No abstract

No abstract

ABSTRAK. Paclobutrazol sebagai zat penghambat biosintesis giberelin selama ini telah digunakan secara luas untuk mengatur produksi di luar musim beberapa buah tropika, namun zat ini meninggalkan residu yang panjang. Prohexadion-Ca adalah zat penghambat biosintesis giberelin yang dalam penggunaannya tidak meninggalkan residu, namun belum pernah diuji efektifitasnya dalam mengatur produksi buah di luar musim. Tujuan dari penelitian ini ialah untuk mendapatkan teknologi produksi buah jeruk di luar musim tanpa meninggalkan residu dalam tanah. Penelitian menggunakan rancangan blok terpisah (split block design). Penelitian berlangsung dari bulan November 2012 sampai Mei 2013. Hasil penelitian menunjukan perlakuan Prohexadion-Ca, Paclobutrazol, dan strangulasi dapat mempercepat pembungaan dan meningkatkan jumlah bunga dan buah tanaman jeruk keprok. Perlakuan Prohexadion-Ca dapat mempercepat mulainya muncul bunga  dibandingkan dengan perlakuan Paclobutrazol dan dapat meningkatkan jumlah bunga dan buah sama dengan Paclobutrazol. Penggunaan Prohexadion-Ca dapat dijadikan sebagai teknologi untuk memproduksi buah jeruk di luar musim tanpa meninggalkan residu dalam tanaman.

<p>ABSTRACT<br />Pummelo productivity is still low, therefore efforts should be made to increase its flowering and production. The objective of study was to determine the effectiveness of strangulation combined with the application of breaking dormancy substances to improve flowering of pummelo. The experiment was conducted in January to November 2015, at the Cikabayan Experimental Research Station, IPB. The carbohydrate and nitrogen analysis was done in laboratory of Postharvest Agriculture Research Institute, Bogor. Three-year-old pummelo grown in field was subjected for this research. Experiment used a completely randomized design (CRD) with two factors. The first factor was treatment to stimulate flowering, consisted of 3 levels i.e. single strangulation, double strangulation and control, and the second factor was the use of dormancy breaking substances, consisted of 3 types i.e. KNO3, Ethepon and BAP. Strangulation was performed by pressing the wire with a diameter of 2.0 mm into stem as deep as the diameter of the wire. Strangulation was done simultaneously and then released after 3 months. Dormancy breaking substance was applied immediately after releasing the wire for strangulation with the concentration of 200 ppm KNO3, 100 ppm Ethepon or 100 ppm BA. Treatments were replicated 4 times. The results showed that single and double strangulation treatments for 3 months were an effective way to induce flowering of young pummelo trees. Double strangulation produced more flowers as compared to single strangulation.<br />Increased carbohydrate content and C/N ratio in leaves were observed on flower induced trees. Strangulation treatment for 3 months can increase flowering of young pummelo trees. Application of dormancy breaking substances did not have any effect on flowering induction in pummelo.</p><p>Keywords: carbohydrate content, dormancy breaking substance, flower induction, pummelo, strangulation</p><p>ABSTRAK<br />Produktivitas pamelo masih rendah sehingga perlu upaya peningkatan pembungaan dan produksinya. Penelitian ini bertujuan untuk mengetahui efektivitas strangulasi yang dikombinasikan dengan aplikasi zat pemecah dormansi dalam meningkatkan pembungaan jeruk pamelo. Penelitian dilaksanakan pada bulan Januari sampai Nopember 2015, bertempat di Kebun Percobaan IPB Cikabayan. Analisis karbohidrat dan nitrogen dilakukan di laboratorium BB Pasca Panen, Bogor. Percobaan menggunakan tanaman jeruk pamelo “Nambangan’ berumur 3 tahun dengan Rancangan Acak Lengkap (RAL) dua faktor. Sebagai faktor pertama yaitu perlakuan untuk menstimulasi pembungaan, terdiri atas 3 taraf perlakuan yaitu perlakuan strangulasi tunggal, strangulasi ganda dan kontrol, dan sebagai faktor kedua adalah penggunaan zat pemecah dormansi terdiri atas 3 jenis yaitu KNO3, Ethepon dan BAP. Masing-masing perlakuan diulang 4 kali sehingga terdapat 36 unit percobaan. Strangulasi dilaksanakan dengan melilitkan kawat dengan diameter 2.0 mm pada batang dengan menekan kawat ke batang sedalam diameter kawat tersebut. Strangulasi dilakukan serentak pada batang, strangulasi dilepas setelah 3 bulan kemudian. Zat pemecah dormansi diaplikasikan segera setelah pelepasan kawat strangulasi dengan konsentrasi masing-masing 200 ppm untuk KNO3, 100 ppm untuk Ethepon atau 100 ppm untuk BAP. Hasil penelitian menunjukkan perlakuan strangulasi selama 3 bulan merupakan cara efektif menginduksi pembungaan tanaman jeruk pamelo. Perlakuan strangulasi ganda menghasilkan bunga lebih banyak dibandingkan dengan strangulasi tunggal. Tanaman yang telah terinduksi menunjukkan tingginya kandungan karbohidrat pada tajuk tanaman sehingga meningkatkan rasio C/N. Perlakuan zat pemecah dormansi tidak memberikan pengaruh yang nyata terhadap pembungaan jeruk pamelo.<br />Kata kunci: kandungan karbohidrat, pamelo, pembungaan, strangulasi, zat pemecah dormansi</p>

