Beet Crops Research Articles

Change in the biochemical activity of leached chernozem during long application of fertilizers in a grain-sugar beet crop rotation

It is found that the 70-year application of fertilizers in a grain-sugar beet crop rotation in the forest steppe of the Central Chernozem Region changes considerably the biochemical indices of leached chernozem fertility and increases the activity of urease by 17.4–26.9%, catalase by 5.6–36.5%, protease by 23.2–54.2%, cellulose-decomposing activity by 96.2–154.2%; phosphatase activity decreased by 65.7–105.1%. The phytotoxicity of soil against a high fertilizer dose background increased 85.7%.

Water Management in Sugar Beet

Water is necessary for sugar beet crops regarding many vital functions. Irrigation needs varies between 100 and 600 mm year−1. In order to set up the best scheduling method, the water balance method is suggested. Thus, water consumption (ETc) in each site can be estimated by following FAO standards. It is very important for the crop the first and the last irrigation before harvesting. Both are revised. Also, futures needs and working lines such as tolerant varieties to drought, deficit irrigation, salinity and interaction between irrigation and nutrition are proposed.

Responses of sugar beet to sulphur fertilizer in England

SUMMARYSix field experiments were carried out in eastern England between 2003 and 2005 to test the effect of sulphur (S) fertilizer on the yield of sugar beet (Beta vulgaris L.). The experiments were undertaken at sites where there had previously been a positive response to S in other crops or where no S-containing materials had been applied for more than 20 years. No individual experiment produced a significant positive response to S application, but the treatments that received no S fertilizer produced the smallest yield in five of the six experiments. Analysis across years using restricted maximum likelihood (REML) procedures showed that there was a positive and significant sugar yield response in beet of 0·56 t/ha where positive responses had previously been recorded in other crops grown on these loamy sand soils. Beet crops grown in soils of this type should receive S fertilizer that can be applied conveniently as sufficient ammonium sulphate to supply the first dressing of N.

THE EFFECT OF POTASSUM AND BORON ON QUANLITY

This study was conducted at growing season of 2002 ـ 2003 at two locations to study the effect potassium (0 , 36 , 72 , 108) kg.ha-1 added to the soil as potassium sulfate and three levels of boron (0 , 5 , 10) ppm sprayed to the leaves of sugar beet and their interaction on the growth ,of sugar beet (Beta vulgaris L.), using randomized complete block design (R.C.B.D) with three replicates. The quantities characteristic for the sugar beet crop, which included, weight per one plant, total yield (ton.ha-1) in roots. The results show that the use of higher levels of potash fertilizer and sprayed with boron and their interactions caused a significant effect on yield quantity by increasing the total yield, yield per one plant and weight per one root. The effect of the interaction of potassium and boron at higher concentration was more significant than each factor alone. potash fertilizer treatment at a rate of (108) kg K/ha with (10) ppm boron gave an increase in each of the characterize in two locations. Higher response to fertilizer (K and/or B) application was found in the soil of Al- Sheikh Mohamed location compared with Qaber Al-Abed location, in the root yield quantity by increasing the total yield Also the fertilizer efficiency were higher in AL-Sheikh Mohamed soil compared with soil of Qaber Al- Abed at all levels of added potassium and boron fertilizers.

Soil Factors Affecting Yield, Quality, and Response to Nitrogen of Sugar Beets Grown on Light-Textured Soils in Northern Greece

