Broad-leaved Weeds Research Articles

Chemical Weed Management in Wheat- A review

Wheat (Triticum aestivum L.) is one of the major cereal food crops of the world and has very important role in attaining food security. Introduction of dwarf wheat varieties coupled with intensive input (assured irrigation and fertilizers) use after Green Revolution led to complex problem of both grassy and broad leaved weeds. Weed management is very important for achieving higher wheat production. Mechanical, cultural, biological and chemical methods can be adopted for weed management in wheat. Due to industrialization, labour is becoming scarce and costly. Among these methods, chemical weed control is more efficient, less costly and less time consuming. Pre-emergence herbicides cannot control the late flushes of weeds especially, grassy weeds. Post emergence herbicides are very effective against weeds in wheat. However, herbicides are effective against some weed groups due to mode of action and they do not kill other weeds. To control other weeds, another herbicide is needed which involves more cost, time and labour. To overcome this, sequential application of herbicides, herbicidal mixtures and herbicidal combinations are used. The herbicidal combinations could be very effective against both grassy as well as broad leaved weeds and help to reduce cost, time and labour. Application herbicidal combinations viz. clodinafop + metsulfuron (vesta) 60 g ha-1, sulfosulfuron + metsulfuron (total) 32 g ha-1 and mesosulfuron + iodosulfuron (atlantis) 14.4 g ha-1 as well as tank mixture of pinoxaden + carfentrazone (50 + 20 g ha-1) is the best way for managing complex weed flora in wheat as of now. Modification in application method like tank mixture with micronutrients also have potential of increasing the weed control efficiency of herbicides and yield of wheat. To give precise and concise information weed management in wheat, his article reviews the latest herbicides recommended for weed management in wheat. Recent advances in herbicidal mixture, combinations and application techniques are also being included in this review.

Effect of pre- and post-emergence herbicides on weeds and yield of soybean

A field experiment was conducted at Agricultural Research Station, Ummedganj, Kota, Rajasthan during rainy (Kharif) season, 2019 to study the comparative efficacy of pre-and post-emergence herbicides in managing weeds and improving productivity of soybean (Glycine max L. Merrill). The experimental field was infested with grassy weeds (48.60%), broadleaved weeds (39.49%) and sedges (11.91%). Cynodon dactylon (L.) Pers., Eleusine indica (L.) Gaertn., Echinochloa crus-galli (L.) Beauv and Echinochloa colona (L.) Link among grassy weeds, Boerhavia diffusa L. nom. cons., Convolvulus arvensis L., Commelina benghalensis L., Digera arvensis Forsk., Celosia argentea L. among broad-leaved weeds and Cyperus rotundus L., the sedge were major associated weeds. Maximum soybean seed yield (1800 kg/ha) and higher weed control efficiency (77.79%) were recorded with hand weeding twice at 20 and 40 days after sowing (DAS) followed by postemergence application of sodium-acifluorfen 16.5% + clodinafop-propargyl 8% (premix) 165 + 80 g/ha (1550 kg/ha).

A Phytosociological Survey on weed Flora and Diversity in Rice Fields of Chidambaram Block, T.N., India

A phytosociological survey was carried out to assess the varied weed flora and diversity in rice fields of Chidambaram block, Tamil Nadu, India. Chidambaram lies in low land habitat and the climate is subtropical. An average annual rainfall varies between 1200 to 1500 mm. The study has been done during 2020, Navarai season to determine the weed flora, species composition, density, frequency and important value index (IVI). To project the types of weed sps that are mainly affected the low land rice ecosystems. A total of 4 sedges, 3 grasses, 8 broad leaved weeds and 1 aquatic weed were detected. Sedges are most prominent weed flora found in the rice fields of Chidambaram block. The findings indicated that Cyperus difformis, Echinochloa colonum are the most abundant weeds in rice field followed by Cyperus rotundus, Echinochloa crusgalli, Leptonchloa chinensis, Eclipta alba and Sphenoclea zelyancia.

