Days After Sowing Research Articles

Impact of biologically synthesized phosphorus nano-particle on green gram (Vigna radiata L.) over molecular phosphatic fertilizer under acid soils of Eastern Sub-Himalayan region of India

A field experiment was conducted at the instructional farm of Uttar Banga Krishi Viswavidyalaya, Cooch Behar, West Bengal, India during early Pre-kharif seasons of 2020 and 2021 to evaluate the comparative performance of green gram (Vigna radiata L. Wilczek) under single super phosphate (SSP) and nano-phosphorus. Experiments consisted of T1: 100% phosphorus through SSP, T2: 75% through SSP +1 ml L−1 of nano-phosphorus at 15 days after sowing (DAS), T3: 50% through SSP +1 ml L−1 of nano-phosphorus at 15 DAS, T4: 25% through SSP +1 ml L−1 of nano-phosphorus at 15 DAS, T5: 100% through nano-phosphorus (1 ml L−1 at 15 and 30 DAS), T6: 100% through nano-phosphorus (2 ml L−1 at 15 DAS), and T7: control (no phosphorus). Results of the experiment revealed that whenever nano-phosphorus was applied either in combination or in alone performed better in terms of growth and yield of green gram over single use of molecular phosphatic fertilizer. Pooled data over the years revealed that application of 2 ml L−1 of nano-phosphorus at 15 DAS (T6) recorded significantly tallest plant, larger root volume, greater leaf area, maximum dry matter, longest pod, and highest number of pod plant−1 which ultimately helped in producing 33.13% more grain yield and contributing 50.28% higher profit over 100% phosphorus through SSP. It can be concluded that farmers of the Eastern sub-Himalayan region can grow green gram profitably during summer season with the foliar application nano-phosphorus 2 ml L−1 along with 20 kg nitrogen and 40 kg potassium ha−1.

The effect combination of organic and inorganic fertilizer on okra (Abelmoschus esculentus) growth

Okra (Abelmoschus esculentus) is the most commonly and popular vegetables. The application of inorganic fertilizer is very important to increase the productivity of the crop, but overuse of inorganic fertilizer can lead to soil acidification that can affect the plant growth. The purpose of these study is to determine the effectiveness combination rate of organic and inorganic fertilizer toward okra growth and yield performance. This study was conducted in a greenhouse by using Randomized Complete Block Design (RCBD) with four replicates. The study was used chicken dung as organic fertilizer. The treatments applied were T0 (NPK), T1 (NPK + 20 g chicken dung), T2 (NPK + 40 g chicken dung), and T3 (NPK + 60 g chicken dung). NPK green was applied only one-time during 14 days after sowing (DAS) and was continued with NPK blue. T3 showed an increasing in fresh pod yield. Thus, combination of organic fertilizer and inorganic fertilizer was showed the positive effect to the crop production. The combination of organic and inorganic fertilizer was proven to be the most effective in okra production.

Growth and Yield Response of Cluster Bean (Cyamopsis tetragonoloba L.) cv. Pusa Navbahar to Integrated Nutrient Management

The investigation on cluster bean with application of integrated nutrient management with comprised of 12 treatments with three level of NPK, two levels of PSB and Rhizobium in factorial randomized block design. The treatment T12 has shown the significant results when applied 100% of NPK with PSB and Rhizobium among the different levels of treatment combinations. Growth parameters viz., plant height (90.96 cm), number of nodules plant-1(59.48), number of branches plant-1 (2.66) at 90 DAS (day after sowing), and yield parameters viz., number of clusters plant-1 (14.62), number of pods cluster-1 (13.39), pod length (17.42 cm),pod yield(77.29 q ha-1) has shown best in treatment T12(NPK @100% + PSB @100% + Rhizobium @100%) of cluster bean (Cyamopsis tetragonoloba L.) in comparison to other treatment combination.

