Weed Suppression Research Articles

Satureja montana L. Cultivated under Polypropylene Woven Fabric on Clay-Textured Soil in Dry Farming Conditions

During a five-year field trial established with Satureja montana L. under polypropylene woven fabric (PPWF) on clay-textured soil in dry farming conditions in South Banat, Serbia, the influence of a single basal application of compost and mineral fertilizers at different planting densities (3.6 and 5 plants m−2) on the yield was investigated. Single-dose fertilization positively influenced the yields of S. montana in both applied fertilization models. In the third production year, the dry herb yield achieved by applying organic fertilizers in dense cultivation (1016 g m−1) was comparable with that obtained in the mineral plot (961 g m−1). Furthermore, the plants were optimally supplied with N, P, and K macronutrients, with equal amounts removed by yield, in both tested fertilization plots. The use of PPWF proved beneficial to cultivated plants in terms of water-use efficiency and weed suppression. However, severe yield loss was observed in the fourth and fifth production years as a result of the extreme rainfall conditions; the excess moisture retained by PPWF applied to heavy clay soil favored the development of soil-borne pathogens. Other mulch materials should be further investigated for the production of S. montana on heavy clay soil.

Fall–winter cover crops promote soil health and weed control in the southeastern clayey soils

AbstractSeven winter cover crops including grasses, legumes, and brassicas were evaluated for biomass production and effects on weed presence, stored soil water, soil health indicators, and the performance of a subsequent soybean [Glycine max (L.) Merr.] crop in the clayey soils of South Carolina during 2019–2020 and 2020–2021. A mixture of Austrian winter pea (Pisum sativum L.), rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth), and oat (Avena sativa L.), a mixture of crimson clover and rye, and single rye ranked high for biomass production. Cover crops did not deplete more soil water than a fallow did (–22 to 8% difference in soil water retention, compared to fallow with or without herbicide application), controlled weeds equally well or better than herbicides (>90% reduction in weed presence, compared to herbicide control), and reduced soil penetration resistance (>40%, compared to fallow with or without herbicide application in the second season). The five‐species mixture also improved soil biological activity (>43% increase in soil respiration at cover‐crop termination, compared to that under a chemical fallow). The subsequent soybean crop's yield was never negatively affected if not improved by the above cover crops (9–173% increase, compared to that following a chemical fallow). Our results indicate the suitability of the above cover crops for the southeastern clayey soils based on biomass production, weed suppression, and improvements in soil health and the subsequent soybean crop's performance and provide the rationale for planting them rather than keeping the land under a chemical fallow.

Biomassa, acúmulo de nutrientes e supressão de plantas daninhas por mix de plantas de cobertura

ABSTRACT Cover crops, isolated or mixed, provide several benefits to agricultural systems, such as nutrient cycling and weed control. The present study aimed to determine the biomass production and nutrient accumulation of a cover crop mix and its effects on weed suppression (biomass production), in the off-season, in a no-tillage area in the Cerrado region. The experimental design was in randomized blocks with six treatments and eight replications. Treatments comprised five cover crop mixes plus the control treatment (fallow). Mixes of cover crops, cultivated between grain harvests in a no-tillage system in the Cerrado region, efficiently reduced weed shoot biomass in the three evaluation periods, 30, 70, and 210 days after sowing. Additionally, it is concluded that the mixes 5 (Black oats, Buckwheat, Millet, Piatã grass, and Crotalaria ochroleuca) and 4 (C. spectabilis, Buckwheat, Pearl millet, and Crotalaria breviflora) are the best among those evaluated for Cerrado conditions because they produce more biomass in the offseason, due to the greater availability of nutrients to the soil, in addition to providing less biomass of weeds compared to fallow.