Bio-efficacy of nicosulfuron against mixed weed flora in maize and its residual effect on succeeding crops

A field study was conducted during Spring and rainy (Kharif) season of 2017 at N.E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar U.S. Nagar, Uttarakhand, India to evaluate the effective dose of nicosulfuron for weed control in maize while assessing its effect on growth and yield of maize along with its residual effect on succeeding pea and cowpea fodder. Eight treatments were tested which include: post-emergence application (PoE) of nicosulfuron at different doses (30, 36, 42 and 50 g/ha), tembotrione 120 g/ha PoE, pre-emergence application (PE) of atrazine 1000 g/ha, hand weeding twice at 20 and 40 days after seeding (DAS) and weedy check. The weed community during both the seasons in the experimental area consisted of, grassy weeds: Phalaris minor, Eleusine indica, Digitaria sanguinalis, Echinochloa colona and Panicum maximum, broad-leaved weeds (BLW): Trianthema monogyna, Chenopodium album, Phyllanthus niruri, Parthenium hysterophorus and Mallugo stricta and a sedge Cyperus rotundus. Nicosulfuron at 50 g/ha resulted in 50-100% weed control, depending on the weed species. Nicosulfuron at 50 and 42 g/ha were equally effective in increasing grain yield of maize when compared with tembotrione and was found superior over atrazine during both the season. No phytotoxic symptoms on maize and no residual effect on succeeding pea and cowpea fodder crop were observed, at any doses of nicosulfuron. Hence, nicosulfuron at 42 g/ha PoE may be safely used for effective weed management and improved yield of maize.

Management of weeds in transplanted rice with XR-848 benzyl ester + cyhalofop-butyl (ready-mix)

A field experiment was conducted during rainy (Kharif) seasons of 2015 and 2016 at Agricultural Research Station, Dhadesugur, University of Agricultural Sciences, Raichur, Karnataka, India to evaluate the efficacy of XR-848 benzyl ester 20 g/l + cyhalofop-butyl 100 g/l EC (ready-mix) on weeds in transplanted rice. The dominant grassy weeds in the experimental field were: Echinochloa colona, Panicum repens, Cynodon dactylon, Brachiaria mutica, Digitaria sanguinalis and Leptochloa chinensis; broad-leaved weeds were: Eclipta alba and Ludwigia parviflora and the sedge was Cyperus rotundus. The post-emergence application (PoE) of XR-848 benzyl ester 20 g/l + cyhalofop butyl 100 g/l EC (ready-mix) 180 g/ha recorded significantly lower weeds biomass, higher weed control efficiency at 30, 45 and 60 days after transplanting (DAT) and higher rice grain yield during both the years and it was at par with XR-848 benzyl ester 20 g/l + cyhalofop butyl 100 g/l EC (ready-mix) 150 g/ha. The hand weeding twice at 20 and 40 DAT recorded significantly higher weed control efficiency and grain yield compared to other herbicide treatments.

Effect of herbicides on weed dynamics in transplanted rice (Oryza sativa L.) in Eastern U.P., India

A field experiment was conducted at Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, UP, India during kharif-2017 and 2018 to evaluate effect of herbicides on weed population and weed dry weight in transplanted rice in eastern UP. There were ten treatments in the combination of herbicides in varying doses, arranged in a randomized block design with three replications. Among dominant weed flora narrow leaf weeds like Cynodon dactylon, Echinochloa colona and Echinochloa crusgalli, sedges like Cyperus rotundus, Cyperus iria and Fimbristylis miliacea and broad-leaved weeds like Eclipta alba and Caesulia axillaris were recorded in the time of experimentation. Combined application of Bispyribac-Na 9.1% @ 24.57 g ha-1 + Metsulfuran methyl 1.2% @ 3.24 g ha-1 + Chlorimuron ethyl 1.2% SC @ 3.24 g ha-1 was recorded minimum weeds density and weeds dry weight and maximum weed control efficiency after weed free treatment at all the crop growth stage 30, 60 and 90 days after transplanting.

