The potential of agroforestry in the high rainfall areas of Zambia: a peasant programming model approach

Existing cropping systems in Northern Zambia cause deforestation and soil degradation. To reduce the environmental problems, the potential of alley cropping and pigeon peas replacing the existing cropping systems was analyzed by the use of multi-objective programming models of peasant households. The models were formulated based on the theories of Chayanov and Nakajima which are suitable under conditions of imperfect labour markets. Risk was incorporated in the models in relation to weather and fertilizer supply. The models provide an opportunity to relate key characteristics of new technologies to key characteristics of peasants' preferences and resource constrains. The models may also be used to identify minimum performance levels required for new technologies to be found acceptable.Models of a small male-headed household are presented under varying conditions: for high and low population densities, with and without fertilizer subsidies, and for households with and without access to off-farm employment under high population density conditions.The analysis showed that the alley cropping technology is very unlikely to replace thechitemene system where there is still sufficient woodland for its continuation. The technology may have higher potential in more densely populated areas, where more intensive forms of agriculture are practised and where there is access to inputs such as lime and fertilizer. The removal of fertilizer subsides as a result of the Structural Adjustment Programs, may favour alley cropping because this technology may increase the efficiency of fertilizer use and reduce the need for nitrogenous fertilizers. The potential of the technology depends very much on the management level and location-specific performance of the trees.The pigeon pea technology has high potential if it is accepted as food since it has a very favourable yield per unit of labour, requires no monetary inputs, and can grow, in very poor soils. Pigeon pea also has potential as a cheap source of protein for the urban poor.     

Traditional utilization of wild date palm （Phoenix sylvestris） in rural Bangladesh： an approach to sustainable biodiversity management

A study was conducted to explore the traditional utilization pattern and indigenous management practices of wild date palm （Phoenix sylvestris Roxb） in the rural agrarian regions of Bangladesh. A multistage sampling method with 10% intensity and a semi-structured questionnaire were used for the study. The farmers manage the palm mainly for sap production with which sugar based secondary goods are manufactured. The sap is either used fresh as drink or after some sort of processing as molasses and/or alcoholic beverage. Seven diversified sites support the palm as its habitat and most palms （20.40%） occur in orchards. Besides growing naturally, the palm is also established in orchards using the wildings as the staple planting material. Although the medium category farmers own most of the palms （33%）, a considerable portion （28.68%） of it is managed by the landless farmers, who earn a substantial livelihood from the palms. The farmers practice their own indigenous wisdom in every stage of the palm＇s maintenance from planting through tapping for sap collec- tion to the processing of products. If managed more scientifically on a sustainable basis with the collaboration of farmers＇ indigenou~ knowledge, this familiar palm could be able to support the rural economy of the country to a great extent. Side by side, it would also be able to contribute to the richness of biodiversity in the region.     

Dynamics of fallow successions and introduction of robusta coffee in shifting cultivation areas in the lowlands of Papua New Guinea

The traditional shifting cultivation system in the lowlands of Papua New Guinea consists of mixed food crop gardens in which yams (Dioscorea spp.), bananas, taro (Colocasia esculenta) and sugarcane predominate. The cropping cycle is usually for 18 months, followed by a fallow cycle of up to 30 years. During the cropping cycle, two species of fruit trees, Pometia pinnata and Artocarpus altilis are also planted, the leaves of the former also being used as a mulch and green manure in yam cultivation. Fallow succession follows rather systematic patterns about which farmers have a thorough understanding. Robusta coffee, a cash-crop component, has been added to the system in some areas since the late 1950s. It is usually grown in permanent blocks, but is interplanted with Leucaena as shade. Food crops are planted in the establishment stage, bananas and Xantohosoma being retained even in mature coffee gardens. The system seems to be a potentially promising one. But very little quantitative information is available on the production and performance of the system and practically no systematic research has been undertaken. Since the Papua New Guinea fallow gardeners are willing to accept innovations, it will be appropriate and timely to undertake serious studies so that the system can be improved. A few items that merit immediate research attention are indicated.     

