Cyanamide Research Articles

석회질소에 의한 배추뿌리혹병 방제효과

The effect of calcium cyanamide() on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

Brotação e produção das videiras 'Cabernet Sauvignon' e 'Pinot Noir' submetidas a diferentes concentrações de cianamida hidrogenada

A ausência de frio invernal na videira produz efeitos adversos, como o atraso e desuniformidade de brotação das gemas, dificuldades de manejo fitossanitário, produção escalonada e de baixa qualidade. O trabalho foi realizado no município de Garibaldi, na região da Encosta Superior do Nordeste do Estado do Rio Grande do Sul, com 640 metros de altitude, com objetivo de testar concentrações de cianamida hidrogenada de 0; 0,5; 1,0; 1,5; 2,0 e 2,5% nas cultivares viníferas Cabernet Sauvignon e Pinot Noir. Os melhores resultados para brotação de gemas de vara foram de 1,75 e 2,0 % em 'Cabernet Sauvignon' e 'Pinot Noir', respectivamente. Concentrações superiores a 1,5 % ocasionaram uniformidade de brotação, independentemente do ano. A maior produtividade foi obtida com cianamida.hidrogenada 2,0% nas duas cultivares, com elevação média de cinco ton/ha. Houve maior fertilidade nas gemas de vara do que em esporão. Os aspectos qualitativos das uvas não foram afetados pela cianamida hidrogenada, com exceção do peso médio dos cachos na 'Pinot Noir', na safra de 2004.

Environmental Problems From Tea Cultivation in Japan and a Control Measure Using Calcium Cyanamide

ABSTRACT A field experiment, involving lime N (calcium cyanamide, CaCN2) fertilization as a control measure, was conducted to study environmental problems induced by long-term heavy N application in Japanese tea fields. Long-term tea cultivation caused serious soil acidification. Seventy-seven percent of the 70 tea fields investigated had soil pH values below 4.0, and 9% below 3.0, with the lowest value of 2.7. Moreover, excess N application in tea fields put a threat to plant growth, induced serious nitrate contamination to local water, and caused high nitrous oxide loss. Compared with the conventional high N application treatment (1100 kg N ha−1) without lime N, the low N application (400 kg N ha−1) with calcium cyanamide effectively stopped soil acidification as well as achieved the same or slightly higher levels in tea yield and in total N and amino acid contents of tea shoots. The application of calcium cyanamide could be a suitable fertilization for the prevention of environmental problems in tea cultivation.

Effect of Deep Placement of Slow‐release Fertilizer (Lime Nitrogen) Applied at Different Rates on Growth, N2 Fixation and Yield of Soya Bean (Glycine max [L.] Merr.)

AbstractA new fertilization method with deep placement of slow‐release N fertilizers, such as coated urea and lime nitrogen (LN) (calcium cyanamide) at 20 cm depth was found to promote soy bean seed yield. In the present study, the effect of deep placement of LN was investigated on different parameters such as growth, N accumulation, N2 fixation activity and yield of soy bean by applying LN at different rates in the rotated paddy field of Niigata, Japan. In addition to the basal fertilizer, ammonium sulphate (16 kg N ha−1), deep placement of LN was conducted by applying various amounts such as 50 kg N ha−1 (A50), 100 kg N ha−1 (A100) and 200 kg N ha−1 (A200) at 20 cm depth in separate plots. A 15N‐labelled LN fertilizer was also employed for each of the above treatments to calculate N utilization from LN in separate plots. Soya bean plant growth and N2 fixation activity were periodically analysed. Both plant growth and N accumulation were found to increase with LN treatment compared with control plants. An increase in N2 fixation activity was found in the A100 plots. The total seed yield was the highest in the deep placement of LN with A100 (73 g per plant) compared with other treatments. The visual quality of harvested seeds also showed that A100 enhanced the quality of seeds compared with other treatments. Thus, it is suggested that N fertilization management with particular reference to optimum amount of fertilizers is important for maximum growth, N2 fixation and enhancement of seed yield of soy bean.