Wheat growth and physiological response and management of herbicide resistant Phalaris minor Retz. as affected by selective herbicides

Weeds are a major constraint of wheat productivity improvement in India. Among the major weeds, Phalaris minor Retz. is the most problematic weed that mimics wheat. Herbicides are mostly used by farmers to manage weeds in wheat and dependency on single herbicide or herbicides with same mode of action resulted in the development of multiple herbicide-resistance in P. minor. A field study was conducted at CCS Haryana Agricultural University, Hisar during 2016-17 and 2019-20 with an objective to study the growth and physiological response of wheat and management of herbicideresistant P. minor with selective herbicides in wheat. The sequential application of tank-mix (TM) pre-emergence application (PE) of pendimethalin + pyroxasulfone (1500 + 102 g/ha) or pendimethalin + metribuzin (1000 + 175 g/ha) followed by post-emergence application (PoE) of pinoxaden 60 g/ha or mesosulfuron + iodosulfuron 14.4 g/ha resulted in complete control of herbicide-resistant P. minor and other broad-leaved weeds (BLW). The better control of weeds resulted in higher wheat leaf area index (LAI) and crop growth rate (CGR) with 43-46% higher wheat grain yield over the weedy check. However, 0-9% visual toxicity on the crop was observed in metribuzin-associated treatments, which was nullified with the advancement of crop stage. The maximum marginal benefit was observed in weed-free check (39,192 ₹/ha) closely followed by pendimethalin + pyroxasulfone (TM) PE fb mesosulfuron + iodosulfuron PoE, while marginal benefit-cost ratio (MBCR) was highest with mesosulfuron + iodosulfuron (17.8) PoE followed by pinoxaden + metribuzin (50+150 g/ha) PoE. It was concluded that sequential application of PE followed by PoE herbicide with a rotational application of herbicides having different mode of action is suitable for management of herbicide-resistant P. minor in wheat.

Determination of chlorpropham residues in animal-derived foods by solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry

建立了固相萃取-超高效液相色谱-串联质谱法(SPE-UHPLC-MS/MS)测定动物源食品中氯苯胺灵残留的分析方法。动物源食品经乙腈溶液提取、正己烷脱脂、ProElut PLS固相萃取柱富集净化,采用C18色谱柱进行分离,以0.2%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,采用电喷雾电离、正离子模式扫描,多反应监测模式(MRM)检测,基质匹配标准曲线外标法定量。研究通过对不同填料的固相萃取柱的考察,最终选择了ProElut PLS固相萃取柱,其能对动物源食品复杂基质中的氯苯胺灵进行有效富集和净化;通过考察3种规格的C18柱对氯苯胺灵的保留能力和出峰效果,选择了Agilent ZORBAX SB-C18(150 mm×2.1 mm, 5 μm)作为氯苯胺灵的分离色谱柱;通过考察氯苯胺灵在正负两种质谱电离模式下的响应情况,选择了正离子模式,确定氯苯胺灵一级质谱准分子离子和相应的碎片离子。结果表明:氯苯胺灵在0.5~100.0 μg/L范围内呈良好的线性关系,相关系数(r2)均不低于0.9929;方法定量限(LOQ)为3 μg/kg(S/N≥10);以猪肉、牛奶、牛肉、鸡肉、鸭肉、鸡蛋、鸡胗、鸭蛋、猪腰、猪肝、牛肝、羊肉、鸭胗共13种动物源食品为基质,在0.003、0.006、0.060 mg/kg添加水平下,氯苯胺灵的平均回收率为74.9%~97.6%,相对标准偏差(RSD)为2.9%~9.5%(n=6)。本方法前处理简便易行、基质干扰小、灵敏度高、准确性高,适用于多种动物源食品中氯苯胺灵的定性和定量检测。