Palms in Indigenous and Settler Communities in Southeastern Ecuador: Farmers’ Perceptions and Cultivation Practices

Most palms used in agroforestry systems are exploited from wild stands or are only occasionally cultivated, while only a few palms have been domesticated. In this study we investigated how socio-economic factors and people's perceptions of changes in palm use and availability, influenced palm cultivation among indigenous Shuar and mestizo settlers in south-eastern Ecuador. We also looked at how different uses of palms influenced which species they cultivated. Our results showed that perceptions of declining palm availability in combination with heavy reliance on palm products was positively related to palm cultivation. Hence, cultivation was more common in more remote villages where alternative products were hard to get. In addition, palm cultivation was more common among wealthier people and among indigenous people than among recent settlers. This points to a limiting role of assets such as land and to the importance of history and culture with regard to cultivation. It was not possible to identify any single palm use as the primary reason for cultivating a species, but the more uses a species had, the more likely it was to be cultivated. These findings have important implications for development projects that promote cultivation of palms and other long-lived tree crops. They illustrate how market access and lack of necessary assets may undermine cultivation of native species even though these are regarded as important resources.     

Semi-wild palm groves reveal agricultural change in the forest region of Guinea

In West Africa, natural regeneration of oil palms (Elaeis guineensis Jacq.) can be favoured by agricultural practices. The structure of palm groves may thus reflect the history of land use. In this study, we examined the connection between biophysical factors, land use and the structure and dynamics of semi-wild palm groves in the village of Nienh, in the forest region of Guinea (Forest Guinea), in order to determine to what extent semi-wild palm groves could be considered as an ecological indicator of the history of regional landscapes. Grove management strategies of farmers were also determined and related to farm characteristics. In Nienh, semi-wild palm groves were found in three cropping systems with differing characteristics in each. Palms were scarce in lowland agricultural areas (8 palms ha⁻¹), while they were significantly taller (15.8 m on average) and less dense (36 palms ha⁻¹) in agroforests than in slash-and-burn cropping systems (9.4 m and 55 palms ha⁻¹ respectively). Interviews with farmers showed that it was possible for a farmer to have a global strategy of semi-wild palm grove densification combined with oil palm elimination on a plot scale. The lack of regeneration of palms in agroforests resulted from the almost systematic elimination of young palms by farmers. Conversely, in slash-and-burn cropping systems, young palms were often preserved. As the structure of semi-wild palm groves was partly explained by agricultural practices, it could be used as an ecological indicator of changes in practice in relation to socio-economic context.     

Intensive plantation cropping,a source of sustainable food and energy production in the tropical rain forest areas in southeast Asia

About 90% of the annual losses of tropical rain forests are caused by transformation into arable land. Most of the cropping activities on the former forest land are characterised by low input, partly shifting cultivation practices, leading to fast degradation of the lands which are finally abandoned owing to infertility. Success in protecting land from further degradation is determined by the economic viability of the respective system. Therefore, sustainability of agricultural systems depends on their economic sustainability. Intensive plantation cropping on former rain forest land appears to offer such an incentive to prevent the land from further degradation by employing the best technology available.Examples of intensive oil palm cultivation as a sustainable cropping system, in terms of economy and ecology, are given. Oil palm cultivation in a suitable environment outyields most annual crops and reveals a significant potential for efficient conversion of solar energy.With the employment of sound agronomic measures the present production potential can be fully realised and new techniques in the production of tissue cultured planting material provide further improved economic viability and environmentally sound cropping systems. Such an intensification offers excellent prospects for reducing the rate of deforestation in the humid tropics.     