Weed biological control with fungi-based bioherbicides

Biological control refers to the use of living beneficial organisms as well as the products of their metabolism in pest control. Weed plants are indispensable companions of cultivated plants, in which they cause substantial damage. Organic food production, human health care and environmental preservation impose a need for the production and application of bioherbicides, particularly in organic systems of plant production. Plant pathogens have significant potential as biological agents in weed control. The aim of the present study was to indicate the most important properties of the weed biological control system, with particular emphasis on the use of fungi-based bioherbicides. According to the organism they suppress, biopesticides are classified into bioinsecticides, biofungicides, bioherbicides, etc. Weed control using plant pathogens can be performed in three ways, by classical, conservation and augmentative biological control. Bioherbicides were initially introduced to the market in 1980, and the majority of them were fungi-based bioherbicides. The most common fungi included in bioherbicides belong to the genera Alternaria, Colletotrichum, Cercospora, Fusarium, Phomopsis, Phytophthora, Phoma, Puccinia, etc. The studies, development and final commercialisation of fungi as biological control agents face many obstacles, ranging from basic biological facts to social and economic factors. There are also challenges in the production, formulation process, environmental friendliness, duration of herbicidal action, and expensive and time-consuming registration procedures. Considering the success in weed suppression with fungi-based bioherbicides, the global market is still dominated by chemical companies manufacturing synthetic herbicides, while there are no such products on the Serbian market yet.

Poly-Coated Brown Wrapping Paper Sheet as an Alternative to Black Plastic Film Mulch in Bhendi

Black plastic film mulching is widely practiced in crop production, especially in horticultural systems, because of its multiple benefits. However, its post-usage polluting residues and limited availability to farmers at all places cause concern. The objective of this study was to evaluate in a field experiment the potential of the commonly available stationery-purpose poly-coated brown wrapping sheet mulching in bhendi [Abelmoschus esculentus (L.) Moench] in comparison with black plastic film mulching. Observations made on plant height and fruit yield, soil temperature and soil microbial population revealed that the less-polluting poly-coated brown wrapping sheet mulching was as good as the black plastic film mulching in performance which is discussed in the light of increase in plant growth and yield, moisture conservation and weed suppression, root-zone temperature moderation and termite activity.

Weed control under increasing cover crop diversity in tropical summer and winter

Description of the subject. Weed pressure is a main biotic constraint in tropical agriculture. Cover crop mixtures have increased in popularity to limit weed growth through competition for resources, but the relationship between cover crop diversity and weed suppression is still under debate. Objectives. This study aimed to assess the impact of increasing cover crop diversity (one to four species) on weed control during two growing seasons (tropical summer and winter) in Reunion Island. Method. Weed control was expressed regarding ground cover by weeds and weed aboveground dry mass in the mixtures during four months of growth and its response to cover crop traits was tested using structural equation models. Results. While cover crops reduced weed ground cover and dry mass by 60% and 68% on average in summer and winter, respectively, a higher number of cover crop species within a mixture did not increase mean weed control. Nonetheless, weed control was influenced by the mixture composition and improved when including Guizotia abyssinica. Additionally, cover crop traits explaining weed control differed between growing seasons. In summer, weed control was mainly explained by the final cover crop aboveground biomass and leaf area (depletion strategy). In contrast, weed control was mainly explained by the cover crop rate of increase in ground cover (obstruction strategy) in winter. Conclusions. Using traits to characterize cover crop mixture enables us to identify mixtures of species and traits adapted to different growing conditions. Our study suggests that particular attention on species identity rather than diversity should be paid in mixture to improve weed control in tropical conditions.

Weed Dynamics, Productivity and Profitability of Transplanted Aman Rice as Influenced by Integrated Nutrient Management and Weeding Regime

The excessive and improper application of fertilizers is the key factor contributing to nutrient losses to the environment and a decrease in the fertility of the soil. Also, using the wrong herbicide, applying higher than the recommended rate, or improper timing of application can cause crop damage. These factors adversely affect soil productivity and environmental stability. There is thus a need to expand an effective and inexpensive integrated nutrient management and weed control practice for acquiring better yields and profit from rice. The aim of the study was to find out the effect of six integrated nutrient management i.e., BRRI Recommended Dose (RD) of chemical fertilizer, 50% RD + 5 t of cowdung ha-1, 50% RD + 10 t of cowdung ha-1, 50% RD + 2.5 t of poultry manure ha-1, 50% RD + 5 t of poultry manure ha-1, USG 1.8 g 4 hills-1 + TSP, MoP, Gypsum and ZnSO4 @RD along with four weeding regimes i.e., control (no weeding), pre-emergence herbicide followed by one hand weeding at 30 DAT, early post-emergence herbicide followed by one hand weeding at 30 DAT, pre-emergence herbicide followed by early post-emergence herbicide on weed control, rice productiveness, and profitability. Our findings suggest that the application of 50% of the RD of chemical fertilizer + 5 t of poultry manure ha-1 with the application of pre-emergence herbicide followed by early post-emergence herbicide enhances weed suppression and provides higher rice productivity and profitability and can be practiced for the maximization of the yield and net return of transplanted aman rice.

