Pasture improvement and the control of sheep tick,Ixodes ricinus L

The sheep tick is confined almost entirely to rough, poor hill and moorland pastures. Agricultural improvement of these pastures involves (among other things) reduction in the depth of the vegetation layer and partial or complete destruction of the moisture-holding underlying 'mat' of decaying vegetable matter. Assessment of the tick populations on improved and on comparable control areas showed a reduction in tick population following upon pasture improvement. But a fairly considerable degree of improvement is required to bring about a satisfactory reduction. Ticks were not completely extirpated even by ploughing. It is probable that pasture improvement affects tick population mainly by reducing cover and thus the humidity.
Unfortunately, effective pasture improvement is not economic on hill and moorland grazings in general. Such improvement as is practicable could only be a supplement to other control measures.
Since the sheep flock supports almost all the female ticks on a pasture, control is most likely to follow from the development of an efficient acaricidal sheep dip.     

Effects of a commercial malathion dip preparation on the cellular and humoral immune response of BALB/c mice

Because of the widespread use of malathion as a treatment for ectoparasitism, a study was undertaken to determine the effects of a malathion dip preparation on the BALB/c mouse immune system. Mice were treated with either 2% (recommended dosage) or 8% solutions of malathion or a water control. The cellular immune response was evaluated by in vitro exposure of lymphocytes to mitogens, and the humoral immune response was assessed by using an enzyme-linked immunosorbent assay (ELISA) to quantify antibody production against sheep red blood cells (SRBC). Responses to the mitogens and to the SRBC were not significantly different between 2% and 8% malathion treated and water treated mice. Results indicated that malathion did not affect these two aspects of the mouse immune system when used as a 2% or 8% dipping solution.     

Reduced glutathione promotes callus growth and shoot development in a shoot tip culture of apple root stock M26

Reduced glutathione (GSH) was applied to prevent browning in shoot tip explants of apple (Malus pumila Mill.). Development was compared between shoot tips treated either by (a) dipping into 0.1 mm GSH solution prior to culture (dip treatment), (b) dipping into the GSH solution and transferring to a medium containing 0.1 mm GSH (dip-and-add treatment), or (c) without dipping or culturing with GSH (control). In the dip treatment, 100% of shoot tips developed into normal shoots after 120 days, while the results with the dip-and-add treatment and control were 50 and 40%, respectively. The results show that application of antioxidant GSH in the initial phase of culture promoted the normal development of shoot tips. Received: 10 October 1997 / Revision received: 12 January 1998 / Accepted: 24 January 1998     

Diseases of the gladiolus: I. Control of hard rot, due to Septoria gladioli Passer., by fungicidal treatment of the corms

Losses from hard rot, measured by an arbitrary disease index, were reduced by treating the dehusked corms before planting with mercuric chloride (with or without the addition of 10% hydrochloric acid), mercurous chloride (calomel), three proprietary mercury compounds (Aretan, Uspulun and Ceresan) and one proprietary non-mercury compound (Folosan). Calomel was the least effective. All the treatments were relatively less effective when corms with definite lesions were treated.
The weight of clean corms produced per old corm planted (weight index) was usually increased by all the fungicides tried, but calomel and Ceresan were less satisfactory than the others.
Mercuric chloride (3 hr. steep in a 0.1% solution) was not rendered more effective by the addition of hydrochloric acid nor by a preliminary dip in methylated spirits to facilitate wetting, while the addition of a proprietary wetting compound (Agral) was definitely harmful to the corms and usually less effective than mercuric chloride alone. Increase in time of steeping or concentration of mercuric chloride was not beneficial and was sometimes harmful. Reduction in time of steeping to 1 hr. gave promising results.
Treatment in November had some advantages over treatment in March.
All the mercury compounds tended to delay flowering, this being most marked in the presence of the wetting compound. Stunted foliage and poor quality flowers resulted from the use of Ceresan.     

Experiments on the control of white rot (Sclerotium cepivorum Berk.) in onions

Experiments-made during 1943 and 1944 on the use of mercurous chloride (calomel) for the control of Sclerotium cepivorum in spring-sown onions are described. The application of 4% calomel dust to the seed drill at sowing time gave better results than seed treatment. 1 lb. of dust per 25 yd. of seed drill gave good disease control in bulb onions, and 1 lb./so yd. may suffice for salad onions.
The relation between disease control and the effective mercury content of the treated soil is discussed.     