Relationships between mass mortality of two oak species (Quercus mongolica Turcz. var.grosseserrata Rehd. et Wils. andQ. serrata Thunb.) and infestation by and reproduction ofPlatypus quercivorus (Murayama) (coleoptera: Platypodidae)

This study investigated the number of adults ofPlatypus quercivorus (Murayama) captured on host oak (Quercus spp.) trees, the attack density (the number of entry holes per 100 cm²), and the number of emerging adults to clarify the relationships between the beetle’s colonization on trees in oak stands and tree mortality. The initial attack ofP. quercivorus, which was the most intense attack, was observed on most living trees simultaneously. Although some attacked trees died within the year of the attack or in the next year, a high density of attack did not usually cause the death of host trees. Surviving trees suffered low levels of consecutive attack after the initial attack. BecauseP. quercivorus successfully produced broods only in the dead trees, the population of the insect seems to be maintained only in stands where oak mortality occurs. However, the adults that landed on most of the surviving trees appeared unable to reproduce probably due to degradation of host quality. Thus, oak mortality probably ceases within 3 or 4 years after the start of infestation in a stand, with subsequent reductions in population density of the borer.     

The potential of alley cropping in improvement of cultivation systems in the high rainfall areas of Zambia I. Chitemene and Fundikila

Three trials investigating the potential of alley cropping to improve the traditional systems of cultivation, chitemene and fundikila, in the Northern Province of Zambia are described. Flemingia congesta, Tephrosia vogelii, and Sesbania sesban, were grown in association with finger millet, groundnut, cowpea, and maize in various traditional cropping sequences. The indigenous species Tephrosia vogelii and Sesbania sesban were not able to withstand repeated pruning and the long following dry season, and were replaced with Calliandra calothyrsus, and Cassia spectabilis.Over a four year period, there was no benefit by alley cropping with any of the tree species on crop yields, and yields in alley crop treatments even dropped significantly below the control treatments in the fourth year, casting doubt on the potential of alley cropping for sustainable production. There was also no consistent effect on soil chemical characteristics in any of the trials. It was suggested that this lack of beneficial response to alley cropping was due to low tree biomass production low quality of prunings, and an inappropriate cropping sequence. There was no evidence that alley cropping contributed to enhanced nutrient recycling, despite substantial localised pools of soil nutrients, particularly in the chitemene, with which recycling could potentially occur.     

Food-crop-based production systems as sustainable alternatives for Imperata grasslands?

Purely annual crop-based production systems have limited scope to be sustainable under upland conditions prone to infestation by Imperata cylindrica if animal or mechanical tillage is not available. Farmers who must rely on manual cultivation of grassland soils can achieve some success in suppressing Imperata for a number of years using intensive relay and intercropping systems that maintain a dense soil cover throughout the year, especially where leguminous cover crops are included in the crop cycle. However, labour investment increases and returns to labour tend to decrease in successive years as weed pressure intensifies and soil quality declines.Continuous crop production has been sustained in many Imperata-infested areas where farmers have access to animal or tractor draft power. Imperata control is not a major problem in such situations. Draft power drastically reduces the labour requirements in weed control. Sustained crop production is then dependent more solely upon soil fertility management. Mixed farming systems that include cattle may also benefit from manure application to the cropped area, and the use of non-cropped fallow areas for grazing. In extensive systems where Imperata infestation is tolerated, cassava or sugarcane are often the crops with the longest period of viable production as the land degrades.On sloping Imperata lands, conservation farming practices are necessary to sustain annual cropping. Pruned tree hedgerows have often been recommended for these situations. On soils that are not strongly acidic they may consistently improve yields. But labour is the scarcest resource on small farms and tree-pruning is usually too labour-intensive to be practical. Buffer strip systems that provide excellent soil conservation but minimize labour have proven much more popular with farmers. Prominent among these are natural vegetative strips, or strips of introduced fodder grasses.The value of Imperata to restore soil fertility is low, particularly compared with woody secondary growth or Compositae species such as Chromolaena odorata or Tithonia diversifolia. Therefore, fallow-rotation systems where farmers can intervene to shift the fallow vegetation toward such naturally-occurring species, or can manage introduced cover crop species such as Mucuna utilis cv. cochinchinensis, enable substantial gains in yields and sustainability. Tree fallows are used successfully to achieve sustained cropping by some upland communities. A variation of this is rotational hedgerow intercropping, where a period of cropping is followed by one or more years of tree growth to generate nutrient-rich biomass, rehabilitate the soil, and suppress Imperata. These options, which suit farmers in quite resource-poor situations, should receive more attention.     

