Direct-seeded Rice Cultivation Research Articles

Identification of anaerobic germination tolerant landraces and validation of molecular marker in rice (Oryza sativa L.)

Poor germination and late seedling establishment are the main obstacles observed for wide spread adoption of direct-seeded rice cultivation in both rainfed and irrigated regions due to the waterlogged condition of the soil. The present experiment was carried out to identify rice landraces with anaerobic germination tolerance for the development of varieties suitable for direct seeded rice cultivation. A total of 53 genotypes of rice landraces were evaluated for anaerobic germination tolerance by following the screening methods of petri plate and tray method. The genotypes namely savudu samba, vellai kavuni, varappu kudaichan and korumbaali recorded the maximum germination percentage (> 90%) under anaerobic conditions and these genotypes also produced high dry matter production. The minimum germination percentage was recorded by malai nellu, surakuruvai and mappillai samba and the remaining landraces observed moderate germination percentage under anaerobic germination. Shoot length recorded for all the genotypes ranged from 0.70 to 6.23 cm under anaerobic germination. Dry matter production of genotypes ranged from 0.031 to 0.265 g/10 seedlings. Based on the screening, the best and least performed genotypes were selected for genotyping using already reported SSR markers. The marker produces the polymorphism between tolerant and susceptible genotypes, which can be exploited further for Marker Assisted Breeding programme. Keywords : Rice, Landraces, Anaerobic, Germination, Validation, Molecular marker.

QTL Mapping of Mesocotyl Elongation and Confirmation of a QTL in Dongxiang Common Wild Rice in China

Direct-seeded rice (DSR) cultivation is an effective and important way to resolve agricultural labor scarcity, water scarcity and high production cost issues. Mesocotyl elongation (ME) is the main driver of the rapid emergence of rice seedlings from the soil and is an important indicator of the suitability of rice varieties for direct seeding. Hence, discovering ME-related genes is particularly important for breeding rice varieties suitable for direct seeding. In this study, a chromosome segment substitution line (CSSL) population generated from a cross between Dongxiang common wild rice and Nipponbare (Nip) was used to map quantitative trait loci (QTLs) for ME. Two QTLs for mesocotyl length were identified on chromosomes 3 and 6 with logarithm of odds (LOD) scores ranging from 5.47 to 6.04 and explaining 15.95–16.79% of the phenotypic variance. Among these QTLs, qML6 accounted for the highest phenotypic variance (16.79%). Then, to confirm the strongest QTL, we generated an F2 segregating population via the CSL127 line harboring the qML6 locus and the recurrent parent Nip. The QTL qML6-1 associated with ME was mapped to a location between markers DX-C6-2 and DX-C6-4, which is consistent with the location of the previously mapped QTL qML6. qML6-1 had an LOD score of 8.45 and explained 30.56% of the phenotypic variance. The QTLs detected in this study provide promising targets for further genetic characterization and for use in marker-assisted selection to develop varieties with improved ME for the cultivation of DSR.

Morphological and physiological traits of roots and their relationships with shoot growth and grain yield in direct-seeded rice in northeastern China

Context In recent years, direct-seeded rice (DSR) cultivation methods have been widely adopted in Asia. Aims The objective of this study was to evaluate the grain yield, nitrogen use efficiency and associated plant traits of DSR in northeastern China. Methods A 2-year field experiment was conducted using two varieties under three cultivation methods (1) conventional transplanted rice (CTR); (2) wet direct-seeded rice (WDSR); and (3) dry direct-seeded rice (DDSR). Key results The grain yield of CTR and DSR ranged from 10.16 to 9.39 t ha−1 and from 8.85 to 6.90 t ha−1, respectively, accross varieties and years. The wide difference was attributed to the differences in spikelet number per panicle and biomass. Compared with the CTR, the DSR decreased the spikelet number per panicle, which resulted in lower spikelet number per m2. Meanwhile, a significant positive correlation was observed between spikelet number per m2 and nitrogen uptake. The nitrogen uptake of CTR and DSR ranged from 151 to 153 kg ha−1 and from 96 to 132 kg ha−1, respectively. The root biomass, root length and zeatin + zeatin riboside contents in roots were higher in CTR than DSR, which contributed to the higher nitrogen uptake. Conclusions These results suggest that DSR reduced nitrogen uptake, thereby resulting in decreased number of spikelets per panicle, and hence lower rice grain yield. Implications These findings have highlighted the deficiencies in direct seeded rice system, and further research is required to overcome these deficiencies.

