Control of postharvest anthracnose of banana using a new edible composite coating

Anthracnose is a postharvest disease of banana caused by the fungus Colletotrichum musae that results in major economic losses during transportation and storage. For the management of banana anthracnose, antifungal effects of Arabic gum (AG) (5, 10, 15 and 20%), chitosan (CH) (1.0%), and the combination of AG with CH were investigated in vitro as well as in vivo. CH at 1.0% and 1.5% had fungicidal effects on C. musae. AG alone did not show any fungicidal effects while the combination of 1.0% CH with all tested AG concentrations had fungicidal effects. However, the potato dextrose agar (PDA) medium amended with 10% AG incorporated with 1.0% CH showed the most promising results among all treatments in suppressing the mycelial growth (100%) and conidial germination inhibition (92.5%). In vivo analysis also revealed that 10% AG incorporated with 1.0% CH was the optimal concentration in controlling decay (80%), showing a synergistic effect in the reduction of C. musae in artificially inoculated bananas. The 10% AG incorporated with 1.0% CH coatings significantly delayed ripening as in terms of percentage weight loss, fruit firmness, soluble solids concentration and titratable acidity. The results showed the possibility of using 10% Arabic gum incorporated with 1.0% chitosan as a biofungicide for controlling postharvest anthracnose in banana.     

Fumigation of stonefruit with acetic acid to control postharvest decay

Acetic acid was an effective postharvest fumigant to destroy fungal spores on peaches, nectarines, apricots, and cherries. Decay by Monilinia fructicola and Rhizopus stolonifer on Harbrite peaches was prevented by as little as 1.4 or 2.7 mg l⁻¹ acetic acid, respectively. Harbrite peaches fumigated with 2.7 mg l⁻¹ acetic acid were slightly injured, the phytotoxicity indicated by light brown streaks. Higher concentrations of acetic acid increased injury; the streaks darkened and became much more pronounced. Glohaven peaches treated in the orchard with captan at 5% bloom, full bloom, ripening fruit, and 2 days before harvest then fumigated with 2.7 mg l⁻¹ acetic acid after harvest had significantly less postharvest brown rot (12.5%) than fruit treated with captan alone (25.0%). Decay of Lambert cherries, primarily due to Alternaria spp., was reduced from 38.9 to 10.0% by fumigation with 2.7 mg l⁻¹ acetic acid. Unfortunately, small pits developed in the fruit surface during storage at 1 °C. Brown rot (M. fructicola) of Tilton apricots was reduced from 100 to 25% by fumigation with 2.0 mg l⁻¹ acetic acid without signs of severe phytotoxicity.     

A liquid bioplastic formulation for film coating of agronomic seeds

Interest in industrial and domestic applications of biodegradable plastics from renewable sources is increasing, but their use in agriculture is still limited (e.g., mulching films, plant pots, and plant clips). However, a sprayable liquid bioplastic formulation was recently evaluated for application of microbial biocontrol agents to agricultural and horticultural crops. In this study bioplastic formulation has been evaluated for use in film-coating seeds of two agronomic species, corn and canola. Bioplastic seed coating was achieved using procedures and equipment designed for commercial polymer film-coating of tablets. Germination of both species was unaffected by the thin bioplastic coating. Bioplastic coatings containing spores of the plant-growth promoting fungus, Trichoderma harzianum, significantly stimulated the growth of corn and canola seeds. In corn seedlings, shoot and root lengths were 29% and 44% longer, respectively, in seeds coated with T. harzianum-containing bioplastic than in uncoated seeds. Similarly, in canola seedlings shoot and root lengths were 19% and 20% longer, respectively, in seeds coated with T. harzianum-containing bioplastic than in uncoated seeds. In a paper-roll assay, including T. harzianum spores prevented reduced germination caused by a mixture of the insecticide imidacloprid and the fungicide metalaxyl-M in bioplastic seed coatings. The adhesive and plastic properties of bioplastic reduced dust-off from bioplastic-coated seeds by 96% in corn and 99% in canola compared to seeds coated with a commercial polymer.     