Effect of Nano Zinc Oxide Seed Treatment on Physiological Growth and Biophysical Traits and Seed Quality of Soybean [Glycine max (L.) Merrill

The field experiment was conducted at Seed Technology Research Center, Department of Plant breeding and Genetics, JNKVV-Jabalpur Kharif-2021. Growth analytical attributes studies indicated superior performance of seed treatment with nano-ZnO @500mg L-1 for LAI @60 DAS (days after sowing), @70 DAS, @80 DAS, LAD, CGR, RGR and BMD w.r.t. 24.26%, 21.39%, 28.50%, 12.09%, 21.42%, 20.17% and 20.56% enhancement over control. Varietal studies revealed superior performance of variety JS 20-116 for LAI, LAD, CGR, RGR and BMD. Biophysical parameters studies revealed superior performance of seed treatment with nano –ZnO @500mg L-1 for chlorophyll content index and energy interception with 5.19% and 26.51% enhancement over control respectively. With respect to variety superior performance of variety JS-20-116 for chlorophyll content index and energy interception. Seed quality parameters studies indicated superior performance of seed treatment with nano–ZnO @500mg L-1 for final plant stand, germination, and seed vigour index I and seed vigour index II with respect to 29.16%, 14.11%, 26.40% and 21.43% enhancement over control. With respect to variety, superior performance of variety JS-20-116 for final plant stand, and seed vigour index I and seed vigour index II and JS 20-34 for seed germination. This results justifies that the seed treatment with nano formulation in the form of ZnO @ 500mg L-1 will improve growth analytical attributes, physiological efficiency and seed quality of the soybean. Hence the seed treatment with nano-ZnO @500mg L-1 is recommended to farmers for maximum productivity, physiological efficiency and sowing seed quality.

Maize (Zea Mays L.) Yield Estimation Using High Spatial and Temporal Resolution Sentinel-2 Remote Sensing Data

ABSTRACT Maize (Zea mays L.) is one of the world’s most important annual cereal crops and its yield can be estimated for a wide variety of purposes. The objective of this work is to evaluate in which stage of crop the best fit between remote sensing data and real yield occurs to predict yield in corn seed crops. For this, polynomial regression models were used between spectral indices of vegetation and real yield in 10 days time’s windows covering the critical period for generation of performance. Subsequently, the predictive capacity of the best goodness of fit model was evaluated by comparing estimates with those made using a conventional field estimation method. This experiment was carried out in production fields located in Tandil and Loberia district inside of the Argentine Pampas Region in southeast of Buenos Aires province in summer (from january to march) of 2020. We found the highest level of adjustment between vegetal index and real yield (R2 = 0.91) in the time window of 110 to 120 days after sowing (DAS) corresponding to the end of the critical period. Then, the predictive performance was evaluated, satellite model shows an underestimation of 53 kg/ha (0.72% relative error) while the conventional method underestimated by 955 kg/ha (13% relative error). A close relationship between remote sensing data and grain yield at the end of the critical period of maize can be evidenced, and this information can be used to predict yield early in the southeast of Buenos Aires province. Using the methodology here developed it is recommended to analyze- time series of satellite vegetal index in maize crops in other regions and climates to make more robust the yield prediction system.

Response of sulphur fertilization and weed management to performance of faba bean (Vicia faba L.)