Hybrid CNN Model for Classification of Rumex Obtusifolius in Grassland

<i>Rumex obtusifolius</i> Linnaeus (R. <i>obtu</i>. L.) is one of the vital broad-leaved weeds in grassland that needs removal. It affects dairy products and reduces their quality. Hand-removal methods are costly and time-consuming. Chemical treatment using herbicides has a negative impact on crops and causes environmental pollution. In smart farming, weeding is performed by using computer vision to recognize the weeds efficiently and effectively. Conventional machine learning (ML)-based algorithms face challenges, especially in identifying the weeds in real-world data due to a lack of features. Deep learning (DL) approaches use self-learning to extract all potential features that assist in classifying malignant weed species accurately. Recently, single deep learning methods achieved high performance in identifying well-separated and illumination but suffered from misclassification in more sophisticated cases such as overlapping and partial occlusion leaves. This paper presents a hybrid Convolutional Neural Network (CNN) model of three state-of-the-art CNNs to classify <i>Rumex obtusifolius</i>. The proposed model utilizes convolutional neural networks to extract features and classify images. The framework of the proposed method comprises three paramount stages to accomplish the classification key idea, including the data preparation phase, pre-processing phase, and classification phase. A hybrid model of three CNN extractor networks is used as the backbone in the classification stage. Our tested data is real-world data that includes multi-circumstances (overlap, occlusion, various illuminations, etc.) acquired from nature. The first extractor is the Visual Graphics Group-16 (VGG-16) for well-separated leaves and non-complicated issues. The second extractor is Residential Energy Services Network-50 (ResNet-50), to overcome complex real-world issues. The third extractor is Inception-v3 to solve the illumination problem. Therefore, combining three networks into one model improves the discriminatory ability to extract additional useful features. The proposed model has been tested using two benchmark datasets for <i>Rumex</i> weed plants. Both of these datasets were captured in real-world environments. The first dataset consists of 900 samples, while the second dataset consists of 677 samples. Each dataset is individually tested in our proposed model to evaluate the classification accuracy using a set of standard evaluation metrics including accuracy, precession, recall, True-Positive Rate (TPR), False-Positive Rate (FPR), and F1-score. The total averages of the proposed model on both datasets are 97.51%, 97.4%, 94.45%, and 95.9% on the accuracy, recall, precision, and F1-score, respectively.

Weed suppression and crop yield in wheat after mustard seed meal aqueous extract application with reduced rate of isoproturon

Weeds are the major biological constraints to wheat production, which reduces the wheat yield up to 80%. The phytotoxic effect of brassica water extracts against weeds has been previously studied; however, the effects of mustard seed meal water extract (MSMWE) alone or in combination with reduced rate of isoproturon (IP) have not yet been explored. Hence, a field experiment was conducted in randomized complete block design to investigate the efficacy of MSMWE, at variable rates, i.e., 113, 225, 338, and 450 L ha −1 alone or combined with IP at 0.50 kg a.i. ha −1 (POST) (IP 0.5), and compared with the recommended rate of IP at 1.0 kg a.i. ha −1 (POST) (IP 1.0), weedy control, and twice-hand weeding (2-HW). Results revealed that 2-HW was the best treatment for weed suppression and wheat yield. Overall, MSMWE 450 L ha −1 + IP 0.5 was highly effective in the suppression of broadleaved weeds (BLWs) as well as of total weeds, and recorded the highest weed control efficiency (47.67) and herbicide efficiency index (0.927). Further, this treatment positively enhanced the tiller count, grain count earhead −1 and grain yield. Application of IP 1.0 effectively suppressed the BLWs, however, failed in the suppression of grassy weeds and total weeds; further, it showed a negative influence on crop dry matter accumulation and grain yield. Sole application of MSMWE suppressed the grassy weeds, dominated by Cynodon dactylon , as compared to combined and sole application of IP. Here we show for the first time that sole MSMWE has potential for suppression of C. dactylon . • Mustard seed meal (MSM) is obtained as by-product during mustard oil extraction. • MSM has herbicidal property, due to high amount of glucosinolates content. • Potentials of MSM water extract (MSMWE) for weed management has yet not explored. • MSMWE 451 L + isoproturon 500 g a.i. ha −1 manages weeds and increase wheat yield. • MSMWE + reduce herbicide rate, increase profitability and reduce environmental pollution.