Genetic analysis of rice germplasm suitable for direct and transplanted establishments

Rice is the staple food crop for most of the population in the world especially in Asia. Due to climate change and labour shortage problems, there is a shift in rice cultivation practices in South Asia. The direct seeded rice cultivation is now preferred over transplanted rice owing to its greater advantage in mechanization and management practices. In the present study, 600 rice germplasm lines were evaluated in transplanted and direct seeded conditions (dry and wet). The principal component analysis revealed that, the first three principal components contributed for 76.54, 78.07 and 80.05 per cent for the total divergence in different establishments viz., dry seeding, wet seeding and transplanting, respectively. The traits viz., days to five per cent flowering, days to 50 per cent flowering, days to 100 per cent flowering and days to maturity contributed the maximum for the total divergence. Further, the genotypes were grouped into 10 clusters based on the dissimilarity coefficient. The clustering pattern of the different establishments was different from one another owing to the differential performance of genotypes in different establishments. The genotypes Tundus, Liu 19, Semiocho and Minchechinhsuthou were found to be very diverse from others in the current study as they were placed in the single solitary clusters in different crop establishments. The genotypes viz., White Ponni, La Hung Ku, IR 78875206B4B and Hsung Tieng 2 had performed better in all the three establishments. Hence, these lines can be used for both direct seeded and transplanted conditions. Key words: Dry seeded, Wet seeded, Transplanted, PCA, Rice, Cluster analysis

Effects of gibberellin priming on seedling emergence and transcripts involved in mesocotyl elongation in rice under deep direct-seeding conditions.

Mesocotyl elongation is a key trait influencing seedling emergence and establishment in direct-seeding rice cultivation. The phytohormone gibberellin (GA) has positive effects on mesocotyl elongation in rice. However, the physiological and molecular basis underlying the regulation of mesocotyl elongation mediated by GA priming under deep-sowing conditions remains largely unclear. In the present study, we performed a physiological and comprehensive transcriptomic analysis of the function of GA priming in mesocotyl elongation and seedling emergence using a direct-seeding japonica rice cultivar ZH10 at a 5-cm sowing depth. Physiological experiments indicated that GA priming significantly improved rice seedling emergence by increasing the activity of starch-metabolizing enzymes and compatible solute content to supply the energy essential for subsequent development. Transcriptomic analysis revealed 7074 differentially expressed genes (false discovery rate of <0.05, |log2(fold change)| of ≥1) after GA priming. Furthermore, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses revealed that genes associated with transcriptional regulation, plant hormone biosynthesis or signaling, and starch and sucrose metabolism were critical for GA-mediated promotion of rice mesocotyl elongation. Further analyses showed that the expression of the transcription factor (TF) genes (v-myb avian myeloblastosis viral oncogene homolog (MYB) alternative splicing 1 (MYBAS1), phytochrome-interacting factors 1 (PIF1), Oryza sativa teosinte branched 1/cycloidea/proliferating cell factor 5 (OsTCP5), slender 1 (SLN1), and mini zinc finger 1 (MIF1)), plant hormone biosynthesis or signaling genes (brassinazole-resistant 1 (BZR1), ent-kaurenoic acid oxidase-like (KAO), GRETCHEN HAGEN 3.2 (GH3.2), and small auxin up RNA 36 (SAUR36)), and starch and sucrose metabolism genes (α-amylases (AMY2A and AMY1.4)) was highly correlated with the mesocotyl elongation and deep-sowing tolerance response. These results enhance our understanding of how nutrient metabolism-related substances and genes regulate rice mesocotyl elongation. This may facilitate future studies on related genes and the development of novel rice varieties tolerant to deep sowing.

Removal of Biomass and Nutrients by Weeds and Direct-Seeded Rice under Conservation Agriculture in Light-Textured Soils of North-Western India.