For 7 years (1997–2003), five nitrogen (N) rates (0, 60, 120, 180, and 240 kg N ha−1) were applied to sugar beets arranged in randomized complete block (RCB) design experiments with six replications and grown on light soils (sand content >50 g kg−1) in northern Greece. The aim of this work was to identify soil characteristics that affect yield, quality, and sugar beet response to N fertilization. Before sowing, soil analyses were conducted in control plots (0 kg N ha−1) at two depths (0–30 and 30–60 cm). Soils differed in their physical and chemical properties and especially in sand content, which ranged from 500 to 732 g kg−1. Quantitative (root number, RN; root yield, RY; and sugar yield, SY) and qualitative (percentage sucrose content in fresh root weight, SC; potassium, K; sodium, Na; and α-amino N) traits of control plots were used as soil fertility index. The RN was positively affected by clay content, and RY and SY were positively related with sand and negatively with silt content. The SC was negatively affected by soil (NO3)-N and sodium (Na) concentrations. Also, soil (NO3)-N concentration was positively related with root impurities (K, Na, α-amino N). In combined data over years, N rates had a negative effect on the RN. The RY was the only trait affected by years, N rates, and their interaction. The SC and SY differed significantly between years, and N rates affected significantly the former but not the latter. In combined data over years, N rates were curvilinearly related with Na concentration in roots, whereas a strong, linear relationship was found between α-amino N concentration and N rates. To study the significant years × N rates interaction evidenced for the RY, the relative response (RR) of the RY to N was introduced. Actually, the RR expresses the increase or decrease of the RY for a 150 kg N ha−1 rate compared to the control (0 kg N ha−1). The RR was strongly related with soil K concentration at the 0- to 30-cm depth (y = –0.00002x2 + 0.0082x + 0.5085, r2 = 0.92, P < 0.01, n = 7) and with total N concentration at the deeper layer (y = 1.8335x2 – 3.5312x + 2.6614, r2 = 0.88, P < 0.05, n = 6). Thus, the RY response to a rate of 150 kg N ha−1, which is the commonly applied to the sugar beet crop in Greece, can be predicted reliably by soil characteristics (K and total N concentration) determined before sowing. The strong relationship between soil K concentration and sugar beet response to N merits further research.

Soil properties estimation by inversion of a crop model and observations on crops improves the prediction of agro-environmental variables

Using data observed on crop status to inverse a crop model is an interesting way of estimating the soil parameters, which are rather difficult to determine. Nevertheless, the results of parameter estimation depend on the observation set and the results of the predictions made with the model are also affected. The goal of this study is to assess the quality of soil parameters estimation and of predictions of selected variables of interest for various observation sets. Several synthetic and real observation sets acquired in different conditions (winter wheat and sugar beet crops grown in different weather, soils and cropping conditions) were used to estimate the values of the soil parameters. These estimates were then reused in the model to predict agro-environmental variables of interest for wheat and sugar beet crops. Parameters were estimated using the Importance Sampling method. The results show that the estimate of parameters related to soil water content and soil depth can be significantly improved as compared to prior information. Concerning the prediction of variables of interest, the best results are obtained for wheat yield. Improvement in both parameter estimation and variable prediction depends on the observation dataset: it is greater for conditions were water stress effects are important, that is for shallow soils, dry weathers and when the observations are made on sugar beet crops.

Downy mildew caused by Peronospora farinosa f. sp. betae newly reported on Swiss chard in Korea

Swiss chard (Beta vulgaris var. cicla) is a popular culinary vegetable crop grown worldwide for its edible leaves. In November 2007, Swiss chard showing typical downy mildew symptoms was initially collected in polytunnels in Yongin and Namyangju, Korea. In Yongin area, many growers abandoned the crop before harvest due to significant damage by the disease. Infected leaves turned pale green to yellowish with greyish to dark brown fungal growth developing mainly on lower surfaces, but spreading to the upper surface in wet conditions. As the disease progressed, the leaves began to curl and wilt. Microscopic examination of two representative samples (KUS-F23152 and KUS-F23163) was done to identify the pathogen. Conidiophores (250–600 × 7–10 μm) were hyaline, straight to substraight, mostly monopodially branched in 4-6(-7) orders. Ultimate branchlets were straight to substraight, 5–13 μm long, 1·5–3 μm wide at the base, with conical to obtuse tips. Conidia were olivaceous brown, broadly ellipsoidal to ellipsoidal, and measured 21·5–30·0 × 17·5–22·5 μm (length/width ratio = 1·17–1·35). Amplification and sequencing of the ITS rDNA region were performed and data deposited in GenBank (Accession No. EU591713). Comparison of sequences available in GenBank revealed that the ITS sequence is identical to Peronospora farinosa found on sugar beet, B. vulgaris var. saccharifera (DQ643843 and DQ643844), and shows two base pair substitutions with an isolate on spinach, Spinacia oleracea (DQ643901). Based on the present results of morphological characteristics and molecular approaches and previous work of host specificity (Byford, 1967), the pathogen was identified as P. farinosa f. sp. betae. Downy mildew of Swiss chard has been previously recorded from USA (as Peronospora schachtii), Mexico (as Peronspora sp.) and China (as P. farinosa) (Farr & Rossman, 2009), but not from Korea. Although downy mildew infection on sugar beet has been recorded in the northern part of Korea before (Nakata, 1914), there has been no sugar beet cropping in Korea since the 1920s. The recent outbreak of the disease seems to be closely related to high humidity and poor ventilation occurring in the polytunnels. This is the first Korean report of downy mildew on Swiss chard, an emerging threat to sheltered production of this important crop.