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from November 2021 to April 2022 to assess the effect of sulphur fertilization and weed management on yield performance of faba bean. The experiment consisted of three levels of sulphur viz. 0, 20 and 40 kg S ha-1 and four levels of weed management practices viz. control (weedy check), weed-free up to 30 days after sowing (DAS), weed-free up to 60 DAS, weed-free throughout the growth period. The experiment was laid out in a randomized complete block design with three replications. The highest number of branches plant-1 (11.63), pods plant-1 (70.68), seeds pod-1 (5.50), 1000-seed weight (267.9 g), seed yield (2.72 t ha-1), and stover yield (2.93 t ha-1) were recorded with 40 kg ha-1. In the case of weed management, the highest number of branches plant-1 (10.16), pods plant-1 (66.03), seeds pod-1 (6.0), 1000-seed weight (266.7 g), seed yield (2.43 t ha-1), stover yield (2.85 t ha-1) and harvest index (45.80%) was found at weed free throughout the growth period. Whereas the lowest values of all parameters were found minimum in weedy check. In interaction, the highest number of branches plant-1 (13.0), pods plant-1 (78.69), seeds pod-1 (7.0), 1000-seed weight (269.5 g), seed yield (2.87 t ha-1), stover yield (2.98 t ha-1) and harvest index (49.37%) were found in 40 kg ha-1 S with weed-free throughout the growth period. Whereas the lowest parameters were found minimum in control. Therefore, application 40 kg ha-1 S along with weed-free conditions throughout the growth period appears as the suitable combination for faba bean cultivation. Res. Agric. Livest. Fish. 10(1): 33-42.

Efficacy of Sulfentrazone 39.6% and Pendimethalin as a Pre Emergence Application against Weed Spectrum of Soybean (Glycine max L. Merrill)

A field experiment was conducted during Kharif season of 2017 at the Research Farm, College of Agriculture, Jabalpur, Madhya Pradesh. The seven treatments comprising of four doses of sulfentrazone (180, 360, 540 and 720 g/ha), application of pendimethalin (750 g/ha) as pre emergence, hand weeding twice at 20 and 40 days after sowing (DAS) including weedy check, were laid out in randomized block design with 3 replications. Results revealed that, Echinochloa colona (28.24%) was the dominant weed species closely followed by Commelina communis (24.42%). However, other monocot weed like Cyperus rotundus (15.56%) and dicots like Phyllanthus niruri (19.34%) and Euphorbia hirta (12.44%) were also found associated with soybean in less numbers. Application of T4- sulfentrazone at 720 g/ha as pre emergence arrested the weed growth remarkably and proved superior to its lower dose (180 g/ha) and application of pendimethalin 750 g/ha. The poor crop-weed competition due to effective control of weeds under this treatment resulted in higher weed control efficiency. Pre-emergence application of T4- sulfentrazone at 720 g/ha recorded maximum grain yield and was at par with other individual herbicides. Similarly, higher net returns and benefit: cost ratio were recorded in T4- sulfentrazone at 720 g/ha fb T3- sulfentrazone at 540 g/ha. It may be inferred from the present investigation that these herbicidal treatments could be used effectively as an alternative for controlling weeds and obtaining optimum seed yield of soybean.

Groundnut Shells and Toddy Palm Shells Recycling Through Vermicomposting Technology and its Efficacy on Growth and Yield Attributes of Cluster Bean (Cyamopsis Tetragonoloba L.) Taub

Farming generates numerous types of agricultural wastes to the environment such as crop residues, animal waste, poultry waste etc,. those are landfilled or burning creates environmental pollutions. The aim of the study was to determining the growth and yield performance of cluster bean (Cyamopsis tetragonoloba L.) Taub on groundnut shells and toddy palm shells based vermicompost with Trichoderma asperelloides, microbial consortium and Eisenia fetida assistance. Pot experiments of plants were grown on six different combination of groundnut shells and toddy palm shells composts and one control treatment. During 25, 50 and 75 DAS (Days After Sowing) growth parameters and 90 DAS yield characters of cluster bean was carried out under pot culture respectively. The combined application of toddy palm shells composted with consortium of microorganisms and earthworm (T6) achieved the maximum growth parameters such as root length (21.9cm), shoot length (84.8cm), number of leaves (46.3), number of nodules (4.6), number of flowers (24.6), number of pods (6.6), fresh weight (17.912g) and dry weight (2.684g) of plant on 75 DAS of cluster bean (Cyamopsis tetragonoloba L.) Taub. During the 90th day the same treatment achieved the yield characters like number of pods (8.0), length of pod (16.6cm), number of seeds/pod (10.3), yield/plant (45.384g), fresh weight (5.673g) and dry weight (1.496g) of pod compared to the control. Based on the results T6 more suitable for growth and yield characters of cluster bean followed by T3 respectively. The study suggested that, the organic fertilizer prepared from groundnut shells and toddy palm shells with microbial consortium and Eisenia fetida assistance promotes the plant development and yield attributes of Cyamopsis tetragonoloba (L.) Taub. simultaneously, reduce the usage of chemical fertilizers.