The escalating scarcity of irrigation water, transplantation of rice on light-textured soils and labour cost acted as major drivers for the transition towards direct-seeded rice (DSR) cultivation from the conventionally flooded transplanting system. Despite these advantages, DSR is a challenge in light texture soil due to heavy weed infestation and a slight decline in crop yield. The weeds compete for nutrients and have an adverse effect on the growth and yield of crops. Hence, to assess the removal of macro and micronutrients by weeds and direct-seeded rice, a field experiment was carried out on sandy loam soil for two consecutive Kharif seasons (2018 and 2019). Three treatments from rice, namely: DSR under zero tillage (DSR-ZT), DSR under conventional tillage (DSR-CT) and DSR under reduced tillage (DSR-RT) were taken as main plots with three tillage treatments in wheat, namely: Conventional tillage without rice straw (CTW-R), Zero tillage without rice straw (ZTW-R) and Zero tillage with straw as mulch using Happy Seeder (ZTW+R) as subplots, replicated thrice. Among the rice establishment methods, DSR-RT showed an edge in terms of rice grain and straw yield (6.18 and 8.14 Mg ha−1, respectively) as well as macro- and micronutrient uptake by rice. Under management practices, ZTW+R proved as an efficient strategy in terms of yield and nutrient uptake by crops. The contribution of weeds towards biomass production was maximum under the ZTW-R (9.44%) treatment followed by DSR-ZT (7.72%). The nutrient budgeting showed that macro- and micronutrient removal by weeds was minimum under reduced tillage (24.51 and 50.35%, respectively), whereas it was 21.88 and 44.87% when wheat was grown under conventional tillage without rice straw. In overall, the research study concluded that weeds on an average remove 25.65 % macronutrients (N, P, K) and 51.47% of micronutrients (Zn, Cu, Fe and Mn) in DSR under rice-wheat cropping system.

Sole and Sequential Application of Herbicide and Straw Mulch on Weed Growth and Productivity of Direct Seeded Rainfed Rice (Oryza Sativa L.)

The sole and sequential application of herbicide and straw mulch on weed growth and productivity of rainfed direct seeded rice, were studied with 12 treatments during kharif 2019. Results showed that the application of oxadiargyl fb rice straw mulch @ 6 t/ha registered significantly the lowest weed density and dry weight at 60 DAS; however, it was statistically at par with oxadiargyl fb hand weeding. Weed free check produced the highest grain yield (3.05 t/ha) which was at par with the sequential application of oxadiargyl fb rice straw mulch @ 6 t/ha (2.99 t/ha) and oxadiargyl fb rice hand weeding (2.90 t/ha). Application of oxadiargyl fb rice straw mulch @ 6 t/ha fetched the maximum net return of Rs. 17528/- per ha and return per rupee invested of 1.52. Application of oxadiargyl fb rice straw mulch @ 6 t/ha could be recommended for managing complex weed flora, higher productivity and greater profit in rainfed direct seeded rice cultivation. Bangladesh J. Bot. 50(3): 671-677, 2021 (September)

New generation post-emergence herbicides and their impact on arbuscular mycorrhizae fungal association in rice

To prevent weed invasion in direct seeded rice cultivation, several new generation post emergence herbicides viz. bispyribac sodium, flucetosulfuron, ethoxysulfuron, fenoxaprop-p ethyl, penoxsulam, fenoxaprop-p-ethyl plus ethoxysulfuron and cyhalofop‑butyl plus penoxsulam are widely used in sub-tropical rice ecosystems of Eastern India. The main objective of this study was to know whether application of above listed post emergence herbicides at recommended (n1) and double recommended dose (n2) has any negative impact on arbuscular mycorrhizal fungal (AMF) association in rice plants. Further, the effects of herbicides on soil microbial properties viz. microbial biomass carbon (MBC), fluroscein diacetate (FDA), dehydrogenase (DHA), acid phosphatase (AcP) and alkaline phosphatase (AkP) activities were analyzed using unsupervised and supervised learning methods. Results indicated that among different herbicides evaluated only application of penoxsulam significantly (p<0.05) reduced the AMF root colonization (58.0%) at recommended dose (n1) compared to only AMF (70.3%) application. Whereas, application of bispyribac sodium (both n1 and n2 dose) enhanced AMF sporulation (1100 spores/100g) and root colonization (86.68%) compared to other herbicides application. Unsupervised learning approaches through PCA found that application of bispyribac sodium enhanced both above ground plant growth responses and soil microbial properties, but penoxsulam had negative impact. But, the combined application of penoxsulam and cyhalofop‑butyl did not show any negative impact on AMF association in rice plants. This study concluded that selection of right type of post-emergence herbicides are very important to minimize the harmful effect or enhance AMF association in rice plants.

