Yahya%2C%20Sudirman, Indonesia

  • Forum Pasca Sarjana Vol. 16 No. 1 (1993): Forum Pascasarjana - Articles
    The Genetic Estimation of Fruit Component Parameters of Seven Coconut Populations Without a Progeny Test
    Abstract  PDF
  • Forum Pasca Sarjana Vol. 32 No. 1 (2009): Forum Pascasarjana - Articles

    Cacao plant is one of the major commodity of plantation in South East Sulawesi, especially in Konawe regency.  Practices of land management implemented by the local cacao farmers in many cases are not in accordance to soil and water conservation principles until caused of soil degradation.  The research was aimed to investigate the alteration of soil physics properties on the local farmers cacao cropping land at different slope as related to canopy cover.  The research was conducted in Amosilu Village, Besulutu District, Konawe Regency, the Province of South East Sulawesi, from December 2006 to September 2007.  The experimental method with field study was applied in split plot design consisting of three factors, namely (i) slope consisting of two levels (10-15% and 40-45%) and (ii) age of the cacao plant consisting of two levels (5 to 7 months and 25 to 27 months) were used as main plots (P1 = 5 to 7 months and 10-15%; P2 = 25 to 27 months and 10-15%; P3 = 5 to 7 months and 40-45%; and P4 = 25 to 27 months and 40-45%), while (iii) vegetatif conservation treatment was used as sub plots consisting of three levels, i.e T1 = cacao with disc clearing, T2 = dry field rice and soybean rotation within cacao plant, T3 = T2 + Arachis pintoi as strip plant.  There was not interaction between both cacao plant and slope treatment with vegetative conservation treatment to soil physics properties, exception on aggregate stability index.  The result showed that vegetative conservation treatment (T1) that is cacao with disc clearing was best alternative because they implied the higher rate of total porosity (61,8%) and the lower rate of bulk density (1,013 g cm-3) as soon as the raising of aggregate stability index as well.

     

    Key words: cacao, canopy cover, conservation, soil physics properties
    Abstract  PDF
  • Forum Pasca Sarjana Vol. 32 No. 4 (2009): Forum Pascasarjana - Articles

    The objective of this experiment was to screen 16 soybean genotypes tolerance to double stresses of Al toxicity and drought stress.  A pot experiment was conducted at Cikabayan Experimental Station of Bogor Agricultural University from January to Maret 2004.  Soybean plants were grown in Gajrug ultisol soil with pH 3.9 and Al saturated 26.61 me/100 g of soil.  Al toxicity and drought tolerance were measured from the root length of seedling grown in 75% Al saturation and 40% field capacity compared to 25% Al saturation and 80% field capacity.  The decrease of root length much lower at 75% Al saturation and 40% field capacity. Result of the study showed that soybean of Moket, B.3799, Malabar, Wilis, Sindoro, and Slamet were tolerant while Dieng, Sinyonya, B.3780, Sicinang, B.3578, Ceneng, Epyek, MLG 3072, and Tidar were susceptible to Al toxicity and drought stress.

    Key words: soybean, Al toxicity, drought stress, selection
    Abstract  PDF
  • Forum Pasca Sarjana Vol. 31 No. 4 (2008): Forum Pascasarjana - Articles

    Soil and water conservation treatment have a significant effect on value of C factor and soil erosion.  Vegetatif conservation treatment aimed to reduce of both C factor and soil erosion of the cacao cropping system.  The decrease of both C factor and soil erosion were affected by density of crop canopy and plant rows in counter line, with organic matter addition from system mentioned above.  Experimental method with field study was applied in split plot design consisting three factors, namely (i) slope consisting two levels (10-15% and 40-45%) and (ii) age of the cacao plant consisting two levels (5 to 7 month and 25 to 27 month) were used as main plots (P1 = 5 to 7 month and 10-15%; P2 = 25 to 27 month and 10-15%; P3 = 5 to 7 month and 40-45%;  and P4 = 25 to 27 month and 40-45%), while (iii) vegetatif conservation treatment was used as sub plots consisting three levels, i.e T1 = cacao with disc clearing, T2 = dry field rice and soybean rotation within cacao plants, T3 = T2 + Arachis pintoi as strip plant.  There was not interaction between both cacao plant and slope treatment  with vegetatif conservation treatment to value of C factor and soil erosion.  The value of  C factor in cacao plant and slope treatment P3 (0,43) was significantly different with P4 (0,37). The value of C factor in the vegetatif conservation treatment T1 (0,25) was significantly lower (P < 0,05) than T2 (0,55) and T3 (0,39).  Soil erosion in cacao plant and slope treatment P2 (15,99 ton.ha-1.year-1) was significantly lower than P1, P3, and P4.  Furthermore, soil erosion in the vegetatif conservation treatment T1 (12,95 ton ha-1 year-1) was significantly lower than T2 and T3.  Data analysis with ANOVA (analysis of variance) and Duncan Multiple Range Test (P < 0,05) were done by using SAS program.

     

    Key words: cacao, erosion, the value of C factor
    Abstract  PDF