EFFECT OF MOISTURE ON SEEDLING STAGE OF SOYBEAN (GLYCINE MAX)

The research was conducted at Rampur Campus, Khairahani, Nepal to analyze the effect of moisture on different soybean (Glycine max) genotypes under a partially controlled environment. The experiment was carried out in a Completely Randomized Design (CRD) with 16 distinct genotypes and 3 water levels (waterlogged, control and drought) as treatment and replicated with 3 times. Various parameters including germination percentage, plant mortality, plant height, number of leaves, and number of branches were measured at different stages of growth. The results showed that genotypes SBO122 and TGX1891116FN exhibited early germination with the highest germination percentage recorded at 5 days after sowing (DAS). TGX1891116FN showed the highest germination percentage of 100% at 15 DAS. However, the germination percentages were lower in other genotypes, which could be attributed to the lower temperatures during the research period. The mortality rate of soybean seedlings varied among genotypes and moisture treatments. Genotype CM9125 showed the highest mortality rate of 100%, followed by Puja and GC8234GC-13 with a mortality rate of 88.87%. Plant height was significantly affected by different genotypes and moisture treatments. Under normal conditions, genotype Puja exhibited the highest plant height at 20 DAS, while under waterlogging conditions, TGX1989-19F had the highest height. Drought conditions also affected plant height, with genotype GC8234GC13 showing the highest height at 30 DAS. These findings can contribute to the development of soybean varieties that are resistant to moisture stress and improve soybean production in Nepal.

Efficacy of Nano Fertilizers on Yield, Attributes and Economics of Wheat

The present investigation was carried out to study the effect of foliar application of nano-fertilizers N and P on yield, and the economics of wheat in Semi-arid and sub-tropical region of Central Plain Zone of Uttar Pradesh. The experiment was laid out in triplicate following a randomized block design with twelve treatments comprising foliar application semi-different doses of Nano N and P. Foliar application of 1st spray of Nano N and P at 30 days after sowing (DAS) + 2nd spray of Nano N and Zn at 45 DAS along with 75% recommended dose of fertilizers (RDF) significantly (P=0.05) increased yield and have better economics. Foliar application of nano-fertilizers leads to significant improvement of crop productivity of wheat in Semi- arid and sub-tropical region of Uttar Pradesh. Moreover, the foliar application of nano-fertilizers, i.e., Nano N has direct role in increasing yield as nutrient get easily available to plant in case of foliar spray.

Performance of Vegetation Indices to Estimate Green Biomass Accumulation in Common Bean

Remote sensing technology applied to agricultural crops has emerged as an efficient tool to speed up the data acquisition process in decision-making. In this study, we aimed to evaluate the performance of the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Red Edge (NDRE) in estimating biomass accumulation in common bean crops. The research was conducted at the Federal University of Lavras, where the ANFC 9 cultivar was used in an area of approximately seven hectares, in a second crop, in 2022. A total of 31 georeferenced points spaced at 50 m were chosen to evaluate height, width and green biomass, with collections on days 15, 27, 36, 58, 62 and 76 of the crop cycle. The images used in the study were obtained from the PlanetScope CubeSat satellite, with a spatial resolution of 3 m. The data obtained were subjected to a Pearson correlation (R) test and multiple linear regression analysis. The green biomass variable was significantly correlated with plant height and width. The NDVI performed better than the NDRE, with higher values observed at 62 Days After Sowing (DAS). The model that integrates the parameters of height, width and NDVI was the one that presented the best estimate for green biomass in the common bean crop. The M1 model showed the best performance to estimate green biomass during the initial stage of the crop, at 15, 27 and 36 DAS (R2 = 0.93). These results suggest that remote sensing technology can be effectively applied to assess biomass accumulation in common bean crops and provide accurate data for decision-makers.