Reaction of cyanamides with N,N-binucleophiles

Reactions of 4,6-dimethylpyrimidin-2-yl-and aroylcyanamides with benzene-1,2-diamine, ethylenediamine, cyclohexane-1,2-diamine, and naphthalene-1,8-diamine leads to 1H-benzimidazol-2-amine, imidazolidin-2-imine, perhydrobenzimidazol-2-imine, and 1H-perimidin-2-amine derivatives, respectively.

Adjuvant and application technologies to minimise offtarget drift from kiwifruit sprays

The productivity and quality of the New Zealand kiwifruit crop depends on dormancy breaking sprays that are applied in high volumes to bare canes The risk from offtarget spray drift is high This study investigated new nozzle and adjuvant technologies to improve the targeting of hydrogen cyanamide sprays and reduce offtarget losses The use of air inclusion (AI) nozzles could reduce vertical and horizontal drift of hydrogen cyanamide airblast sprays relative to conventional cone nozzles The combination of an adjuvant with AI nozzles resulted in a significant decrease in offtarget drift by as much as 86 compared to current industry standard application methods Deposits on target canes were not adversely affected by the use of AI nozzles and biological efficacy of the budbreaking agent was maintained

Application of Hydrated Lime to Hydrogen Cyanamide-treated Grapevines Reduces Lemon Leaf Abscission in Neighboring Lemon Orchards

Previous research in our laboratory provided evidence that hydrogen cyanamide (HC) applied to grapevines (Vitis vinifera) to stimulate budbreak resulted in ethylene production, which, in addition to HC drift at application, caused abscission of leaves in neighboring `Eureka' lemon [Citrus limon (L.) Burm. F.] orchards. Foliar-applied hydrated lime [Ca(OH)2] at 140 kg per 2337 to 2807 L·ha-1 to commercial `Thompson Seedless', `Perlette', `Red Flame', or `Princess' vineyards 2–48 h after HC treatment reduced leaf abscission from 2-year-old'Eureka' lemon trees placed inside the vineyards, with no negative effects on budbreak or yield of any grape cultivar. Hydrated lime is an effective inexpensive tool that grape growers can use to protect neighboring lemon orchards.

The effect of spent mushroom sawdust compost mixes, calcium cyanamide and solarization on basal stem rot of the cactus Hylocereus trigonus caused by Fusarium oxysporum

A severe epidemic of basal stem rot of the cactus Hylocereus trigonus occurred in 2001, in greenhouses of Goyang City, South Korea, possibly due to continuous cultivation in soil beds. Fusarium oxysporum was isolated and its pathogenicity was demonstrated. Inoculation of mycelial plugs on stem disks of cactus showed brown discoloration. Inoculation of a spore suspension of F. oxysporum (1.40×10 4 or 1.24×10 8 spores ml −1) on the underground basal stems of cactus plants, followed by incubation at 28 °C in a growth chamber, led to the development of brown spots identical to the original symptoms after 3 months. The effect of amendment with spent mushroom sawdust, calcium cyanamide, straw and solarization on the development of the disease was studied. In a greenhouse study, amendment with spent mushroom sawdust compost to the disease-conducive soil reduced the disease incidence to 3–12%, as compared to 44–59% with the unamended disease-conducive soil. Autoclaved spent mushroom sawdust compost did not reduce the disease incidence. The bacterial (1.95×10 11 cfu g −1) and fungal population (9.50×10 7 cfu g −1) of spent mushroom sawdust was significantly higher than those (2.0×10 9 cfu g −1 and 0.13×10 5 g −1 for bacteria and fungi, respectively) of disease-conducive soil. Also, disease-suppressive soil had a higher fungal population (1.25×10 5 cfu g −1) compared to disease-conducive soil (0.13×10 5 cfu g −1). This trend was repeated in the second experiment. Solarization with and without calcium cyanamide of disease-conducive soil reduced effectively pathogen population and disease development, resulting in 16–53% disease incidence, as compared to 81% in the untreated control. Rice straw as an organic amendment did not have synergistic effect on disease control when it was used along with calcium cyanamide for solarization. The results indicate that the control of basal stem rot with spent mushroom sawdust compost may be due to biological activity, and that solarization with calcium cyanamide is a highly effective tool for controlling basal stem rot.

