Abstract Background: Apple is one of the oldest and most valuable fruits. Water restriction is one of the major problems in the production of this fruit in some planting areas. Methods: Effects of kaolin spray treatments were studied on two early apple cultivars of Golab and Shafi-Abadi under sustained deficit irrigation (SDI) in Alborz province, Iran during 2017 and 2018. Irrigation treatments were 100%, 85%, and 70% ETc and kaolin application were concentrations of 0, 3 and 6% in 2017 and 0, 1.5 and 3% in 2018. Results: Results showed that 85% ETc treatment compared to other irrigation treatments improved apple tree crown volume in 2017. Deficit irrigation treatments significantly reduced fruit weight in both years. Application with 6% kaolin resulted in 33.3% increase in apple fruit weight compared to non-kaolin treatment at 100% ETc irrigation in the first year. Severe deficit irrigation (70% ETc) significantly reduced apple fruit length in both years, but 6% kaolin increased fruit length in both apple cultivars in 2017. Severe deficit irrigation treatment increased the firmness of apple fruit compared to control and mild deficit irrigation (85% ETc) in the first year of experiment. There was no significant difference between irrigation treatments for apple fruit firmness in the second year of experiment. Kaolin treatments of 1.5% and 3% at full irrigation increased the soluble solids content of apple fruit by 36.6% and 44.1% in 2018, respectively. Deficit irrigation treatments significantly increased leaf proline content compared to control in both years. In the first year, kaolin treatments increased leaf proline but in the second year, leaf proline was not significant. Deficit irrigation treatment of 70% ETc and 6% kaolin had the highest amount of glycine betaine content, malondialdehyde and hydrogen peroxide in apple leaf in the first year of experiment. Conclusions: Severe deficit irrigation stress (70% ETc) increased the activity of nonenzymatic defense systems of apple trees. Kaolin as a drought stress reducing agent can be recommended in apple orchards of Golab and Shafi-Abadi cultivars as an effective and inexpensive method to improve tolerance to drought stress conditions.

To reduce the dependence on the sometimes unwise use of synthetic pesticides in fruit and vegetable plantations, the toxicity and repellence of Peganum harmala L. (Zygophyllaceae) acetonic seed extract was assayed against several insect pests. For contact toxicity, 3- to 4-d-old individuals of Aphis fabae Scopoli, A. gossypii Glover, A. nerii Boyer de Fonscolombe, and Myzus persicae (Sulzer) were included, as well as 1- to 7-d-old adult Tribolium castaneum (Herbst). Repellent effect experiments were conducted on adult, 1- to 2- and 3- to 4-d old M.persicae individuals. At 60 mg mL4, the topical bioassay mortality percentage was significantly higher in A. gossypii than in A. fabae and A. nerii after 12-72 h. Mortality of the treatments on M.persicae was 87.1% and 90.0% after 24 and 48 h, respectively, and significantly higher than A. fabae and A. nerii during this period. At 60 mg mL-1, the mortality of T. castaneum was much lower than that of the aphid species. The highest repellent index (over 72%) was observed on 1- to 2-d-old M. persicae individuals.

Para reducir la dependencia de los pesticidas sintéticos en plantaciones frutales y hortalizas, se realizó un ensayo para medir la toxicidad y repelencia de un extracto acetónico obtenido a partir de semillas de Peganum harmala L. (Zygophyllaceae) contra diferentes especies de plagas. Para evaluar la toxicidad del extracto al contacto con los insectos, se incluyeron individuos de 3-4 d de edad de Aphis fabae Scopoli, Aphis gossypii Glover, Aphis nerii Boyer de Fonscolombe, y Myzus persicae (Sulzer), así como adultos 1-7 d de edad de Tribolium castaneum (Herbst). Experimentos para medir el efecto repelente se llevaron a cabo con individuos de 1-2 y 3-4 d de edad de M. persicae. En los resultados de los bioensayos tópicos el porcentaje de mortalidad fue significativamente mayor en la especie A. gossypii que en A. fabae y A. nerii, después de 12-72 h con una concentración de 60 mg mL-1. La mortalidad de los tratamientos contra M. persicae fueron 87,1% y 90,0% después de 24 y 48 h, respectivamente, la cual fue significativamente mayor que la obtenida con A. fabae y A. nerii durante el mismo período de tiempo. Con la concentración de 60 mg mL-1, la mortalidad de T. castaneum fue muy inferior a las obtenidas con las diferentes especies de áfidos. El mayor índice de repelencia (mayor a 72%) se observó en individuos de 1 a 2 d de edad de M. persicae entre los diferentes tratamientos.

