African Journal of Agronomy

African Journal of Agronomy Vol. 1 (3), pp. 051-059, September, 2013. © International Scholars Journals

Full Length Research Paper

Leaf nitrogen and potassium concentrations for optimum fruit production, quality and biomass tree growth in Clementine mandarin under Mediterranean climate

Abdelkader Hammami*, Salah Rezgui and Rachid Hellali

National Agronomic Institute of Tunisia

*Corresponding author. E-mail: [email protected]. Tel: (00216)72 28 74 41. Fax: (00216)72 28 77 35

Accepted 4 March, 2013

Abstract

Leaf analysis is a useful tool to evaluate the nutrient status of citrus trees, but diagnosis standards for ‘Clementine mandarin’ are not available. Nutrition recommendations of the current fertilization practices are mainly based on the same recommended nutrient rates for orange trees. A three-year (2005 - 2007) field experiment was conducted in North Eastern Tunisia (El Gobba). This experiment was carried out using 25 years old ‘Clementine mandarin’ trees (CITRUS RETICULATA OSBECK) on ‘Sour orange’ (CITRUS aURANTIUM OSBECK) rootstock; grown on a sandy soil; to establish leaf nutrient (N and K) concentration standards for optimum biomass tree growth, fruit production and quality. Nitrogen and potassium rates ranging from 160 to 232 and 200 to 290 kg/ha/yr, respectively, were applied in a drip irrigation system (12 fertigations events/yr). Irrigation was scheduled based on tensiometer readings at the root zone. Fruit yield was positively associated with N (r² = 0.91) and K (r² = 0.84) rates; as well as with leaf N concentration (r² = 0.92) and tree fruit load (r² = 0.91). Leaf N concentration was significantly correlated with N rates (r² = 0.72) and biomass tree growth (r² = 0.52). These findings indicate that 192 and 200 kg/ha/yr of N and K₂O (N:K = 0.9), respectively, are required to support optimal fruit yield of 43 T/ha/yr with tree fruit load of 2.4 kg/m³ (fruit yield/tree canopy size ratio) and optimum fruit quality. At 90% of maximum relative fruit yield, leaf N and K concentrations were 27 to 29 and 10 to 12 g/kg_, respectively. Leaf nutrient concentration ranging from 27 to 29 g/kg for N; and from 10 to 12 g/kg for K corresponding to a fertilizer management program of 192 kg/ha/yr and 200 kg/ha/yr, could be recommended as optimum levels of N and K for ‘Clementine mandarin’ grown under Mediterranean conditions.

Key words: Leaf nutritional status, optimum fruit yield, biomass tree growth, Clementine mandarin, semi arid Mediterranean climate.

African Journal of Agronomy Vol. 1 (4), pp. 060-068, September, 2013. © International Scholars Journals

Full Length Research Paper

Policy impact on resource use and conservation in Miombo woodland, Pindanganga, Mozambique

M. P. Falcão¹*, R. U Sumaila², C. J. Geldenhuys³

¹Faculty of Agronomy and Forestry Engineering, Eduardo Mondlane University, Mozambique.

²Fisheries Centre, University of British Columbia, Vancouver, BC Canada.

³Department of Forest and Wood Science, University of Stellenbosch., South Africa.

*Corresponding      author.       E-mail:      [email protected], [email protected]

Accepted 30 May, 2013

Abstract

A case study was carried out in Pindanganga to analyse the impact of alternative forest management regimes and sectorial and extra sectorial policies on the well being of stakeholders and conservation of the woodlands using a dynamic game theoretic model, MIOMBOSIM. This study shows that the cooperative management regime is potentially beneficial to local communities if properly implemented and can improve the condition of rural livelihoods and woodland resources. It also shows that regulated forest management regimes, incorporating social concerns or social and environmental concerns, are potentially more beneficial to the household sector that the open access regime, an increase by 100% on sales amount or 100% increase in marketing selling prices of NTFPs can lead to an increase in the per capital benefits of the household sector. An increase by 100% in off-miombo employment opportunities has an insignificant impact on resource use and conservation for the local communities. A combination of these two policy instruments under ceteris paribus condition can improve the well being of the rural communities depending on the management regime, but can not lift the household benefits above the poverty line of one US$ per day per person.