Sensory Quality of `Bing' Sweet Cherries Following Preharvest Treatment with Hydrogen Cyanamide, Calcium Ammonium Nitrate, or Gibberellic Acid

`Bing' sweet cherry (Prunus avium L.) trees were treated with hydrogen cyanamide (CH2N2) or calcium ammonium nitrate (CaNH4NO3) during dormancy, or gibberellic acid (GA3) 26 days before harvest during three consecutive years. Fruit were evaluated at harvest for sensory taste quality using twenty trained panelists sampling for firmness, sweetness, tartness, and cherry flavor. Nondestructive instrumental firmness preceded destructive sensory firmness on the same untreated and GA3-treated cherries in one year when used as a supplementary evaluation. Sensory firmness was consistently higher in GA3 fruit and to a lesser extent in CH2N2 fruit than in CaNH4NO3 and untreated fruit. Instrumental firmness of GA3 fruit did not increase significantly compared with untreated fruit yet instrumental firmness of each treatment correlated relatively well with perceived sensory firmness. Sensory sweetness and cherry flavor scored very similarly, yet both attributes simultaneously varied between treatments across the years. Perceived sensory tartness of treated fruit was variable among years; yet, on average, was rated among treated and untreated fruit as similar. Under the assumption that elevated sensory firmness, sweetness, and cherry flavor intensity reflects improved sweet cherry quality, GA3 fruit were rated of higher quality than untreated fruit given their increased firmness and similar or occasionally elevated sweetness and cherry flavor intensity. CH2N2 fruit maintained quality similar to that of untreated fruit, despite often having marginally higher firmness, due to similar or reduced ratings for sweetness and cherry flavor intensity. Notwithstanding similar firmness between CaNH4NO3 and untreated cherries, sensory quality of CaNH4NO3-treated cherries was reduced due to their often-diminished levels of perceived sweetness and cherry flavor.

Endogenous cytokinin levels of table grape vines during spring budburst as influenced by hydrogen cyanamide application and pruning

Abstract Cytokinins play an important role in budburst, flowering and fruit set in table grapes. Rest-breaking treatments with hydrogen cyanamide and pruning practices modify budburst and reproductive development in table grapes, especially in regions with low and often inadequate winter chilling. The effect of these treatments on the xylem sap and bud Zeatin riboside (ZR) content was determined during late winter and budburst in ‘Sultanina’, ‘Sunred Seedless’, and ‘Alphonse Lavallee’ canes in a total of nine trials conducted between 1997 and 2001. Bud ZR levels of hydrogen cyanamide treated ‘Sultanina’ canes showed an earlier and increased cytokinin peak, in particular in the distal buds. Large ZR peaks before budburst and noticeable differences between distal and proximal buds were absent on non-sprayed canes. The xylary ZR content of long pruned ‘Sultanina’, ‘Sunred Seedless’, and ‘Alphonse Lavalee’ canes showed a significantly higher and earlier cytokinin peak than in short pruned spurs. By contrast, the bud ZR content tended to be higher in spurs than canes. Pruning and rest-breaking treatments enhanced budburst and increased endogenous cytokinins in these experiments. Long pruning in ‘Sultanina’ and ‘Sunred Seedless’ (both parthenocarpic) is necessary for acceptable fruit set and yields. Possibly, in longer canes more cytokinin is available for reproductive development. ‘Alphonse Lavalee’ (seeded) is sufficiently fruitful and produces adequate yields following spur pruning.