Grit effects on grass weeds and grit-weeding in aronia berry (Aronia melanocarpa)

Abstract Two sequential experiments examined the effects of abrasive grit on seedlings of grass weeds and young shoots of perennial weeds. First, four types of grit derived from agricultural residues (bone meal, eggshell, hazelnut shell, and sugar beet pulp) were tested under high air pressure in a controlled environment for their abilities to abrade seedlings of an annual grass, Setaria faberi Herrm., and the perennials Festuca arundinacea Schreb., Poa pratensis L., and Elymus repens (L.) Gould. Differing grit particle sizes and amounts, as well as weed seedling stages, were examined for efficacy after abrasion by each type of grit. Second, hazelnut shell grit was used to control P. pratensis and Taraxicum officinale Weber in field trials with aronia (Aronia melanocarpa [Michx.] Elliott), which is a new, shrubby, berry crop in the midwestern USA. Grit weeding was compared to two other treatments: manual weeding (hand-hoeing + hand-pulling) and no weed control (weedy check) over two years. In the grit comparison experiment, control of S. faberi was highest for egg-shell grit (63–100% across grit particle sizes, rates, and seedling stages) and least for sugar beet pulp (17–97%). The former grit had the highest bulk density of all grits, and the latter had the lowest bulk density. For damage to perennial weeds, egg-shell grit performed best (17–80% control) and bone meal least (10–47% control). Elymus repens was controlled better than other perennial grasses, especially by eggshell grit (up to 73% control) and hazelnut shell grit (up to 67% control) with particle sizes of 1–2 mm. In the aronia experiment, both grit abrasion and manual weeding achieved comparable levels of weed suppression (≥87%) and required similar amounts of cumulative seasonal time spent weeding (3–4 min per shrub). Thus, applications of abrasive grit derived from agricultural residues are potential alternatives for non-chemical management of weeds in aronia and, perhaps, in other high-value perennial crops.

Management of weed diversity through organic mulching and alternative weed suppression practices on ginger (Zingiber officinale)

Management of weed diversity through organic mulching and alternative weed suppression practices on ginger (Zingiber officinale)

Management of weed diversity through organic mulching and alternative weed suppression practices on ginger (Zingiber officinale)

A field experiment was conducted at the Regional Research Station (Hill Zone), Uttar Banga Krishi Viswavidyalaya, Kalimpong, Darjeeling, West Bengal, during 2019 and 2020 to study the effect of weed diversity, growth and yield of ginger (Zingiber officinale Rose) as influenced by organic mulching and alternative weed management practices. The randomized block design, having seven varying treatments with three replications was used. The treatments consisted of dry weed biomass mulch @ 5.0 t/ha (T1), paddy straw mulch @ 5.0 t/ha (T2), FYM Mulch @ 5.0 t/ha (T3), dry leaves of Schima wallichi@ 5.0 t/ha (T4), dry leaves of Artimesia sp. and Eupatorium sp. @ 5.0 t/ha (T5), hand weeding (twice) at 45 and 90 DAS (T6) and unweeded control (T7). The result showed that hand weeding twice at 45 and 90 DAS (T6) appreciably reduced the total weed population/m2 and total dry weight of weeds than unweeded control plot (T7) at all the stages of crop growth. The highest plant height (82.10 cm), number of leaves/clump (65.41), number of pseudo stem/clump (5.17), rhizome length (7.22 cm), rhizome width (5.50 cm), number of fingers/rhizome (6.42), yield/plant (0.268 kg/plant), yield (20.33 t/ha) and weed control efficiency were recorded under the hand weeding twice at 45 and 90 DAS (T6) compared to other treatments. The results showed that it is necessary to cover the soil surface with different mulch materials and manual weed control practices to achieve a good control of weeds along with enhanced yield attributes and yield.

