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Drought stress can have substantial negative impacts on cocoa plant growth until affect the death of plant. The present study aimed to determine theeffect of drought stress on the some physiological characters of cacao (Theobroma cacao L.) seedlings. The research was carried out at the Indonesian Coffee and Cocoa Research Institute, Jember, East Java, Indonesia. This research was conducted from January–December 2017. The experiment was designed by using completely randomized block design with two factors and with three replications. The first factor was clones, namely ICS 60, Sulawesi 1 and KW 641 clones. The second factor was interval of watering treatment, namely watering every 2 days (control/adequate water condition), watering every 5 days (moderate stress), and watering every 8 days (severe stress). Result of this study concluded that drought stress reduced the growth of cocoa seedlings, mainly as a result of reducing photosynthetic activities in all stressed cocoa clone seedlings. Under drought stress, KW 641 and Sulawesi 1 had higher leaf area, chlorophyll a, chlorophyll b, total chlorophyll content, relative water content, and photosynthetic rate than ICS 60 clone.

The objective of this research was to determine appropriate annual food crops in the areas of a year-old oil palm. Field trials were arranged in a single factor of randomized completely block design. A factor to be tested was the species of annual food crops, namely, soybeans and groundnuts. Controls in this study were monocultures of oil palm, soybean and groundnuts. The results showed that soybean and groundnut could give high yields when planted between rows of one year-old oil palms, which were similar to the yield of those crops in the monoculture system. In addition, the presence of soybean and groundnut between the rows of one year-old oil palms was found not inhibiting the growth rate and development of oil palms as the main crop. On the contrary, there was a tendency that the oil palms planted with soybeans and groundnut to grow faster than those planted in monoculture.

Peatland in Indonesia has a potential for maize cultivation, but it has constraints that low of soil pH and of nutrient availability. Use of ameliorants from coastal sediment and salted fish waste was an alternative to improve peatlands productivity and maize yields. Objective of the study was to examine effects of coastal sediment and salted fish waste on growth and yield of maize at three kinds of soil of peatlands of Kubu Raya, West Kalimantan. This research was conducted  in  field  using  Inter-area analysis  design.  The  first  factor  was  combination  of  each ameliorants  which consisted of 5 levels, namely: 1) treatment under farmer custom at the sites (control); 2) coastal sediment of 20 Mg ha-1 + 0.75 Mg of salted fish waste ha-1; 3) coastal sediment of 40 Mg ha-1 + 1.5 Mg of salted fish waste ha-1, 4) coastal sediment of 60 Mg ha-1 + 2.25 Mg of salted fish waste  ha-1. The second factor was soil types which consisted of three levels, namely: Typic Haplohemists, Typic Sulfisaprists and Typic Haplosaprists. Each treatment was repeated 5 times. The results showed that combination of 40 Mg ha-1 of coastal sediment and 1.5 Mg ha-1 of salted fish waste was the best combination for all soil type. It increased plant height (33% - 44%), shoot dry weight (74% - 75%), number of seeds per cob (31% -110%), weight of 100 seeds (58% -71%) and dry grain weight per plant (136 % -160 %) at each soil. The highest yield was found in soil of Typic Haplosaprists (219.54 g), followed by Typic Sulfisaprists (210.72 g) and Typic Haplohemists (208.82 g).Keywords: Coastal sediment, maize, peat soils, salted fish waste [How to Cite: Denah S, BH Sunarminto, D Shiddieq and D Indradewa. 2014. Use of Ameliorants to Increase Growth and Yield of Maize (Zea mays L.) in Peat Soils of West Kalimantan. J Trop Soils 19: 35-41. Doi: 10.5400/jts.2014.19.1.35]