A theoretical study for North Vietnam of alternative agroforestry systems to pure cassava

Cassava is recognized in the region as the second most important crop after paddy rice. In Vinh Phu province of Vietnam, it is usually grown on highly erodible slopes of the small hills surrounding paddy fields. Cassava crop land is generally in annual use until the yield is less than 3–4 t fresh tubers/ha. This constant cropping system rapidly depletes the soil as fertilizers are infrequently used and crop residues are usually removed from the fields. Erosion is a major problem as the soil is exposed through hand cultivation and regular weeding during a cropping season which coincides with the wet season. Sustainable and productive cropping systems are needed.In order to take a first step towards sustainability, this paper presents several possible agroforestry systems in which cassava could be intercropped with a number of nitrogen fixing trees and shrubs. Several theoretical combinations have been examined assuming a critical lower production limit of 3–4 t fresh tubers/ha. Those with sustained high potential yields are recommended for future field experimentation.     

Yields of maize/cassava intercrops grown with hedgerows of three multipurpose trees on an acid Ultisol of Cameroon

Maize/cassava were intercropped between hedgerows of Senna spectabilis [(DC.) Irwin and Barneby], Flemingia macrophylla [(Willd.) Merrill] and Dactyladenia barteri [(Hook f ex Oliv.) Engl.] for five consecutive years on an Ultisol in southern Cameroon. Crop yields and hedgerow biomass production in the third to fifth year of cropping are reported. S. spectabilis produced more biomass than F. macrophylla and D. barteri in all years. Cumulative maize grain and cassava tuber yields were highest in F. macrophylla alley cropping, outyielding the no-tree control consistently by 42 to 67% (average 56%). Between hedgerows of D. barteri and S. spectabilis, crops yielded 17% and 16% more than the no-tree control, respectively. However, between S. spectabilis hedgerows, yields were highly variable between years (–15% to +35% compared to the no-tree control) and thus the system is at risk of failure. F. macrophylla is recommended for continuous alley cropping of maize/cassava intercrop. The use of D. barteri may require fallow phases for biomass accumulation followed by cropping phases with rigorous pruning. Although this may lead to lower cumulative yields, the products of the fallow phase, such as stakes and firewood, may provide some compensation.This revised version was published online in November 2005 with corrections to the Cover Date.     

Effects of alley cropped Calliandra calothyrsus and Cliricidia sipium hedges on weed growth,soil properties,and taro yields in Western Samoa

Field experiments were conducted on a tropical Inceptisol at Apia, Western Samoa to evaluate the effects of alley cropping on soil characteristics, weed populations, and taro yield. Taro yields were compared from Calliandra calothyrsus and Gliricidia sipium alleys, spaced at 4 m, 5 m, and 6 m, and a no tree control. Measurements were made for soil moisture and temperature, weed growth, hedge biomass production, and taro growth and yield. Data was analyzed over 4 consecutive years from 1988 to 1991.Hedge biomass yields ranged from 5.1 to 16.1 t/ha/yr dry weight over the 4 years of the trial, with Calliandra and Gliricidia performing equally well. Biomass yields decreased by about 2 mt/ha with increasing alley width from 4 to 6 m alleys. Weed populations were significantly lower in the 4 m alleys compared to the 5 m, 6 m, and control plots. The 6 m alleys supported the significantly highest weed populations. Soil from alley plots held significantly more water in the 0.3 to 1 bar range than soils from the controls. Four years of mulch application measurably improved soil water holding capacity and bulk density. However, no improvement was seen in nitrogen, phosphorus, potassium, calcium, magnesium and organic carbon content in the alley plots compared to the controls. There was no positive yield effect of alley cropping on taro yield. Yields in the 5 m and 6 m alleys were not significantly different from the control, while the 4 m alleys produce significantly lower yields than the control. Thus, alley cropping did not prove a viable alternative to traditional shifting cultivation after 4 years of continuous cropping, in this trial.     

