Aphidicidal activity of some indigenous plant extracts against bean aphid <Emphasis Type="Italic">Aphis </Emphasis><Emphasis Type="Italic">craccivora</Emphasis> Koch (Homoptera: Aphididae)

Aphidicidal activity of hot and cold water extracts of some indigenous plants, Azadirachta indica A. Juss (neem), Calotropis procera (Aiton) W.T. Aiton (akanda), Polygonum hydropiper L. (biskatali) and Ipomoea sepiaria J. Koenig ex Roxb. (bankalmi), were tested against the bean aphid, Aphis craccivora Koch. Hot water extract of P. hydropiper and A. indica was found to be the most effective (87.6–94.5 and 80.47–89.6% mortality respectively, P < 0.01) among all the extracts. Other hot and cold water extracts also appeared to be useful (59.5–87.5% mortality) as pesticides for A. craccivora. The highest yield (3.25 kg per plant) was obtained using hot water extract of P. hydropiper followed by hot water extract of A. indica (3.15 kg per plant). The lowest yield (0.32 kg per plant) was recorded from the control block. All the phytoproduct treatments had significantly (P < 0.01) better yield than the control block.     

Breaking Seed Dormancy of Laurel (Laurus nobilis L.)

Laurel (Laurus nobilis L.) seeds were collected from the west part of Turkey in the fall of 2002. Seeds with pericarp (+) or without pericarp (−) were treated with 1000 mg/l, 2000 mg/l and 3000 mg/l GA₃ concentrations, cold stratified at +4 ± 1°C for 25 and 50 days, punctured and seed coat removed to overcome and assess the mechanism of laurel seed dormancy. A period of 50 days cold stratification and removing seed coat significantly increased germination rate to 55% ± 1.91 (Mean ± SE) and 85% ± 3.00, respectively. None of the seeds with pericarp germinated regardless of treatment they underwent. Results suggested that seed dormancy was mainly due to pericarp and perhaps inhibitors linked to seed coat.     

Viability retention of seeds of shisham (Dalbergia sissoo Roxb.) on the trees after maturity

In 1991 and 1992 studies on Dalbergia sissoo Roxb. showed the availability of ample amount of viable seed from November to May. Viability of seeds collected from December to March was more than 90 per cent. There was a slight but significant decrease in germination from March to may. Again germination per cent was slightly and significantly decreased from May to July. Thereafter, seed availability and viability were got drastically reduced. Sufficient viable seed of Dalbergia sissoo Roxb. can be collected at any time from November to July.     

Comparative efficacy of NeemAzal and local botanicals derived from <Emphasis Type="Italic">Azadirachta indica</Emphasis> and <Emphasis Type="Italic">Plectranthus glandulosus</Emphasis> against <Emphasis Type="Italic">Sitophilus zeamais</Emphasis> on maize

The efficacy of NeemAzal powder, two local neem (Azadirachta indica ) products [neem seed powder (NSP) and neem seed oil (NSO)], as well as a local Lamiaceae, Plectranthus glandulosus leaf powder, applied at four different rates for the control of Sitophilus zeamais was determined. Mortality was recorded 1, 3, 7 and 14 days after S. zeamais infestation, followed by the determination of F₁ progeny production. Grain damage, population increase and grain germination were assessed for treated grains that were stored for 4 months. Grains treated with P. glandulosus powder and NSP had relatively low mortality (5.0–22.5%) after 3 days whereas NeemAzal and NSO had higher mortality (55.0–98.8%). Maximum mortality of 99, 100, 96 and 74% were achieved for NeemAzal (12 g/kg after 14 days), NSO (4 ml/kg after 7 days), NSP (40 g/kg after 14 days) and P. glandulosus powder (40 g/kg, after 14 days), respectively. In the same order, 7-day LC₅₀ values were 0.02 g/kg, 1.46 ml/kg, 12.44 g/kg and 28.9 g/kg. The three neem products greatly reduced progeny emergence, while P. glandulosus powder was less effective. NeemAzal protected the grains against S. zeamais damage better than the local neem products, which in turn provided far better grain protection against the weevil damage than P. glandulosus powder. NeemAzal was superior to the local neem products in grain protection against germination loss, with P. glandulosus being the least effective. NeemAzal and NSO had sufficient efficacy to be a component of an integrated management package for S. zeamais.     