Control of citrus postharvest penicillium molds with sodium ethylparaben

The curative antifungal activity of postharvest sodium ethylparaben (SEP) treatments against citrus green mold (GM) and blue mold (BM) was determined on different citrus species and cultivars artificially inoculated with Penicillium digitatum or Penicillium italicum and incubated at 20 °C and 90% RH for 7 d or stored at 5 °C and 90% RH for 8 weeks plus 7 d of shelf-life at 20 °C. The best concentration was selected in in vivo primary screenings with ‘Valencia’ oranges. SEP at 80 mM was tested at 20, 50 or 62 °C for 30, 60 or 150 s in small-scale trials to determine the best dip treatment conditions. Dips of 80 mM SEP at 20 °C for 60 s were selected and applied alone or in combination with 25 μL L⁻¹ of the conventional fungicide imazalil (SEP + IMZ 25). Imazalil at the very low concentrations of 25 (IMZ 25) or 50 μL L⁻¹ (IMZ 50) was also tested. Effectiveness of SEP alone at 20 °C for 60 s was significantly higher on oranges (cvs. ‘Valencia’ and ‘Lanelate’) than on mandarins (cvs. ‘Clemenules’, ‘Nadorcott’ and ‘Ortanique’), with GM and BM incidence reductions of up to 57–73% after 7 d at 20 °C. SEP was compatible with IMZ 25 and consistently improved its performance, irrespective of citrus cultivars and storage conditions. All treatments were less effective on ‘Clemenules’ mandarins. On ‘Valencia’ oranges stored for 8 weeks at 5 °C and 7 d at 20 °C, the combined treatment was significantly more effective than the single treatments (reductions of GM and BM incidence of about 96–93% and 55–39%, respectively). In additional tests, SEP, IMZ 25 and the combination applied at 20 °C for 60 s prevented GM on ‘Valencia’ oranges treated, inoculated with P. digitatum 24 h later and incubated at 20 °C for 7 d. It can be concluded from these results that SEP might be an integrating nonpollutant control alternative to be included in citrus postharvest disease control programs in the future.     

Biofumigation with the endophytic fungus Nodulisporium spp. CMU-UPE34 to control postharvest decay of citrus fruit

Forty-six fungal endophytes were isolated from Lagerstroemia loudoni. Only one fungus, identified as Nodulisporium spp. CMU-UPE34, produced antifungal volatile compounds. It produced 31 volatile compounds, primarily composed of alcohols, acids, esters and monoterpene. The most abundant volatile compound was eucalyptol. In vitro tests showed that volatile compounds produced by Nodulisporium spp. CMU-UPE34 inhibited or killed 12 different plant pathogens. In vivo mycofumigation with jasmine rice grain cultures of Nodulisporium spp. CMU-UPE34 controlled green mold decay on Citrus limon caused by Penicillium digitatum, blue mold decay of Citrus aurantifolia and Citrus reticulata caused by Penicillium expansum. Nodulisporium spp. CMU-UPE34 has potential as a biofumigant for controlling postharvest disease.     

A review on the use of essential oils for postharvest decay control and maintenance of fruit quality during storage

Postharvest diseases are one of the major causes for the postharvest loss of horticultural fresh produce during the supply chain. The incidence of postharvest diseases can affect the quality and restrict the shelf life of the horticultural fresh produce. At present strict regulations are enforced by the fresh produce importing countries regarding the minimum pesticide residue levels in the edible portion of the fresh produce. Some fungal pathogens were reported to develop resistance to synthetic fungicides. Waste disposal of fungicides has an impact on environmental footprint. All theses above-mentioned reasons have necessitated the search for a natural novel fungicide to replace the synthetic fungicide application in the packing line as postharvest treatment.Consumer preference to organic fresh produce is increasingly becoming popular in the developed countries. Therefore, this review summarises the use of essential oils in the control of postharvest diseases of horticultural commodities, their mode of actions, effects on the defence mechanism and quality of fresh fruit. Future research must be focused on conducting large scale trials to prove the feasibility of combination treatments. The cost benefit analysis of the treatments needs to be carried out in order to implement their application and the commercial applications of essential oils and host pathogen infection must be investigated in detail in order to control latent infections during postharvest storage.     

Complementary physical and chemical treatments as an alternative to fungicide use to control postharvest decay incidence and fruit quality of Montenegrina tangerines

Heat treatments affect the germination and development of pathogens and enhance the ability of fruits to resist infection after harvest. In the present work, the effects of heat, in combination with other alternative decay control methods, were studied on ‘Montenegrina’ tangerines along with the effects on the cuticular surface of the fruit. Different treatment combinations using hot water (60 °C), brushing, and immersion in chloride dioxide, imazalil, sodium bicarbonate, and hand-applied carnauba wax were used. The tangerines were then put in cold storage for 20 days at 5 °C and retrieved to ambient conditions for 7 more days. Fruit samples were analyzed for total soluble solids, titratable acidity, epidermal color, weight loss, and decay incidence; an analysis of fruit surface was done through scanning electron microscopy. Heat treatments significantly reduced the number of tangerines with decay symptoms and enhanced the efficacy of the tested products. Carnauba wax significantly increased the number of rotten fruits, exerting a protective effect on the fungi by covering their structure. Sodium bicarbonate in combination with heat exerted a good control on decay incidence. The heat treatments partially removed the hyphae and spores of pathogens on the surface and also melted the cuticular waxes that cover stomata and cracks, reducing possible entry points for pathogens.     