Managing Amazonian palms for community use: A case of aguaje palm (Mauritia flexuosa) in Peru

Amazonian palms are prime candidates for sustainable management of non-timber forest products and yet useful species are often harvested destructively. This paper examines a promising management initiative for one of the most useful Amazonian palms – Mauritia flexuosa – in a rural community of northeastern Peru. Based on data from household surveys (n = 57), filmed in-depth interviews, focus groups and participant observation, we identify the factors that influence: (1) the adoption of a locally developed climbing device for wild-harvesting of aguaje palm fruit; (2) the continued practice by some households of palm felling for harvesting fruit; and, (3) investment by households in planting and cultivation of aguaje palm. Our findings identify key conditions for palm management and point to the particular importance of the adoption of palm-climbing devices, not only for reducing wild palm felling but also for stimulating broader community-level conservation as well as efforts to cultivate the palm.     

The Costa Rican Association for the Study of Native Forestry Species (CANS)

SUMMARY

In the Gran Sabana of Venezuela and the North Rupununi Savannah of Guyana, protected areas have been established primarily for purposes of conservation. However, both Canaima National Park in Venezuela and the Iwokrama International Centre for Rainforest Conservation and Development in Guyana are multiple use areas where a variety of resource use occurs and/or is planned. Shifting cultivation by the indigenous population is currently both the most common use of the forest and the use of longest duration in both areas. Surveys were conducted of paired primary and secondary forests in order to test the hypothesis that traditional, dispersed shifting cultivation with long fallows and no post-cultivation disturbance is sustainable, resulting in the eventual re-establishment of diverse secondary forests. Interviews and observations of agricultural practices and surveys of agricultural fields were conducted to determine the contemporary forest use practices and the extent to which traditional practices have changed. Results indicate that even dispersed, long fallow shifting cultivation requires careful management and several disturbance-free decades before diversity levels in secondary forests approach those in old growth. Further, that the process of integration and cultural “development” has destabilized this traditionally sustainable system in some areas. A central assumption of the paper is that with an understanding of the impacts of shifting cultivation and of the conditions under which it is sustainable, informed decisions about protected area management can be made. The data provide valuable and hitherto missing information on the levels of forest disturbance that can be sustained in the two protected areas while still meeting conservation goals.     

Root distribution ofDactyladenia (Acioa) barteri andSenna (Cassia) siamea in alley cropping on Ultisol. I. Implication for field experimentation

Root observations were carried out on a typic Paleudult in the humid forest zone of south eastern Nigeria in an alley cropping trial usingDactyladenia (Acioa) barteri andSenna (Cassia) siamea as hedgerow trees and the interrow space planted to maize/cassava intercrop. Rooting depth ofD. barteri andS. siamea exceeded 1.6 m. Lateral root propagation ofS. siamea was 15 m, and ofD. barteri was 5 m from the hedgerows. The whole no-tree control plot was within the range of roots of the adjacent hedgerows. Rooting density and depth ofS. siamea in the no-tree control plot was generally higher than of cassava.S. siamea and cassava root density were inversely correlated. Assuming radial symmetry of root propagation, water and nutrients were available from an area 6.1 and 2.3 times larger than the allocated plot size ofS. siamea andD. barteri, respectively. Data obtained in alley cropping trials, not considering lateral root propagation, can be invalidated through exploitation of the no-tree control treatment and nutrient acquisition by hedgerow species from a larger area than allocated, thus underestimating and overestimating the performances of the respective treatments. Possible alternative measures for avoiding root interference are discussed but no good solution can be given.     