Speed of action and in vitro efficacy of spinosad against sheep body lice, Bovicola ovis (Schrank) (Phthiraptera: Trichodectidae), resistant to pyrethroid, organophosphate or insect growth regulator insecticides

Abstract  Results of laboratory bioassays indicated that spinosad was equally effective against sheep lice populations that were susceptible to insecticides or resistant to pyrethroid, organophosphorus or insect growth regulator (IGR) insecticides. Spinosad had similar toxicity against susceptible strains of lice to that previously reported for diazinon, but lower toxicity than cypermethrin. Lethal concentrations of spinosad and diazinon caused knock down of lice within 6 h of exposure and death within 24 h. Prior to the current phasing out of diazinon as a sheep dip, most wool producers, needing to control pyrethroid- or IGR-resistant lice infestations in short-wool, would have chosen to use diazinon. Our results suggest that spinosad is an effective alternative for treatment of lice resistant to other chemical groups.     

Further experiments on the control of white rot (Sclerotium cepivorum Berk;) in onions, shallots and leeks

Trials in 1945 confirmed earlier work on the efficacy of mercurous chloride (calomel) for the control of Sclerotium cepivorum in spring-sown onions. The application of 1 lb. 4% calomel dust to 50 yd. of seed drill at sowing time gave sufficiently good control of the disease in salad onions. Broadcast application of 1 oz. 4% calomel dust per sq.yd. before sowing was less effective but promising. Post-emergence application of the dust was useless. In autumn sowings, seed-drill treatment at 1 lb./so yd. controlled the disease in the following spring, but caused severe retardation and loss of crop.
Onion seedlings raised in heat and dipped in an aqueous paste of calomel dust before transplanting showed a high degree of resistance to a severe attack. Similar treatment of shallot bulbs was also effective. In both cases, the treatment substantially increased the yield and somewhat reduced storage losses.
Leek seedlings transplanted into dibber holes did not develop the disease.     

Effect of Antifungal Compounds on Aspergillosis in Hatching Chick Embryos

Aspergillosis was induced experimentally in hatching chick embryos by dipping them in water containing spores of Aspergillus fumigatus or A. flavus. The addition to the dip water of antifungal compounds prevented the development of this syndrome. Of the compounds studied, amphotericin B was most effective, followed by pimaricin and nystatin. Sorbic acid was without effect.     

The effect of seed, furrow and stem base spray treatment with iprodione on white rot disease (Sclerotium cepivorum) in spring-sown salad onions

Seed treatment with iprodione at 125 and 150 g a.i./kg was superior to calomel seed treatment at 500 g a.i./kg in reducing disease losses and increasing yields in field experiments with salad onions infected with white rot; iprodione at 50, 62·5 and 100 g a.i./kg and thiophanate-methyl at 150 g a.i./kg were as effective as calomel. Furrow treatment with iprodione or thiophanate-methyl at 0·05 and 0·15 g a.i./m row or calomel at 0·5 g a.i./m row gave similar control as equivalent rates of seed treatment. Neither seed nor furrow treatments gave adequate control with prolonged exposure of the crop to the disease. A single stem base spray of iprodione at 0·0625 g a.i./m row applied 5 wk after drilling, reduced losses from 46% with a standard calomel seed treatment to 20%; increasing the stem base spray concentration to 0·25 g a.i./m row did not improve the control but resulted in a doubling of yields. The most effective control was obtained with iprodione applied as a seed treatment at 62·5 g a.i./kg combined with a single stem base spray at 0·0625 g a.i./m row 5 wk after drilling and this reduced losses to 6% compared with losses of 46% with calomel treated seed and 88% with untreated seed; increasing the stem base spray concentration did not improve control but resulted in higher yields.     

Efficient floral dip transformation method using Agrobacterium tumefaciens on Cosmos sulphureus Cav.