九兴牌多·福·克大豆种衣剂应用效果研究

九兴牌 2 0 %多·福·克大豆种衣剂 ,有提高保苗率和有效防治苗期病虫害的作用 ,并能明显地提高大豆产量     

高巧包衣种对棉苗素质的影响效果

深圳创世纪公司与美国拜尔公司合作,在江西彭泽开展了高巧（600g／L悬浮种衣剂）对棉花蚜虫和苗期病虫害的防治效果、安全性和逆境屏蔽作用及促进棉花苗齐、苗壮、根系发达的效果试验,探讨该种衣剂抑制棉花枯萎病、棉蚜发生的科学方法,从而促进棉花持续稳定增产,棉农增收增效。     

Effects of kaolin-based particle film to control Ceratitis capitata (Diptera: Tephritidae) infestations and postharvest decay in citrus and stone fruit

Ceratitis capitata (Wiedemann) is a major pest of fruit crops due to its wide host range and distribution. The objectives of this study were to evaluate the effectiveness of Surround WP, a kaolin-based particle film, as an alternative to synthetic insecticides to control medfly infestations and postharvest decay in citrus and stone fruit. No-choice, choice and half-choice laboratory experiments with citrus fruit, nectarines and peaches showed a significant reduction of medfly punctures and landings on kaolin-treated fruit. The total loss at harvest in satsumas sprayed with Surround WP (17%) was significantly lower than in those untreated (57%) or treated with trichlorfon (68%). In 2004, the yield loss at harvest in peaches and nectarines treated with Surround WP was not different compared to fruit sprayed with fenthion and trichlorfon, while in 2005 Surround WP was significantly more effective than insecticides in reducing the incidence of damaged fruit. Citrus and stone fruit treated with Surround WP showed a lower incidence of postharvest decay than control and insecticide-treated fruit. The present study shows for the first time the lower incidence of postharvest decay in fruit protected with Surround WP, which represents a suitable alternative to conventional insecticides in integrated and traditionally managed orchards.     

Development of superhydrophobic polyester fabrics using alkaline hydrolysis and coating with fluorinated polymers

Alkaline hydrolysis is one of the most classic fiber finishing methods, however, its potential as tuning surface superhydrophobicity in mass scale has not been studied much. In this research, fine roughness was formed on the polyester fiber surfaces by alkaline hydrolysis at room temperature and fluorinated polymer mixtures were further coated. The developed superhydrophobic fabrics were evaluated in terms of structural changes, mechanical properties, surface hydrophobicity, and permeability for practical applications. As alkaline hydrolysis treatment time increased, surface roughness was increased as a lot of nano-craters were generated with the decrease of fabrics weight and tensile strength as well. As air pockets formed through nano-craters on the fiber surfaces, static contact angle increased, and shedding angle tended to decrease. In this study, the sample treated with alkaline hydrolysis for 20 minutes showed the highest static contact angle of 167.8±1.3° and lowest shedding angle of 4.4±2.3°. Considering tensile strength loss, however, the 15-minute alkaline hydrolyzed fabrics which showed static contact angle of 162.2±2.7° and shedding angle of 8.8±0.2° was selected as the optimal condition for practical application. The newly developed superhydrophobic fabrics were found to have higher water vapor and air permeability than those of untreated samples. At the same time, fluoropolymer coating played a certain role for tensile strength and water vapor permeability demonstrating the importance of understanding and designing proper fluorinated-compound treatment processes.     