Acacia albida and other multipurpose trees on the fur farmlands in the Jebel Marra highlands,Western Darfur,Sudan

This paper describes the traditional agroforestry systems based on Acacia albida and other multipurpose trees as practised by the sedentary Fur people on the lower slopes and highlands of the Jebel Marra massif, Sudan. The basic agrosilvopastoral system consists of terraced village fields, where semipermanent rainfed cropping of staple millet and other subsistence crops takes place under stands of multipurpose trees dominated by Acacia albida, Cordia abyssinica and Ziziphus spina-christi. Trees have been retained primarily for food, wood and fodder. Thorn from cut and browsed branches makes a good fencing materal.This system has been able to sustain self-sufficiency of a densely settled population over centuries. However, recent out-migration of people from the montane dry-farming areas has caused gradual return to shifting cultivation. As a consequence, the present-day subsistence farming in the region is characterized by a general level of carelessness and exploitative management and this is reflected in a successive decrease of the tree cover.The evaluation of the AF practices described includes a discussion on their regional importance and extrapolability within the framework of similar situations, especially in Africa, emphasis being given to mountain and highland conditions. The outstanding potential for Acacia albida-based AF systems to be sustained and spread almost all over semiarid to semihumid Africa is highlighted by illustrating its ecologic and economic variability. Extrapolation of such examples, however, is not feasible, without thorough feasibility studies concerning the ecologic, ethnologic and socio- economic conditions in the respective project areas. Basic research needs for improving and extending the system are also indicated.     

The potential of alley cropping im improvement of cultivation systems in the high rainfall areas of Zambia II. Maize production

Theee trials to evaluat the potential of alley cropping in maize production on the low fertility, acidic soils in Northern Zambia are described. Leucaena leucocephala, Gliricidia sepium, Sesbania sesban, Albizia falcataria, Fleminga congesta, and Cassia spectabilis, were grown in alley crops with hybrid maize and soybean. All trials received recommended rates of P and K fertiliser; N fertiliser was applied at three rates as a subplot treatment. One trial received lime before establishment.Only in the limed trial was there a significant improvement in maize yields through alley cropping; when no N fertiliser was applied, incorporation of Leucaena leucocephala prunings resulted in an increase of up to 95% in yields, with a smaller improvement being produced by Flemingia congesta. There was a significant correlation between the quantity of prunings biomass applied and the proportional increase in maize yields over the control treatment. It is suggested that the lack of effect of most of the tree species on crop yields was due to low biomass production.An economic analysis showed that alley cropping with limed Leucaena was only profitable when fertiliser costs were high in relation to maize prices. However, lime is both expensive and difficult to obtain and transport for most small scale farmers in the region, and is therefore not a practical recommendation. It is suggested that future alley cropping research should focus on screening a wider range of tree species, including other species of Leucaena, for acid tolerance and higher biomass production.     

Growth and survival of termite-piped Eucalyptus tetrodonta and E. miniata in northern Australia: Implications for harvest of trees for didgeridoos

The most common canopy trees in the savannas of northern Australia, Eucalyptus tetrodonta and E. miniata are also two of the most common species harvested to make didgeridoos, the traditional musical instrument of northern Australian Aboriginal peoples now experiencing high demand from international markets. Most of the trees of the area naturally have hollow cores, or pipes, due to termite activity, but little is known of the relationships of the cores to size of tree, tree growth or survival. In a wooded savanna of northern Australia, 267 individual trees with known growth and survival rates were cored to determine degree of termite-piping. Generalized linear modelling and multi-model inference showed that frequency of piping increased with diameter (dbh) tree for E. tetrodonta, but >85% of E. miniata trees were piped regardless of dbh. Growth (dbh increment) and survival (4-year) were size-dependent. Survival of both species decreased strongly with degree of piping (pipe ratio). For any given diameter, the growth rate of E. miniata trees was independent of pipe ratio, but for E. tetrodonta trees decreased strongly with pipe ratio. From modelled data, a 10-cm tree with pipe ratio of 0.60 was very vulnerable, growing at 0.0 cm year⁻¹ with 46% survival rate, whereas a 40-cm tree, even with large pipe ratios (0.80), grew 0.05 cm year⁻¹ with 98% survival rate. Traditional methods of tree harvesting remove only those smaller hollow trees that are already suffering low growth rates and are likely to die before reaching maturity, whereas current large-scale commercial methods also remove trees with higher growth and survival rates—those trees most likely to contribute to sustainable tree populations. Incorporating traditional selection and harvest methods into current commercial operations would help ensure longevity of this source of livelihood for indigenous peoples of the region.     