A new poly(vinyl chloride) membrane electrode that is highly selective to Fe3+ions was prepared by using 4,4'-Dimethoxybenzil bisthiosemicarbazone (DBTS) as a suitable neutral carrier. Membrane incorporating 4,4'-Dimethoxybenzil bisthiosemicarbazone (DBTS), as ionophore with composition DBTS :NaTPB:NB:PVC in the ratio 2:2:64:32 (w/w) exhibits the best result for potentiometric sensing of Fe3+ ions. The electrode exhibited a near-Nernstian response to Fe3+ in the concentration range of 1.0 x 10-6to 1.0x10-2M with a slope of 19.4 ± 0.5 mV per decade. The proposed sensor can be used over a period of 2 months. The lower limit of detection was 3.6x 10-7 M. This electrode showed high selectivity with respect to alkaline, alkaline earth, and heavy metal ions and could be used over a pH range of 1.8-5.0. It has been successfully used as an indicator electrode in potentiometric titration of Fe3+ against EDTA as well as for the determination of Fe3+ in water sample solutions (tap and mineral water samples).

In this work, we introduce a highly selective and sensitive silver(I) PVC-membrane sensor. Dilaktam Crown ether (DLCE) was used as a membrane-active component to prepare a highly sensitive Ag(I)-selective polymeric membrane electrode. This sensor illustrated very good selectivity and sensitivity towards silver ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor exhibited a Nernstian behavior (with a slope of 59.8 ± 0.2 mV per decade) for a concentration range (1.0 x 10-5-1.0 x 10¹ M) with a detection limit of 6.8xl0-6 M. It displayed a response time in the whole concentration range (~20 s) and its usage exceeded a 75 days period in the pH range of 5.1-7.2. The proposed electrode application was found to be successful as an indicator electrode in the titration with NaCl.

Este trabalho apresenta o desenvolvimento de um eletrôdo de membrana de PVC, que contém 3-{[2-oxo-1(2H)-acenonaftilideno]amino}-2-tioxido-1,3-tiazolidino-4-ona (ATTO), que mostrou ser seletivo para íons Sm3+. Os dados obtidos mostram uma resposta Nernsteniana com inclinação de 19,3 ± 0,6 mV por década para íons Sm3+ em uma ampla faixa de concentração , de 1,0 × 10-6 a 1,0 × 10-1 mol L-1. O limite de detecção encontrado foi (5,5± 0.3) × 10-7 mol L-1 numa faixa de pH entre 3,5 e 7,5, com tempo de resposta pequeno (~10 s). O sensor potenciométrico mostrou boa seletividade para diferentes cátions, como os alcalinos, alcalinos terrosos e para íons de metais pesados.

This paper introduces the development of an original PVC membrane electrode, based on 3-{[2-oxo-1(2H)-acenaphthylenyliden]amino}-2-thioxo-1,3-thiazolidin-4-one (ATTO) which has revealed to be a suitable carrier for Sm3+ ions. The resulting data illustrated that the electrode shows a Nernstian slope of 19.3 ± 0.6 mV per decade for Sm3+ ions over a broad working concentration range of 1.0 × 10-6 to 1.0 × 10-1 mol L-1. The lower detection limit was found to be equal to (5.5± 0.3) × 10-7 mol L-1 in the pH range of 3.57.5, and the response time was very short (~10 s). The potentiometric sensor displayed good selectivities for a number of cations such as alkali, alkaline earth, transition and heavy metal ions.

