INDONESIAN JOURNAL OF AGRICULTURAL SCIENCE

1-10

Authors: Nurindah, Dwi Adi Sunarto

Cotton production nationally is low due to various constraints, including pests. Two main pests commonly found in cotton plantation in rain fed fields are cotton leafhopper (Amrasca biguttula) and cotton bollworm (Helicoverpa armigera). The study aimed to evaluate four packages of integrated pest management (IPM) techniques to control cotton leafhopper and cotton bollworm in rain fed fields. The experiment was conducted in farmers’ fields at Asembagus, East Java, between January and July 2012. Four packages of IPM evaluated were cotton varieties, i.e. Kanesia 10 or Kanesia 13, and seed treatment with synthetic insecticide (imidacloprid) before sowing or spraying molasses (10 ml L-1 water) as food for natural enemies. The cotton plants were intercropped with groundnut and sprayed with neem seed extract (NSE) at the action threshold level for pest control. These packages were compared among themselves and also with the methods usually used by farmers, i.e. planting cotton variety Kanesia 8 intercropped with groundnut and pest control using synthetic chemical insecticides. Twenty five plants were sampled randomly per plot and measured for their growth, leafhopper and bollworm populations, as well as cotton seed yield per plot. Observations were made weekly, starting at 30 days after planting (DAP) until 120 DAP. The results showed that the use of Kanesia 10 or Kanesia 13 intercropped with groundnut and spraying molasses to conserve natural enemies was the best pest management practice and superior to farmers’ practices. Conserving natural enemies is not only profitable (saving production cost of IDR1,150,000 to IDR1,500,000 ha-1 season-1), but also safe for the environment (no need to spray chemical insecticides).

17-28

Authors: Puspi Eko Wiranthi, Heny Kuswanti Suwarsinah, Andriyono Kilat Adhi

Indonesian Food Security Council in 2009 issued a Food Security and Vulnerability Atlas (FSVA) which stated that there were 100 districts in Indonesia which were most vulnerable to food insecurity and 79% of which were located in eastern region. By using Susenas regular data in 2008, this study aimed to analyze determinants of household food security in eastern compared to western region. The ordered logistic regression model was employed to investigate the determinants of household food security. The result showed that most of households in Indonesia were vulnerable to food insecurity (41.76%). The percentage in eastern region (48.56%) was higher than that in western region (41.76%). Increase in expenditure equivalent, age and education level of household head, female household head, small household size, household head’s occupation in non-agriculture and urban household would increase the probability of a household to become food secure in both regions. The difference was in the factor of access to electricity in eastern and access to safe drinking water and loan in western region. Policies which aim to increase education, credit access, and intensive family planning have big roles in improving household food security.

35-45

Authors: Eni Maftu’ah, Azwar Ma'as, Benito Heru Purwanto

Peat soil is characterized by poor nitrogen (N) availability. Ameliorants are expected to rectify this problem. This research aimed to study the effect of ameliorant on N availability and N uptake by sweet corn plant in degraded peatland. The experiment was conducted in the greenhouse in May-July 2011 and on peatland of Kalampangan Village, Palangkaraya, Central Kalimantan in September-December 2011. Burnt peat soil of Kalampangan was used in the greenhouse experiment and sweet corn was used as an indicator plant. The treatments consisted of two factors, i.e. compositions of ameliorants by weight (A1 = 80% chicken manure + 20% dolomite; A2 = 80% local farm weed + 20% dolomite; A3 = 80% mineral soil + 20% dolomite; A4 = 20% chicken manure + 20% local farm weed + 20% residue of Chinese water chestnut (Eleocharis dulcis) + 20% mineral soil + 20% dolomite; and A5 = 19% chicken manure + 71.5% mineral soil + 9.5% dolomite) and rates of those ameliorants (5, 10, 15, 20 and 25 t ha-1). The experiment was arranged in a completely randomized block design with three replications. Data were collected every two weeks for five times. Observations were made on soil pH, available N (NH4+, NO3-), plant height, and N uptake in root and shoot. The results showed that treatment A1 increased soil pH and availability of NH4+ and NO3- in peat soils at the maximum vegetative stage. Treatment A1 provided the highest N availability and N uptake by the plant. Field experiment showed that N uptake increased with the plant yield. Optimum yield of fresh corn cob was obtained from treatment A1 at the rate of 20 t ha-1. This research reconfirms the effectiveness of chicken manure and dolomite as peat soil ameliorant.