ABSTRACT
The bioecology and infestation aspects of Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) on plants are poorly known. This insect fed on the leaves of common purslane, Portulaca oleracea L. (Portulacaceae) for two consecutive years, which triggered its study in the following five years in Januária, Minas Gerais State, Brazil. The objective of this work was to study the bioecology and infestation aspects of N. platensis on P. oleracea plants in the field and laboratory. The mean duration (± SD) of the egg, larva and pupa stages was 3.6 ± 0.89, 11.5 ± 2.81 and 10.7 ± 1.97 days, respectively. The mean numbers of egg masses and eggs per female (± SD) were 3.8 ± 1.16 and 891.6 ± 116.83, respectively. The percentage of infested plants was 59, 74, 0, 78 and 75% and the mean numbers of larvae per plant (± SD) ranged from 0.7 ± 0.45 to 1.6 ± 0.49 individuals, respectively from 2015 to 2019. Neotuerta platensis larvae infested P. oleracea plants in four out of five years evaluated.
Os aspectos de bioecologia e infestação de Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) em plantas são pouco conhecidos. Esse inseto se alimentou das folhas de beldroega comum, Portulaca oleracea L. (Portulacaceae) por dois anos consecutivos, o que desencadeou seu estudo nos cinco anos seguintes em Januária, Minas Gerais, Brasil. O objetivo deste trabalho foi estudar a bioecologia e os aspectos da infestação de N. platensis em plantas de P. oleracea em campo e laboratório. A duração média (± DP) dos estágios de ovo, larva e pupa foi de 3,6 ± 0,89, 11,5 ± 2,81 e 10,7 ± 1,97 dias, respectivamente. Os números médios de posturas e ovos por fêmea (± DP) foram de 3,8 ± 1,16 e 891,6 ± 116,83, respectivamente. A porcentagem de plantas infestadas foi de 59, 74, 0, 78 e 75% e os números médios de larvas por planta (± DP) variaram de 0,7 ± 0,45 a 1,6 ± 0,49 indivíduos, respectivamente de 2015 a 2019. Larvas de N. platensis infestaram plantas de P. oleracea em quatro dos cinco anos avaliados.
Subject(s)
Animals , Portulaca/parasitology , Larva , LepidopteraABSTRACT
Abstract The bioecology and infestation aspects of Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) on plants are poorly known. This insect fed on the leaves of common purslane, Portulaca oleracea L. (Portulacaceae) for two consecutive years, which triggered its study in the following five years in Januária, Minas Gerais State, Brazil. The objective of this work was to study the bioecology and infestation aspects of N. platensis on P. oleracea plants in the field and laboratory. The mean duration (± SD) of the egg, larva and pupa stages was 3.6 ± 0.89, 11.5 ± 2.81 and 10.7 ± 1.97 days, respectively. The mean numbers of egg masses and eggs per female (± SD) were 3.8 ± 1.16 and 891.6 ± 116.83, respectively. The percentage of infested plants was 59, 74, 0, 78 and 75% and the mean numbers of larvae per plant (± SD) ranged from 0.7 ± 0.45 to 1.6 ± 0.49 individuals, respectively from 2015 to 2019. Neotuerta platensis larvae infested P. oleracea plants in four out of five years evaluated.
Resumo Os aspectos de bioecologia e infestação de Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) em plantas são pouco conhecidos. Esse inseto se alimentou das folhas de beldroega comum, Portulaca oleracea L. (Portulacaceae) por dois anos consecutivos, o que desencadeou seu estudo nos cinco anos seguintes em Januária, Minas Gerais, Brasil. O objetivo deste trabalho foi estudar a bioecologia e os aspectos da infestação de N. platensis em plantas de P. oleracea em campo e laboratório. A duração média (± DP) dos estágios de ovo, larva e pupa foi de 3,6 ± 0,89, 11,5 ± 2,81 e 10,7 ± 1,97 dias, respectivamente. Os números médios de posturas e ovos por fêmea (± DP) foram de 3,8 ± 1,16 e 891,6 ± 116,83, respectivamente. A porcentagem de plantas infestadas foi de 59, 74, 0, 78 e 75% e os números médios de larvas por planta (± DP) variaram de 0,7 ± 0,45 a 1,6 ± 0,49 indivíduos, respectivamente de 2015 a 2019. Larvas de N. platensis infestaram plantas de P. oleracea em quatro dos cinco anos avaliados.