Components of the essential oils of Azadirachta indica A. Juss, Azadirachta siamensis Velton, and Azadirachta excelsa (Jack) Jacobs and their comparison

The components of the essential oils from seeds of Azadirachta indica, Azadirachta siamensis, and Azadi-rachta excelsa were studied by gas chromatography and gas chromatography-mass spectrometry. The main components of A. indica oil were hexadecanoic acid (34.0%), oleic acid (15.7%), 5,6-dihydro-2,4,6-triethyl-(4H)-1,3,5-dithiazine (11.7%), methyl oleate (3.8%), and eudesm-7(11)-en-4-ol (2.7%). The major components of A. siamensis oil were hexadecanoic acid (52.2%), tricosane (10.5%), tetradecanoic acid (6.8%), oleic acid (4.9%), and pentacosane (4.9%). Azadirachta excelsa oil contained oleic acid (31.3%), hexadecanoic acid (14.2%), octadecanoic acid (13.0%), 4-octylphenol (9.7%), and O-methyloximedecanal (6.8%) as the main constituents. The essential oils from A. indica, A. siamensis, and A. excelsa were found to contain fatty acids (52.6%–72.3%) as major components. The minor components of the oils were n-alkanes, aromatics, esters, sulfur and nitrogen compounds, and terpenoids. Differences in oil composition were observed between the three species.     

Impact of tree coppicing on tree-crop competition in parkland and alley farming systems in semiarid Burkina Faso

The aim of this study was to evaluate the effects of tree coppicing on tree-crop competition in farmed parkland and in alley farming, both in semiarid Burkina Faso.Azadirachta indica A. Juss (neem) was studied in the parklands, while neem,Albizia lebbeck (L.) Benth. (albizia) andLeucaena leucocephala (Lam.) de Wit (leucaena) were investigated in the alley farming system. The crop was sorghum (Sorghum bicolor (L.) Moench) in both cases.Under non-coppiced neem trees in the parkland, the sorghum yield at 0–3 m distance from the tree (under the tree canopy) was 82% of open field yields at 6–9 m distance, but the difference was not significant (p=0.07). Close to trees (0–3 m distance) which had been coppiced before planting, the sorghum yield was 148% of open field yields. In alley farming, early coppicing was superior; sorghum yields were highest close to trees coppiced early and lowest close to trees coppiced late.

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Résumé La présente étude se propose d'évaluer les effets de la taille sur la concurrence entre arbres et cultures dans les parcs arborés et dans les cultures en couloir, en climat semiaride (Burkina Faso). Les espèces étudiées ont été:Azadirachta indica A. Juss (neem) dans les parcs et neem,Albizia lebbeck (L.) Benth. (albizia) ainsi queLeucaena leucocephala (Lam.) de Wit (leucaena) dans les cultures en couloir. Dans les deux cas la plante cultivée concerné a été le sorgho blanc (Sorghum bicolor (L.) Moench).Sous les neems non taillés des parcs, le rendement du sorgho cultivé de 0 à 3 m de l'arbre (sous le bouppier de l'arbre) a atteint 82% du rendement obtenu en plein champ, soit à une distance de 6 à 9 m de l'arbre (différence non significative,p=0.07). Une taille effectuée en début de campagne a entraîné un accroissement du rendement de 148% pour les cultures situées de 0 à 3 m de l'arbre, par rapport aux rendements en plein champ.Dans les cultures en couloir, on a constaté qu'une taille precoce est préférable, c'est à dire que les rendements de sorgho ont été supérieurs dans les lignes proches des arbres taillés tôt que dans celles proches des arbres taillés tard.