Effect of weed management practices on growth and yield of transplanted rice (Oryza sativa L.) under system of rice intensification

A field experiment was carried out in wetland farms of TNAU, Coimbatore during summer 2021 to evaluate efficient weed management practices for transplanted rice under the System of Rice Intensification (SRI). The treatments consisted of different combinations of weed management practices including herbicides viz., butachlor 1.25 kg ha-1 and bispyribac sodium 40 g ha-1, cono weeding and hand weeding and were compared with unweeded control. The predominant weed flora present in the experimental field was Echnichloa colona (L.), Echnichloa crusgalli (L.), among grasses, Cyperus difformis (L.), among sedges and Eclipta alba (L.), Ammania baccifera (L.), among broad leaved weeds. The results revealed that application of early post emergence herbicide bispyribac sodium @ 40 g ha-1 at 15 DAT + cono weeding at 30 and 40 DAT recorded lesser weed density (4.18, 2.88 no. m-2 at 40 and 60 DAT), weed dry weight (3.20, 1.61 g m-2 at 40 and 60 DAT) and higher weed control efficiency (82.1 and 93.6 per cent at 40 and 60 DAT) which resulted in increased number of productive tillers m‑2 (445) and filled grains per panicle (176). Application of early post emergence herbicide bispyribac sodium @ 40 g ha-1 + cono weeding at 30 and 40 DAT recorded higher grain and straw yields of 6975 kg ha-1 and 9905 kg ha-1, respectively. This treatment was on par with application of early post emergence herbicide bispyribac sodium 40 g ha-1 + cono weeding at 30 DAT and hand weeding at 40 DAT.

Residues of Reduced Herbicides Terbuthylazine, Ametryn, and Atrazine and Toxicology to Maize and the Environment through Salicylic Acid.

Terbuthylazine (TBA), ametryn (AME), and atrazine (ATZ) are triazine family herbicides. They are dominantly used in the field of cereal crops like wheat and maize for prevention of upland from annual gramineous and broad-leaved weeds, with attributes of weed efficiency broad spectrum and good market performance. Salicylic acid (SA) is a kind of natural plant growth regulator existing widely in the plant kingdom and participating in many physiological and defense processes. In this study, the effects of SA on the detoxification and degradation of herbicides TBA, AME, and ATZ in maize were investigated. When maize plants were exposed to 6 mg kg–1 of the triazine herbicides, the growth and chlorophyll concentration were reduced, while the membrane permeability increased. After maize was sprayed with 5 mg kg–1 SA, the herbicide-induced phytotoxicity was significantly assuaged, with the increased content of chlorophyll and decreased cellular damage in plants. Activities of several biomarker enzymes such as SOD, POD, and GST were repressed in the presence of SA. The concentration of the triazine herbicides in maize and the soil determined by high-performance liquid chromatography was drastically reduced by spraying SA. Using LC/Q-TOF-MS/MS, six metabolites and nine conjugates of AME in maize and soil were characterized. The relative contents of AME metabolites and conjugates in maize with SA were higher than those without SA. These results suggest that SA is able to promote the detoxification and decay of these triazine herbicides in maize and soil.

Biological and economic efficiency of herbicides on spring rape in the conditions of the south of the Non-black earth zone

The results of studies to determine the biological and economic efficiency of a complex of herbicides in crops of spring rape variety Neman in the south of the Non-Chernozem zone are presented. According to the data of the experiments, it was revealed that in the crops of rape there is a polyspecific composition of weeds. The most was the used for the control of broad-leaved weeds Etamaster, VDG, (etametsulfuron-methyl 750 g/kg), 0.025 kg/ha and for the control grass weeds Miura, EC (quizalofop-P-ethyl 125 g / l), 1 l/ha. The decrease in the number of weeds was 90%, weight – 92% compared to the control. The economic efficiency on this option was also the highest, the yield was 2.94 t/ha, the increase to the control was 1.04 t/ha, the collection of crude fat was 1.25 t/ha, the collection of crude protein was 0.82 t/ha.