Métodos de forçamento de borbulhas e aplicação de cianamida hidrogenada para produção de mudas de laranja 'Valência' sobre citrumelo 'Swingle' em viveiro telado

O objetivo deste experimento foi avaliar diferentes métodos para o forçamento de borbulhas de laranja 'Valência' enxertada em citrumelo 'Swingle': vergamento e decapitação, associados à aplicação de cianamida hidrogenada. Utilizando-se do delineamento experimental inteiramente casualizado, em esquema fatorial 2 x 2, avaliaram-se o curvamento ou a decapitação da haste do porta-enxerto, e a aplicação ou não do regulador de crescimento à base de cianamida hidrogenada 1% (C.H.). Avaliou-se o índice de brotação das borbulhas aos 50 e 80 dias, bem como o comprimento, diâmetro da haste e número de folhas aos 80; 110 e 140 dias após a aplicação dos tratamentos. A C.H. não influenciou significativamente na brotação de borbulhas. A decapitação elevou a brotação em 26% em relação ao vergamento. Por outro lado, o vergamento da haste do porta-enxerto proporcionou maior vigor às plantas, considerando-se comprimento, diâmetro e número de folhas das hastes. Na avaliação final, as plantas submetidas ao vergamento apresentavam altura de haste 75% maior do que as submetidas ao forçamento por decapitação.

Indução da brotação da macieira 'Eva' em região de baixa incidência de frio

A macieira caracteriza-se pela queda das folhas no final do ciclo e a conseqüente entrada em dormência. Na região norte do Paraná, onde o frio é insuficiente para a quebra natural da dormência da macieira, é necessário o uso de produtos químicos para estimular a brotação das plantas. O objetivo deste trabalho foi comparar o efeito de diferentes doses de cianamida hidrogenada, associada ao óleo mineral, sobre a quebra de dormência de gemas da macieira 'Eva', na região de Londrina-PR. Foi avaliado o efeito da aplicação de cinco concentrações de cianamida hidrogenada (0,00%; 0,25%; 0,50%; 0,75% e 1,00%), associadas ao óleo mineral 3%, sobre a quebra de dormência das gemas laterais e terminais das plantas. Avaliou-se a relação entre o número de frutos e o número de gemas brotadas por ramo de cada tratamento. Observou-se que a cianamida hidrogenada 0,50% associada ao óleo mineral 3% foi a concentração que resultou na melhor eficiência da brotação das gemas e da frutificação da macieira 'Eva' na região.

Uso de cianamida hidrogenada e óleo mineral na floração, brotação e produção do pessegueiro 'Chiripá'

O frio acumulado em regiões de inverno ameno é insuficiente para superar a dormência de algumas cultivares de pessegueiro, como o Chiripá, sendo necessária a utilização de produtos químicos para melhorar a brotação, a floração e a produção. O objetivo deste trabalho foi avaliar o efeito de diferentes doses de cianamida hidrogenada (CH2N2) e óleo mineral (OM) na floração, brotação e produção do pessegueiro cv. Chiripá, cultivado no município de Pato Branco. O uso de 1% CH2N2 combinada com 1% de OM antecipa, aumenta e uniformiza a floração, a brotação e a colheita de pessegueiro cv. Chiripá, promovendo maior frutificação efetiva e produção por planta, viabilizando o plantio comercial dessa cultivar.

EFFECT OF SOME CHEMICAL MATERIAL AND GERMINATION MEDIA ON SEED GERMINATION AND GROWTH OF GRAFTED CASIMIROA TRANSPLANTS

This investigation was carried out in the plastic house of Horticulture Research Institute, Agriculture Research Center, Giza during two consequent seasons (2002 – 2003) and (2003 – 2004). The study was aimed to enhance growth of Casimiroa rootstock seedlings to reach grafting size in a short time, beside defineding the suitable method of grafting. In this concern, results revealed that seed soaked in MgSO4 at 5 % for 15 min. and planted in media consists of peat and sand at 1 : 1, was increased seed germination percentage (92.1 and 94.8 %) and minimized the germination period (19.1 and 19.3 days), as compared with the other treatments. Thus it reached to the grafting size at a period of (179 and 180 days) in both seasons, respectively. However, Dormex (hydrogen cyanamide) treatment at 2% gave the highest root length (24.6 and 24.8 cm), and number of roots per plant (19.4 and 19.0). Results also showed that shield budding by using soft wood grafts, gave the highest percentage of success (69.2 and 72.4%), shortest period of bud / scion (23.0 and 24.0 days), highest values of scion length (26.5 and 25.7 cm) and highest leaf area (38.28 and 40.67 cm2). However, cleft grafting with softwood grafts increased average number of leaves per sprouted graft (6.0 and 6.6) and shoot scion diameter (0.6 and 0.5 cm). Generally, seeds treated with MgSO4 at 5% berfore sowing in media consists of peat and sand at 1 : 1 in volume, induced healthy and sizeable rootstocks in a short time. Moreover, grafting rootstocks by soft wood grafts was the best method.