Dynamics of residues from a novel nano-imidacloprid formulation in soyabean fields

Imidacloprid has been widely used to control vegetable pests in China. This research was conducted to establish a method for preparing a novel imidacloprid nano-formulation and develop a simple and efficient method for determination of residues of the novel imidacloprid formulation in soyabean fields. Imidacloprid micro-crystals were directly encapsulated with chitosan and sodium alginate through layer-by-layer self-assembly. The coated colloids and photocatalysts were characterized using confocal laser scanning microscopy and scanning electron microscopy. Residues of the novel imidacloprid were determined by HPLC equipped with a UV detector. The results showed that imidacloprid micro-crystals were obtained by association and had a mean length of 7 μm and a zeta potential of −37.5 mV. The pesticide loading and encapsulation efficiency were 56.2 ± 0.96% and 81.6 ± 0.96%, respectively. Degradation of the nano-imidacloprid and the suspension concentrate imidacloprid formulations in soil coincided with C = 0.227e^−0.152t and C = 0.544e^−0.177t with half lives of about 2.8 d and 6.2 d, respectively. Degradation of the two imidacloprid formulations in soyabean plants coincided with C = 6.644e^−0.475t and C = 8.585e^−0.573t with half lives of about 1.9 d and 4.5 d, respectively. Thus, in soil, the degradation rate of the nano formulation was faster than that of the suspension concentrate, but the degradation rates were vice versa in the plant. The final residue of the nano imidacloprid formulation after 35 days was below the limit of detection but in the soyabean plant, the final residue was 0.003 mg kg⁻¹, much lower than the USA Environment Protection Agency’s Maximum Residue Level. Therefore, a dosage of 900 ml hm⁻² is suggested for the nano-imidacloprid concentrate, which could be considered as safe to fields.     

两种悬浮种衣剂对燕麦蚜虫及红叶病的防治效果

为给种衣剂在燕麦上的推广应用提供依据,研究了吡虫啉和噻虫嗪两种种衣剂对燕麦蚜虫及红叶病的田间防治效果及增产作用.结果表明,两种种表剂以4～6 mL/kg种子剂量一次性包衣后,对燕麦蚜虫和红叶病均有较好防效,在燕麦扬花期对麦蚜的防效大于50%,成熟期对红叶病的防效也在43%以上,增产效果显著.相比而言,吡虫啉种衣剂防治效果优于噻虫嗪.     

A systematic identification of cold tolerance genes in peanut using yeast functional screening system

Peanut(Arachis hypogaea L.) is a thermophilic crop, and low temperature leads to a significant reduction in annual yields. Despite a few cold tolerant germplasms or cultivars have been discovered and developed, molecular mechanisms governing peanut cold tolerance is poorly understood. Identification of keys genes involved in cold tolerance is the first step to address the underlying mechanism. In this study, we isolated and characterized 157genes with potentials to confer cold tolerance in peanu...     

氨基寡糖素对棉花病害的防治效果

氨基寡糖素是从海洋生物外壳中提取出来的一种多糖类物质。据相关资料报道，它能对多种植物病原菌孢子、菌丝有明显的抑制作用。具有抗逆、抗病、促进根系发育、提高产量和改善品质的功效。针对近年来棉花苗床病害和枯黄萎病大面积发生而导致产量与品质下降，植棉比较效益低，植棉面积下滑的严峻形势，为寻求较为理想的防治药物特此开展氨基寡糖素对棉花病害防治效果探讨。     

Efficacy of a new glyphosate formulation for weed control in maize in southwest Nigeria

A field trial in 2003 and 2004 assessed the efficacy of a new formulation of glyphosate, Touchdown Forte HiTech (glyphosate-TF) and two older versions, Roundup (glyphosate-RP) and Touchdown (glyphosate-TD) for weed control in Nigeria. Treatments were glyphosate-TF at 0.25–1.25 kg a.i./ha, glyphosate-RP at 1.8 kg a.i./ha, and glyphosate-TD at 1.0 kg a.i./ha. Weeded and unweeded treatments were controls. Visual evaluations of weed control at 4 and 8 weeks after treatment (WAT) in both years indicated that glyphosate-TF at all doses gave moderate to complete control of all major weeds (50–100%). At 4 WAT, control of Ageratum conyzoides L., Commelina benghalensis L., Ipomoea involucrata P. Beauv., Brachiaria comota [Hochst ex A. Rich] stapf, and Acalypha ciliata Forssk was at a level similar to that in the weeded control. In 2003, all herbicide formulations and the weeded control reduced Imperata cylindrica (L.) Beauv. shoot dry biomass to the same level at 8 WAT (91–100%) and at maize harvest (83–88%). In 2004, 0.50–1.25 kg a.i./ha of glyphosate-TF and 1.8 kg a.i./ha of glyphosate-RP gave 95% reduction at 8 WAT and 97% at harvest, similar to the weeded control. Maize grain yield in the weeded control and herbicide treatments was 2.8 times higher than that in the unweeded control in both years. These results indicate that glyphosate-TF is effective for weed control in maize at herbicide doses lower than the older formulations.     