Um novo sensor potenciométrico constituído por uma membrana de PVC, altamente seletivo a íons Tb(III) foi preparado usando-se 4-amino-3-{2-[4-amino-6-metil-5-oxo-4,5-diidro-1,2,4 -triazina-3(2H)-ilidina] hidrazono}-6-metil-3,4-diidro-1,2,4-triazina-5(2H)-ona (ATO) como um carregador adequado. O sensor trabalha satisfatoriamente no intervalo de concentração de 1,0 × 10-6 a 1,0 × 10-1 mol L-1 (limite de detecção 8,6 × 10-7 mol L-1) com uma inclinação Nernstiniana de 19,4 ± 0.5 mV per década de atividade. O eletrodo mostrou rápido tempo de resposta (~15 s) e foi usado por um período superior a 2 meses. Os valores do coeficiente de seletividade potenciométrica (para cátions mono-, di-, e trivalentes) como determinado pelo método match potential (MPM) indicou boa resposta para Tb3+ na preseça de íons interferentes. A membrana sensora foi usada como um eletrodo indicador na titulação potenciométrica de íons Tb(III) com EDTA. Foi também aplicado na determinação de íons fluoreto em amostras de preparados para enxágue bucal e na recuperação de Tb3+ de várias misturas binárias.

A new PVC membrane potentiometric sensor that is highly selective to Tb(III) ions was prepared by using 4-amino-3-{2-[4-amino-6-methyl-5-oxo-4,5-dihydro-1,2,4-triazin-3(2H)-yliden] hydrazono}-6-methyl-3,4-dihydro-1,2,4-triazin-5(2H)-one (ATO) as a suitable carrier. The sensor works satisfactorily in the concentration range of 1.0 × 10-6 to 1.0 × 10-1 mol L-1 (detection limit 8.6 × 10-7 mol L-1) with a Nernstian slope of 19.4 ± 0.5 mV per decade of activity. This electrode showed a fast response time (~15 s) and was used for a period of more than 2 months. The potentiometric selectivity coefficient values (for mono-, di-, and trivalent cations) as determined by the match potential method (MPM) indicate good response for Tb3+ in the presence of interfering ions. The membrane sensor was used as an indicator electrode in the potentiometric titration of Tb(III) ions with EDTA. It was also applied to the determination of fluoride ions in mouth wash preparation sample and the Tb3+ recovery from various binary mixtures.

A substância 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabiciclo[8,8,8]hexacos-5-eno (BHDE) foi usada como um excelente ionóforo na construção de um sensor de membrana para Zn(II ), em PVC. O melhor desempenho foi obtido para a membrana com a composição de 30% de policloreto de vinila, 64,5% de nitrobenzeno (NB), 2,5% BHDE e 3% de tetrafenilborato de sódio (NaTPB). Este sensor mostra alta seletividade e sensitividade ao íon zinco, frente a uma grande variedade de cátions, incluindo íons de metais alcalinos, alcalinos terrosos, de transição e de metais pesados. O sensor revelou um grande aumento nos coeficientes de seletividade para íons zinco, em comparação a sensores de zinco previamente relatados. O sensor proposto exibe um comportamento Nernstiniano (com inclinação de 29,1 ± 0,4 mV por década) em um grande intervalo de concentração (1,0 <FONT FACE=Symbol>´</FONT> 10-6 a 1,0 <FONT FACE=Symbol>´</FONT> 10-1 mol L-1), com limite de detecção de 6,3 <FONT FACE=Symbol>´</FONT> 10-7 mol L-1 (41,2 ng mL-1). Mostrou, em toda faixa de concentração usada, um tempo de resposta relativamente curto (< 10s), e pode ser usado por, no mínimo, 10 semanas em um intervalo de pH de 2,8 - 7,3. O sensor proposto foi usado com sucesso na determinação direta de íons zinco em águas de descarte de companhias de eletrodeposição de zinco industrial, e também como um eletrodo indicador na titulação com EDTA.

