Phytophthora Spot in Taro ( Leaf Blight)

The cause of this disease is Phytophthora colocasiae, one of the downy mildews, closely allied to late blight of potato.  The fungus produces its spores on the spots,the above-mentioned fuzz consisting of many thousands of conidia or sporangia,as the spores are termed.  The sporangia are blown by the wind or splashed by rain from diseased to healthy leaves,where they germinatein the presence of moisture to reproduce the disease in 3 to 5 days.  There is a close connection between these verity of phytophthora spot and abnormal atmospheric conditions, particularly rainy weather accompanied by high winds which whip the leaves about and scatter the sporangia.  The practice of close interplant-spacing is conducive to the development of leaf spot,due to poor air drainage and maintenance of a high humidity a round the leaves of the taro plant,which permit the sporangia to germinate easily and abundantly.

The disease can be controlled by spraying with 4-4-50 bordeaux as fungicide  at 10- to17-day intervals.   A spreader must be added to the Bordeaux for the waxy surface of the taro leaf is not easily wetted. (1)


Six fungicides were evaluated under greenhouse, laboratory, and dryland field conditions for control of Phytophthora leaf blight of taro incited by P. colocasiae. Five separate criteria were utilized to evaluate these fungicides: fungicidal activity in vitro; and fungicidal activity in vivo under conditions of simulated dew, simulated rainfall, greenhouse, and dryland field environments. In in vitro tests zoospores were killed at the following concentrations: Dithane M-45, 5 ppm; Difolatan, 9 ppm; Polyram, 65 ppm; Tribasic Copper Sulphate, 145 ppm; Benlate, 210 ppm; and Dyrene, 260 ppm. Excellent control was obtained with Difolatan; good control with Dithane M-45 and Polyram; and poor control with Benlate, Tribasic Copper Sulphate, and Dyrene. Results of in vivo tests correlated with those of the in vitro tests. Difolatan, Benlate, and Dyrene were the most phytotoxic while Tribasic Copper Sulphate, Polyram, and Dithane M-45 were the least phytotoxic.(R.R Bergquist 1971)(2)


Intended for readers from Indonesia,...please

Cara membuat larutan 4:4:50 bordeaux :
Untuk membuat 5 liter larutan 4:4:50 bordeaux
Siapkan 400 gr CuSO4 (Tembaga sulfat) dan 400 gr Ca(OH)2 ( Kapur hydrate) 

• Buat Larutan kapur : 400 gr Ca(OH)2 dalam 1 Liter air dan diaduk hingga terbentuk larutan seperti susu, kemudian buat larutan tembaga sulfat : 400 gr CuSO4 dalam 1 liter air dan aduk beberapa menit hingga terlarut sempurna (larutan berwarna biru).
• Siapkan ember atau wadah plastik, kemudian diatasnya letakan kain saringan dan ikat dengan karet ban, tuangkan larutan kapur dan tembaga sulfat. Penyaringan diperlukan agar padatan yang belum terlarut tidak menyumbat nossel sprayer.
• Setelah itu tambahkan air dalam ember hingga total volume menjadi 5 Liter dan aduk rata, larutan fungisida ini siap digunakan.(fungisida ini dibuat pada saat akan digunakan)

Kapur hydrate bisa di buat dari kapur bakar atau kapur mati  yang memiliki kemurnian n % CaO, dan umumnya kemurnian berkisar antara  60-85% CaO
CaO+ 2H2O (excess)==> Ca(OH)2 (mengendap) + H2O
(Reaksi eksotermis atau melepaskan panas)
untuk mendapatkan 400 gr Ca(OH)2 , 
diperlukan Kapur bakar sebanyak = 400/74 x 56 x (1/n%)= 303 gr x (1 / (n % CaO)), kemudian ambil endapan dan keringkan.
Ref :

1. DISEASES OF TARO IN HAWAII AND THEIR CONTROL With Notes on Field Production by G. K. PARRIS, Plant Pathologist Honolulu , 1941 
2. Efficacy of Fungicides for Control ofPhytophthora Leaf Blight of Taro, R. R. BERGQUIST, 1971

Nutrient Deficiencies and Excesses in Taro

Susan C. Miyasaka, Randall T. Hamasaki, and Ramon S. de la Pena
Departments of Tropical Plant and Soil Sciences, Plant and Environmental Protection Sciences, and Natural Resources and Environmental Management

Identifying and correcting plant nutrient deficiencies and toxicities are essential for good crop management and contribute to higher economic returns. Failure to correct soil problems or to apply sufficient amounts of fertilizers can result in poor yields and wasted effort. Applying too much or the wrong kind of fertilizer can have many negative consequences, including :

• nutrient toxicities or imbalances that reduce plant growth and yield

• excessive foliage growth that invites damage by plant diseases and insect pests

• environmental contamination from runoff into surface water bodies and leaching into the groundwater, and

• economic loss due to wasted fertilizer.