ABSTRACT
Weeds negatively influence agricultural production. However, those losses depend on weed specie, its time of emergence, and period of interference on agricultural crops. Synthetic herbicides are commonly used to control these plants species; however, they may cause damage to the environment, human beings and animals health, and this problem justify the need to develop alternative bioherbicides. To evaluate the allelopathic potential of Ricinus communis (Castor bean) and light spectrum variation on the emergence and growth of Cyperus rotundus L., a trial was carried out in a protected environment with 15% of brightness reduction at the Center for Agricultural and Environmental Sciences at the Paraíba State University. Four aqueous extract concentrations of R. communis leaves were tested (0, 5, 10, and 15%) and four light spectrums variations (white, purple, blue, and red lights). Variables such as emergence, length, dry matter accumulation and growth rates of shoots and root of C. rotundus seedlings were assessed. Data were analyzed by normality test, analysis of variance, polynomial regression, and averages test. Soot and root emergence, length, and dry matter accumulation of C. rotundus seedlings were reduced due to the allelopathy caused by R. communis aqueous extract leaves (15% concentration) and under purple or red light spectrum radiation.
Subject(s)
Ricinus , Cyperus/growth & development , Weed ControlABSTRACT
INTRODUCTION@#Cannabis has consistently been the third most commonly abused drug among drug arrestees in Singapore over the past few years. Accordingly, this study aimed to understand the profile of cannabis users in Singapore and explore the effects of cannabis use on drug progression.@*METHODS@#A total of 450 participants who had used cannabis at least once in their lifetime were recruited from the National Addictions Management Service, prisons, the Community Rehabilitation Centre and halfway houses from August 2017 to May 2018. A face-to-face questionnaire was administered and descriptive analyses were conducted.@*RESULTS@#The mean participant age was 40.9 ± 14.51 years, and 93.1% of them were male. The participants generally initiated cannabis use during adolescence, at a mean onset age of 16.5 ± 4.46 years. Most (89.6%) were introduced to cannabis by peers. Approximately half of them (46.9%) had used cannabis before other illicit drugs and 42.1% of them had used heroin as the succeeding drug.@*CONCLUSION@#In Singapore, cannabis use is often initiated during adolescence, largely under peer influence. Cannabis users may progress to other illicit drugs, particularly heroin, later in life.
Subject(s)
Adolescent , Humans , Male , Adult , Middle Aged , Child , Young Adult , Female , Cannabis , Singapore/epidemiology , Heroin , Substance-Related Disorders/epidemiology , Illicit DrugsABSTRACT
The biodiversity of the agroecosystem leads to changes in the Floristic composition, diversity, and abundance of weed species in crop and orchard farms. The present study is considered the first attempt to categorize, evaluate, and document the diversity of weed populations among different grape farms in Tayma, Tabuk region, Saudi Arabia. The results of ANOVA showed that the number of weed species varied significantly across the six grape farms. During six grape farms under study, 30 weed species belonging to thirteen families and 28 genera were recorded. In total, twelve weed species belong to the Poaceae family with a rate of 40%. While the other families are represented either by one or two species with rates of 3.3% and 6.7%, respectively. Biogeographic origins analysis showed that the Tropical area represented 23.3% of total weed flora, followed by Saharo Arabian (16.7%), Mediterannean-Euro Siberian-Irano-Turanian (13.3%) and American (10.0%). Therophytes were the dominant life forms with a rate of 66.7%, followed by Hemicryptophyte (20.0%), Geophyte (6.7%), and Chamaephyte (6.7%). A total of 16 and 14 weed species belong to the annual and perennial life span, respectively. Also, the grass and herb habits represented 40% and 60% of 30 weed species, respectively. According to the abundance score, the most common weed species of those grape farms in the region study are Cynodon dactylon, Desmostachya bipinnata, and Setaria verticillata, they belong to the Poaceae family. Based on the presence and absence of weed species in grape farms, the Principal Component Analyses (PCA) show that the grape farms and weed species (into two groups) are distinguished mainly along the first two components. Also, positive correlations were observed among most grape farms, according to PCA. Generally, more studies on the ecological aspects and floristic composition of weed species in grape farms are also needed.
