Penelitian ini bertujuan untuk mendapatkan dosis pupuk K dan saat panen enam genotipe bawangmerah yang tetap, sehingga diperoleh hasil maksimal. Penelitian ini dilaksanakan di kebun percobaan PusatPenelitian dan Pengembangan Kedelai (SRDC) Universitas Jenderal Soedirman, Purwokerto, sejak bulanJuni sampai September 2006. Rancangan percobaan yang digunakan adalah Rancangan Petak Terbagi (RPT)dengan 3 kali ulangan. Petak utama adalah pepumukan K, K0: kontrol dan K1=150 kg KCl/ha, dan anakpetak berupa kombinasi antara genotipe bawang merah dan saat panen. Keenam genotip bawang merahmenunjukkan pertumbuhan dan hasil bervariasi, tetapi bukan disebabkan oleh variasi pemupukkan K. Hasilumbi bervariasi ketika panen dilakukan pada saat yang berbeda. Umur panen 70 hst (U2) memberikan hasillebih baik daripada umur panen 60 hst (U1). Bobot kering askip tanaman per rumpun, dan diameter umbisetiap genotip bawang merah ditentukan oleh saat panen. Galur K (V3) pada umur panen 70 hst (U2)menunjukkan hasil yang paling tinggi. Jumlah umbi per rumun keenam genotip bawang merah ditentukanoleh pemberian pupuk K dan saat panen. Jumlah umbi per rumun Galur K (V3) dan varietas Tiron (V6)meningkat sejalan dengan pemberian pupuk K (K1) dan jika dipanen pada umur 70 hst (U2), sehinggadiameter umbinya menjadi kecil-kecil.Kata Kunci: bawang merah, genotipe, pupuk K, saat panen. ABSTRACTThis research project aimed to find out the proper dose of K fertilizer and harvest time for shallot, soas to gain their maximal yield. Its was carried out in Soybean Research and Development Center (SRDC)field of Jenderal Soedirman University, Purwokerto, since June until September 2006. A three replication ofSplit Plot Design arranged in Randomized Completely Block Design was employed. The main plot consistedof K0: control and K1: 150 kg KCL per hectare, whilst sub plot was combination between six shallotgenotype and harvesting time. The growth and yield of six shallot varieties varies and its variation dependedon K fertilizer and harvesting time. K application (K0 and K1) was not affect all of observed variables. Bulbyield varies when its harvest was done in different time. Harvesting time in 70 days after planting (U2)resulted higher yield than those of 60 days after planting (U1). Askip dry weight of crop per clump and bulbdiameter of each variety depended on harvesting time. K line (V3) produced the highest yield when shallotwaa harvested in 70 days after planting (U2). The number of tuber per clump for all varieties was determinedby both K application and harvesting time. The number of tuber for K line (V3) and Tiron variety (V6)increased when K fertilizer was applied and shallot was harvested in 70 days after planting (U2), and hencethe diameter of tuber decreased.Key words: shallot, genotype, K fertilizer, harvesting time.