Journal of Tropical Crop Science Vol. 6 No. 3, October 2019 www.j-tropical-crops.com 182 Versi Putra Jaya Hulu, Heni Purnamawati, Anas Dinurrohman Susila, Slamet Susanto Sources and Rates of Potassium for Drip Irrigation of Polyethylene-mulched Bean Production Versi Putra Jaya Hulu A , Heni Purnamawati* B , Anas Dinurrohman Susila B , Slamet Susanto B A Postgraduate School, IPB University, Bogor, 16680, Indonesia. B Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University, Bogor 16680, Indonesia Corresponding author; email: henipurnamawati1@gmail.com Abstract Common bean is a type of vegetable that can be consumed in the form of young pods. Potassium is one of the macro nutrients needed to achieve maximum yield in common bean. Therefore this research is aimed at determining a suitable potassium source as well as an appropriate rate for drip irrigation in common bean using polyethylene mulch. The study was conducted from January to May 2018 at University Farm, IPB University. This experiment was set up as a nested randomized block design with two factors i.e. potassium sources as the main factor ( KCl, ZK, and NPK), and potassium rates (0, 37.5, 75, 112.5, 150 kg of K 2 O per ha). Fertilizer rates were nested in the main factor and fertilizers were applied Fetilization through a drip irrigation fertigation system with emitters placed close to the roots of plants. Fertilizer sources had significant effects on the variables of growth and bean yields. NPK resulted in a better growth and yield compared with KCl and ZK. Fertilizer sources that have very significant effect were likely related to the shape and solubility of the fertilizers, the ease of application, and also completeness of nutrient content in fertilizer. Based on the pod weight per plot, the productivity per hectare of bean pods produced in this study reached 7.52 ton.ha -1 . Potassium (K 2 O) rate did not have significant effects on the variables of growth and yields of the bean. Keywords: fertigation, fertilizer, Phaseolus vulgaris, pod weight, yield and yield components Introduction Common bean (Phaseolus vulgaris L.) is an introductory crop in Indonesia. Common bean originates from western Mexico-Guatemala (Kay, 1979). Common bean pods can be consumed in the form of young pods; young bean pods have a sweet taste which make them suitable for vegetable consumption. Common beans have a fairly high nutrient content, i.e. every 100 g of beans contains 35 g of calories, 2.4 g of protein, 0.2 g of fat, 7.7 g of carbohydrates, 65 g of calcium, 44 g of phosphorus, 1.1 g of iron, and water 88.9 g (IPGRI, 2003). Community demands for beans continue to increase along with population growth. The average consumption per capita from 2013 to 2015 had been increasing from 0.782, 0.826, 1.143 kg/capita/year (Pusdatin, 2017). On the other hand, the statistical data from Direktorat Jenderal Hortikultura (2018) showed that the production of bean vegetables has been declining from 2013 to 2016, by 327.38, 318.21, 291.31, 275.51 tons, respectively. The expansion of productive land has not keep up with the increasing population growth. It is important to carry out agricultural intensification to increase production using more efficient water and fertilizer uses. One of the methods to increase efficiency of watering and fertilizer is by using fertigation system. Weeds can reduce fertilizer intake and increase competition with the main crops for sunlight. Weeds can also be the host of plant diseases. The use of land cover or mulch could potentially solve these problems. One of the types of mulch that can be used is polyethylene. Bosland and Votava (2012) stated that the use of polyethylene mulch has several advantages, which are to increase the yield and quality of crop yields, accelerate fruit maturity, maintain moisture and soil structure, increase soil temperature (stable), reduce evaporation or evaporation of soil, suppress weed growth, reduce nutrient loss, reduce soil compaction, and control pests and diseases. The disadvantage is the increase in cost of production at the beginning of planting, and fertigation through drip irrigation can compensate for this initial cost. Mulched plant beds do not get rainwater directly, except when heavy rain floods the beds. To obtain high-quality beans, the ideal growing conditions and cultivation techniques need to be maintained by supplying nutrients. Nutrients available