ABSTRACT
Multiple field visits were performed to investigate weed flora of wheat fields in Rohtak district of Haryana, conducted during 2018 which revealed infestation of 28 weed species comprising 15 families of grasses and broadleaf weeds. The weeds were identified with the help of available literature and through comparison with the already identified weed species. Poa annua, Polypogon monspeliensis and broadleaf weeds Chenopodium album, Rumex retroflex, Coronopus didymus were the pre-dominant weeds in moist region, whereas Cynodon dactylon, Fumaria parviflora, Chenopodium album, Polypogon monspeliensis in light soil with low salinity. There was a greater variety of weeds in Bohar and Kharawar villages and the least was found in village Sheria and Garnavati from vegetative to fully grown stage. Maximum number of species were of family Poaceae and Asteraceae. This study will be helpful as an additional tool in maintaining the floristic composition of District Rohtak as well as in controlling the weed problem
ABSTRACT
For instant weed management, widely used herbicide formulations (HFs) are Paraquat based formulation (PBF) or Glyphosate based formulation (GBF). Here, we investigated the effect of PBF Gramoxone® and GBF Roundup® on the structure and function of the testis of the male Wistar rats at the pubertal or post pubertal stage. Male rats were gavaged with Gramoxone® (5 mg/kg body wt.) or Roundup® (250 mg/kg body wt.). The treatment period of 25 days starts on a postnatal day (PND) 28 to 53 (from pre-pubertal to the pubertal stage) or 60 days from PND 28 to 88 (from prepubertal to the post pubertal stage). Age-matched control animals received distilled water. The structure of the testes was evaluated by observing changes in its histology and the function of the testes was assessed by estimating serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone levels. No significant effect was observed in the structure and function of the testes of the pubertal stage rats on exposure to both herbicide formulations. However, shrunken and distorted seminiferous tubules with oligozoospermia in testes, a non-significant decrease in FSH and LH, and a significant reduction in testosterone levels were noted in the post pubertal stage rats. The results indicated that changes in the testes of post pubertal groups are due to a longer duration of exposure to the Gramoxone® or Roundup® than in pubertal groups, and also the effect of these two formulations was more on the testis structure and function than on the pituitary-testis axis
ABSTRACT
Antibiotic associated diarrhoea (AAD) is caused mostly by disruption of the physiological gut microflora. One potential strategy to prevent this is the concurrent use of probiotic bacteria or yeast. Tribal populations of West Garo Hill region of Meghalaya use locally available unique microflora to prepare fermented food products whichserve as a potential source of novel probiotic organisms and bioactive compounds. In this context, here, we have evaluated the potentiality of laboratory made functional fermented rice beverage in mitigating AAD on animal models viz. Wistar rats. The animal models were administered with fermented rice beverage (test group A1), combination of indigenous Lactobacillus isolates (test group A2), a yeast isolate (test group A3), loperamide (test group STD), normal control (test group NC) and disease control (test group DC). Furthermore, various diarrhea assessment parameters were checked from each group followed by analysis of fecal microbiome, haematological parameters, histopathology of colon, liver and cecal short chain fatty acids (SCFAs) determination. NC and A1 was least affected by AAD induction with a faecal consistency score of 1 on the final day of the study. After day 10, a significant reduction (P <0.05) in the faecal water content was observed in A1, A2 and STD till day 15. Compared to the NC, a slight decrease in body weight was found in the rest of five test groups at day 5, 10 and 15. Except NC, the remaining five test groups showed a significant decrease of lactobacilli and yeast counts in faecal microbiota at 5th day. An increase in the enterococci and coliform counts indicated severe diarrheal condition but A1 reported with significant increase (P <0.05) in the population of Lactobacillus at day 15. An increase in red blood corpuscles, haemoglobin, packed cell volume, mean cell haemoglobin, mean corpuscular volume, mean corpuscular hemoglobin concentration was observed. During the histopathology analysis of colon and liver, normal layers of mucosa, submucosa, muscularis and serous with absence of any abnormal changes or lesions was seen in A1. The cecal concentrations of lactate, acetate and propionate were significantly higher in A1 as compared to the other test groups. Therefore, fermented rice beverage possesses potential to be used in inhibition of antibiotic associated diarrhea with further clinical investigations.