Impact of Different Water Management Regimes on the Growth, Productivity, and Resource Use Efficiency of Dry Direct Seeded Rice in Central Punjab-Pakistan

Dry direct-seeded rice has been shown to save irrigation water and labor. Nonetheless, irrigation management in dry direct-seeded rice has received very little attention. Here, we examined the potential of different irrigation regimes: aerobic rice (AR), alternate wetting and drying (AWD) and continuous flooding (CF) in dry direct-seeded rice cultivation on two rice cultivars (Pride-1 (hybrid indica) and NB-1 (inbred indica)). Growth, yield attributes, grain yield, total water input, water productivity and benefit cost ratio were measured. Our results showed that AR saved 11.22 and 28.40%, and 5.72 and 32.98% water compared with AWD and CF during 2018 and 2020, respectively. There was a significant difference in grain yield among treatments and cultivars. AWD and CF produced statistically same total dry weight and grain yield, while AR reduced the total dry weight by 31.34% and 38.04% and grain yield by 34.82% and 38.16% in comparison to AWD and CF, respectively, across the years. Except for 1000-grain weight and harvest index in AWD and CF, further differences in total dry weight and grain yield among irrigation treatments were primarily correlated with variations in yield attributes. Among the cultivars, hybrid rice performed better than inbred rice. Over the two-year period, hybrid rice increased total dry weight, grain yield, and water productivity by 9.28%, 13.05%, and 14.28%, respectively, as compared to inbred rice. Regarding water productivity (WP), the maximum percentage (40.90 and 26.53%) was recorded for AWD compared to AR and CF. Among cultivars, more water productivity (14.28%) was calculated for hybrid rice than inbred one. Chlorophyll and carotenoid contents, leaf area index and crop growth rate contributed to higher grain yield of hybrid rice under AWD and CF. In contrast to WP, the maximum benefit cost ratio was estimated to be higher for CF than that of AR and AWD. For the cultivars, the maximum value (2.26 in 2018 and 2.32 in 2020) was calculated for hybrid rice compared with the inbred one. In conclusion, these results suggests that AWD with maximum WP and CF with maximum BCR could be more efficient approaches than AR. Under CF, hybrid rice cultivars with higher yield and yield-related attributes, WP and BCR performed better.

Growth and Yield of Wet Direct-Seeded Paddy Rice Cultivation Using Only Delayed-Release Coated Urea Fertilizer without Use of Phosphorus and Potassium in Rice-Barley Double-Cropped Paddy Field

Growth and Yield of Wet Direct-Seeded Paddy Rice Cultivation Using Only Delayed-Release Coated Urea Fertilizer without Use of Phosphorus and Potassium in Rice-Barley Double-Cropped Paddy Field

Dry Direct-seeding Rice Cultivation Method Incorporating a Water-leakage Prevention Process Using a Vibratory Roller

Dry direct-seeding rice cultivation requires less labor than traditional transplanting cultivation, as there is no need for seedling production, the puddling process, and the transfer of seedling trays. In northern Kyushu, a double-cropping area in southern Japan, dry direct-seeding rice cultivation has generally not been adopted due to water leakage and the accompanying weed overgrowth. This situation prompted the authors to devise a water leakage prevention technique that can be rapidly implemented after winter cropping, with the aim of guaranteeing a reliable rice harvest. In this study, we use a vibratory roller to compact the soil, investigate the optimal conditions for effective compaction, and demonstrate the procedures for confirming these conditions on-site. This article provides an overview of the research process used to develop this water leakage prevention technique and an outline of our dry direct-seeding rice cultivation method for double-cropping areas, including weed control during the dry period.

Effect of Plant Density, Humic Acid and Weed Managements on Yield, Yield Components and Water Use Efficiency in Direct-Seeded Rice (Oryza sativa) Production

Rice is the most important crop after wheat in Iran. Since direct seeded rice cultivation has recently started in Golestan province and complete information about the effect of weed management, plant density and humic acid on rice grain yield and yield components as well as water use efficiency is not available, these issues have been investigated in this study. Therefore a study was carried out on direct-seeded rice cultivation (cv. Tarom Hashemi) in the cropping years 2018 and 2019 in Gonbad Agricultural Research Station as a split-factorial experiment based on randomized complete block design with three replications. Plant density (plant distance on row) was considered as the main factor (5, 10, 15 and 20 cm), and combination of humic acid consumption (consumption of humic acid, non-consumption of humic acid) and weeds management (control, chemical management and weeding) were considered as sub plots. The results showed that the effect of year on panicle length, number of seeds per panicle, paddy protein and water use efficiency was significant. Also, the effect of humic acid, plant distance on row and type of weeds management on all studied traits including plant height, panicle length, number of fertile tillers per hill, number of grains per panicle, paddy yield, biological yield, harvest index, paddy protein and water use efficiency were significant. Also, the highest paddy yield, biological yield, harvest index and water use efficiency were obtained from plant distance on row 5 cm under humic acid consumption or chemical management and weeding, but the amount of paddy protein was higher in the plant distance on row 10 cm.

