Rekomendasi Waktu Tanam Kapas di Lahan Tadah Hujan - PRIMA DIARINI RIAJAYA (Puslitbang Perkebunan, 2008)
ABSTRAKPenanaman kapas di lahan tadah hujan membutuhkan perkiraan waktu tanam yang tepat agar tanaman mendapatkan suplai air yang cukup selama pertumbuhannya. Rekomendasi waktu tanam kapas di daerah tadah hujan Sulawesi Selatan, Jawa Timur, Jawa Tengah, DIY, dan Nusa Tenggara Barat telah ditetapkan berdasarkan analisis data curah hujan lebih dari 20 tahun dengan metode peluang Markov Order Pertama dan perhitungan peluang selang kering berturut-turut. Rekomendasi waktu tanam dalam minggu tanam paling lambat (MPL) di Sulawesi Selatan yaitu di Kabupaten Jeneponto, Takalar dan sebagian besar Gowa berkisar minggu I-IV Desember. Sedangkan di Kabupaten Soppeng dan Wajo berkisar minggu III Februari sampai minggu III Maret. Di Bone dan Bulukumba MPL berkisar minggu III Maret sampai minggu III April. MPL di Jawa Timur yaitu di Kabupaten Pasuruan, Probolinggo, Situbondo, Jember dan Banyuwangi berkisar minggu I-IV Desember, dan di kabupaten Lumajang berkisar minggu I Januari, kemudian di Kabupaten Lamongan, Mojokerto dan Tuban berkisar minggu II Desember sampai minggu I Januari. MPL di Jawa Tengah meliputi Kabupaten Grobogan dan Wonogiri berkisar minggu I Desember sampai minggu I Januari sedangkan di Blora, Pemalang, Tegal dan Brebes adalah minggu I-IV Januari. MPL di Nusa Tenggara Barat yaitu di sebagian besar Lombok dan Sumbawa berkisar minggu I-II Desember. Tipe iklim di wilayah tersebut didominasi oleh tipe iklim D dan E dengan musim hujan hanya 3-4 bulan sehingga mempunyai resiko tinggi terhadap kekeringan. Untuk meningkatkan produktivitas kapas di lahan kering maka tambahan air irigasi mutlak diperlukan untuk mengatasi kekurangan air atau kekeringan.Kata kunci: Gossypium hirsutum, waktu tanam, periode kering ABSTRACTRecommendation on Rainfed Cotton Planting TimesRecommendation on cotton planting time is needed as cotton is mostly grown under rainfed condition. The right planting times were determined for South Sulawesi, East Java, Central Java, DIY, and West Nusa Tenggara. The rainfall analysis was done based on more than 20 years daily rainfall data using Markov Chain First Order Probability and dry spell probability method. The planting times in South Sulawesi varied from the first week to the forth week of December for Jeneponto, Takalar and Mostly Gowa. The planting times in Soppeng and Wajo were ranged from the third week of February to the third week of March. Moreover, cotton planting times in Bone and Bulukumba were ranged from the third week of March to the third week of April. The planting times in East Java varied from the first week to the forth week of December for Pasuruan, Probolinggo, Situbondo, Jember and Banyuwangi. The planting times in Lumajang, Lamongan, Mojokerto and Tuban ranged from mid December to early January. The planting times in Central Java varied from the first week of December to the first week of January for Grobogan and Wonogiri. The planting times in Blora, Pemalang, Tegal and Brebes were ranged from early to late January. The planting times in West Nusa Tenggara varied from the first week to the second week of December for most areas of Lombok and Sumbawa. Lack of water or drought in rainfed cotton growing areas is a regular phenomenon since cotton is developed in the dry areas (climate classification D and E) to which rainfall only lasts three to four months. Irrigation water is highly needed in rainfed areas to meet the crop water need especially when lack of water or drought occurs.Key words: Gossypium hirsutum, planting time, dry spell