Functionally diverse cover crops support ecological weed management in orchard cropping systems

Abstract Diverse agricultural management practices are critical for agroecosystem sustainability, and cover crops provide opportunity for varied management and increased biodiversity. Understanding how cover crops fill open ecological niches underneath the trees, interact with weeds, and potentially provide ecosystem services to decrease pest pressure is essential for ecological agricultural management. The goal of this study was to test the weed suppression potential of two cover crop treatments with varied functional diversity compared to standard weed management practices in commercial almond orchards in California. Transect plant surveys were used to evaluate orchard plant communities under a functionally diverse seed mix including grasses, legumes, and brassicas, and a relatively uniform cover crop mix that included only brassica species. Winter annual orchard cover crops reduced bare ground from 39.3% of total land area to 15.9 or 11.4%, depending on treatment. Furthermore, winter cover crops displaced weeds with a negative correlation of 0.74. The presence of cover crops did not consistently affect weed community composition for low-richness weed communities found in California orchards. Diverse cover crop mixes more reliably resulted in increased ground cover across site years compared to uniform cover crop mixes, with coefficients of variation for ground cover at 49.6 and 91.5%, respectively. Cover crops with different levels of functional diversity can contribute to orchard weed management programs at commercial scales. Functional diversity supports cover crop establishment, abundance, and competitiveness across varied agroecological conditions, and cover crop mixes could be designed to address an assortment of orchard management concerns.

Effect of polyethylene sheet colour and in situ solarization durations on the phytosociological structures of the predominant weeds in humid environment of southern Nigeria.

High humidity favours the proliferation of a wide range of weed species. Studying the phytosociological attributes of weeds in a humid area provides insight into the dynamism and relative importance of each weed species peculiar to the area which is very important in understanding crop-weed interrelationships and highlights the bases for effective management stratages. An experiment was conducted in 2019 and 2020 cropping seasons at the Department of Crop Science Teaching and Research Farm, University of Calabar, to identify the predominant weeds in the farm area and assess their responses to polyethylene colour and soil solarization duration. The experiment was a factorial combination of two polyethylene colour (black and transparent) and five in situ soil solarization durations (0, 8, 12, 16 and 48 weeks), laid out in randomized complete block design (RCBD) with three replications. Data were collected on the phytosociological characteristics of the weeds on four weekly intervals up to the twentieth week. The predominant weeds identified in the experimental area were Eragrostis ciliaris L., Cynodoon dactylon L., Panicum maximum Jacq., Axonopus compressus Beav., Kyllinga bulbosa Beav. and Kyllinga erecta Schum., Gloriosa superba L., Ipomoea involuncrata P., Calapogonium mucunoides Desv., Aspillia bussei O. Hoff, Ageratum conyzoides L., Phyllantus amarus Schum., Caldum bicolor Vent., Triumfeta rhomboidea Jacq., Cleome rutidosperma DC., Euphorbia heterophylla L., Mitracarpos villosus DC., Oldenladia. herbacea L. The relative density of Caladum bicolor was higher across the treatment in both years, reaching up to 37.7 % in the plot solarized for 16 weeks using black polyethylene, followed by P. maximum with upto 18.40 % in 2019 and Gloriosa superba (20.50 %) in 2020. The highest Important Value Index was recorded by Caladum bicolor reaching up to 28.7 % in the plot solarized for 16 weeks using black polyethylene. The lowest species variation was recorded in the plots solarized for 16 to 48 weeks irrespective of the polyethylene colour. In situ solarization of up to sixteen weeks using black polyethylene effectively controlled majority of the weed species in both years and is recommended for effective weed suppression in cassava farms in humid environment.