Influence of Stage of Harvest on Seed Yield and Quality in Soybean Varieties

A field experiment was conducted at Agricultural Research Station, Bidar during Kharif 2018 and 2019 to determine the influence of appropriate stage of harvest on seed yield and quality parameters of soybean varieties JS-335 and DSb-21. The research plots were laid out in replication using factorial RCBD design. The crop was harvested according to the stage of harvest which was fixed as treatments i.e. at 80, 85, 90, 95 and 100 days after sowing (DAS) in both the varieties and threshing was done manually. The results revealed that among different harvesting stages, the seeds of the variety JS-335 harvested at 85 DAS showed highest seed yield and quality characters compared to early and delayed harvesting stage. Likewise in case of DSb-21 variety the crop harvested at 90 DAS recorded highest seed yield and quality parameters compared to other stages of harvest.

PHENOLOGY, CROP STAND, AND DRY MATTER PRODUCTION OF WHEAT IN RESPONSE TO BENEFICIAL MICROBES AND ORGANIC MATTER SOURCES

Adding organic matter to soil proved an efficient strategy for restoring soil fertility and improving crop dry matter – an indicator of yield potential. In this regard, evaluating the sources of organic matter (OM) (control, poultry manure [PM], farmyard manure [FYM], compost, and mungbean residues [MR]) to provide 120 kg N ha-1 and effective microbes (EM) (0, 100, 200, and 300 L ton-1 of OM) as 2% solution proceeded in field conditions during 2017–2019. The sowing of wheat seeds (cv. Pirsabak 2015) at 120 kg ha-1 took place in the field using RCB design with four replications. Results showed that PM/FYM had delayed the phenology and improved the biomass-related parameters, dry matter (DM) accumulation, and crop growth rate (CGR) more than compost and MR. However, the results were more pronounced when applied with 300 L EM ton-1 of OM from the PM. The maximum DM (55%) accumulation in plant parts occurred beyond 100 days after sowing (DAS). A marked increase in DM and CGR beyond 60 DAS and a reduction in CGR beyond 120 DAS appeared irrespective of treatments. In the case of EM, the 300 L ton-1 revealed superior in terms of growth, DM accumulation, CGR, and delayed phenology. Structural equation modeling suggested that DM production gained a direct effect from crop phenology (46.1%) and crop stand (30.4%) but no indirect effect from crop growth (24.8%). In conclusion, the 300 L EM ton-1 of OM applied to PM or FYM had improved the crop stand, development, and DM production in wheat.

Optical sensor-based nitrogen management: an environmentally friendly and cost-effective approach for sustainable wheat (Triticum aestivum L.) production on Eastern plains of India

An optical sensor like Green Seeker (GS) is an emerging tool for site-specific in-season fertilizer nitrogen management strategy. The objective of this study was to establish an in-season estimate of yield (INSEY)–grain yield (GY) relation in wheat grown under Eastern plains of India using normalized difference vegetation index (NDVI) at 45 and 65 days after sowing (DAS). Data revealed lower NDVI values at 65 DAS over 45 DAS in no-nitrogen (N), phosphorus (P), and potassium (K) applied control plots as well as in N-rich plots (225 kg ha−1 N); on the contrary, the values were higher at 65 DAS over 45 DAS in treatments where some N fertilizers were added based on NDVI readings at 45 DAS. Response index (RI) showed higher chances of response to external application of N in NDVI-based treatments. The INSEY–GY relation for wheat at 45 and 65 DAS was worked out as a power function of y = 64265x1.171 and y = 46949x1.036 (y is the attainable yield in kg ha−1 and x is INSEY), respectively. The yields could fairly be predicted through this relation even at 45 DAS, though the relationship was more robust at 65 DAS (R2 = 0.94). A prescriptive dose of 60 kg N ha−1 as basal + 60 kg N ha−1 at crown root initiation (CRI) stage followed by NDVI sensor-guided N application (at 45 and 65 DAS) brought about a significant improvement in yield performances, N use efficiencies with higher net returns, and benefit-to-cost ratio. The results proved the reliability of the NDVI sensor as an important tool for the optimization of fertilizer nitrogen in wheat grown under the Eastern plains of India. The new INSEY–GY relation developed through this trial could successfully be used for yield prediction in the Eastern plains of India under changing climate.