ABSTRACT
Agroforestry systems are examples of soil exploration that is closer to the natural form of the forest, with intercropping of several species within an area, thus being sustainable alternatives. Therefore, the objective of this work was to evaluate the weed community in agroforestry systems in two ecosystems: solid ground and floodplain in the state of Pará. Such collections were made in eight areas, with about one hectare each, cultivated in agroforestry systems, four of which are on dry land and four on floodplains, in the rural area of Cametá-PA. Four plots of one square meter per area were randomly sampled, where the species were identified, counted, and taken to weigh to evaluate the weed community. Among the evaluated environments, the species that stood out the most in the solid ground environment was Kyllinga brevifolia, leading most of the evaluated indices. In the lowland ecosystem, the Brachiaria species purpuracens were the most relevant.
ABSTRACT
Image processing techniques are one of the fastest developing technologies in the current world. These techniques encompass generic enhancement operations on images that make images viable for extractions of required information (Maier et al., 2019; Fernández-Pacheco et al., 2014). They are core research areas within the disciplines of engineering and computer sciences. Computer algorithms essentially process digital images using various tasks including reconstructions, restorations, compressions, enhancements, estimations of spectrums in images. Executions of these tasks result in analyses or classifications or detections of objects in digital images. Though image processing techniques can contribute towards growth of agriculture and specifically in determining weeds in cultivations, classification of weeds from images is a huge challenge. This chapter details on classification of crops and weeds using image processing techniques while focusing on improving classification accuracies using preprocessing, feature extractions, optimizations of feature selections, classifications, and deep learning approaches.
ABSTRACT
Eichhornia crassipes (EC) is a well-known invasive weed in different aquatic ecosystems. Its effective and complete eradication remains a challenge. The plant is a heavy metal (HM) hyperaccumulator in water bodies; however, studies regarding its biomass utilisation post-phytoremediation remain limited. The abundant growth rate and biochemical composition make EC a promising lignocellulosic feedstock for biofuel production; hence could be a deterministic approach for solving the twin problems of water pollution and higher energy demand, which are the global pressing issues in today’s scenario. The present study aimed at evaluating the phytoremediation potential of EC followed by proximate and biochemical analysis to investigate its suitability for biofuel production. After two weeks, the EC removed above 90% of Lead (Pb) and 60% of Cadmium (Cd) at all experimental doses. Lower doses of HMs, especially Pb, showed stimulatory effects on E. crassipes leaf biomass (ECLB). The recovered ECLB from Pb contaminated water (1 mg L?1) was further analysed for moisture (89.23±0.86%), dry matter (10.77±0.60%), ash (11.91±1.20%), organic carbon (51.56±1.08%), cellulose (21.89±0.64%), hemicellulose (26.50±1.13%), lignin (5.62±0.83%), total carbohydrate (32.00±1.58%), and protein (20.83±0.52%) content. SEM imaging of harvested ECLB confirmed compact and rigid structure. The recorded peaks in FTIR-spectra (1015.21, 1153.71, 1246.01, 1339.63, 1419.71, 1540.71, 1646.80, 1736.73, 2933.03, and 3263.72 cm?1) indicate the presence of lignocellulosic biomass. XRD peak at 21.55? confirmed the crystalline fraction of cellulose in ECLB. The results of theoretical yields of H2 and CH4 co-generation (HMG) (210.85 mLH2/g DW and 150.28 mL CH4/g DW) and Bioethanol (0.278 g/g DW) derived from cellulose and hemicellulose content of ECLB were comparable to those in reported studies. Overall, this work demonstrates an integrated methodology of phytoremediation followed by biofuel production from the recovered phytobiomass.