Control of apothecia of Sclerotinia sclerotiorum by soil amendment with S–H mixture or Perlka ® in bean, canola and wheat fields

Ascospores of Sclerotinia sclerotiorum produced from apothecia are the primary source of inoculum for causing diseases such as white mold of common bean, pod rot of pea, stem blight of canola and head rot of sunflower and safflower in the Canadian prairies. A field study was conducted for 4 years to determine efficacy of control of production of apothecia from carpogenically germinated sclerotia of S. sclerotiorum by soil amendment with Perlka ® (calcium cyanamide) and S–H mixture (a formulated compound). Results of the 4-year experiments showed that amendment of soil with Perlka ® at low (30 g/m 2) or high (60 g/m 2) rate was effective in reducing carpogenic germination of sclerotia and production of apothecia under the canopy of host crops (common bean and canola) and a non-host crop (wheat). In the experiments of 1988, for example, the numbers of apothecia produced in the treatments of Perlka ®-low rate (30 g/m 2), Perlka ®-high rate (60 g/m 2) and untreated control were 42, 46, and 182 apothecia/plot (m 2), respectively, for bean; 89, 42, and 318 apothecia/plot (m 2), respectively, for canola; and 146, 143, and 412 apothecia/plot (m 2), respectively, for wheat. However, soil amendment of S–H mixture at low (30 g/m 2) or high (60 g/m 2) rate was ineffective in reducing carpogenic germination of sclerotia and production of apothecia for all the 4 years of testing in all three crops. The ineffectiveness of S–H mixture and the practicality of Perlka ® for control of Sclerotinia diseases of crops grown under Canadian prairie conditions are discussed.

Grafting and calcium cyanamide as alternatives to methyl bromide for greenhouse eggplant production

Eggplant ( Solanum melongena L.) seedlings (cv. Tsakoniki) were cultivated in soil artificially infested with V. dahliae Kleb. and then sterilized by either methyl bromide (MB) or calcium cyanamide. Grafted seedlings on the wild species Solanum torvum Sw. and the control seedlings (auto-rooted) were cultivated in soil sterilized by MB and then artificially infested with V. dahliae. The plants grafted on S. torvum and the ones grown in soil treated with calcium cyanamide (2001) exhibited significantly lower leaf symptom index (average value LSI = 1.55 and LSI = 1.00) and disease index (average value DI = 2.05 and DI = 1.20), respectively, as compared to the controls (average value LSI = 3.80 and DI = 5.50). Grafted plants on S. torvum and plants grown in soil treated with calcium cyanamide (2001) were more vigorous, as measured by plant height, stem diameter and root biomass than the controls. This resulted in an increased (over years) early (487.8% and 416.2%, 2001) and late production (277.0% and 241.3%, 2001) and mean fruit weight (over years) in early (93.7% and 49.6%, 2001) and late production (38.3% and 22.8%, 2001) as compared to the controls. In conclusion, grafting of eggplant and soil sterilized by calcium cyanamide had positive effects on growth, production and Verticillium wilt control.