Allelopathic Potential of Winter Wheat Varieties for Weed Suppression

Allelopathic Potential of Winter Wheat Varieties for Weed Suppression

Mitigating agricultural intensification in the Western Cape with landscape elements: a synopsis of applicable ecological weed management strategies

Background The agricultural landscape has deteriorated rapidly because of human population growth and the concomitant increased demand for food. Although necessary to feed the global population, production intensification accounts for reduced resilience of cropping systems due to the increased inputs required for greater yields. Objective The purpose of this synopsis is to highlight applicable ecological weed management strategies in order to promote weed suppression in intensively managed agricultural production systems of the Western Cape. Methods In order to achieve [...]

Влияние некоторых агроэлементов технологии возделывания на эффективность выращивания подсолнечника в условиях степной зоны Кабардино-Балкарии

The article presents the results of long-term (2016–2018) studies conducted on the Ciscaucasian (carbonate) chernozems of the steppe zone of the Ka-bardino-Balkarian Republic. The efficiency (technical – the degree of weed suppression, economic – the yield of sunflower oil seeds, economic – the revenue from the sale of products, the amount of net income, cost, profitability, etc.) of some elements in sunflower cultivation technologies has been studied. A high degree of weed suppression in the crops of the studied sunflower varieties has been proven using normal (63.0–77.6%) and intensive (82.5–91.4%) technologies by the end of the growing season of the crop. In the variant with extensive technology, this indicator did not exceed 60.8 % in the variety Lakomka and 43.3% of weed death in the variety Belochka. The crude aboveground mass of weeds, determined 30 days after the treatment of sowings, was also the smallest in variants with normal (35.0–43.0 g/m2) and intensive (15.0–35.0 g/m2) agrotechnologies. On the background of extensive technology, these results exceeded 87.0 and 93.0 g/m2, respective-ly, for sunflower varieties. The different degree of contamination of sowings had an impact on the yield of sunflower oil seeds. Therefore, in the variant with extensive technology, it did not exceed 2.1 and 1.8 t/ha in the Lakomka and Belochka, respectively. On the background of normal and intensive technologies, these data were 2.7–3.5 t/ha for the Lakomka and 2.5–2.8 t/ha for the Belochka, respectively. In a production test (2020) conducted with sunflower sowings of the Lakomka variety, the high economic efficiency of intensive technology with a seed yield of 2.9 t/ha at a gross product value of 72.5 thousand rubles/ha with a net income of 37.0 thousand rubles/ha and a profitability of 104.0% was confirmed. For the variant with normal technology, gross output in monetary terms amounted to 57.5 thousand ru-bles/ha with a net income of 33.8 thousand rubles/ha with a profitability of 143.0%. On the variant of extensive technology, the gross product value was 35.0 thousand rubles/ha with the amount of production costs of 18.6 thousand rubles/ha. Under these conditions, both the amount of net income (16.4 thousand rubles/ha) and profitability (88.0%) of production were the lowest.

The Influence of Different Crop Mulches on Weed Infestation, Soil Properties and Productivity of Wheat under Conventional and Conservation Production Systems.

Pakistan and other South Asian countries rely on wheat for human nutrition. However, wheat yield is declining in the region due to several biotic and abiotic constraints. Weeds are among the major factors responsible for yield decrease and farmers manage them by intensive tillage practices. Several studies have investigated the impact of various tillage practices on weed management in wheat. However, weed suppression abilities of different mulch types are rarely tested. This three-year (2019-20, 2020-21 and 2021-22) study investigated the impact of different mulch types (prepared from different crops) on weed infestation, soil properties and productivity of wheat under conventional and conservation production systems at three locations (Multan, Hafizabad and Faisalabad) in Punjab, Pakistan. The mulches included in the study were cotton sticks mulch, mungbean straw mulch, sorghum straw mulch, rice straw mulch, sunflower straw mulch, plastic mulch, and no mulch (as control). The production systems opted for wheat cultivation were conventionally tilled wheat (CTW), zero-tilled wheat (ZTW) and zero-tilled wheat sown with happy seeder machine (HSW). The CTW resulted in the lowest soil bulk density and the highest soil porosity after wheat harvest, while ZTW behaved oppositely. Similarly, incorporation of crop mulches resulted in the highest soil porosity and the lowest soil bulk density, while no-mulch incorporation and plastic mulch recorded the highest bulk density and the lowest soil porosity. Regarding mulches by production systems' interaction, CTW with sorghum straw- and plastic mulches recorded the lowest weed density and biomass, while ZTW with no-mulch recorded the highest weed density and biomass at all locations. The CTW with mungbean straw- and plastic mulches resulted in the highest yield due to significant improvement in yield-related traits. However, ZTW with sorghum straw mulch and no-mulch resulted in the lowest wheat yield. Although sorghum straw mulch suppressed weed infestation, it negatively affected wheat growth. Economic analysis revealed that CTW with mungbean straw mulch resulted in the highest gross and net incomes and benefit:cost ratio (BCR), while the ZTW with rice straw- and sorghum straw mulches produced the lowest gross and net incomes and BCR at all locations. Therefore, mungbean straw mulch is a viable option to improve wheat productivity and net economic returns under different agro-climatic conditions of Punjab, Pakistan.