ABSTRACT
Saflufenacil is a herbicide recommended for use in the main agricultural crops in Brazil to control eudicotyledonous weeds. However, the application of saflufenacil has been carried out without previous knowledge of this herbicide interactions with soil colloids, which may increase environmental contamination risks. In this study, the leaching of saflufenacil in soil samples was estimated with different organic matter contents. Therefore, PVC columns were filled with samples of Xanthic Ferralsol (XF) and Ferralsol (F), with different physical and chemical attributes. Twelve hours after herbicide (70 g i.a. ha-1) application, the PVC columns were subjected to a rainfall of 60 mm. For the evaluation of saflufenacil leaching, the columns were sectioned in ten parts with 5-cm each. Saflufenacil leached up to 50 and 40 cm deep in the samples, with the lowest contents of organic matter of XF and F, respectively. The increase in organic matter content of Ferralsol and Xanthic Ferralsol samples reduced saflufenacil leaching and the symptoms of intoxication in the indicator species. There was an inverse relation between the content of organic matter and the leaching of the herbicide in both soils studied. It was observed that the application of saflufenacil in soils with low organic matter contents may represent a significant environmental contamination risk of soils and watercourses.
Subject(s)
Soil Pollutants , Percolation , Herbicides/adverse effectsABSTRACT
A significant level of yield losses in the vegetable and fruit farms are attributed to the weed populations of the area. This study was conducted for eighteen months during 2019-2020 to assess the presence of various weed families, related species, and their densities in the vegetable (CROP A) and fruit (CROP B) farms of Taif, Saudi Arabia. During the study, fourteen and ten weed families were noted in the vegetable and fruit farms of the studied area, respectively. Poaceae family weeds (729) were significantly higher in numbers followed by the families Asteraceae (414), Chenopodiaceae (338), and Gisekiaceae (153). In the vegetable farms, two weed species of the family Poaceae including Setaria viridis (437) and Eleusine indica ssp (277) were present in the higher numbers followed by Chenopodium murale (166) of the Chenopodiaceae family. In the fruit farms, the weed species Cynodon dactylon of the family Poaceae represented the highest weed density (172) followed by Gisekia pharnaceoides L. species (153) of family Gisekiaceae and Portulaca oleracea (59) belonging to the family Portulacaceae. The vegetable and fruit farms of the Taif region face severe weed pressure that affects the cultivated crops. This study depicts a comprehensive picture of weed diversity and density in the vegetable and fruit farms of the area. The results of this study will be beneficial in developing effective weed management practices for better crop production.
Um nível significativo de perdas de rendimento nas fazendas de hortaliças e frutas é atribuído às populações de ervas daninhas da área. Este estudo foi conduzido por dezoito meses durante 2019-2020 para avaliar a presença de várias famílias de ervas daninhas, espécies relacionadas e suas densidades nas fazendas de vegetais (CROP A) e frutas (CROP B) de Taif, Arábia Saudita. Durante o estudo, catorze e dez famílias de plantas daninhas foram observadas nas fazendas de hortaliças e frutas da área estudada, respectivamente. As plantas daninhas da família Poaceae (729) foram significativamente maiores em número, seguidas pelas famílias Asteraceae (414), Chenopodiaceae (338) e Gisekiaceae (153). Nas hortas, duas espécies de plantas daninhas da família Poaceae, incluindo Setaria viridis (437) e Eleusine indica ssp (277), estavam presentes em maior número, seguidas por Chenopodium murale (166) da família Chenopodiaceae. Nas fruticulturas, a espécie de plantas daninhas Cynodon dactylon da família Poaceae representou a maior densidade de plantas daninhas (172) seguida das espécies Gisekia pharnaceoides L. (153) da família Gisekiaceae e Portulaca oleracea (59) pertencentes à família Portulacaceae. As fazendas de hortaliças e frutas da região de Taif enfrentam uma forte pressão de ervas daninhas que afeta as culturas cultivadas. Este estudo apresenta um quadro abrangente da diversidade e densidade de plantas daninhas nas fazendas de hortaliças e frutas da região. Os resultados deste estudo serão benéficos no desenvolvimento de práticas eficazes de manejo de plantas daninhas para uma melhor produção das culturas.