Productivity of zero-till wheat (Triticum aestivum) under different establishment methods, seed rate and weed control

Field experiment was planned to investigate the integration of establishment methods, variable seed rates and weed control in zero-till wheat (Triticum aestivum L.). The experiment was conducted in split-plot design with four replications. Treatments consisted of two establishment methods, i.e. zero till wheat with residue, viz. ZT+R (6 t/ha) and zero till wheat without residue, viz. ZT-R (0 t/ha), two levels of wheat seed rate (100 kg/ha (recommended) and 150 kg/ha) and four levels of weed control (weedy check, weed free, clodinafop + metribuzin 275 g/ha (recommended) and clodinafop + metribuzin 206.3 g/ha). The results revealed that clodinafop + metribuzin 275 g/ha in ZT + R had significantly lower P. minor biomass (25-27%) than ZT-R; however 16 and 14%biomass of broadleaved weeds were recordedat 90 days after sowing. Interaction effect revealed that in 2017-18, under weedy check, ZT+R had lower weed biomass and gave 14.9% higher grain yield than ZT-R; however in 2016-17, both ZT+R and ZT-R methods recorded almost similar yield. Integrated use of clodinafop+metribuzin 275 g/ha in zero till wheat sown in paddy residues gave the highest wheat grain yield (5465-5531 kg/ha) which was similar to weed free.

Topramezone: A selective post-emergence herbicide in chickpea for higher weed control efficiency and crop productivity

Chickpea (Cicer arietinum L.) is a dominant pulse crop in the world for its climate resilience and nutritional values. Weed infestation causes a significant yield loss in chickpea and jeopardize in realizing the potential yield across regions. Pendimethalin as pre-emergence (PRE) is the ruling herbicide, however, post-emergence (POST) herbicides are limited in this crop particularly for managing broad-leaved weeds and higher yield gain. We assessed the impact of POST herbicides available in different crops on weed phytotoxicity, crop selectivity and yield performance in chickpea on sandy-loam soil of Kanpur, India. The experiment was undertaken for two consecutive years (2016-17 and 2017-18) comprising nine herbicides, besides unweeded control (UWC) and weed-free check (WFC). Among the herbicides tested, halosulfuron-methyl 70 g a.i. ha−1 and tembotrione 100 g a.i. ha−1 showed the maximum phytotoxicity scale of 5-10 on chickpea. Clodinafop-propargyl + sodium-acifluorfen 122.5 g a.i. ha−1 and imazethapyr + imazamox 70 g a.i. ha−1 had a recoverable phytotoxicity (scale 3–5) on chickpea. Topramezone 20.6 g a.i. ha−1 at 25 days after sowing (DAS) resulted in higher phytotoxicity on weeds (toxicity scale of 7–10) without any phytotoxicity on chickpea. It significantly controlled the dominant broad-leaved weeds: Chenopodium album L., Lepidium didymum L., Spergula arvensis L., Medicago polymorpha L. and Fumaria parviflora Lam. compared to the remaining herbicides. Topramezone reduced total weed density by 68-70% and 48–51% (P ≤ 0.05) at 45 and 95 DAS compared with UWC, respectively. Therefore, this herbicide had higher (P ≤ 0.05) weed control efficiency in both years (89.8% in 2016-17 and 76.5% in 2017-18) than remaining treatments. Topramezone increased 15.3-19.6% chickpea seed yield than the recommended herbicide pendimethalin 1000 g a.i. ha−1 - quizalofop-p-ethyl 100 g a.i. ha−1 without affecting the nodulation and fluorescein diacetate activity. The UWC resulted in 64% (mean of two years) yield loss compared to the WFC in chickpea. Importantly, topramezone gave comparable yield with WFC. Hence, topramezone can be safely used in chickpea for managing broad-leaved weeds and realizing higher productivity.

Weed Flora Dynamics in Maize (Zea mays L.) Field as Influenced by Cover Crop Types and Planting Densities at Jalingo, Northeast, Nigeria