Long-Term Conservation Agriculture Influences Weed Diversity, Water Productivity, Grain Yield, and Energy Budgeting of Wheat in North-Western Indo-Gangetic Plains

Wheat is grown in an area totalling 31.1 million hectares in India. The North-western Indo-Gangetic Plains (IGP) constitutes the major share of area and production of wheat in India and is known as the wheat belt of India. However, sustaining wheat production under declining/lower resource-use efficiency in the existing rice–wheat cropping system has led to considerations about diversifying this system with a pigeon pea–wheat system (PWS) in the IGP of India. However, little or no information is available on the impact of CA-based PWS on weed dynamics, productivity, profitability, and resource-use efficiencies. Therefore, we studied these aspects in wheat under a long-term (~12 years) conservation agriculture (CA)-based PWS. Treatments were conventional till flatbed (CT), ZT permanent narrow beds (PNBR & PNB), broad beds (PBBR & PBB), and flat beds (PFBR & PFB) with and without residue (R) retention and different N levels (75% and 100% of the recommended N). The results showed that the Shannon–Weiner index and the Simpson dominance index were higher under the CA system in 2021–2022 than in 2010–2011 and 2015–2016, indicating a change in weed diversity over the period. Furthermore, the Sorensen similarity index showed that there was not much difference in weed diversity for 2010–2011. However, in 2015–2016 and 2021–2022 respectively, only 89% (0.89) and 62% (0.62) of weed species were common to both CT and CA systems, indicating a shift in weed species in the long-term CA system in 2021–2022. Residue retention and N dose decreased weed density at 30 days after sowing (DAS). All the CA-based (PFBR100N, PBBR100N, PNBR100N, PFBR75N, PBBR75N, and PNBR75N) treatments reduced the weed density and dry weight compared to CT at 30 DAS. Wheat grain yield and net returns increased by 11.6–14.9% and 19.4–23.8% over CT in CA treatments, of which PFBR100N and PBBR100N were superior. The PBBR100N and PBBR75N systems had water productivity significantly higher than CT. Residue retention in ZT permanent beds reduced energy productivity in CA than CT and no residue treatments. In the 12th year, CA with 75% N (PFBR75N, PBBR75N, PNBR75N) resulted in a higher partial factor productivity of N and total NPK applied. Contrast analysis showed that 75% N was comparable with 100% N on crop, water, and energy productivities and 75% N was superior to 100% N on partial factor productivity of N and total NPK. Thus, the permanent broad bed with residue and 100% N in the initial years and 75% N in later years can be adopted in the north-western IGP for better weed suppression, higher yield, profitability, and resource-use efficiency.