Reduction of Volunteer Rice Using a Combination of Cultural and Chemical Control in Dry Direct-Seeded Rice Cultivation

Reduction of Volunteer Rice Using a Combination of Cultural and Chemical Control in Dry Direct-Seeded Rice Cultivation

Weed Management in Dry Direct-Seeded Rice: A Review on Challenges and Opportunities for Sustainable Rice Production

Rice cultivation always remains significant for food and livelihood security. The predictions of increasing water deficiency under a changing climate and escalating labor shortages in agriculture have brought a paradigm swing in rice cultivation from conventionally flooded transplanting to direct-seeded rice (DSR). DSR cultivation can potentially address the concerns of diminishing natural resources and mounting production costs in the establishment of transplanted rice. The transition towards DSR saves water, reduces duration to maturity as well as labor required, and reduces negative environmental footprints. Despite all these recompenses, the potential yield losses through enormous weed menaces under DSR remains a challenge and may reduce yield by up to 50%. In this review, we examine the extent of weed infestation, weed shift and the losses in dry DSR (DDSR). Various regional and global scientific efforts made under DDSR have been assessed in the present and the smart weed-management strategies suggested can be adopted after scrutiny. Integration of different weed management approaches, namely prevention, cultural, mechanical, and chemical, have been discussed, which can pave the way for worldwide adoption of DDSR, especially in South Asia. In Asia, 22% of the acreage of total rice cultivation is under DSR and the region-specific integration of these weed-management approaches might reduce herbicide use in these areas by up to 50%.

Adoption of Direct Seeded Rice Cultivation Technology among Farmers of Haryana - A Sociological Analysis

Adoption of Direct Seeded Rice Cultivation Technology among Farmers of Haryana - A Sociological Analysis

Proper Growing Regions and Management Practices for Improving Production Stability in Direct-seeded Rice Cultivation

Proper Growing Regions and Management Practices for Improving Production Stability in Direct-seeded Rice Cultivation

Adaptation Approaches for Direct Seeded Rice to Reduce Greenhouse Gas Emission in the Perspective of Climate Change

A field experiment was conducted at research farm, Bihar Agricultural University, Sabour, India during 2017 and 2018 to gain insight crop phonology mediated greenhouse gas emission under different tillage and nitrogen management practices in direct seeded rice (DSR). The experiment was conducted in split plot design with two tillage viz. zero tillage (ZT) and conventional tillage (CT) as main plot and four nitrogen management practices viz. 100% nitrogen through neem coated urea (S1), SPAD based nitrogen management (S2), 75% through neem coated urea + 25% nitrogen through vermicompost, (S3) and ¼ nitrogen as basal and rest in equal three splits at 20, 40, 60 DAS (S4) as sub plot, in three replication. The highest yield (4.69 t ha-1), net return (Rs 46440 ha-1) and B:C ratio (1.44) were recorded from zero tilled DSR. Further, highest yield (4.82 t ha-1), net return (Rs 44880 ha-1) and B:C ratio (1.36) was obtained under split application of nitrogenous fertilizers among other subplot treatments. The range of methane (0.57- 1.47 mg m-2 hr-1) carbon dioxide (0.32- 0.61 mg m-2 hr-1) and nitrous oxide (19.58- 38.79 µg m-2 hr-1) emission was recorded lowest in zero tilled plots and split application of nitrogenous fertilizer also emitted lowest values of 1.59 mg m-2 hr-1 methane, 0.86 mg m-2 hr-1 carbon dioxide and 46.76 µg m-2 hr-1 nitrous oxide at maximum tillering stage of crop growth. Moreover, methane and nitrous oxide emission was gradually decreased from maximum tillering to harvesting stage. Zero tilled DSR with split nitrogen fertilizer application ascribed lowest greenhouse gas intensity among the other crop establishment and nitrogen management options. Thus, zero tilled method of crop establishment with split application of nitrogenous fertilizer could be a remunerative and environmentally stable method for direct seeded rice cultivation.