     

Desiccation and storage behavior of bay laurel (Laurus nobilis L.) seeds

The effect of seed moisture content (m.c.) and seed storage conditions of bay laurel (Laurus nobilis L.) was investigated in relation to seed viability. In the first experiment, the effect of drying rate on seed moisture and seed germination was investigated. Fresh seeds, with their original moisture content displayed a germination percentage of 55.1%. When the seed moisture content was reduced by 2.0% in an oven, the germination percentage rose to 81.0%. When the seed moisture content was reduced even more by using the same method, the germination percentages decreased dramatically. Reducing the seed moisture content to 28.7 and 23.5% by drying the seeds in alternating room conditions resulted in an increase of seed germinability to 84.3 and 90.9%, respectively. The drying of the seeds for 45, 60 and 75 days reduced their seed germination to 66.8, 49.4 and 48.0%, respectively. Reducing seed moisture content below 15.0% resulted in practically nullifying seed germinability. The fact that bay laurel seeds cannot retain their germinability at lower moisture contents demonstrates that it is a species with recalcitrant seeds. In the second experiment, moist and dry storage conditions were tested under different temperatures and moisture contents. The storage experiment showed that the most effective way of conserving the bay laurel seeds is moist storage at 0 ± 1°C for 4 months without previous drying of the seeds.     

芍药种子含油率与脂肪酸成分研究

[目的]本文对芍药种子含油率、脂肪酸成分及含量进行了探讨,为芍药开发成油料植物提供参考。[方法]选取芍药36个栽培品种和1个野生居群为样本,采用索氏提取法提取种子油脂并测定含油率,用气相色谱—质谱联用仪(GC-MS)对提取的籽油成分进行分析。[结果]表明:芍药36个栽培品种和1个野生居群种子平均含油率为20.20%。芍药籽油主要含有豆蔻酸、棕榈酸、棕榈一烯酸、硬脂酸、油酸、亚油酸、亚麻酸和花生酸8种脂肪酸,其中,亚麻酸含量最高,平均达34.14%,其次为油酸和亚油酸,这3种不饱和脂肪酸的含量占全部脂肪酸的93.37%。芍药籽油脂肪酸含量变化相对稳定,各脂肪酸成分的变异系数从大到小依次为亚油酸(13.90%)油酸(13.51%)亚麻酸(10.71%)棕榈酸(0.18%)硬脂酸(0.09%)花生酸(0.002%)、棕榈一烯酸(0.002%)豆蔻酸(0.00%)。[结论]芍药种子含油率高,富含亚麻酸、亚油酸和油酸,且含量相对稳定,变异很小,具有开发为高含量亚麻酸食用油潜力。     

Maturity indices of Indian horse-chestnut (<Emphasis Type="Italic">Aesculus indica</Emphasis> Colebr.) seeds under temperate Kashmir conditions

Our study on maturity indices of Aesculus indica Colebr.seeds was conducted under temperate Kashmir conditions in 2006.Seed collection was started from 15 July and continued until the maturation of seeds in December.The seeds were harvested fortnightly from identified trees and on each collection date maturity indices,viz.seed color,seed weight,moisture content,seed dimension,specific gravity and germination percentage were recorded.The study revealed that at the time of maturity (Nov.–Dec.) the seed color ...     

Zur Wirkung von Niemprodukten aufBemisia tabaci Genn. an Auberginen bei Verwendung verschiedener Zusatzstoffe

As neem (Azadirachta indica A. Juss.) seed is still quite expensive in the Dominican Republic, it was tried to reduce the dosage by increasing the efficiency of the insecticide using the adjuvant Tersan (Alcohol-9-ethylen-oxid).The effect of various aqueous neem seed extracts (25 g seeds per 1, 40 g/l, 60 g/l, oilcake 15 g/l) and formulated neem oil mixed with the adjvant was tested in laboratory and field trials againstBemisia tabaci on eggplant. In laboratory trials the efficiency of all tested products except neem oil was increased by 24% to 48%. The increase of efficiency was more pronounced on very hairy than on glabrous plants. These positive results could not be confirmed in field trials, where the adjuvant had no effect or even reduced the efficiency of the insecticide.The effect of the adjuvant is a reduction of the surface tension of the spraying mixture for better wetting and to adhere it to the leaf. As the laboratory plants usually possessed much more hairs than those in the field, the insecticide could develop its full effect in the field even without support by the adjuvant.