Maize genotype susceptibility to Rhizoctonia solani and its effect on sugar beet crop rotations

Root and crown rot is the major soil-borne fungal disease in sugar beet. In Europe, the disease is mainly caused by the anastomosis group (AG) 2-2IIIB of the basidiomycete Rhizoctonia solani (Kühn). No chemical fungicide to control the disease has been registered in Europe. Therefore, agronomic measures must be optimized to keep the disease severity below an economic damage threshold and to minimize white sugar yield losses. R. solani AG 2-2IIIB infects many other crops besides sugar beet, including maize, where it causes root rot. Sugar beet and maize are frequently grown in the same crop rotation. The proportion of cultivated maize in several European sugar beet growing areas is expected to rise due to a projected increase in demand for renewable resources over the next few years. Although the susceptibility to and tolerance of the disease varies among cultivars in both crops, little is known about the effects of cultivar susceptibility in the pre-crop on a subsequent susceptible crop. The cultivation of R. solani-resistant maize genotypes in rotation with resistant sugar beet might therefore be a useful tool in an integrated control strategy against R. solani, eliminating the need to restrict the desired crop rotation for phytosanitary reasons. A crop rotation experiment with artificially inoculated R. solani was conducted in the field to investigate the pre-crop effects of maize cultivars which differed in their susceptibility to R. solani on a susceptible sugar beet cultivar. We hypothesized that the maize genotype would influence the inoculum potential and performance of a susceptible sugar beet genotype grown after a maize pre-crop, and that this would correlate with the susceptibility of the maize genotype. The results demonstrate that the susceptibility of maize genotypes is consistent over a period of years and that cultivated maize genotypes influenced the inoculum potential measured as disease severity in sugar beet. However, disease severity in sugar beet did not correlate with the disease susceptibility of the genotype of the maize pre-crop. Possible reasons for this missing relationship might be differences in the quality of maize residues for the saprophytic survival of the pathogen or a genotype-specific alteration of the antagonistic microbial community. However, our findings showed that in the presence of maize- and sugar beet-pathogenic R. solani, the most favourable maize cultivar for a crop rotation cannot be determined solely on the basis of its resistance level against Rhizoctonia root rot.

Interferência de caruru-de-mancha sobre características de crescimento e produção da beterraba

A beterraba (Beta vulgaris), importante hortaliça cultivada no Brasil, é muito suscetível à interferência de plantas daninhas, sendo Amaranthus viridis uma das principais espécies encontradas em áreas de horticultura. O objetivo deste trabalho foi estudar a resposta da beterraba à competição com diferentes densidades de A. viridis, por meio da avaliação de características de crescimento e produção da cultura. Um experimento em caixas, com área útil de 0,25 m², foi conduzido em Jaboticabal-SP, Brasil, mantendo-se constante oito plantas por caixa de beterraba em convivência com 0, 1, 2, 3, 4 e 6 plantas por caixa de A. viridis. A cultura da beterraba foi muito suscetível à interferência imposta por plantas de A. viridis, tendo sua área foliar, número de folhas, massa seca de folhas, diâmetro médio da raiz e massa fresca de raízes significativamente reduzidos mesmo em baixas densidades populacionais da planta daninha; a massa fresca de raízes foi a mais sensível à interferência.

Agronomic practices as potential sustainable options for the management of Pentastiridius leporinus (Hemiptera: Cixiidae) in sugar beet crops

AbstractCixiid planthoppers (Hemiptera: Fulgoromorpha: Cixiidae) have been shown to vector phloem‐limited prokaryotes associated to prominent plant diseases world‐wide. However, little information is available on the management of such insects that spend a significant part of their life cycle underground as nymphal stages. Preliminary assays were carried out to analyse the potential of some agronomic practices to reduce the underground populations of Pentastiridius leporinus, a cixiid vector of plant pathogenic bacteria to sugar beets that completes its life cycle in the cropping rotation sugar beet‐winter wheat. A first field assay was carried out to test the effect of spring barley as an alternative crop to winter wheat, a second one analysed the effect of reduced tillage as alternative to ploughing. Planthopper abundance, as evaluated by using horizontal sticky sheets to intercept flying adults that emerged from the soil beneath traps, showed a reduction of 80% and 28% of planthoppers when barley was grown instead of wheat and when reduced tillage was applied instead of ploughing, respectively. Barley roots had 81% fewer nymphs than did wheat roots. Indirectly this study demonstrates how conventional cultural practices for sugar beet production can promote the establishment of P. leporinus populations in sugar beet crops in eastern of France.

