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41.
Summary Yield of Deli dura oil palms after four generations of selection was 60% greater than that of the unselected base population. Total above-ground dry matter production was increased by selection, apparently through better utilisation of solar radiation. The dry matter requirement for vegetative growth was unchanged, so a greater surplus remained for fruit production in the selected palms. Crossing the dura and pisifera to give the thin-shelled tenera fruit type improved partitioning of dry matter within the fruit, giving a 30% increase in oil yield at the expense of shell, without changing total dry matter production. 相似文献
42.
The epidemic of bud rot disease affecting oil palm in Colombia is primarily caused by Phytophthora palmivora. The pathogen has a cosmopolitan presence that includes Southeast Asia, but to date, bud rot has not been reported in this region. This study provides an overview of the potential risk of Malaysian P. palmivora isolates cross‐infecting other host species, including cocoa, durian, rubber and Malaysian oil palm planting materials (Dura × Pisifera, D × P). On cocoa pods, the durian isolate PP7 caused dark brown necrotic lesions. Detached leaf bioassays showed that P. palmivora isolates PP3 and PP7 infected different hosts, except rubber foliage without wounding. Inoculation tests on cocoa, durian and rubber seedlings caused brown necrotic lesions when stems were wounded, with 10% mortality in cocoa and durian at 17 days post‐inoculation (dpi). However, no further infection was observed, and lesions closed within 14–28 dpi on the non‐wounded seedlings. Pathogenicity tests of oil palm seedlings inoculated with isolates PP3 and PP7 indicated that Malaysian P. palmivora isolates were not pathogenic to oil palms based on localized infection observed only through wounding. Overall, the work demonstrated that Malaysian P. palmivora isolates were able to cross‐infect multiple hosts but did not show severe infections on oil palms. 相似文献
43.
44.
Abstract. The African oil palm ( Elaeis guineensis ) is relatively well adapted to the pedoclimatic conditions of central Amazonia. The clayey upland soils of the region are well supplied with nitrogen, although they are deficient in most other nutrients. Under these conditions, oil palm does not respond to N fertilization with yield increases. In this research, the N status of a central Amazonian upland soil was evaluated after having supported a productive oil palm plantation for 15 years without N fertilization. Mineral N in the upper 2 m of soil showed pronounced spatial patterns, with very low concentrations close to the palms, indicative of efficient N uptake by the palms, and evidence for nitrate leaching into the subsoil in the inter-tree spaces despite the near-absence of a leguminous cover crop during the previous ten years. The pronounced increases of mineral N with increasing tree distance were explained by increases in N mineralization and a strong decrease in fine root length density of the palms, especially in the subsoil. Failure of the palms to fully occupy the available soil volume with their roots was apparently related to fertilizer placement close to the stem base, which over the years had led to steep fertility gradients between the soil under the trees and the inter-tree spaces. Broadcast fertilization would have presumably favoured a more extensive lateral root development of the palms, and consequently improved nutrient and water uptake from the inter-tree spaces. The incomplete soil occupation by the palm roots also suggests that young oil palms can be associated with shade tolerant crops without much risk of root competition. These conclusions may be valid also for other tree crops and may help to reduce nitrate leaching and consequently the need for N fertilization in Amazonian tree crop agriculture. 相似文献
45.
Cécile Madelaine Eric Malézieux Nicole Sibelet Raphaël J. Manlay 《Agroforestry Systems》2008,73(3):189-204
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. 相似文献
46.
马来西亚优良油棕品种的引种与栽培 总被引:1,自引:0,他引:1
油棕是热带著名的油料作物,是一种重要的食用油和生物柴油资源,在中国热区颇具发展前景。笔者从马来西亚引进优良油棕品种,在西双版纳进行育苗和试种,结果表明:优良油棕品种在中国热区能正常生长发育,3年生植株高4.22 m,地径0.45 m,定植后第4年开花,花穗饱满,生长良好,引种已基本成功。文章还介绍了油棕的育苗和造林技术,为中国热区油棕产业发展奠定技术基础。 相似文献
47.
R. Russell M. Paterson 《Forest Pathology》2020,50(4)
Oil palm (OP) is affected by climate change and the cultivation of the crop also contributes to climate alteration. Simulation modelling and large data sets indicated the effects of climate change on OP will be to (a) reduce growth and yields and (b) cause death of some OP. Furthermore, basal stem rot (BSR) caused by Ganoderma boninense, a serious disease of OP, has increased over the past two or three decades because of the disease spreading from infection foci at a greater rate in repeated crops of OP planted on infested sites. The disease may increase further by natural selection of more virulent strains of the fungus. In this paper, increased mortality of OP is predicted based on climate change scenarios for Kalimantan and other South‐East Asian countries with palm oil industries. Climate suitability scenarios for growing OP are also used to assess how BSR will change in the specified region and countries. The data suggest that Kalimantan and the Philippines may be more suitable for growing OP than Thailand and Myanmar, with Papua New Guinea being intermediate. Development of methods for mitigating the effects of climate change on OP is urgently required. 相似文献
48.
49.
C. J. Breure 《Euphytica》1986,35(1):65-72
Summary Selection criteria of dura female parents and pisifera male parents were investigated by employing a step-wise multiple regression procedure. Independent parental variables entered in the regression equation were (1) yield (Y) and (2) bunch index (BI), i.e. the proportion of total dry matter used for fruit bunches, of the female parents. As secondary characters of both parents were included: (3) leaf-Mg level (LMG), (4) leaf area ratio (LAR), i.e. the ratio of new leaf area produced to new dry matter used for vegetative growth, and (5) sex ratio (SR), i.e. the ratio of female to total inflorescences. The joint contribution of LMG in both parents accounted for 80% of the variance in Y of the offspring. The amount of the total variance in BI of the offspring was substantially explained, in decreasing order, by LMG of the pisifera parents, and Y and LAR of the dura parents. The first two variables explained 70% of the variation in offspring BI. SR and BI appeared to be not significant for explaining Y as well as BI of the offspring. A practical implication is that for pisifera testing programs, pisifera can be efficiently screened on the exclusive basis of LMG. Dura tester parents should be selected for high, and little variable, values of LMG, Y and LAR. 相似文献
50.
The effects of inbreeding were studied in three oil palm (Elaeis guineensis Jacq.) trials in the Democratic Republic of Congo (Congo). In selfings, marked inbreeding depression was observed for yield of fruit bunches, mean bunch weight and bunch number, but there was little effect on bunch composition. Most vegetative measurements were significantly affected by selfing, but leaf production rate and leaf area ratio were unaffected. Sib-crossing had less depressive effect than selfing, and in some families sib-crosses were superior to outcrosses. Where selection needs to be done within inbred families, our study suggests that leaf area ratio and bunch composition would be useful criteria. 相似文献