation in RILs for all the traits studied. The investigation revealed high estimates of GCV and PCV along with high heritability and genetic advance as percent of mean (GAM) for all culm strength (CS) traits revealing the role of additive gene effect and selection of these traits shall be effective in rice improvement. Correlation studies revealed that the internode breaking weight (IBW) and bending moment at breaking(M) had a high significant positive correlation with all the CS traits, panicle weight and grain yield. Thus, the direct selection of positively associated traits can improve the lodging resistance in rice. The principal component analysis (PCA) showed that, seven principal components (PCs) out of 23 traits attributed approximately 92.9% of the total cumulative variability. The traits culm thickness (CT), Internode breaking weight (IBW), section modulus (SM), bending stress (BS), Bending moment at breaking (M) contributed maximum to the total diversity and the lines with higher trait values for the aforementioned traits could be utilized as donors to improve the culm strength and its attributing traits in future breeding programs. From this study, it is evident that tropical japonica lines can be a great source of genetic diversification for rice improvement.

Selection of Genotypes for Enhancing Tef Productivity Through Farmers’ Participation in Potential Environments of Ethiopia

Tef, <i>Eragrostis tef</i> (Zucc.) Trotter is the main crop grown in Ethiopia. However, its productivity remains low compared to its potential yield. A multi-location trial was conducted to evaluate selected best-performing lines from previous trials in terms of stability and yield coupled with farmers’ opinions and preferences, aiming to identify superior lines. A total of twenty tef genotypes, including a standard and a local check were field evaluated using RCBD with four replications. The lines were grown in 4 m² plots across eight different locations in Ethiopia during the 2018/19 and 2019/20 cropping seasons. Additionally, an on-farm participatory variety evaluation involving 198 participants, comprising farmers and agricultural experts, was conducted during the 2019 cropping season. Phenological and agromorphological traits were collected and subjected to statistical analysis to identify the best genotypes. The pooled analysis of variance revealed significant variation (at the 0.01% level) among genotypes, locations, and years for all traits except grain yield and days to maturity. While some genotypes produced comparable grain yields, none surpassed the standard check variety Negus. Additionally, Participatory variety selection was conducted during the crop maturity stage using the direct-matrix ranking method. Farmers sets their own selection criteria, these are crop stand, tillering capacity, panicle weight, lodging tolerance, culm strength, and pest infestation or infection. Based on their evaluation, the genotypes DZ-01-974 X GA-10-3 RIL 51, DZ-01-974 X GA-10-3 RIL 47 and DZ-01-974 X GA-10-3 RIL 68 were identified as farmers preferred varieties from direct matrix ranking evaluations and chosen for their performance in the field. Thus, this study highlights the feasibility of participatory variety selection in gaining insights into farmer’s perceptions, preferences, strengths and weaknesses of tef genotypes.

Yield Trait Association Studies through Principal Component Analysis in Bi-Parental Population Derived from indica/tropical japonica Inter Sub-Specific Cross in Rice (Oryza sativa L.)

In the present investigation, a mapping population consisting of 189 lines derived from an inter sub-specific cross between an indica cultivar, ‘Samba Mahsuri’ and a tropical japonica accession, ‘Cuba 65’ was investigated to assess the trait contribution to variability employing principal component analysis (PCA). The study aimed at determination of inter-relationships among various yield attributing traits vis-à-vis individuals of the mapping population. Out of eleven principal components (PC), first four PCs exhibited Eigen value more than one accounting to a total of 68.73% cumulative variance among the characters. The first PC accounted for the highest variability (PC1 31.6%) to the total variability, followed by 14.51% (PC2), 12.69% (PC3) and 9.91% (PC4). The highest positive Eigen value observed for the tiller number (0.33) and panicle number (0.32) in PC1 indicated their pronounced effect in the overall variation in the population. The analysis revealed the traits that contribute maximum for the variation. PCA also revealed negligible effect of days to fifty percent flowering, grain size and spikelet fertility to the variability in the mapping population. Although all the studied traits except grain size showed significant positive association with grain yield; negative correlation was observed between some of the component traits. Panicle weight, thousand grain weight and grain number showed negative association with tiller number and panicle number. The latter two traits contributed to the maximum variability in the population. The trait associations identified in the present investigation will help in determining the selection criteria to be adopted in the development of high yielding cultivars involving indica/tropical japonica populations.

Genetic Variability Studies for Yield and its Attributing Traits in Rice F4 Mapping Population (Oryza sativa L.)

An experiment was conducted at ICAR-IIRR during the wet season of 2023 in a mapping population derived from the cross TI-128 X BPT-5204, along with five checks in an augmented block design with eight blocks. This study revealed that, significant variability was present among the population for all the traits examined. High genotypic coefficient of variation was observed for number of tillers per plant (29.68), number of productive tillers per plant (30.56) and total number of grains per panicle (29.66). High phenotypic coefficient of variation and genotypic coefficient of variation was observed for the trait grain yield per plant. High heritability coupled with high genetic advance as percent of mean was recorded for number of tillers per plant, number of productive tillers per plant, total number of grains per panicle and grain yield per plant showing that these traits are regulated by additive gene effects, making them suitable for selection criteria in rice breeding programs. The traits viz., number of tillers per plant (0.42***), number of productive tillers per plant (0.41***), filled grains per panicle (0.20**), total number of grains per panicle (0.18**) and test weight (0.18**) exhibited significantly positive association with grain yield per plant.