Subject(s)
Vegetables/growth & development , Plant Weeds/growth & development , Farms , Fruit/growth & development , Saudi ArabiaABSTRACT
The objective of this research was to evaluate weed control in a successional soybean-sorghum system by using preemergent herbicides. Two trials were conducted in soybean and two in sorghum, in different soil types (sandy in Rio Verde city and clayey in Montividiu city). All trials were established in a completely randomized block design with five preemergent herbicides in soybean (rates in): diclosulam 35.3 g a.i.·ha1, chlorimuron 20 g a.i.·ha1, sulfentrazone 200 g a.i.·ha1, flumioxazin 50 g a.i.·ha1, S-metolachlor 1728 g a.i.·ha1, and two controls (hand weeded and untreated). Treatments in sorghum trials were the same to the soybean plus atrazine 1250 g a.i.·ha1 and atrazine 1250 g a.i.·ha1 + S-metolachlor 1728 g a.i.·ha1. All treatments had four replicates. Weed control was assessed at 7, 14, 21 and 28 days after planting (DAP) in both crops. In addition, yield was measured when grains reached physiological maturity. All preemergent herbicide treatments successfully controlled weeds, specially Commelina benghalensis, Cenchrus echinatus and Eleusine indica, in both soybean trials until 28 DAP. In some weeds of sorghum, sulfentrazone, diclosulam and chlorimuron sprayed at soybean preemergence performed better than atrazine sprayed at sorghum preemergence. All preemergent herbicides sprayed at soybean preemergence did not affect soybean and sorghum yield, showing similarity with the hand weeded treatment. The results of this research provide evidence that the mix of crop succession and preemergent herbicide applications can be a strong strategy for integrated weed management.
Subject(s)
Glycine max/parasitology , Crop Production , Sorghum/parasitology , Weed Control/methods , Herbicides/analysisABSTRACT
The presence of weeds in silvicultural systems has been considered one of the main obstacles to the success of projects designed to recover degraded areas. The aim of this study was to evaluate the selectivity of herbicides applied at post-emergence in the initial growth of seedlings of capixingui (Croton floribundus), açoita-cavalo (Luehea divaricata), and guaritá (Astronium graveolens), in the municipalities of Jaboticabal and Junqueirópolis, state of São Paulo. The experimental design was completely randomized, with four replications, and the treatments consisted of herbicides (g a.i.·ha-1) clethodim + phenoxaprop-p-ethyl (50 + 50), sethoxydim (184), quizalofop-p-ethyl (75), nicosulfuron (50), fluazifop-p-butyl (125), fomesafen (225), haloxyfop-methyl (48), bentazon (720), chlorimuron-ethyl (15), in addition to control without herbicide. The characteristics analyzed were: plant height increase and visual phytointoxication at 7, 14, 21, 28, 35, and 42 days after herbicide application. At the end of the experiment, the shoots of the plants were removed to assess shoot dry matter. The herbicides clethodim + fenoxaprop-p-ethyl, fluazifop-p-butyl, and quizalofop-p-ethyl showed selective potential for the species capixingui, açoita-cavalo, and guaritá. The herbicide chlorimuron-ethyl caused mild intoxication symptoms when applied to seedlings of capixingui and açoita-cavalo; also, it was not selective for the guaritá species grown in Jaboticabal. All species showed selectivity to the herbicides sethoxydim, fomesafen, haloxyfop-methyl, and nicosulfuron, as their growth and initial development were not influenced. The herbicide bentazon caused high percentages of injury to açoita-cavalo plants in both cultivation places, but it did not influence the growth and development of the species.