Nano-Hydroxyapatite and ZnO-NPs Mitigate Pb Stress in Maize

Heavy metals (HMs) stress, particularly lead (Pb) stress, is one of the most hazardous environmental stresses that can negatively affect plants’ growth, yield, and quality. Therefore, the effects of zinc oxide nanoparticles (ZnO-NPs; 50 mg L−1), nano-hydroxyapatite (HP-NPs; 50 mg kg−1), and their combination on growth, physiological, and yield traits of maize grown in soil contaminated with Pb (i.e., 100 mg kg−1) were investigated. The results showed that Pb stress significantly reduced plant leaf area by 50.9% at 40 days after sowing (DAS), 55.5% at 70 DAS, and 54.2% at 100 DAS in comparison to the unstressed plants (control). However, the combined application of ZnO-NPs (50 mg L−1) + HP-NPs (50 mg kg−1) reduced the adverse effects of Pb on plant growth in terms of increasing leaf area by 117.6% in plants grown in Pb-contaminated soil (100 mg kg−1). Similarly, the combined application of ZnO-NPs + HP-NPs resulted in increments in the total chlorophyll content by 47.1%, photosynthesis rate by 255.1%, and stomatal conductance by 380% in comparison to that obtained from maize stressed with Pb. On the other hand, antioxidants such as sodium dismutase (SOD; 87.1%), peroxidase (POX; 90.8%), and catalase (CAT; 146%), and proline content (116%) were significantly increased as a result of Pb stress compared to unstressed plants. Moreover, N, P, K, and Zn contents in the whole plant grown under Pb stress were decreased by 38.7%, 69.9%, 46.8%, and 82.1%, respectively, compared to those obtained from the control. Whereas the combined treatment of ZnO-NPs (50 mg L−1) + HP-NPs (50 mg kg−1) resulted in increased uptake of plant nutrients and, consequently, the highest values of ear weight, grain yield, and harvest index were obtained. Furthermore, the combined application of HP-NPs + ZnO-NPs in contaminated soil reduced Pb uptake in plant biomass by 77.6% and grains by 90.21% in plants exposed to Pb stress. In conclusion, the combined application of ZnO-NPs and HP-NPs significantly improved growth, physiological traits, antioxidants, and yield as well as elemental uptake of maize grown under Pb stress.

Competitiveness of Bensulfuron-Methyl-Susceptible and -Resistant Biotypes of Ammannia auriculata Willd. in Direct-Seeded Rice

Ammannia auriculata Willd. (eared redstem) has become one of the most troublesome weeds in paddy rice in China. Resistance to bensulfuron-methyl (BSM) has spread extensively in this species. Greenhouse and field experiments were conducted to determine how the eared redstem biotype and density affect competition against rice. In the greenhouse experiment, five treatments were tested: a BSM-susceptible biotype at low density (58 plants m−2, SL), a BSM-susceptible biotype at high density (288 plants m−2, SH), a BSM-resistant biotype at low density (RL), a BSM-resistant biotype at high density (RH), and a control without eared redstem (CK). Eared redstem grew slowly until 15 days after sowing (DAS); however, growth accelerated after 20 DAS, and the eared redstem plants were taller than the rice from 55 DAS on. The SH and RH treatments were associated with greater intraspecific competition: eared redstem plants in the SH and RH treatments had fewer branches, fewer capsules, and less shoot dry weight per individual plant relative to the SL and RL treatments. The SH and RH treatments also caused greater reductions in the rice yield. The dry weight of rice at 141 DAS was reduced by 73% in the SL treatment, 98% in the SH treatment, 51% in the RL treatment, and 82% in the RH treatment, all relative to the CK. At 141 DAS, BSM-resistant plants were smaller than BSM-susceptible plants, suggesting a fitness cost of herbicide resistance in the absence of a herbicide. In the field study, eared redstem densities as low as 5 plants m−2 reduced the rice yield by 22%. A density of 50 eared redstem plants m−2 reduced the rice yield by 70%. Overall, these findings demonstrate that eared redstem is a highly aggressive weed species and threatens the rice yield even at a low density. However, the findings also demonstrate that BSM-resistant populations are less competitive. There is an urgent need to develop integrated management programs for this aggressive weed, which may include tactics to shift competitive dynamics in favor of rice. Additionally, this research provides the theoretical basis for the damage level, resistance risk evaluation, and management strategy of eared redstem in rice cropping systems.