Yellow cosmos (Cosmos sulphureus Cav.) is a specific flowering plant and considered a suitable genetic engineering model. Agrobacterium-mediated plant transformation is commonly used for plant genetic engineering. Floral dip transformation is one of the plant genetic transformation methods, and it involves dipping flower buds into an Agrobacterium suspension. Studies on floral dip transformation of yellow cosmos have never been reported. Therefore, an efficient method in plant genetic engineering must be established. This study developed an effective and efficient floral dip transformation method for yellow cosmos.In this study, flower buds with sizes of 5–7 mm were used. Several parameters have been observed to optimize the floral dip method. These parameters included the optical density (OD₆₀₀) of Agrobacterium culture, concentration of surfactant, and duration of flower bud dipping into the Agrobacterium suspension.The results showed that the floral dip method was most efficient when the flower buds were dipped into Agrobacterium suspension with OD₆₀₀ = 0.8 and containing 5% sucrose and 0.1% Silwet L-77 for 30 s. This method enhanced the transformation efficiency at a rate of 12.78 ± 1.53%. The neomycin phosphotransferase II and green fluorescent protein genes with sizes of 550 and 736 bp, respectively, were confirmed by polymerase chain reaction. In addition, the transgenic plants were kanamycin resistant and fluorescent under ultraviolet light observation. This finding suggests that the proposed floral dip transformation provides new insights into efficient plant genetic engineering methods for yellow cosmos.     

Investigation of the application of Acadian Marine Plant Extract Powder (AMPEP) to enhance the growth, phenolic content, free radical scavenging, and iron chelating activities of Kappaphycus Doty (Solieriaceae, Gigartinales, Rhodophyta)

An optimization study on concentration (viz. 0.01, 0.1, and 1.0 g L^?1) and dipping time (i.e., 30 and 60 min) was conducted on three different color morphotypes (i.e., reddish brown, yellowish brown and purple) of the commercial carrageenophyte Kappaphycus alvarezii (Doty) Doty. The study tested the efficacy of Acadian Marine Plant Extract Powder (AMPEP) on the growth rate and occurrence of macro-epiphytes from August to November, representing the wet season of the Philippines. The optimum concentration and dipping time were obtained at 0.1 g L^?1 and 30 min, respectively. These optimum parameters were then further verified in a commercial nursery using the yellowish brown morphotype. In another experiment, K. alvarezii (tambalang purple morphotype) and Kappaphycus striatum (Schmitz) Doty (sacol green morphotype) with, and without, AMPEP dippings were tested for their total phenolic content, free radical scavenging and iron chelating activities. Seaweed dipped in AMPEP demonstrated higher growth rates than the control. Lower concentrations (i.e., 0.01-0.1 g L^?1) and shorter dipping time (e.g., 30 min) produced higher growth rates than the highest concentration (1.0 g L^?1) and longer (60 min) dipping time. The presence of macro-epiphytes such as filamentous Ulva did not adversely affect the robust growth of the three color morphotypes of K. alvarezii. The lowest and highest growth rates obtained in a commercial seaweed nursery using the optimum concentration and dipping time of AMPEP were observed in July and January with 0.8% and 6.7% day^?1, respectively. The antioxidant content of K. alvarezii (tambalang purple) and K. striatum (sacol green) responded differently to AMPEP dipping. The changes in total antioxidant activity followed almost the same trend as in phenolic content, in both K. alvarezii (tambalang purple) and K. striatum (sacol green), whereas, the iron chelating ability of both seaweeds with and without AMPEP dipping varied monthly. The results obtained for the use of AMPEP dips for commercial Kappaphycus cultivation demonstrated an effective management tool for improved farming protocols.     

THE PROTECTIVE EFFECT OF ARSENIC AND DERRIS DIPS AGAINST THE SHEEP TICK, IXODES RICINUS L

Sodium arsenite used at a bath strength of 0.2% As₂O₃ is shown to protect sheep to a large extent from infestation for periods of from 1 to 2 weeks. Coal-tar creosote dips, though usually effective in killing attached ticks, have no protective effect against reinfestation. Derris, either as ground root or as extract, kills all attached ticks at dilutions down to the order of I part extract in 15,000 of water. At a concentration of 1 part in 5000 it has an effective duration comparable to that of arsenic at 0.2% As₂O₃. Its maximum effective duration, when applied as an emulsion wash, appears to be 14–17 days.
The addition of wool grease enhances the effective duration of arsenic, but not of derris. The effect of immersion time is important for both arsenical and derris dips, but is especially important for the latter. For full effect with derris washes sheep must be immersed for at least half a minute.
A protective dip is described which markedly lowers the infestation of dipped sheep for about 3 weeks.     

Some Studies on Root Membrane Potentials

Root membrane potentials were measured with two calomel electrodesby placing barley roots between two different potassium solutionsin which the electrodes dip. These potentials were found todepend on the type, concentration, and pH of the salt used.This is taken to indicate that the transport number of K inthe membrane is dependent on these factors. Furthermore, thepotential measurements as a function of pH and KCI concentrationallowed the determination of the point of zero charge of thebarley root which was found to be at pH 2–9.     