Fall-sown small grain cover crops for weed suppression and soil moisture management in an irrigated organic agroecosystem

Abstract Adoption of cover crops in arid agroecosystems has been slow due to concerns regarding limited water resources and possible soil moisture depletion. In irrigated organic systems, potential ecosystem services from cover crops also must be considered in light of the concerns for water conservation. A constructive balance could be achieved with fall-sown small grain cover crops; however, their impacts on irrigated organic systems are poorly understood. Our first objective was to determine the ability of fall-sown small grains [cereal rye (Secale cereale L), winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.)] to suppress winter weeds in an irrigated, organic transition field in the southwestern USA. Small grains were planted following the legume sesbania (Sesbania exaltata (Raf.) Rydb. ex A.W. Hill) during Fall 2012 and Fall 2013. In Spring 2013 and 2014, weed densities and biomass were determined within each cover crop treatment and compared against unplanted controls. Results indicated that both barley and oat were effective in suppressing winter weeds. Our second objective was to compare weed suppression and soil moisture levels among seven barley varieties developed in the western United States. Barley varieties (‘Arivat’, ‘Hayes Beardless’, ‘P919’, ‘Robust’, ‘UC603’, ‘UC937’, ‘Washford Beardless’) were fall-sown in replicated strip plots in Fall 2016. Weed densities were measured in Spring 2017 and volumetric soil moisture near the soil surface (5.1 cm depth) was measured at time intervals beginning in December 2016 and ending in March 2017. With the exception of ‘UC937’, barley varieties caused marked reductions in weed density in comparison with the unplanted control. Soil moisture content for the unplanted control was consistently lower than soil moisture contents for barley plots. Barley variety did not influence volumetric soil moisture. During the 2017–2018 growing season, we re-examined three barley varieties considered most amenable to the cropping system requirements (‘Robust’, ‘UC603’, ‘P919’), and these varieties were again found to support few weeds (≤ 5.0 weeds m−2). We conclude that several organically certified barley varieties could fill the need for a ‘non-thirsty’ cover crop that suppresses winter weeds in irrigated organic systems in the southwestern United States.

An optimized biofumigant improves pepper yield without exerting detrimental effects on soil microbial diversity