Synthesis of 2‐Aminotriazole Derivatives Based on Cyanamides and Hydrazides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

15N Analysis of the Promotive Effect of Deep Placement of Slow-Release N Fertilizers on Growth and Seed Yield of Soybean

It is well known that nodulation and nitrogen fixation of soybean are generally depressed by the application of N fertilizers. We previously reported that a new fertilization method consisting of deep placement of slow-release N fertilizers, such as coated urea and lime nitrogen (calcium cyanamide) at a 20 cm depth enhanced soybean growth and seed yield. In the present study, the effect of deep placement of various 15N-labeled N fertilizers (100 kg N ha−1) was compared in converted paddy fields located at Niigata Agricultural Research Institute, in Nagaoka. Fertilizers consisting of 15N-labeled ammonium sulfate (AS), urea (U), coated urea (CU) or lime nitrogen (LN) were applied at a 20 cm depth for nodulated soybean (cv. Enrei) and for a non-nodulated isogenic line (En1282). The plants without deep placement of N fertilizer were used as control (Cont) for both Enrei and En1282. Whole plants were sampled at maturing stage, and 15N abundance and N concentration in each part were determined. The evaluation of the amounts of Ndfa, Ndfs and Ndff was conducted by the 15N dilution method using En1282 as a reference plant. Also the amounts of Ndfa and Ndfs+Ndff were estimated by the N balance method for comparing Cont and the other treatments. In all the deep placement treatments, the non-nodulated line exhibited only 36–40% of total dry weight and 16-30% of total N accumulation compared with the nodulated line, due to N deficiency associated with the lack of nitrogen fixation. In both nodulated and non-nodulated soybeans, plant growth and the total amount of accumulated N showed the highest values by the application of LN, followed by CU, U, AS and Cont, respectively. The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments. The value of Ndfa estimated by the 15N dilution method was higher in the LN (3.6 g N plant−1) and CU (2.8 g N plant−1) treatments than in the U (2.3 g N plant−1) and AS (2.2 g N plant−1) treatments. In addition, the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1). The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment. These results indicate that deep placement of LN and CU is effective to improve soybean growth and seed yield. The combination of “deep placement” and “slow-release N fertilizers” is important to supply N until the maturation stage, resulting in the increase of seed yield.

Soil solarization as an ecological method for the control of Fusarium wilt of melon in Italy

In the climatic conditions of the Piedmont north-western Po Valley (Italy), soil solarization and semi-solarization were tested in five consecutive years, alone or in combination with calcium cyanamide soil amendments or a non-pathogenic suppressive strain of Fusarium oxysporum, to develop alternative and ecologically compatible methods to control Fusarium oxysporum f. sp. melonis ( Fom). Compared with the control, semi-solarization and full solarization (solarization) increased the mean soil temperature at 25 cm depth by 8.6–12.6 and 12.6–16.3 °C, respectively. Solarization reduced the total fungal population by 57.8–96.0% at 25 cm and 97.0–99.7% at 5 cm depth. The populations of native Fusarium spp. were reduced from 2–7×10 3 to 0–25 colony forming units (cfu) per gram of soil. Solarization reduced the population of Fom grown in sterile soil samples from 3.8–60×10 5 cfu g −1 to 0–60 cfu g −1 in samples buried at 5 cm depth and 0–90 cfu g −1 in those placed at 15 and 25 cm depth in four out of five trials. Semi-solarization had a significant detrimental effect on total fungi, Fusarium spp. and Fom populations in some experiments. Solarization reduced Fusarium wilt incidence by 82–90% in three out of five trials. In one assay wilt was reduced by 43.5%, and in another there was no reduction in disease, possibly because of rainy weather during the treatment. The reduction in disease incidence (%) was proportional to the Ln of the time soil temperatures remained at or above 40 °C ( R 2=0.87) or at or above ⩾42 °C ( R 2=0.91) at 25 cm depth. Soil amendment with calcium cyanamide (80 g m −2) did not improve the efficiency of soil solarization.

Hydrogen-Cyanamide-Related Severe Cutaneous Reactions Simulating Erythema multiforme and Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

Fifteen grapevine workers developed skin reactions resembling erythema multiforme (EM) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) following exposure to Dormex, a plant growth regulator, the active ingredient of which is hydrogen cyanamide. Five patients needed hospitalization, and all recovered following treatment. Whether these were contact EM-like reactions due to hydrogen cyanamide or classical EM, SJS-TEN induced by this chemical remains elusive. An awareness regarding the safe use of agricultural chemicals is needed among the general population.