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Zur Wirkung von Niemprodukten aufBemisia tabaci Genn. an Auberginen bei Verwendung verschiedener Zusatzstoffe

Zusammenfassung Eine Verringerung der Dosis von Niemprodukten kann mitunter zu einer signifikanten Minderung des Wirkungsgrades und zu Ernteverlusten führen. Geringer Befall sollte aber immer auch mit einer Dosis unterhalb der empfohlenen 50 g Samenpulver pro Liter Wasser bekämpfbar sein. Der Zusatz von Stoffen, die eine bessere Benetzung der Pflanze gewährleisten, zu Niemsamenwasserextrakten führte im Labor bei wenig behaarten Auberginenpflanzen kaum zu Wirkungssteigerungen gegenüberB. tabaci. Bei stark behaarten Pflanzen jedoch konnte die Effektivität um bis zu 90% gesteigert werden, da die Behaarung eine Benetzung der Blattspreite und damit eine Wirkung verhindert. Im Feld konnten Wirkungssteigerungen durch Zusatz von Netzmitteln nicht erreicht werden. Im Gegenteil: Die Wirkung der wässrigen Niemsamenextrakte wurde oft aus unerklärlichen Gründen herabgesetzt. Die Wirkung von Niemöl konnte weder im Feld- noch im Laborversuch durch Zusatzstoffe gesteigert werden.

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Mit 3 Abbildungen     

Variations in seed germination of Hippophae salicifolia with different presoaking treatments

Mature seeds of H. salicifolia, collected from five provenances (i.e. Hanuman Chatti, Helang, Lata, Rambara and Janggal Chatti) in west Himalaya, India, were treated with stratification (at 4°C for 15, 30 and 60 days) and in different concentrations of GA₃ (5, 10, 20 mM), KNO₃ (50, 100, 200 mM) and Thiourea (50, 100, 200 mM) solution to determine the variations in seed germination. Results reveal that the germination rates of seeds from different provenances under different pre-sowing treatments are significantly increased compared to those in control (24%–30%). The seeds treated with Thiourea (100 mM) have highest germination rate (76%–83% for different seed sources), followed by those (63%–71% for different seed sources) pretreated with stratification (4°C, 30 days). GA3 treatment significantly shortens the mean germination time (MGT) and improves seed germination percentage. Considering the practical applicability and cost effectiveness, thiourea (100 mM) and stratification (at 4°C) treatments for seed germination are recommended for mass multiplication through seeds of H. salicifolia in village/forest nurseries of the west Himalaya, India.     

Beobachtungen über Nutznießer der Früchte des Niembaumes (Azadirachta indica) in Afrika mit besonderer Berücksichtigung von Senegal

Zusammenfassung Die Früchte des NiembaumesAzadirachta indica werden in Senegal und anderswo durch mehrere Tierarten als Nahrung genutzt. Ziegen fressen die Samen einschließlich des sehr bitteren Samenkerns. Das süße Fruchtfleisch wird vom Menschen und von Flughunden, besonders dem PalmenflughundEidolon helvum helvum gegessen. Gleiches gilt für einige Vogelarten wie den DorfweberTextor cucullatus, den GraubülbülPycnonotus barbatus, den LangschwanzglanzstarLamprotornis caudatus und andereLamprotornis-Arten sowie für den MausvogelUrocolius macroursus. Alle fruchtfleischfressenden Tiere sind nützlich, da sie die Niemsamen für das Sammeln durch den Menschen vorbereiten. Dies macht den arbeits- und zeitaufwendigen Prozeß des Entpulpens überflüssig, was für die wirtschaftliche Anwendung von Niemsamen für Pflanzenschutzzwecke sehr wichtig ist, zumindest in Westafrika. Andererseits könnten sich Ziegen als wichtige Konkurrenten für den Menschen entwikkeln, wenn sie in Zukunft große Mengen an Niemsamen verzehren sollten.