Subject(s)
Thiadiazines/analysis , Forests , Plant Weeds , Herbicides/administration & dosage , BrazilABSTRACT
Abstract A significant level of yield losses in the vegetable and fruit farms are attributed to the weed populations of the area. This study was conducted for eighteen months during 2019-2020 to assess the presence of various weed families, related species, and their densities in the vegetable (CROP A) and fruit (CROP B) farms of Taif, Saudi Arabia. During the study, fourteen and ten weed families were noted in the vegetable and fruit farms of the studied area, respectively. Poaceae family weeds (729) were significantly higher in numbers followed by the families Asteraceae (414), Chenopodiaceae (338), and Gisekiaceae (153). In the vegetable farms, two weed species of the family Poaceae including Setaria viridis (437) and Eleusine indica ssp (277) were present in the higher numbers followed by Chenopodium murale (166) of the Chenopodiaceae family. In the fruit farms, the weed species Cynodon dactylon of the family Poaceae represented the highest weed density (172) followed by Gisekia pharnaceoides L. species (153) of family Gisekiaceae and Portulaca oleracea (59) belonging to the family Portulacaceae. The vegetable and fruit farms of the Taif region face severe weed pressure that affects the cultivated crops. This study depicts a comprehensive picture of weed diversity and density in the vegetable and fruit farms of the area. The results of this study will be beneficial in developing effective weed management practices for better crop production.
Resumo Um nível significativo de perdas de rendimento nas fazendas de hortaliças e frutas é atribuído às populações de ervas daninhas da área. Este estudo foi conduzido por dezoito meses durante 2019-2020 para avaliar a presença de várias famílias de ervas daninhas, espécies relacionadas e suas densidades nas fazendas de vegetais (CROP A) e frutas (CROP B) de Taif, Arábia Saudita. Durante o estudo, catorze e dez famílias de plantas daninhas foram observadas nas fazendas de hortaliças e frutas da área estudada, respectivamente. As plantas daninhas da família Poaceae (729) foram significativamente maiores em número, seguidas pelas famílias Asteraceae (414), Chenopodiaceae (338) e Gisekiaceae (153). Nas hortas, duas espécies de plantas daninhas da família Poaceae, incluindo Setaria viridis (437) e Eleusine indica ssp (277), estavam presentes em maior número, seguidas por Chenopodium murale (166) da família Chenopodiaceae. Nas fruticulturas, a espécie de plantas daninhas Cynodon dactylon da família Poaceae representou a maior densidade de plantas daninhas (172) seguida das espécies Gisekia pharnaceoides L. (153) da família Gisekiaceae e Portulaca oleracea (59) pertencentes à família Portulacaceae. As fazendas de hortaliças e frutas da região de Taif enfrentam uma forte pressão de ervas daninhas que afeta as culturas cultivadas. Este estudo apresenta um quadro abrangente da diversidade e densidade de plantas daninhas nas fazendas de hortaliças e frutas da região. Os resultados deste estudo serão benéficos no desenvolvimento de práticas eficazes de manejo de plantas daninhas para uma melhor produção das culturas.
ABSTRACT
Abstract Light is considered a factor that influences the seed germination of many weed species, and it can signal whether the environmental conditions are favorable or are not favorable for germination. We aimed to study if there is an influence of light quality and dormancy overcoming in seed germination of Echium plantagineum L. We carried out a 2 x 6 factorial experiment, with and without dormancy overcoming with potassium nitrate followed by immersion in gibberellic acid; six light qualities, obtained through the light filters: blue, green, red, far-red, white light and absence of light. The evaluations performed were germination speed index (GSI), average germination time (AGT), germination at the four and 14 days after seeding (DAS), accumulated germination and relative frequency of germination. We observed significant interaction among the light qualities and seed dormancy overcoming or not for the studied variables. There was no significant effect of light qualities, in the evaluated variables, when performing dormancy overcoming, presenting germination above 90% in all the light qualities. However, without dormancy overcoming, we observed greater GSI, germination at four and 14 DAS for the red light filter with 5, 4, 29 and 45%, respectively. When the seeds were submitted to the absence of light, and without dormancy overcoming, there was only 7% of germination at 14 DAS. The seeds of E. plantagineum presented greater germination under incidence of red light, without dormancy overcoming, being classified as preferably positively photoblastics, provided that the dormancy is not overcome.