Biocontrol of Phytophthora cactorum the causal agent of root and crown rot on apple (Malus domestica) by formulated Pseudomonas fluorescens

In this study 284 isolates were isolated of apple trees' rhizosphere from Iran and 128 isolates were obtained from the collection of Research Department of Biological Control of University of Tehran. Four strains (P60, P61, P96, and P97) of Pseudomonas fluorescens were selected for greenhouse trials. The results of greenhouse trials showed dipping the crown and root of apple seedlings (MM106) combined with soil drench was more effective than dipping the crown and root on reducing the disease. After 6 weeks, strain P60 in dipping method combined with soil drench with 70% control, exhibited greatest effect on reducing the crown and root rot and was more effective than the fungicide metalaxyl-mancozeb. After 12 weeks, strains P60 and P96 in dipping method combined with soil drench with 55.6% and 44.5% control respectively, exhibited greatest effects on reducing the diseases Study of media on growth rate populations of effective strains exhibited that the beet molasses yeast extract (1:1) had more effect than nutrient broth(NB) medium. The initial high populations of powder formulations of strains P60 and P96 decreased during the storage at 4 and 25 degrees C over a 150-day period. In addition, formulations of strains stored at 4 degrees C had longer shelf life than those stored at 25 degrees C. In glasshouse trials, after 6 weeks, formulation of strain P60 and unformulated P60, obtained from NB medium and formulated P60, obtained from molasses yeast extract medium, and metalaxyl-mancozeb had highest effect on reducing the disease on apple rootstocks. After 12 weeks, formulation of strain P60 and unformulated bacteria obtained from both media, and metalaxyl-mancozeb with 57.1% control showed greatest effect on reducing the disease.     

Chimpanzees use tools to harvest social insects at Fongoli, Senegal

Use of flexible probes to fish for macrotermitine termites and manufactured wands to dip for doriline ants is reported for a new site of chimpanzee field study. The flexible probes of vegetation used in termite fishing and ant dipping by the chimpanzees of Fongoli, in southeastern Senegal, are similar to those used at Assirik (Senegal) and Gombe (Tanzania). Based on the principle that form reflects function, we predict that ant dipping when seen will prove to be the two-handed technique.     

Ant dipping and meat eating by wild chimpanzees in the kalinzu forest, uganda

New evidence of ant dipping and meat eating by chimpanzees was recorded in the Kalinzu Forest, Uganda. We found stems and branches at the nests of driver ants,Dorylus molestus, just after chimpanzees had left the spot. Fecal samples also revealed that chimpanzees sometimes ate driver ants. The configuration of stems and branches and the condition of holes at the driver ant's nests suggested that chimpanzees used them as wands to dip for ants. The frequency of ant dipping and length of wands may be more related to culturel rather than ecological factors. Although hunting was not seen, we found chim-panzees eating a blue monkey and a redtail monkey. In both cases, they ate meat and leaves alternatively, and shared meat with each other.     

FIELD EXPERIMENTS ON POTATO SKIN-SPOT DISEASE CAUSED BY OOSPORA PUSTULANS OWEN & WAKEF

In experiments on skin-spot disease of potatoes, caused by Oospora pustulans Owen & Wakef., Kerr's Pink proved the most susceptible of twenty-four commercial varieties; Arran Banner, Majestic and King Edward were highly susceptible; Home Guard and Golden Wonder were highly resistant.
Thymol and tetrachlornitrobenzene, applied as dusts to pits of potatoes at lifting, did not give satisfactory control of the disease. The efficacy of an organo-mercury dip treatment at lifting time was confirmed.
The incidence of the disease was considerably decreased by storing tubers in boxes instead of in pits, by digging the crop about a month before normal harvest, or by cutting the haulms at this time and digging at the normal time.
Ware tubers showed a significantly higher infection than seed tubers of the same crop, indicating that susceptibility of tubers increases towards maturity.
The difference in eye infection between varieties may not be related to that of general superficial infection. It is suggested that, in future, the assessment of varietal susceptibility should be based upon the degree of eye infection, which is in practice the measure of the economic importance of the disease. Tubers having pustules at or near all the eyes gave markedly reduced sprout emergence and plant stand.     