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Observations on man and animals utilizing the fruits of neem tree,Azadirachta indica A. Juss. in Senegal and other parts of Africa

The fruits of the neem tree,Azadirachta indica A. Juss., are utilized in Senegal and elsewhere by man and numerous animals for food. Goats eat the seeds including the very bitter seed kernel. The sweet pulp is consumed by man and flying foxes (fruit bats), specially the straw-coloured flying fox,Eidolon helvum helvum (Kerr.). The same applies to some bird species, such as the v-marked or village weaver,Textor cucullatus (Müll.), the white vented bulbul,Pycnonotus barbatus (Desfont.), the long-tailed starling,Lamprotornis caudatus (Müll.), and otherLamprotornis spp., as well as to the mousebird,Urocolius macrourus (L.). All fruit-pulp eating animals are useful as they prepare the neem seeds for collection by man. This makes the labourious and time consuming process of depulping unnecessary, which is very important for the economic use of neem seeds for crop protection purposes, at least in W. Africa. On the other hand, goats may develop as important competitors of man if they consume large amounts of seeds in future.

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Mit einer Abbildung     

Seed dormancy in bay laurel (Laurus nobilis L.)

The germination of bay laurel (Laurus nobilis L.) seeds wasexamined both in the laboratory and in the field during twoyears. Seeds were collected from a grove in a garden in the townof Drama, Northern Greece, by mid November in the first year andby late November in the second year. The seeds with and withoutpericarp were given a warm-moist (20 °C day/12 °C night) oncold-moist (4±1 °C) treatment in peat or sand. After treatment theseeds were placed in the germinator along with controls. Thegermination of seeds with and without pericarp was alsoinvestigated in the field (late fall sowing). It was found thatthe pericarp caused dormancy. In seeds without pericarp,cold-moist and warm-moist stratification both proved to besuccessful in breaking embryo dormancy (100% and 96% successrespectively). The required stratification duration was 50 daysfor the warm-moist and 60 days for the cold-moist treatments.During the cold-moist stratification no germination was observed.On the other hand, seeds started to germinate during thewarm-moist stratification by about the 50th day. In the fallsowing germination was 20% for seeds with pericarp and 41% for seeds without pericarp. Drying bay laurel seeds caused areduction of the seed germination.     

The root-knot nematode problem in sesbania fallows and scope for managing it in western Kenya

Sesbania (Sesbania sesban), which is promoted as a short-duration-fallow species in eastern and southern Africa, is an alternative host to root-knot nematode (Meloidogyne spp.). Therefore, it is important to know the extent of sesbania infection by the nematode on farms and its effects to crops grown in rotation with sesbania. A survey of 14 farms in western Kenya indicated that sesbania was infected by root-knot nematode in all the farms. The potential to build up the nematode population was much greater on farms where maize (Zea mays) was previously intercropped with a susceptible bean (Phaseolus vulgaris). Screening of 30 single plant accessions of four sesbania provenances (Kakamega, Siaya, Kisumu, and Kisii) from western Kenya in pots indicated limited scope for selecting material resistant to the nematode. All four provenances were infested by the nematode, and they increased its population in soil and root. A rangewide collection of sesbania germplasm needs to be screened to determine the scope of finding nematode-resistant material. Transplanted seedlings produced in heat-sterilized, nematode-free soil showed less nematode infection than direct-seeded plants. However, both direct seeding and transplanting seemed to increase nematode population similarly. A number of Crotalaria spp. that were found resistant to nematodes can be considered as alternatives to sesbania-planted fallows, but further field-scale testing is necessary to select appropriate species based on biomass production. Among other species suitable for short-duration fallows, only pigeonpea (Cajanus cajan) and senna (Senna siamea) showed promise. Species such as neem (Azadirachta indica), casuarina (Casuarina junghuhniana), and grevillea (Grevillea robusta) that are suitable for boundary plantings were free from the root-knot nematode.This revised version was published online in November 2005 with corrections to the Cover Date.     