Improving the Traditional Acacia Senegal-Crop System in Sudan: The Effect of Tree Density on Water Use, Gum Production and Crop Yields

The traditional Acacia senegal bush-fallow in North Kordofan, Sudan, was disrupted and the traditional rotational fallow cultivation cycle has been shortened or completely abandoned, causing decline in soil fertility and crop and gum yields. An agroforestry system may give reasonable crop and gum yields, and be more appealing to farmers. We studied the effect of tree density (266 or 433 trees ha⁻¹) on two traditional crops; sorghum (Sorghum bicolor) early maturing variety and karkadeh (Hibiscus sabdariffa), with regard to physiological interactions, yields and soil water depletion. There was little evidence of complementarity of resource sharing between trees and crops, since both trees and field crops competed for soil water from the same depth. Intercropping significantly affected the soil water status, photosynthesis and stomatal conductance in trees and crops. Gum production per unit area increased when sorghum was intercropped with trees in low or high density. However, karkadeh reduced the gum yield significantly at high tree density. Yields of sorghum and karkadeh planted within trees of high density diminished by 44 and 55% compared to sole crops, respectively. Intercropping increased the rain use efficiency significantly compared to trees and field crops grown solely. Karkadeh appears to be more appropriate for intercropping with A. senegal than sorghum and particularly recommendable in combination with low tree density. Modification of tree density can be used as a management tool to mitigate competitive interaction in the intercropping system.     

Effect of host plants on development and reproduction of <Emphasis Type="Italic">Rhynchophorus ferrugineus</Emphasis> (Olivier) (Coleoptera: Curculionidae)

The development, survivorship and reproduction of red palm weevil Rhynchophorus ferrugineus, reared on five ornamental palm slices, were studied in the laboratory at constant temperature of 26°C. The developmental time of R. ferrugineus was 68.8 days on Washington palm (Washingtonia filifera), 74.1 days on Canary Island date palm (Phoenix canariensis), 82.1 days on Chusan palm (Trachycarpus fortunei), 85.4 days on pindo palm (Butia capitata) and 90.6 days on silver date palm (Phoenix sylvestris), respectively, and the developmental time on silver date palm was significantly longer than that on the other plants. The survival of immature R. ferrugineus ranged from 25.0 to 38.3%. Most mature larvae began to pupate at eighth-instar on Canary Island date palm and Washington palm, while on Chusan palm, Pindo palm and silver date palm, most of them began to pupate at ninth-instar. The mean lifetime fecundity of R. ferrugineus on Canary Island date palm, Chusan palm, Pindo palm, Washington palm and silver date palm was 267.8, 134.0, 109.8, 216.0, and 131.4 eggs, respectively, and lifetime fecundity on Canary Island date palm and Washington palm was significantly greater than that on the other plants. The intrinsic rate of natural increase (r _m ), net reproductive rate (R ₀) and mean generation time (T) were 0.038, 78.3 and 115.0 days on Canary Island date palm, 0.028, 33.1 and 125.5 days on Chusan palm, 0.029, 40.9 and 128.2 days on Pindo palm, 0.041, 64.0, 101.4 days on Washington palm, and 0.025, 30.6, 135.6 days on silver date palm, respectively. Based on population growth parameters, it is concluded that Canary Island date palm and Washington palm were the more suitable host plants and silver date palm was the least suitable host plant for R. ferrugineus.