Key words: Game theory, forest management regimes, efficiency, non-timber forest products.

African Journal of Agronomy Vol. 1 (2), pp. 030-036, July, 2013. © International Scholars Journals

Full Length Research Paper

Genetic diversity and inbreeder specie of Andrographis paniculata (Burm. f.) Nees by randomly amplified polymorphic deoxyribonucleic acid (RAPD) and floral architecture analysis

Parwat Wijarat^1,2*, Vichien Keeratinijakal³, Theerayut Toojinda⁴, Apichart Vanavichit^4,5 and Somvong Tragoonrung⁶

¹Genetic Engineering Program, Kasetsart University, Bangkok 10900, Thailand.

²Agricultural Science Program, Mahidol University, Nakhon Sawan Campus, Nakhon Sawan 60000, Thailand. ³Department of Agronomy, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.

⁴Rice Gene Discovery Unit, Rice Science Center and DNA Technology Laboratory, National Center for Genetic Engineering and Biotechnology, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.

⁵Department of Agronomy, Faculty of Agriculture, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.

⁶Genome Institute, National Center for Genetic Engineering and Biotechnology, Thailand Science Park, Pathumthani 12120, Thailand.

*Corresponding author. E-mail: [email protected]

Accepted 07 October, 2011

Abstract

“Fha-Tha-Laai-Joan” (Andrographis paniculata (Burm. f.) Nees) is a medicinal plant that is, widely used in Thailand and some other countries for therapeutic value, but the lack of their genetic information may cause confusion in its utilization. The randomly amplified polymorphic DNA (RAPD) markers were used to identify and elucidate the phylogenetic relationships among 58 accessions of A. paniculata which were collected throughout Thailand. Of thirty random primers tested, only eight primers generated a total of 66 bands, of which 26 bands were polymorphic, with an average of 8.25 bands per primer pair. The phylogenetic tree derived from RAPD data showed that A. paniculata were divided into only one group in which the high similarity values were between 0.81-1.00. The results obtained indicated that the distributions of A. paniculata among each region are likely to belong to the same variety and are relatively undifferentiated across a large geographic range. The floral architecture and reproductive habitat study of A. paniculata revealed the same results as of RAPD markers analysis. This species is thus hermaphroditic and acts as habitual inbreeder.

Key words: Andrographis paniculata, randomly amplified polymorphic DNA (RAPD), floral architecture, monomorphic, Thailand.

African Journal of Agronomy Vol. 1 (3), pp. 046-050, August, 2013. © International Scholars Journals

Full Length Research Paper

Agronomic and molecular evaluation of recombinant inbred lines (RILs) of lentil

C. Bermejo², V. P. Cravero², F. S. López Anido¹ and E. L. Cointry¹*

¹Department of Plant Breeding, Rosario National University, (UNR), CC 14, Zavalla S2125ZAA, Argentine.

²CONICET, Zavalla, Argentina.

 *Corresponding author. E-mail: [email protected]

Accepted 6 April, 2013

Abstract

Sequence-related amplified polymorphism (SRAP) and morphological markers were studied to compare the efficiency of both marker systems in the evaluation of twenty five lentil (Lens culinaris Medik.) recombinant inbred lines (RILs) and four testers. Data on 13 morphological traits were collected and analyzed. A total of 240 polymorphic SRAP’s bands (76.7%) were scored using four combinations of primers. Cluster analysis and both principal component and principal coordinate analysis were carried out. The entries were grouped in five clusters through procrustes generalized analysis. Relationships among lines revealed by molecular markers were significantly correlated with those based on the agronomic traits (r = 0.75), suggesting that the two systems give similar estimates of genetic relations among the RILs. In future breeding programs parent selections could be based on these traits information in order to broaden the genetic.

Key words: Genetic distance, molecular markers, morphological markers, recombinant inbred lines, SRAP marker.