Are traditional neem extract preparations as efficient as a commercial formulation of azadirachtin A?

Neem seeds contain many substances with insecticidal properties, the main insecticidal ingredient being azadirachtin A. In developing countries such as Mali, a neem seed water extract is prepared by soaking ground seeds in water for three or seven days. The aim of this study was to check the effectiveness of this extract in terms of azadirachtin A extraction yield and insecticidal activity. The yield of extraction was 0.19 g azadirachtin A/100 g seeds. The concentration of azadirachtin A in the seed extract was approximately 200 mg l⁻¹, eight times higher than the recommended concentration of commercial products (25 mg l⁻¹). A comparison of the extractive capacity of different solvents indicated that the best solvents were water and methanol. The azadirachtin A concentration declined in extracts stored for more than 3 days at a temperatures higher than 30 °C. Bioassays were performed on target insects (the leafhopper Macrosteles quadripunctulatus, the moth Spodoptera littoralis and the tobacco whitefly Bemisia tabaci) in order to compare the insecticidal activity of the neem extract with that of the commercial product Neemazal T/S and of a solution of pure azadirachtin A. The bioassays conducted on the leafhopper and the moth demonstrated that the neem extract at the recommended concentration (25 mg l⁻¹ active ingredient) was as effective as the azadirachtin-based commercial product at the same concentration, while for the control of the whitefly B. tabaci a higher concentration of the water extract was needed.     

Impact of aggregate coating with a PEC elastomer on properties of lightweight flax shive concrete

Lightweight concrete becomes an important subject of research because of its insulating properties. The main objective of this research is to present a process improving the flax shive behaviour in a cement matrix. Flax shives stem from flax culture. It is the major product (50% of biomass weight). To be used as aggregates, shives should have a hydrophobization treatment. The aim of this work is the treatment of shives with a biodegradable elastomer: poly(PEG-co-CA). This elastomer is synthesized by the polycondensation of polyethylenglycol (PEG) and citric acid (CA). After their treatment with PEC elastomer, flax shives show a decrease in water absorption. Then, they are incorporated in a cement matrix. Mechanical properties, thermal properties and behaviour towards water (dimensional variations) of concrete are determined. The shive treatment shows an improvement in compressive and flexural strengths but an increase in thermal conductivity. The extreme dimensional variations (EDVs) and drying shrinkage (DS) decrease also with concrete prepared with treated shives compared to the standard. Overall the lightweight concrete obtained exhibits performances close to those of wood concrete.     

Development of a formulation of Pseudomonas fluorescens PfALR2 for management of rice sheath blight

Pseudomonas fluorescens isolates that inhibited growth of Rhizoctonia solani, the rice sheath blight pathogen, were isolated from the rhizosphere of different crops. One of the most effective strains, PfALR2, was developed as an antibiotic resistant strain and a peat-based formulation was developed for this bacterium. The effective dose of a peat formulation was assessed for seed treatment, root treatment, soil application and foliar spraying. All individual treatments controlled the disease effectively. However, a combination of all four treatments resulted in the best sheath blight control in the greenhouse. In field trials, application of the peat-based formulation of PfALR2 effectively controlled the disease, increased yield, and efficacy was comparable to that of the commercially available fungicide, carbendazim.     

Surfactant effects on application of a hydrophobic, fluoropolymer coating to cotton by admicellar polymerization

Various methods have been used previously to impart hydrophobicity to cotton. In this study, thin co-polymer films of trifluoroethyl acrylate (TFEA) and octafluoro pentyl methacrylate (OFPM) were formed on cotton using individual fluorosurfactants and surfactant mixtures through the process of admicellar polymerization. Efficacy of 6 different fluorosurfactant systems and process conditions including surfactant type, concentration, adsorption/adsolubilization time, polymerization time, and monomer concentration have been investigated in order to obtain hydrophobic coatings on woven cotton fabric. Adsolubilization times as short as 2 h and polymerization times as short as 1 h yielded satisfactory performance. Characterization of the hydrophobic polymer films obtained included static contact angles, SEM imaging, elemental analysis and XPS analysis. Treated fabrics exhibited good water repellency for several surfactants and surfactant mixtures with initial supernatant monomer concentrations of 4 mM. Surfactant mixtures were able to outperform the separate individual species in admicellar polymerization.