Influence of biostimulants on growth and productivity of foxtail millet (Setaria italica L.) genotypes

A field experiment was carried out at AHRS, Bavikere, Karnataka during late kharif season of 2021to find out the “Influence of biostimulants on growth and productivity of foxtail millet (Setaria italica L.) genotypes’’. The field trial was laid out in split plot design with 12 treatment combinations. The study involves three genotypes in the main plot viz., SiA-3156 (G1), HMT-100-1 (G2) and DHFt-109-3 (G3). Foliar application of biostimulants in sub plots viz., 0.1 % humic acid (F1), 3 % panchagavya (F2), 0.1 % humic acid and 3 %panchagavya (F3) at 30 and 60 days after sowing (DAS) and recommended dose of fertilizer (RDF) as control (F4). Genotypes and Foliar application of biostimulants exhibited significant variation in growth and yield components of foxtail millet. Among the different genotypes, HMT-100-1 recorded significantly higher plant height (142.00 cm), number of tillers per meter (81.87) and leaf area (18.40 dm2/plant) at harvest and also yield components like panicle length (16.60 cm), grain weight per panicle (4.02 g) and grain yield (1701.0 kg/ha) compared to DHFt-109-3 and SiA -3156. In biostimulants, Foliar application of 0.1 % humic acid and 3 % panchagavya recorded significantly higher plant height (142.32 cm), number of tillers per metre (83.75) and leaf area (18.51 dm2/plant) at harvest and also yield components like panicle length (16.99 cm), grain weight per panicle (4.33 g) and grain yield (1781.2 kg/ha). While, they were found to be at their lowest with application of RDF alone. Interaction between genotypes and biostimulants was also found to be significant in which combination of HMT-100-1 with foliar application of 0.1 % humic acid and 3 %panchagavya recorded significantly higher growth and yield compared to other treatment combinations.

Growth and development of Paspalum virgatum L.

The objective of the work was to evaluate the growth and development of the razor-blade grass (Paspalum virgatum L.). The experimental design was a randomized complete block design with 17 treatments, and the growth evaluations were performed at 20, 27, 34, 41, 48, 55, 62, 69, 76, 83, 90, 97, 104, 111, 118, 125, 132 days after sowing (DAS) and five replications, considering as sowing date the day the seeds were placed in the plastic boxes. The evaluated characteristics were: total dry mass (Mt), shoot dry mass (Ma) and dry mass of roots (Mr), number of leaves and number of tillers per plant. The quantitative variables related to plant growth were analyzed by applying the F test on the analysis of variance followed by non-linear log-logistic regressions, with the objective of modeling the data in the form of equations. The razor-blade grass (Paspalum virgatum L.) is a weed with slow initial development and growth, but with high dry mass production at the end of the cycle.

Effect of Integrated Weed Management Practices on Microbial Population in Soil, Yield and Economics in Wet Direct Seeded Rice

An experiment had been conducted at the Agronomy Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur, (C.G.) in the kharif season of 2019, to determine the effects of integrated weed management practices on microbial population in soil, yield and economics in wet direct seeded rice. Pre-emergence herbicides (Oxadiargyl and Pretilachlor) were followed by post-emergence herbicide (Bispyribac-Na), mechanical and manual weeding. Plots treated with oxadiargyl performed better than pretilachlor. When Oxadiargyl was integrated with Hand Weeding (HW) at 35 days after sowing (DAS) gave results which were better than twice HW plot (T10). Oxadiargyl @ 70g/ha at 7-11 DAS fb HW at 30-35 DAS (T4) proved to be superior over all the treatments when yield and economics of wet direct seeded rice was concerned and was statistically at par with twice HW plot (T10) and oxadiargyl @ 70 g/ha at 7-11 DAS fb bispyribac-Na @ 25 g/ha at 30-35 DAS (T2). The unsprayed and two-hand weeding treatments had much lower levels of fungi, actinobacteria, and bacteria than the other weed control methods. The herbicidal treatments had much higher microbial populations at all stages of observation.