Development and test of a crop growth model for application within a Global Change decision support system

When examining potential impacts of Global Change on water resources on the regional scale, spatial and temporal changes in crop water and nitrogen demand are of fundamental significance. State-of-the-art crop growth models are powerful tools to assess the response of crops to altered environmental conditions and cultivation practices. In this paper, the process-based, object-oriented and generic DANUBIA crop growth model is presented. To evaluate the performance of the model, a validation analysis is carried out by comparing modelled data with various field measurements of sugar beet, spring barley, maize, winter wheat and potato crops. Model performance statistics show that crop growth is efficiently simulated. The closest agreement between measured and modelled biomass and leaf area index is achieved for sugar beet and winter wheat. Additionally, the response of the model to changed nitrogen availability caused by cultivation practices is analysed and reveals good results. The results suggest that the model is a suitable tool for numerically assessing the consequences of Global Change on biomass production, water and nitrogen demand, taking into account the complex interplay of water, carbon and nitrogen fluxes in agro-ecosystems.

Identifying key life-traits for the dynamics and gene flow in a weedy crop relative: Sensitivity analysis of the G eneSys simulation model for weed beet ( Beta vulgaris ssp. vulgaris)

The benefits of genetically modified herbicide-tolerant (GMHT) sugar beet ( Beta vulgaris) varieties stem from their presumed ability to improve weed control and reduce its cost, particularly targeting weed beet, a harmful annual weedy form of the genus Beta (i.e. B. vulgaris ssp. vulgaris) frequent in sugar beet fields. As weed beet is totally interfertile with sugar beet, it is thus likely to inherit the herbicide-tolerance transgene through pollen-mediated gene flow. Hence, the foreseeable advent of HT weed beet populations is a serious threat to the sustainability of GM sugar beet cropping systems. For studying and quantifying the long-term effects of cropping system components (crop succession and cultivation techniques) on weed beet population dynamics and gene flow, we developed a biophysical process-based model called G eneSys-B eet in a previous study. In the present paper, the model was employed to identify and rank the weed life-traits as function of their effect on weed beet densities and genotypes, using a global sensitivity analysis to model parameters. Monte Carlo simulations with simultaneous randomization of all life-trait parameters were carried out in three cropping systems contrasting for their risk for infestation by HT weed beets. Simulated weed plants and bolters (i.e. beet plants with flowering and seed-producing stems) were then analysed with regression models as a function of model parameters to rank processes and life-traits and quantify their effects. Key parameters were those determining the timing and success of growth, development, seed maturation and the physiological end of seed production. Timing parameters were usually more important than success parameters, showing for instance that optimal timing of weed management operations is more important than its exact efficacy. The ranking of life-traits though depended on the cropping system and, to a lesser extent, on the target variable (i.e. GM weeds vs. total weed population). For instance, post-emergence parameters were crucial in rotations with frequent sugar beet crops whereas pre-emergence parameters were most important when sugar beet was rare. In the rotations with frequent sugar beet and insufficient weed control, interactions between traits were small, indicating diverse populations with contrasted traits could prosper. Conversely, when sugar beet was rare and weed control optimal, traits had little impact individually, indicating that a small number of optimal combinations of traits would be successful. Based on the analysis of sugar beet parameters and genetic traits, advice for the future selection of sugar beet varieties was also given. In climatic conditions similar to those used here, the priority should be given to limiting the presence of hybrid seeds in seed lots rather than decreasing varietal sensitivity to vernalization.