Freeze-dried powder of cow urine reduces the viability of the snail Lymnaea acuminata

Molluscicidal activity of cow urine alone and with different additives was studied against Lymnaea acuminata. The toxicity of cow urine kept for 15 days in sunlight (8 h/day) or ambient laboratory conditions against the snail was time- and concentration-dependent. The pH of fresh cow urine is 7.4 which changes to 10.9 when kept for 15 days in laboratory; exposure to sunlight for the same period alter the pH to 10.85. Binary combinations (1:1) of freeze-dried cow urine kept for 15 days separately with each of Allium sativum (Liliaceae) bulb powder, Azadirachta indica (Meliaceae) oil, Annona squamosa (Annonaceae) seed powder, Ferula asafoetida (Apiaceae) root latex and tea leaves, and Camellia sinensis (Theaceae) were more toxic to the snail than treatment with urine alone. Additives to cow urine in sunlight were more effective than those under laboratory conditions.     

Seed viability of selected tree,shrub, and vine species stored in the field

Seeds from 10 species were collected, sealed in fiberglass screen pouches, and stored under hardware-cloth cages on both a forest and cleared site for up to five years. At each site, half of the pouches were placed under leaf litter and the other half were planted in mineral soil. Liquidambar styraciflua and Callicarpa americana seeds had high germination rates under all conditions. Quercus falcata, Sassafras albidum, Rhus copallina, and Vaccinium arboreum required planting in mineral soil to ensure germination. Planted Myrica cerifera and Vitis aestivalis seeds germinated well on both sites. Myrica cerifera also germinated well if placed under litter on the forest floor and Vitis aestivalis if placed under litter on the cleared site. Germination of Crataegus uniflora seeds was erratic. Most Lonicera japonica were unsound when collected. Germination rates generally decreased over time, but some Sassafras albidum, Myrica cerifera, and Vaccinium arboreum seed germinated after four years, and Rhus coppalina, Callicarpa americana, Crataegus uniflora, and Vitis aestivalis seeds germinated after five years in the field.     

Revisiting the relationship between common weather variables and loblolly–shortleaf pine seed crops in natural stands

Seed production was monitored during24 years using seed-collection traps inloblolly–shortleaf pine (Pinus taeda L.–P.echinata Mill.) stands located in southeast Arkansas,north-central Louisiana, and southwest Mississippi onthe southeastern Coastal Plain, USA. Sound seedproduction was correlated with mean monthlyprecipitation and temperature from National Oceanicand Atmospheric Administration weather stationslocated near the seed-collection areas to determinethe potential of weather factors in forecasting pineseed crops. Correlations were restricted to threecritical periods in the pine reproductive cycle –strobili primordia differentiation, pollination, andfertilization. The most important (P 0.05)variables correlated with pine seed production for combined locations were cumulative precipitation (r = +0.60) during July, August, and September at 27 to 25 months before seed dispersal and mean temperature (r = –0.45) in August at 26 months before seed dispersal. Because multiple environmental factors can negatively impact pine seed development during the two yearsfollowing strobili primordia differentiation,seed-production forecasts based on weather variablesshould be verified by on-site cone counts during thesummer preceding autumn seed dispersal.     

Seed production of western larch in seed-tree systems in the southern interior of British Columbia

A series of surveys and experiments were conducted on four sites to identify constraints to seed production and natural regeneration in western larch seed-tree systems in the southwestern interior of British Columbia, Canada. These surveys included pollen monitoring, a cone analysis to evaluate seed production potential, seed trapping to estimate seed rain and the installation of field germination trials to assess the effects of germination substrate and seed losses due to bird and rodent predators. Pollen shedding was found to be adequate for moderate seed production with filled seed counts ranging from 9 to 30 per cone (10–34% of all seeds/cone). No significant differences in seed yields per cone and cone characteristics were observed between uncut control stands and seed-tree stands. Seed rain was generally good in 1995, ranging from 70,000 to 4.6 million seed/ha. For the four seed-tree stands, the average filled seed percentage of the trapped seeds ranged from 9–30%. Seed rain and seed quality were much reduced in 1996. Field germination trials showed western larch seeds germinated and survived best (15–70%) on mineral soil but rodent and/or bird predation reduced germination success significantly. Germination/germinant survival on undisturbed forest floor, covered with predator exclusion screens, was intermediate.     

