Reviews

Europe In the Round CD‐ROM, Guildford, Vocational Technologies, 1994

Leaf nutrient concentrations in oil palm as affected by genotypes, irrigation and terrain

Four clonal oil palm materials namely AVROS, Yangambi, La Me and NIFOR and two DxP hybrid Yangambi, grown on terraced and unterraced fields were subjected to irrigated and non-irrigated conditions. There were significant differences in all leaf nutrient concentrations for all the planting materials for both terrain and irrigation conditions. For non-irrigated palms, most of the leaf nutrients were higher than the irrigated palms, especially K and Mg concentrations. Most of the leaf nutrient concentrations in palms grown on undulating area were also high, especially for leaf Mg and K concentrations. Leaf K concentration for DxP hybrid Yangambi-DQ8 was consistently lower than AVROS-A122 by almost 15-20% in all the growing conditions. In contrast, the leaf K contents for Yangambi-DQ8 and Yangambi-Y103 were comparable to that of AVROS-A122 and these three planting materials produced the highest oil yields. In view of future high current fertilizer cost, selecting oil palm genotypes that are able to produce good oil yields on low fertilizer inputs and giving consistent leaf nutrition need to be given consideration

Effect of reactive phosphate rock and its NKMg fertilisers under two placement methods on oil palm yield

Studies on the efficiency of phosphate (P) through exploitation of integrated approach on P sources, organic matter and placement methods for mature oil palm in Malaysia are rather limited. A field trial was conducted to evaluate the reactivity of P, its NKMg fertiliser under two placement methods i.e frond heap (FH) or broadcasted at the edge of weeded circle (EWC) on oil palm yield on inland sedentary Rengam series soils (Typic Paleudult). The trial was laid out on an 1992 DxP Felda oil palm planting located at Muadzam Shah, east of Pahang state with high yield potential at 30 tonnes per hectare per year. Two types of reactive phosphate fertilisers namely Senegal Phosphate Rock (low reactive) and Tunisia Phosphate Rock (high reactive) were evaluated in this trial, including a control treatment without phosphate fertiliser. The phosphate rocks (PR) fertilisers were tested at two rates i.e 0.50 kg P2O5 per palm per year and 1.0 kg P2O5 per palm per year. The mineral fertilisers (P or NKMg) were applied at frond heap (FH) or broadcasted at the edge of the weeded circle. Results over six years showed that palm without phosphate and grown under good rainfall distribution, maintained high yield at 28.6 tonnes per hectare per year. In contrast, there was a decrease in foliar, rachis and depleted soil P fertility over time in the plot without PR resulting in reduced overall FFB yield on an average by almost 1.5 tonnes per hectare or 5.3 per cent as compared to those plots with PR at 30.1 tonnes per hectare per year. Therefore, it is vital to continue applying PR to sustain high yields. The trial also showed that applying reactive PR at low rate (0.5 kg P2O5/palm/year) and integrating with other mineral nutrients NKMg at the frond heap enabled to obtain high yields. Overall, performance of high reactive PR is more superior than the low reactive PR

Rachis nutrient concentrations of different oil palm genotypes as affected by irrigation and terrain

Four clonal oil palm materials namely AVROS, Yangambi, La Me and NIFOR, and two D × P hybrid Yangambi have been planted on terraced and non-terraced contours that are subjected to irrigated and non-irrigated conditions. Under favourable growing environment, i.e., through irrigation, and to some extent favourable terrain of undulating plain, the palms were able to retain higher rachis nutrient concentrations, and subsequently had larger petiole cross-section and exhibited higher rachis nutrient contents. There were significant differences in all rachis nutrient concentrations for all of the planting materials for both terrain and irrigation conditions except for sulphur (S) nutrient. Previous study revealed that leaf potassium (K) concentration for D × P hybrid Yangambi-DQ8 was consistently lower than AVROS-A122 by almost 15%-20% in all the growing conditions. In contrast, the rachis nutrient concentrations for both materials were comparable. In fact, D × P Yangambi-DQ8, retained higher rachis K content (by 22%) due to larger petiole cross-section (PCS) as compared to that of AVROS-A122. The poor yielding materials, appeared to contain lower nutrient concentrations particularly those of magnesium (Mg), chlorine (Cl) and calcium (Ca). The present fertiliser regime is able to sustain high yields and capable of producing more than 10.5 t ha-1 yr-1 of total economic product (TEP) without the need for additional fertiliser inputs. Therefore, the understanding of rachis nutrient behaviour on different oil palm genotypes is crucial to produce sustainable oil yield in the near future

Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

Sperm DNA fragmentation: A new guideline for clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations

An empirical study on the underpricing phenomenon of initial public offerings in Singapore and its association with corporate governance mechanisms.

Effects of corporate governance mechanisms on underpricing have been investigated to see whether corporate governance mechanisms serve as a signal of the quality of the investment in a given IPO to the investors

Pillars of salt

This project book is a documentation of the process taken to create "Pillars of Salt".Bachelor of Fine Arts in Media Ar