Aim: Competition from weeds is an obstacle to profitable maize production. Knowledge of weed species limiting productivity is essential for sustainable management. A two years field experiment was conducted to evaluate the effect of a leguminous cover crop, akidi (Vigna unquiculata sub-sp sequipedalis) and two non-leguminous cover crops (melon and sweet potato) planted at three densities on weed flora composition and shift in maize at Jalingo, North-eastern Nigeria.&#x0D; Study Design: There were 11 treatments replicated three times in a randomized complete block design.&#x0D; Methodology: Low, moderate and high densities (20,000, 30,000 and 40,000 stands/ha respectively) of Akidi, Melon and Sweet potato (A1, A2, A3, M1, M2, M3, S1, S2, S3) with weeded (C1) and unweeded (C2) checks constituted the treatments laid out in a randomized complete block design replicated three times. Weed flora abundance, percentage density, percentage frequency, frequency index and percentage contributions were determined from a 50cm x 50cm quadrat thrown twice per plot at various phases of maize growth.&#x0D; Results: Thirteen weed families made up of 11 broad leaves, one grass and one sedge were identified. The abundance was in the order Broad leaf &gt; Grass &gt; Sedges. The most abundant weed species were: Imperata cylindrica L (3.8), Mucuna utilis (3.0), Oldenlandia herbacea L. (2.6) Sida acuta Burm F, Tridax procumbens L. (2.5 each), Leucas martinicensis, Pennisetum pedicellatum (2.3 each). Commelina benghalensis, Cyperus difformis (3.5), Digitaria horizontalis, Fimbristylis littoralis (2.8 each). The influence of selected cover crops on individual weed percentage the contribution shows: Commelina benghalensis ( C2&lt;C1 &lt; M &lt;S&lt; A), Euphorbia hyssopifolia (C2&lt;M/S &lt; A&lt;C1), Euphorbia heterophylla (M&lt;S&lt;A), Leucasmartinicensis (C1&lt;C2&lt;M&lt;A&lt;S), Mucunautilis (S&lt;M&lt;C1&lt;C2&lt;A) and Sida acuta (M&lt;S&lt;A&lt;C2&lt;C1) while grassy weeds, Imperata cylindrical (A&lt;C2&lt;S&lt;M), Pennisetum pedicellatum (A&lt;C2), Digitaria horizontalis (C1/ C2&lt; A &lt; M &lt;S), Kyllinga squamulata (M/S &lt;C2&lt;A &lt;C1). Commelina spp. increased in status from an accessory (21.2%) to abundance (66.7%) while others increased from rare to accessory (from 0.0 to 20-40%).&#x0D; Conclusion: Akidi was more effective on broad-leaved weeds while melon and sweet potato were more effective on grasses and Commelina benghalensis need to be monitored.

Effect of New Pre-Emergence Herbicides on Quality and Yield of Potato and Its Associated Weeds

Potato is an economically important vegetable crop in Egypt. Weed infestation, especially broad-leafed, during the vegetative growth stage substantially affects both crop yield and tuber quality. In the current study, the impact of new ready-mix pre-emergent herbicides on broadleaf weeds, tuber yield, and quality was evaluated. The two-year field experiment comprised the following treatments: (1) Un-weeded control, (2) Hand hoeing, (3) Sencor, (4) Ecopart, (5) Zeus, (6) Kroki, and (7) Flomex. The results showed that weed control treatments significantly reduced the weed density compared to un-weeded control and the herbicides efficacy reached over 90%. The herbicidal treatments also significantly increased the activity of antioxidant enzymes peroxidases (POX) and catalase (CAT) and improved the non-enzymatic antioxidant (carotenoids) compared to un-weeded control. Conversely, the higher content of malondialdehyde (MDA) in potato leaves was obtained for un-weeded control. Moreover, weed control treatments caused significant enhancement in plant growth parameters, yield, and its components in addition to tuber quality of potato. Compared to the un-weeded control, maximum tuber yield was observed in Flomex followed by Ecopart, Kroki, Zeus, and Sencor, respectively. The higher number of tubers and total yield were recorded in plants treated with Flomex plus compared to all the other treatments. Higher content of total soluble sugar, total soluble protein, and total starch content was observed in weed control treatments compared with un-weeded control. Based on Pearson’s correlation and heatmap analysis, the changes in agro-physiological parameters data are linked to the herbicidal treatments. The results indicate that the applied herbicides could be alternative products for Sencor and an option for controlling broadleaved weeds. However, further studies are needed to ensure their efficacy and safety under other conditions.

English

The present study intended to know the pesticides usage pattern by cotton and chilli farmers in Kurnool district of Andhra Pradesh. For the study Kurnool district was purposively selected as it occupies first place in gross area sown in Andhra Pradesh. Among the crops cultivated in Kurnool district, cotton and chilli were selected as the pesticide’s consumption is high in these crops. The collected data was analyzed by using percentage and frequencies. From this investigation it was found that 92.5 per cent of the sample farmers used Monocrotophos 36% SL for cotton and used as the first spray of insecticide in cotton to control sucking pests by every farmer. In chilli Pendimethalin 30% EC by 97.5 per cent by sample farmers as it controls annual grasses and broad-leaved weeds.