The 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacos-5-ene (BHDE) was used as an excellent ionophore in construction of a Zn(II) PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 64.5% nitrobenzen (NB), 2.5% BHDE and 3% sodium tetraphenylborate (NaTPB). This sensor shows very good selectivity and sensitivity towards zinc ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients for zinc ions, in comparison to the previously reported zinc sensors. The proposed sensor exhibits a Nernstian behavior (with slope of 29.1 ± 0.4 mV per decade) over a wide concentration range (1.0 <FONT FACE=Symbol>´</FONT> 10-6-1.0 <FONT FACE=Symbol>´</FONT> 10-1 mol L-1) with a detection limit of 6.3 ×10-7 mol L-1 (41.2 ng mL-1). It shows relatively fast response time, in the whole concentration range (< 10s), and can be used for at least 10 weeks in a pH range of 2.8-7.3. The proposed sensor was successfully used in direct determination of zinc ions in wastewater of industrial zinc electroplating companies, and also as an indicator electrode in titration with EDTA.

Fusarium oxysporum é um fitopatógeno amplamente difundido nos solos. A doença amarela do grão-de-bico (Cicer arietinum), causada por ele é destrutiva e um grande problema nas regiões produtoras do Irã. Três métodos de laboratório: amplificação aleatória de DNA genômico (RAPD), coloração de atividade enzimática e determinação das dimensões de colônia, foram usados para diferenciar isolados de Fusarium oxysporum altamente virulentos (HV) e fracamente virulentos (WV). Baseado no tamanho da colônia (método morfológico tradicional) e na capacidade dos isolados produzirem enzimas pécticas, cinco isolados HV foram diferenciados de três WV. Enquanto os isolados HV formaram colônias grandes (entre 10,1 e 12,6 mm de diâmetro) e apresentaram o mesmo padrão enzimático, os isolados WV produziram colônias pequenas (entre 5,8 e 7,8 mm de diâmetro) e não tiveram atividade enzimática detectável no gel de cobertura corado. Doze primers arbitrários foram testados nos 8 isolados de Fusarium oxysporum por reação de polimerase em cadeia (PCR). As análises dos dados da amplificação de DNA pelo método de amplificação aleatória do DNA polimórfico (RAPD) diferenciaram os isolados HV dos WV. Os resultados obtidos pelo teste RAPD confirmaram a classificação dos 8 isolados pelos testes de patogenicidade, tamanho da colônia e atividade enzimática de coloração nos dois grupos, HV e WV.

Fusarium oxysporum is a common soilborn plant pathogen with a worldwide distribution. Fusarium yellows disease of chickpea (Cicer arientinum) caused by F.oxysporum is one of the most destructive soilborn disease which is a major production constraint in chickpea-growing regions of Iran. Three laboratory methods "amplification of genomic DNA using random primers, enzyme activity staining, and colony size determination" have been used to discriminate between highly virulent (HV) and weakly virulent (WV) isolates of F. oxysporum. On the basis of colony size (a traditional morphological method) and the ability of isolates to produce pectic enzymes, five HV isolates were differentiated from three WV isolates. The HV isolates formed large colony (ranging from 10.1 to 12.6 mm in diameter) and showed the same enzyme pattern,while the WV isolates produced small colony (ranging from 5.8 to 7.8 mm in diameter) and had not detectable enzyme activity in the stained overlaying gel. Twelve arbitrary 10-mer primers were tested on these 8 isolates of F. oxysporum by Polymerase Chain Reaction (PCR). Cluster analysis of the data from the DNA amplification by Random Amplified Polymorphic DNA (RAPD), differentiated HV from WV isolates. The results obtained from RAPD test confirmed the classification of these eight isolates based on pathogenicity test, colony size, and enzyme activity staining into two groups (HV and WV).