Floral spray transformation can efficiently generate Arabidopsis transgenic plants

In this study, floral spray and floral dip were used to replace the vacuum step in the Agrobacterium-mediated transformation of a superoxide dismutase (SOD) gene into Arabidopsis. The transgene was constructed by using a CaMV 35S promoter to drive a rice cytosolic CuZnSOD coding sequence in Arabidopsis. The transgene construct was developed in binary vectors and mobilized into Agrobacterium. When Arabidopsis plants started to initiate flower buds, the primary inflorescence shoots were removed and then transformed by floral spray or floral dip. More than 300 transgenic plants were generated to assess the feasibility of floral spray used in the in planta transformation. The result indicates that the floral spray method of Agrobacterium can achieve rates of in planta transformation comparable to the vacuum-infiltration and floral dip methods. The floral spray method opens up the possibility of in planta transformation of plant species which are too large for dipping or vacuum infiltration.     

Disinfection Alternatives for Control of Ditylenchus dipsaci in Garlic Seed Cloves

Hot-water dips with and without the additives abamectin and sodium hypochlorite were evaluated for control of Ditylenchus dipsaci infection of garlic seed cloves. All treatments were compared to hot water-formalin clove dip disinfection and to nontreated infected controls for garlic emergence, midseason infection, bulb damage, and yield at harvest in field plots in 12 experiments. Hot-water treatments without additives only partially controlled D. dipsaci when a warming presoak dip (38 C) of 30, 45, or 60 minutes'' duration was followed by a hot-water dip (49 C) of 15-30 minutes'' duration. Exposure to 49 C for 30 minutes caused slight retardation of garlic emergence, although normal stand was established. Abamectin at 10-20 ppm as the 20-minute hot dip (49 C) or as a 20-minute cool dip (18 C) following a 20-minute hot-water dip and sodium hypochlorite at 1.052-1.313% aqueous solution as the 20-minute hot dip were highly effective in controlling D. dipsaci and were noninjurious to garlic seed cloves. None of these treatments was as effective as a hot water-formalin dip and were noneradicative, but showed high efficacy on heavily infected seed cloves relative to nontreated controls. Abamectin was most effective as a cool dip. These abamectin cool-dip (following hot-water dip) and sodium hypochlorite hot-dip treatments can be considered as effective alternatives to replace formalin as a dip additive for control of clove-borne D. dipsaci. Sodium hypochlorite was less effective as the cool dip, and at concentrations of 1.75-2.63% was phytotoxic to garlic.     

An innovative approach to <Emphasis Type="Italic">ex vitro</Emphasis> rooting and acclimatization of <Emphasis Type="Italic">Fragaria</Emphasis> × <Emphasis Type="Italic">ananassa</Emphasis> Duch. microshoots using а biogenic silica- and green-tea-catechin-based mechanocomposite

A new approach for rapid ex vitro rooting and acclimatization of Fragaria × ananassa micropropagated plantlets of two cultivars (“Alpha” and “Festivalnaya”) has been developed using a mechanocomposite based on biogenic silica and green-tea catechins. Two different mechanocomposite treatments were studied: dipping the cut ends of microshoots in the mechanocomposite powder (the dry dip method) and single watering with solutions at concentrations of 0.3, 1.0, and 3.0 g L^?1. These variants were compared with pulse treatment of microplants with 30 mg L^?1 indole-3-acetic acid (IAA) for 4 h and a control group of microshoots that were moistened with hormone-free ¼-strength MS medium. The frequencies of ex vitro rooting at the end of the acclimatization period (30 d) varied from 24.8 to 99.7%. The dry dip treatment was best (rooting frequency about 100%) with up to 7.15?±?0.54-cm root length, and 6.10?±?0.31 roots per plantlet. Moreover, this study showed that the growth-stimulating effect of this mechanocomposite treatment on root formation resulted in increased rosette height, leaf number, leaf area, and dry weight of aerial parts. Histological analysis of the leaf blades revealed decreased mesophyll thickness of microshoots treated with the mechanocomposite (up to 88.77?±?2.95 vs. 111.51?±?3.56 μm for the control). Morphometric analysis of scanning electron microscopy data showed that mechanocomposite treatments led to increased stomata density and stomata length. These structural changes led to normalization of the water regime and indicated successful acclimatization. The combination of ex vitro rooting and acclimatization reduced the procedure time by 4 wk, and may be used for commercial strawberry micropropagation.