BackgroundBiofumigation is a non-chemical sustainable approach that reshapes soil microbiota to overcome challenges in way of continuous cultivation. However, the type and quantity of substrate have a significant impact on microbiota shifts and the subsequent success of biofumigation. Moreover, studies on the effects of biofumigant concentration in combination with fumigation duration on soil microbiota dynamics are very rare.Research methodsWe performed microcosm experiments to investigate how a biofumigant (Korean canola cultivar, HanRa) at various concentrations (0.5%, 1%, 2–4% w/w: biofumigant/soil) and fumigation periods (2–4 weeks) affects the soil bacterial and fungal communities. Subsequently, pot experiments employing two Korean canola cultivars (HanRa and YongSan) at 1% (w/w) were carried out.ResultsIllumina MiSeq analysis revealed that 2–4% biofumigant, regardless of incubation period, had a significant negative impact on microbial diversity and network complexity. In contrast, 1% biofumigant transformed the bacterial, fungal, and inter-kingdom networks into a highly connected and complex network without affecting microbial diversity. Bacillus, Clostridium, and Pseudomonas were the most highly stimulated bacterial genera in the biofumigated soils, whereas the abundance of Acidobacteria members was greatly reduced. The 2–4% amendments had substantially and more differentially abundant Fusarium than the 1%. Soil nutrition (e.g., pH, nitrate, ammonium, and exchangeable potassium), fruit yield, and weed suppression were enhanced in subsequent pot experiments. Of the nine soil chemical properties, phosphate and exchangeable potassium were the main factors influencing the microbial community assembly.ConclusionsOptimized biofumigation-mediated increase in nitrate, ammonium, and potassium availability in the soil without causing any negative effects on soil microbial diversity indicates its potential as a preplant to improve crop productivity. This study contributes significantly to our understanding of how an optimal biofumigant can help ameliorate obstacles in continuous cropping.Graphical

Impact of multi mix herbicide on growth and weed indices in irrigated groundnut (Arachis hypogaea L.)

Food and nutritional security for the country India depends on the agriculture sector. Groundnut is an important food legume cum oilseed crop and weed infestation is the major problem causing yield reduction. Therefore, the field experiment study was conducted during the winter season of 2022 at Central farm, Agriculture College and Research Institute in Madurai to evaluate the newer multi-mix herbicide combinations and find out the appropriate weed management practices for yield enhancement and weed suppression in irrigated groundnut (Arachis hypogaea L.). The experiment consisted of twelve treatments (T1 to T12) laid out in a randomized complete block design. Among the weed flora, almost two third of the weed infestation was documented as broad-leaved weeds (51%), followed by grassy weeds (36%) and less infestation by sedges (13%) in groundnut at the experimental site. Application of pre-emergence alone and post-emergence alone does not suppress the weed infestation efficiently. For that, this study focused on using multi-mixed herbicides along with hand weeding to determine herbicide's efficacy on weed control and growth parameters. Among the weed control methods, weed-free check (T12) increased the growth parameters viz., Plant height (65.3 cm), Leaf Area Index (4.34) and Dry matter accumulation (5536 kg ha-1) and higher weed control efficiency (99.2%). Among the herbicidal treatments, pre emergence application of pendimethalin + imazethapyr (ready mix) followed by hand weeding at 40 days after sowing (T7) gave significantly (P=0.05) higher results in growth components of groundnut and weed suppression compared to other herbicidal treatments.

Influence of Mowing and Trampling on the Allelopathy and Weed Suppression Potential of Digitaria ciliaris and Cyperus microiria

A long-term, sustainable solution to weed infestation is extremely desirable because weeds have the potential to reduce crop productivity and the aesthetic appeal of the environment. In this study, the impacts of mowing and varying degrees of trampling pressure on the suppression of weeds, alongside wound-induced changes in the allelopathic potential, of the rhizosphere soil and the root exudates of southern crabgrass (Digitaria ciliaris) and Asian flatsedge (Cyperus microiria) were evaluated under both field and greenhouse conditions. The field study results showed that all trampling treatments induced the relative suppression of weed growth. Grass weeds showed higher resistance to trampling than broad-leaved weeds. However, laboratory bioassays showed that light trampling caused a significant increase in the growth-inhibitory effects of southern crabgrass rhizosphere soil on lettuce. Moreover, mowing (9.11% of control) and trampling (16.4% of control) resulted in a marginal increase in the growth-inhibitory effects of root exudates released from southern crabgrass. Furthermore, the growth-inhibitory activities of the Asian flatsedge rhizosphere soil were significantly reduced after heavy trampling pressure. Moreover, mowing and trampling resulted in marginal reductions in the growth-inhibitory activities of root exudates released from Asian flatsedge against lettuce (i.e., 18.7% and 28.5%, respectively). In general, mowing and varying degrees of trampling induced contrasting and integrated impacts on weed suppression as well as the allelopathic potential of both southern crabgrass and Asian flatsedge.