This publication explains the role of essential plant nutrients in taro (Colocasia esculenta) and shows the visual symptoms that occur when there is a nutrient inadequacy (deficiency) or excess (toxicity) in the taro plant.

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Chemical Content of Agarwood

Yoneda et al. (1984) mentions that there are eight components sesquiterpena on agarwood (gaharu) from Indonesia, namely α-agarofuran, 10-epi-γ-eudesmol, agarospirol, jinkohol, jinkoh-eremol, jinkohol II, kusunol, and oxo-agarospirol. Nakanishi et al. (1984) reported that there are 3 sesquiterpena which has a fragrant aroma, namely α-agarofuran, (-)-10-epi-γ-eudesmol, and oxo agarospirol. Besides sesquiterpena, Indonesia agarwood ( A. malaccensis )  contains the principal components of chromone. Chromone is what causes the scent of agarwood when burned (Burfield 2005). Konishi et al. (2002) report has identified six new derivatives Chromone that play a role in determining the fragrance of agarwood.

Chemical substances which are usually found in Aquilaria malaccensis Lamk.

No	Chemicals	%
1	2-(2-(4 methoxyphenyl)ethyl)chromone	27.0
2	2-(2-phenylethyl)chromone	15.
3	oxo agarospirol	5.0
4	9,11-eremophiladien-8-one	3.0
5	6-methoxy-2(2-(4-methoxyphenyl)ethyl)chormone	2.5
6	guaia-1(10),11-dien-15-al	1.5
7	selina-3,11-dien-ol	1.5
8	kusunol	1.4
9	selina-2,11-dien-14-ol	1.0
10	guaia-1(10), 11-dien-15-oic acid	1.0
11	selina-3,11-dien-9-one	0.8
12	jinko-eremol	0.7
13	selina-4,11-dien-14-al	0.7
14	dihydrokaranone	0.7
15	selina-3,11-dien-14-al	0.6
16	2-hydroxyguaia-1(10),11-dien-15-oic acid	0.4
17	b-agarfuran	0.4
18	guaia-1(10),11-dien-15-ol	0.3
19	guaia-1(10),11-dien-15,2-olide	0.3
20	selina-3,11-dien-14-oic acid	0.3
21	norketoagarfuran	0.2
22	agarspirol	0.2
23	sinenofuranol	0.2
24	selina-4,11-dien-14-oic acid	0.2
25	9-hydroxyselina-4,11-dien-14-oic acid	0.2
26	dehydrojinkoh-eremol	0.2
27	rotundone	0.1
28	a-bulnesene	0.1
29	karanone	0.1
30	a-guaiene	0.1
31	bulnesene oxide	0.1
32	guaia-1(10),11-dien-9-one	0.1
33	1,5-epoxy-norketoguaiene	0.1
	Total Source	65

Ref:

1. Ishihara et al., 1993 http://rakbankerd.com/agriculture/wb/show.php?Category=agriculture&No=312
2. Tony Burfield 2005 http://www.cropwatch.org/agarchem.htm
3. http://pubchem.ncbi.nlm.nih.gov

Chemical compounds of Tabat barito ( Ficus deltoidea Jack )

Tabat barito (Ficus deltoidea Jack) is an epiphytic shrub which is native and widely distributed in several countries of the Southeast Asia. It is easily found in the coastal, but not in mangrove area. Different parts of the plant are used traditionally to treat various kinds of ailments. The fruits are chewed to relieve headache, toothache and cold. Powdered root and leaves of the plant has been applied externally to wounds and sores and for relief of rheumatism . Decoction from the whole plants is well known as traditional herbal drink for women after childbirth to help strengthen the uterus . The plant sap was used to detach wart from the skin . Moreover it improves blood circulation and pharmacologically blood glucose . On the other hand, there is no report related to its chemical constituent and bioactivity.[2]

A total of 19 chemical compounds were successfully identified with the phenol 27.12 % and 2,4-bis (dimethylbenzyl)-6-t-butylphenol 11.83 % as the major compounds [1]

Chemical compounds of Ficus deltoidea Jack. leaf extract

Compound	composition (%)
Phenol 2,4-Bis(dimethylbenzyl)-6-t-butylphenol Cyanogen Octaethyleneglycol Octaethylene glycol monododecyl ether Phthalicacid 2-Pentadecanone,6, 10, 14-trimethyl Carbonic acid 1,4,7,10,13,16-Hexaoxacyclooctadecane Hexagol Butanoic acid 1H-Indene,2,3-dihydro-1,1,3-trime 15-Crown-5,[2-(diethylboryl) pheny]- 4-amino-2,6-dimethyl-3-pyridyl 1-adamantanecarboxylate Hexadecanoic acid, methyl ester 2-methoxybenzoic acid, cyclopenthyl ester Heptadecanoic acid, 16- methyl-, methyl ester 1-propoxy-3,3-diethyltriazene 2-oxide Heptacosane	27.12 11.83 8.83 6.36 6.29 5.70 5.50 5.03 4.59 3.01 2.68 2.68 2.46 2.30 2.10 1.62 1.31 1.15 1.06
Total	100.00

This was supported by the detection of 6 chemical compounds such as phthalic acid, carbonic acid, butanoic acid, hexadecanoic acid, methyl ester, 2-methoxybenzoic acid, cyclopenthyl ester and heptadecanoic acid, 16- methyl-, methyl ester that are presumably responsible for the antimicrobial activity of the plant extract

The antioxidant activity showed by this plant extract may be due to chemical compounds such as phenol and 2,4-bis (dimethylbenzyl)-6-t-butylphenol that were successfully identified. These two major phenolic compounds were well known for their antioxidant activity.