Evaluation of anaerobic germinability in various rice subpopulations: identifying genotypes suitable for direct-seeded rice cultivation

Anaerobic conditions in waterlogged soil lead to low germination rates, which significantly reduce crop yields. Good seed germination is prerequisite for direct-seeded cultivation of rice to obtain optimal yields not only in irrigated lowland but most importantly in rain-fed and waterlogged areas where water supply could be more than needed. Due to the limited availability of rice genotypes suitable for anaerobic germination, there is an urgent need to select diverse rice germplasm with enhanced anaerobic germinability. In this study, we evaluated 185 rice accessions from six subpopulations for germination rate (AGR) and coleoptile length (ACL) under anaerobic conditions. The highest average AGR (60%) and longest average ACL (2.13 cm) were observed in tropical japonica (TRJ) and temperate japonica (TEJ) germplasm, respectively. Meanwhile, the highest proportion of accessions with “very long” ACL was in the TEJ subpopulation, whereas those with the “highest” AGR were in the aus subpopulation based on our criteria. We selected seven strong accessions for anaerobic germinability (AG) based on AGR and ACL and analyzed the relative expression patterns of four AG-related genes in strong and weak accessions via qRT-PCR. In general, proton pyrophosphatase locus (OVP3) was expressed at the highest levels in strong accessions, whereas the expression level of rice ethylene response element binding protein locus (EREBP1) did not significantly differ among accessions under normal and anaerobic conditions. The relative expression results of rice alpha amylase locus (RAmy3D) and OVP3 showed distinct patterns and divided all strong accessions into two groups, suggesting that major genes involved in AG may vary depending on the germplasm. These findings could be helpful for breeders and lay the foundation for further genetic analysis.

Cross-Resistance to Imazapic and Imazapyr in a Weedy Rice (Oryza sativa) Biotype Found in Malaysia

ABSTRACT: The Clearfield® rice production system is an effective management tool for weedy rice and other weeds in the direct-seeded rice culture. However, if farmers cultivating the Clearfield® rice disregard stewardship recommendations, the industry could face a problem of herbicide-resistant weedy rice which would occur through the selection of outcrosses. This study aimed to confirm imidazolinone-resistant weedy rice in Malaysia. The resistant weedy rice (R-WR) was found to be 67 fold more resistant to OnDuty® (premix of imazapic and imazapyr) than the susceptible weedy rice (S-WR) based on the GR50 values (rate that causes 50% inhibition of shoot growth). The Clearfield® rice cultivar was 32-fold more tolerant to OnDuty® than the S-WR. Furthermore, the R-WR was 54 and 89 fold more resistant to imazapic and imazapyr applied separately than the S-WR, respectively. The Clearfield® rice was 140- and 40-fold more tolerant to imazapic and imazapyr, respectively than the S-WR. The R-WR biotype was susceptible to non-selective herbicides glyphosate and glufosinate, as well as the selective graminicide quizalofop. Oxadiazon controlled the R-WR biotype, but pretilachlor was ineffective. The present study documented the first case of weedy rice that was cross-resistant to imazapic and imazapyr in Malaysian Clearfield® rice field.

Effect of Pre-Soaking on Seedling Establishment and Pretilachlor Tolerance in Four Rice Genotypes

This study aimed to investigate the effects of pre-soaking for 2 h before seeding on rice seedling establishment after 15-day spraying with pretilachlor. The cytochrome P-450 content, glutathione S-transferase (GSTs), and root activity were also determined. Seedlings of four rice cultivars with contrasting tolerance of pretilachlor were compared. Seed pre-treatment by pre-soaking increased the survivability and growth under pretilachlor spray and improved seedling establishment by increasing P-450, GSTs and root activities. Tolerant genotypes, super hybrid rice, responded better to pre-soaking in direct-seeded rice treated with pretilachlor. It is important for establishment in direct-seeded rice with pre-soaking seeds before sowing in improving emergence and seedling. The positive effect of pre-soaking was proved in all four rice genotypes. Seed pre-soaking will be effective in direct-seeded rice culture to protect rice treated with pre-emergence herbicide and control weedy rice.