Survival and growth of rattan intercropped with coffee and cacao in the agroforests of Indonesia

This study investigated the intercropping of rattan, an important non-timber forest product, in coffee and cacao agroforests in Sulawesi, Indonesia. The viability of producing seedlings from seeds and vegetative cuttings with the large-diameter rattan, Calamus zollingeri Beccari, and initial seedling survival, growth and response to light and soil drainage were investigated in village nurseries and perennial farms. Over 96% of seeds and 61% of vegetative cuttings were raised to transplanting size (25 cm with two to three leaves) over 20 months. One hundred C. zollingeri seedlings produced from cuttings were transplanted into each of three coffee or cacao farms and one primary forest site and exhibited an overall survival rate of 96%, 12.7 cm of height growth and the production of 0.8 new leaves per plant after eight months. No significant differences were observed between the four sites with respect to seedling survival, growth, or leaf production and no significant differences were found between seedling survival, growth or leaf production and light intensity (based on multiple PAR measurements). However, poorly drained sites exhibited significantly reduced C. zollingeri seedling survival and growth. The cultivation of C. zollingeri rattan in coffee and cacao agroforests represents a potential means of intensifying and diversifying perennial cash crop farming systems.This revised version was published online in November 2005 with corrections to the Cover Date.     

Repellent effects of different products of the neem tree on the red locust,Nomadacris septemfasciata Serv., in maize fields in the southwestern parts of Madagascar

The repellent effect of 3 different neem formulations was tested on red locust,Nomadacris septemfasciata Serv., in a maize field in the southwest of madagascar. A simple water extract from neem seed kernels (200 l and 600 l per ha), an enriched neem ULV-formulation (2 l per ha) and a dust, prepared on the base of neem seed cake (5 kg per ha) were applied. All four treatment provided protection from attack for at least five days. The water extract was significantly active until 7 days, the neem-ULV-formulation until 9 days after treatment. The application of neem seed kernel water extract could be a simple means for Malagasy farmers to protect their fields against red locust. N. septemfaxciata is a very interesting test organism because it is much easier to work with this species compared to the taxonomical closely related desert locust (Schistocerca gregaria Forsk.).

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Zusammenfassung Drei verschiedene Niemprodukte wurden auf ihre fraßabschreckende Wirkung auf die rote WanderheuschreckeNomadacris septemfasciata in einem Maisfeld im Südwesten Madagaskars überprüft. Ein einfacher Wasserextrakt aus 50 g gemahlenen Niemsamen pro Liter wurde in zwei Applikationsvolumina (200 l und 600 l pro ha) gespritzt. Eine angereicherte Niem-ULV-Formulierung wurde mit Hilfe eines ULV-Spritzgerätes bei 2 l/ha appliziert. Fünf kg aus Niempreßkuchen hergestellter Puder pro ha wurde ebenfalls ausgebracht. Alle 4 Behandlungen schützten den Mais mindestens für 5 Tage vor Fraßschäden durchN. septemfasciata. Der Wasserextrakt verminderte den Befall über 7 Tage und die Niem-ULV-Formulierung über 9 Tage signifikant. Der leicht herzustellende Wasserextrakt könnte ein für die Maisbauern geeignetes Mittel sein, um ihre Felder vor dem Befall vonN. septemfasciata wirksam zu schützen. Da es auf Grund ihrer Biologie viel einfacher ist, mitN. septemfasciata als mit der taxonomisch sehr eng verwandten Wüstenheuschrecke (Schistocerca gregaria Forsk.) zu arbeiten, eignet sichN. septemfasciata hervorragend als Modellorganismus für Versuche mit Niemprodukten im Freiland.

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