Evaluation of the influence of irrigation methods and water quality on sugar beet yield and water use efficiency

Abstract Rapid urbanization and industrialization have increased the pressure on limited existing fresh water to meet the growing needs for food production. Two immediate responses to this challenge are the efficient use of irrigation technology and the use of alternative sources of water. Drip irrigation methods may play an important role in efficient use of water but there is still limited information on their use on sugar beet crops in arid countries such as Iran. An experiment was conducted to evaluate the effects of irrigation method and water quality on sugar beet yield, percentage of sugar content and irrigation water use efficiency (IWUE). The irrigation methods investigated were subsurface drip, surface drip and furrow irrigation. The two waters used were treated municipal effluent (EC = 1.52 dS m−1) and fresh water (EC = 0.509 dS m−1). The experiments used a split plot design and were undertaken over two consecutive growing seasons in Southern Iran. Statistical testing indicated that the irrigation method and water quality had a significant effect (at the 1% level) on sugar beet root yield, sugar yield, and IWUE. The highest root yield (79.7 Mg ha−1) was obtained using surface drip irrigation and effluent and the lowest root yield (41.4 Mg ha−1) was obtained using furrow irrigation and fresh water. The highest IWUE in root yield production (9 kg m−3) was obtained using surface drip irrigation with effluent and the lowest value (3.8 kg m−3) was obtained using furrow irrigation with fresh water. The highest IWUE of 1.26 kg m−3 for sugar was obtained using surface drip irrigation. The corresponding efficiency using effluent was 1.14 kg m−3. Irrigation with effluent led to an increase in the net sugar yield due to an increase in the sugar beet root yield. However, there was a slight reduction in the percentage sugar content in the plants. This study also showed that soil water and root depth monitoring can be used in irrigation scheduling to avoid water stress. Such monitoring techniques can also save considerable volumes of irrigation water and can increase yield.

Controle do tombamento de plântulas de beterraba e tomate pelo tratamento de sementes com quitosana

O objetivo deste trabalho foi avaliar o efeito do tratamento de sementes, com o indutor de resistência quitosana, sobre o tombamento de plântulas de beterraba e tomate, e sua relação com alterações bioquímicas e a defesa vegetal. Cada parcela foi representada por 25 sementes. Os tratamentos consistiram da imersão das sementes em quitosana nas concentrações de 0; 0,25; 0,5; 1; 2 e 4%. Posteriormente, as sementes foram semeadas em bandejas com o substrato infectado com Rhizoctonia sp., e mantidas em casa de vegetação por 14 dias. A quitosana induziu a resistência das plântulas de beterraba e tomate e reduziu a incidência de tombamento. As concentrações de 1,1 e 2,5% apresentaram maior eficiência na redução do tombamento, para as culturas da beterraba e tomate, respectivamente. O uso da quitosana induz o aumento na atividade da enzima fenilalanina amônia-liase (FAL) e interfere nas variáveis bioquímicas foliares de proteínas e açúcares totais e redutores.

Impact of protein concentrate coproducts on net land requirement for European biofuel production

AbstractA methodology is proposed for calculating the net land area requirement for European biofuels, accounting for the substitution impact of animal feed protein coproducts such as dried distillers grains and solubles (DDGS) and rape meal. For example, when bioethanol is produced from cereal grain starch, grain protein is preserved in the DDGS coproduct. Each tonne of wheat DDGS has the potential to replace 0.59 tonnes of soy meal and 0.39 tonnes of cereals in EU animal feed, and the land area required for soy and cereal feed production offsets much of the land requirement for wheat bioethanol feedstock. While the land area needed for bioethanol from feed wheat in North West Europe is 0.40 ha t−1, the net requirement after accounting for coproducts is just 0.03ha t−1 of bioethanol produced, 6% of the gross land requirement. Calculated in this way, the net land area required to produce biofuel from EU cereal, rapeseed and sugar beet crops is much lower than the gross land requirement, and from cereal and sugar beet crops is less than the land requirement of biofuel from oil palm and sugar cane.

Identifying key components of weed beet management using sensitivity analyses of the GeneSys-Beet model in GM sugar beet