Pruning is one of the techniques to improve plant growth and production. The aim of this research was to determine the effect of pruning on vegetative and generative growth, and fruit quality of 'Crystal' guava. The experiment was conducted from September 2016 to April 2017 at Cikabayan Research Station of Bogor Agricultural University, Dramaga, Bogor, Indonesia (-6.550780, 106.714531). The experiment used completely randomized design with six replications. There were three treatments i.e. a) pruning by leaving 4 pairs of leaves, b) pruning by leaving 8 pairs of leaves, and c) control (without pruning). Pruning was applied after shoot leaves grew fully. The result showed that pruning significantly increased the total number of shoots and generative shoots. Pruned plants produced more flower and fruit than un-pruned ones. Pruning by leaving 4 pairs of leaves tended to produce higher number of flower and fruit than those by leaving 8 pairs of leaves. Fruit weight and internal fruit quality were not affected by pruning. CONCLUSIONPruning had significant effect to the increase of total number of shoots and generative shoots. Pruned plants produced more flower and fruit than un-pruned ones. Pruning by leaving 4 pairs of leaves tended to have higher number of flower and fruit than by leaving 8 pairs of leaves. Fruit weight and its quality were not affected by pruning.

<p>ABSTRACT</p><p><br />The objective of this research was to study the differences effects of interstock on scion growth, flowering and fruiting of ‘Nambangan’ pummelo (Citrus grandis (L.) Osbeck). The research was conducted from January to December 2005 in a green house of Cikabayan Research Station IPB, Dramaga. Th e research was <br />arranged in randomized completely block design with singe factor i. e. kind of intertock consisted of Flying Dragon, Troyer, Citrumelo, and Rangpur Lime. All interstocks were grafted on Javanche Citroen rootstock. The result showed that the growth, flowering and fruiting of ‘Nambangan’ pummelo was significantly <br />affected by kind of interstock. Citrumelo interstock tended to induce more vegetatif with low generatif growth of ‘Nambangan’ scion. Troyer, Rangpur Lime and Flying Dragon resulted in moderate growth of ‘Nambangan’ scion, however only Flying Dragon induced ‘Nambangan’ scion to produce more flower and fruit as compared with other interstocks. There was no significant different in carbohydrate content in leaves and C/N ratio among scion with four interstock studied.</p><p><br />Key words: interstock, Nambangan, pummel o, flowering</p>

Experiments were conducted to determine the role of polyamines and ethylene in the ripening of banana and papaya fruits. In the first experiment, fruits were stored either at room (25-30 o C) or cool (13-18 o C) temperatures. The second experiment consisted of four treatments of exogenous polyamines infiltration: control, putrescine (3 or 10 mM), 1 mM spermidine and 1 mM spermine. The experiments were replicated three times. Results of the first experiment showed that cool storage inhibited fruit softening, the increase of ACC content, rate of ethylene production and respiration, total sugar, and peel color development. Spermidine was the polyamine found in banana and papaya fruits. Spermidine decreased at both temperatures with slower decreases at cool temperature than at room temperature. In the second experiment, infiltration of polyamines inhibited fruit softening, peel color development, the increase in ACC content, rate of ethylene production and respiration, and ACC oxidase activity.

No abstract