Resumo A luz é considerada um fator que influencia a germinação das sementes de muitas espécies de plantas daninhas, podendo sinalizar se as condições ambientais são favoráveis ou não para a germinação. Objetivou-se estudar se há influência da qualidade da luz e superação de dormência na germinação de sementes de Echium plantagineum L. Realizou-se um experimento fatorial 2 x 6, com e sem superação de dormência com nitrato de potássio seguido pela imersão em ácido giberélico; seis qualidades de luz, obtidas através de filtros de luz: azul, verde, vermelho, vermelho-distante, luz branca e ausência de luz. As avaliações realizadas foram índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), germinação aos quatro e 14 dias após a semeadura (DAS), germinação acumulada e frequência relativa de germinação. Observou-se interação significativa entre as qualidades de luz e a superação ou não de dormência das sementes para as variáveis estudadas. Não houve efeito significativo das qualidades de luz, nas variáveis avaliadas, ao realizar superação de dormência, apresentando germinação acima de 90% em todas as qualidades de luz. Todavia, sem superação de dormência, observou-se maior IVG, germinação aos quatro e 14 DAS para o filtro de luz vermelha com 5,4, 29 e 45%, respectivamente. Quando as sementes foram submetidas à ausência de luz, e sem superação de dormência, houve apenas 7% de germinação aos 14 DAS. As sementes de E. plantagineum apresentam maior germinação sob incidência de luz vermelha, sem superação de dormência, sendo classificadas como fotoblásticas positivas preferenciais, desde que não seja superada a dormência.
Subject(s)
Boraginaceae , Echium , Seeds , Germination , Plant DormancyABSTRACT
ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.
RESUMO: O objetivo do trabalho foi avaliar a eficiência de uso de herbicidas no controle de capim-annoni em função da disponibilidade de radiação solar e da presença ou ausência de lâmina de água. Para isso, foram conduzidos dois experimentos em delineamento inteiramente casualizado, em esquema fatorial 2x2x4 e 2x2x5, em que o fator A equivaleu ao ambiente (radiação natural ou reduzida); fator B à condição hídrica (com lâmina d'água de 2 cm ou sem); e, o fator C aos herbicidas: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1+ 1080 g ha-1) e testemunha (sem aplicação) no primeiro experimento. No segundo experimento, os herbicidas utilizados foram: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184 g ha-1), imazethapyr (106 g ha-1) e testemunha (sem aplicação). Glyphosate controla eficientemente plantas de capim-annoni com quatro afilhos (>90%), sendo superior a cyhalofop butyl, imazethapyr e sethoxydim, independente das condições. A redução da disponibilidade de radiação solar gera menor produção de matéria seca da parte aérea pelo capim-annoni, podendo inclusive, contribuir para maior eficiência de controle somente por imazethapyr e cyhalofop. De maneira geral, a condição de lâmina d'água não afeta o controle de capim-annoni pelos herbicidas.
ABSTRACT
Weeds is one of the important parts of agricultural ecosystem of Chinese materia medica. Weeds is a double-edged sword with advantages and disadvantages for the cultivated medicinal plants. In this study, we firstly analyzed the positive and negative effects of weeds on the yield and quality of Chinese materia medica. We then explored the possible mechanisms for the weeds' positive effects from the aspects of interspecific relationship, soil microecological environment, light environment, natural control of pests and so on. We also summarized three basic principles of weed control, that is, "making medicinal plants and weeds coexist harmoniously, achieving the overall optimum growth of medicinal plants", "prevention first, integrated control" and "preserving beneficial weeds and increasing their beneficial effects, removing harmful weeds and control their adverse effects". Finally, we introduced several common weed ecological control technology in field of the cultivated medicinal plants in China, including technology of controlling weeds by no-tillage, stral mulch, rotation, alternative herbs, competitive crops, and allelopathy. This study is aimed to apply the ecology theory to guide weed management and control, so as to achieve the goal of advantages promotion and disadvantages elimination of weeds to cultivated medicinal plants, making weeds into treasure and to promote the sustainable and healthy development of Chinese medicinal materials production and the protection of weed diversity.