Introduction <\/B>
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Shorea platyclados<\/I> Sloot. ex Foxw. is a montane species which can be found in Borneo, Peninsular Malaysia and Sumatra (Ashton & Appanah 2004). The species can achieve diameters at breast height (dbh) above 175 cm. In Peninsular Malaysia, it usually found at elevations between 800 and 1,000 m, in the upper hill dipterocarp forest zone, where Shorea curtisii<\/I> usually begins to disappear. Shorea platyclados<\/I> timber is a light hardwood of the dark red meranti group. It is among the most durable species of the group. The timber is highly suited for general utility purposes such as exterior doors and doorframes, windows and facades. It is also used for decking of boats.
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In Peninsular Malaysia, a 27.5-year-old naturally regenerated S. platyclados<\/I> stand in Pahang and a 26.5 year-old plantation in Kepong were measured by Vincent (1961). He found that both stands recorded MAI of dbh of 1.26 to 1.63 cm yr-1<\/SUP> and of height of 1.13 m yr-1<\/SUP>. Zuhaidi, Weinland and Kollert (1995) found that a 62 year-old stand in Kepong recorded dbh of more than 66 cm. In Bogor, Indonesia, Masano and Harun (1991) found that growth of the species in planting trials was exceptional and recorded a mean height of 25 m in and mean dbh of 41 cm after 25 years. In North Sumatra, Indonesia, S. platyclados<\/I> plantations of 37, 38 and 40 years recorded MAI of dbh of 1.03 to 1.16 cm yr-1<\/SUP> (Butarbutar & Supriana 1988). Ang and Maruyama (1995) suggested that S. platyclados<\/I> has great potential as forest plantation species as it establishes well in open areas. The species recorded a survival rate of 92.2% 26 months after planting and collar diameter and height increments of 35 mm and 2.5 m respectively. <\/I> Establishment of tree plantations need large numbers of healthy, uniform and hardened seedlings to ensure maximum survival and vigor after planting in the field. Fertilizing is a common practice in the nursery to produce healthy and sizeable seedlings in a specified period of time in the tropics. However, fertilization practices are rarely based on any quantitative knowledge of the requirements of the species being planted. In a number of nursery studies, growth of dipterocarps seedlings was enhanced by N addition (Yap & Moura-Costa 1996, Bungard et al.<\/I> 2000). Nitrogen is essential for plant growth. Better N nutrition often causes greater partitioning of biomass to above ground components, especially leaves (Charles-Edwards 1982), resulting in increased yields. Photosynthesis is an important determinant of growth. The photosynthetic capacity of plants is influenced by their N nutrition (Evans 1989). Effects of N application on partitioning and carbon assimilation in S. platyclados<\/I> are not known as very little is known about the nutritional requirements of this species; yet such information are needed to ensure maximum survival, growth and productivity. So, the objective of this study is to determine the effect of N supply on growth and net photosynthesis of S. platyclados<\/I> seedlings. The results, hopefully, will provide some useful guidelines for the fertilization of this species in the nursery and facilitate the development of protocols for the successfully establishment of S. platyclados<\/I> plantations in the tropics. <\/I> <\/I> Materials and Methods<\/B> The potting medium used was a 7:3:1 mixture of topsoil, sand and peat. Eight-month-old seedlings raised in the nursery of Faculty of Forestry, Universiti Putra Malaysia were used in this study. The seeds were collected from trees along the Tapah to Cameron Highlands road. Uniform seedlings in terms of height were transplanted into 7.7 L pots at the beginning of the study. Source: 8th Round-Table Conference on Dipterocarps<\/I><\/p>\n","protected":false},"excerpt":{"rendered":" The effects of urea application on the growth and rate of photosynthesis in Shorea platyclados (meranti bukit) seedlings were assessed in a pot experiment. The levels of fertilizer tested were 0 g, 3 g, 6 g and 9 g per pot of urea. The use of urea led to a significantly higher growth and photosynthetic rate (A). The A of S. platyclados was within the range reported for other timber tree species in Malaysia. Whole-plant N content (wpNc) is higher in urea treated seedlings than the control. A increased linearly with foliar N (Nla) suggesting that higher A may be achieved with increase urea application. The increase in growth and biomass could be due to a higher leaf area which enabled the plants to intercept a larger amount of light and also photosynthesize more. <\/p>\n Keywords: Growth, photosynthetic rate, Shorea platyclados, urea fertilizer<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[8],"tags":[],"_links":{"self":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts\/300"}],"collection":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/comments?post=300"}],"version-history":[{"count":0,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts\/300\/revisions"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/media?parent=300"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/categories?post=300"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/tags?post=300"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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