Genetically-modified (GM) sugar beet varieties tolerant to non-selective herbicides would be useful for managing weed beet, an annual form of Beta vulgaris impossible to eliminate with herbicides in sugar beet. However, it is highly probable that the herbicide-tolerance transgene would be transmitted to the weed through pollen flow. It is therefore essential to study how weed beet. particularly Herbicide-Tolerant (HT) populations, develop in cropping systems and how to optimise crop succession and management for controlling these weeds. As multiple interactions and long-term effects make field experiments impractical, we carried out a simulation study with a deterministic and mechanistic model, GeneSys-Beet, which quantifies weed beet dynamics and gene flow in cropping systems with interactions with climate, soil structure and hydro-thermal conditions. The sensitivity analysis consisted of 250 000 random combinations of input variables to rank cropping system components according to their effect on both total and GM weed beet infestations. Frequency of sugar beet crops, crop succession, manual and mechanical weeding and tillage were identified as the most important variables. Several cultivation techniques must be combined to efficiently control weed beet. Our recommendations are complex, but a delayed return of sugar beet in the rotation. Harvest should be followed as soon as possible by a shallow tilling; tillage should always be as shallow and as early as possible, except before sugar beet where mouldboard ploughing is advisable. If possible, sowing dates should be delayed. Sugar beet should be weeded mechanically and/or manually, aiming at late and efficient, rather than early or frequent operations. Herbicides should be applied whenever possible and target all weed beet stages and genotypes. Set-aside must be cut as frequently and as late as possible.

Adaptive detection of volunteer potato plants in sugar beet fields

Volunteer potato is an increasing problem in crop rotations where winter temperatures are often not cold enough to kill tubers leftover from harvest. Poor control, as a result of high labor demands, causes diseases like Phytophthora infestans to spread to neighboring fields. Therefore, automatic detection and removal of volunteer plants is required. In this research, an adaptive Bayesian classification method has been developed for classification of volunteer potato plants within a sugar beet crop. With use of ground truth images, the classification accuracy of the plants was determined. In the non-adaptive scheme, the classification accuracy was 84.6 and 34.9% for the constant and changing natural light conditions, respectively. In the adaptive scheme, the classification accuracy increased to 89.8 and 67.7% for the constant and changing natural light conditions, respectively. Crop row information was successfully used to train the adaptive classifier, without having to choose training data in advance.

Capture and use of solar radiation, water, and nitrogen by sugar beet (Beta vulgaris L.)

Sugar beet is spring-sown for sugar production in most sugar beet-growing countries. It is grown as a vegetative crop and it accumulates yield (sugar) from very early in its growth cycle. As long as the sugar beet plants do not flower, the sugar accumulation period is indefinite and yield continues to increase. This paper reviews the success of the sugar beet crop in capturing and using solar radiation, water and mineral nitrogen resources. The prospects for improved resource capture and therefore increased sugar yield are also considered, particularly the potential to increase solar radiation interception in the future by sowing the crop in the autumn.

Physicochemical properties of chernozem and crop productivity in primary tillage systems in crop rotation

It is shown that, in a nine-course grain-sugar beet crop rotation, a combined tillage system (non-moldboard for cereals and moldboard for row crops)with annual application of 5 tons of manure and N53P56K53 per hectare of rotation area restrains deterioration of the physicochemical properties of chernozem. The yield of all crops in the rotation increases.

LAND SNAILS ATTACKING SUGAR BEET FIELDS: II–EFFICIENCY OF CERTAIN BIOCIDS AND MOLLUSCICIDES AGAINST Monacha contiana SNAILS AT KAFR El-SHEIKH AND DAKAHLIA GOVERNORATES.

Field experiments had been conducted to evaluate the efficiency of certain biocides compared with some molluscicides against M. contiana land snails infesting sugar beet crop in Dakahlia and Kafr El-Sheikh governorates during 2008-2009 season. Results can be concluded that Agrein, Diple 2X, Protecto and Vertimec were tested as poisonous baits with rates of 2, 4 and 6 %. Reduction percentages were [(26.91, 30.19 and 41.10 %) and (26.14, 28.03 and 31.09 %)], [(26.91, 29.62 and 37.67 %) and (23.16, 28.67 and 32.66 %)], [(35.98, 45.15 and 47.36 %) and (27.12, 36.11 and 39.7 %)] and [(76.95, 82.07 and 81.05) and (72.60, 78.51 and 80.37)] in the two districts 21 day after treatment, respectively. Biocides reduced M.contiana population density with low values after 3 days of treatment but thereafter the reduction increased gradually to reach its maximum after 21 days, this reduction isn't satisfactory so, it wasn't reached fifty percent except Vertimec. The efficiency of Gastrotox, Molotov and Neomyl were ( 78.14,79.68 and 68.17% ) and (80.22, 78.61 and 72.14 %) 3 days after application, respectively. while values were (96.78, 98.46 and 97.18 %) and (94.36, 96.14 and 92.75 %) 21 days after treatment for above mention molluscicides in two districts, respectively.