The Impact of Ensiling at Different Moisture Contents on Germinability and Viability of Selected Weed Species’ Seeds

Weeds are an increasingly significant issue inhibiting agricultural production worldwide. Forage conservation could form part of an integrated weed management program if ensiling killed weed seeds. In Experiment 1, seeds of five grass (Hordeum spp., Bromus diandrus, Bromus hordeaceum, Lolium rigidum and Vulpia spp.) and two broad-leaved temperate weed species (Echium spp. and Raphanus raphanistrum), that were either untreated, ensiled in pasture (Trifolium subterranean/Lolium rigidum mixture) forage for a minimum of three months, underwent 48 h in sacco digestion in steers or ensiled prior to digestion were tested for germinability and viability. In Experiment 2, seeds of eight tropical weed species (Cenchrus ciliaris, Rumex spp., Bidens pilosa, Sorghum halepense, Urochloa panicaoides, Paspalum dilatatum, Brachiara eruciformis and Choris truncata) were ensiled in Sorghum bicolor forage. In Experiment 3, L. rigidum and R. raphanistrum seeds were ensiled in either Medicago sativa forage wilted to 336.9, 506.5 or 610.7 g/kg dry matter; or in chaff to which water or water plus acid was added at rates to achieve 350, 450 or 550 g/kg dry matter content with lactic plus acetic acid added in the ratio of 3:2 at 80, 45 or 10 g/kg DM, respectively. In Experiment 4, L. rigidum and R. raphanistrum seeds were ensiled in cotton wool to which water or water plus acid was added at the same rates as in Experiment 3. Germinability of all seeds following ensiling was substantially reduced or nil. The extent of the reduction varied with species and experiment. In sacco digestion reduced germinability in Experiment 1, but to a lesser extent than ensiling; while ensiling plus digestion reduced germination rates to 0%.

Impact of management practices on weed infestation, water productivity, rice yield and grain quality in irrigated systems in Côte d'Ivoire

• AWD reduced weed biomass due to reduction of lowland and broad-leaved weeds. • AWD increased water productivity without yield penalty compared to CF. • Soil pH and N fertilization affected rice yield and water productivity in AWD fields. • Choice of rice variety largely determined grain quality. Management practices that simultaneously enhance rice yield, water productivity, labor productivity, and grain quality are needed for improving crop production and mitigating the negative impact of water scarcity on food security. The objectives of this on-farm study were to evaluate the effects of water management practices including the safe alternate wetting and drying (AWD) method of irrigation on rice yield, water productivity, weed biomass, and grain quality, and identify the factors associated with their variabilities in the fields with AWD. On-farm trials were conducted over two years in 30 fields within two irrigation schemes in the region of Bouake, central Côte d’Ivoire. Before rice cultivation, in each field, three plots consisting of water management practices were established: continuous flooding (CF), safe AWD, and farmers’ practice (FP). Lowland weeds were dominant in rice fields in this study area. Large variations in weed biomass, rice yield, and water productivity were found across fields for each water management practice. Weed biomass and irrigation water input were lower under safe AWD than CF due to higher soil drying while there was no significant difference in rice yield between safe AWD and CF. Water productivity was higher under safe AWD than CF and FP. Rice milling recovery, head yield, and chalkiness were not significantly different among water management practices. Higher rice yield and water productivity in the safe AWD fields were associated with higher soil pH and nitrogen (N) fertilizer rate and better congruence between nitrogen fertilizer application and crop N demand. Milling recovery, head yield, and chalkiness in the safe AWD fields were strongly affected by the choice of rice variety. Combination of safe AWD with varieties having good grain quality characteristics and improved nutrient management practices could be recommended to the smallholder rice farmers to improve rice yield, water productivity, and grain quality and reduce labour requirement for irrigation and weeding particularly in schemes where lowland weeds are dominant.