Classification
Kingdom: Plantae (Plants)
      Subkingdom: Tracheobionta (vascular plants)
          Super Division: Spermatophyta (seed Produce)
              Division: Magnoliophyta (flowering plants)
                  Class: Magnoliopsida
                      Sub Class: Dilleniidae
                          Order: Urticales
                              Family: Moraceae
                                  Genus: Ficus
                                      Species: Ficus deltoidea Jack
Common name :
Indonesia: Tabat barito
Melayu: Emas cotek, emas kotek, telinga beruk


Ref:

1. Lee Seong Wei et al. / Journal of Biologically Active Products from Nature (JBAPN) 1 (1) 2011 pp 1-6
2. Suryati et al./Indo. J. Chem., 2011, 11 (1), 67 - 70

How to Grow Alfalfa

By Ahmad Suhendra

Alfalfa is grown across a wide range of soil, water and climate conditions which challenges the management decision of growers to produce the highest quality and high yielding hay. Over the past decade, there has been a shift of alfalfa plantings from some of the fertile soils in the Central Valley to the more marginal soils once thought to be unsuitable for alfalfa. With these changes and the demand for higher quality and increased production, alfalfa growing requires a keen eye and ability to recognize signs or symptoms of problems that can cause significant production losses.

Intended for readers from Indonesia,..Please 

Cara menanam Alfalfa

Sebelum membudidayakan tanaman alfalfa, sebaiknya anda perlu mengetahui tekstur dan jenis tanah, pH, Salinitas, kandungan N, P, K dsb yang ada dalam tanah untuk menghitung berapa kebutuhan pupuk, kapur yang harus ditambahkan. Adapun cara persiapan dan penanaman alfalfa yang  kami lakukan pada jenis tanah regosol dan bertekstur sandy loam dengan pH 5-5,5 adalah sebagai berikut ( jika tidak ada data analisa tanah, maka kesuksesan budidaya sangat tergantung pada keberuntungan) :

1. Buat lahan penanaman lihat gambar ( photo diambil tgl 10 Januari 2012)
2. Di dalam lahan dengan jarak antar petakan 40 cm yang berupa parit sedalam 20 cm untuk drainase/ jalan orang.
3. Taburkan kapur dolomit setara 4 ton/ha  (atau 0,4 kg/m2)  merata dipermukaan petakan, kemudian disiram air atau tunggu hujan turun biarkan selama 2-3 hari agar reaksi netralisasi berjalan dengan baik.
4. Setelah tahap pengapuran, dianjurkan untuk diberi pupuk kandang ( yang sudah matang) sebanyak 1-1,5 kg/m² ( 10-15 ton/ha)* dan aduk rata (Cangkul halus).
5. Buat larikan sedalam 1-1,5 cm, lebar 3-5 cm dan jarak antar larikan 20 cm , sepanjang petakan.
6. Siapkan biji alfalfa sebanyak = 1,38 gr biji per larikan sepanjang  4m, campur dengan pasir halus yg kering dengan perbandingan berat sekitar 1 : 30 = Alfalfa : Pasir,  kemudian aduk rata. Dalam 1,38 gr biji mengandung sekitar = 600 biji alfalfa, ( setara dengan kepadatan dalam 1 m²  , yang biasanya di gunakan oleh petani di Amerika )
7. Tebarkan biji yg bercampur pasir tersebut kedalam larikan hingga habis  sepanjang larikan, kemudian tutup dengan tanah ( sekedarnya saja ).
8. Berikan sejumlah pupuk SP36(36 % P₂O₅) = 250 kg/ha dan KCl(60% K₂O)= 500 kg/ha, tempatkan pupuk dalam larikan yang dibuat disebelah kanan / kiri larikan dgn jarak 5 cm dari larikan biji alfalafa. Kemudian siram dengan air hingga jenuh (100 % kapasitas lapang).
9. Jika tahapan diatas sudah dilakukan, maka disarankan untuk memberikan potongan rumput alang-alang / jerami ( 5 cm ) yang di tebarkan merata diatas permukaan petakan ( asal menutupi permukaan tanah) untuk menjaga kelembaban tanah.
10. Perlu menjaga ketersedian air untuk perkecambahan alfalfa, dengan memperhatikan kelembaban pada permukaan tanah, jika cuaca panas dan tanah terlihat kering maka segeralah  di siram ,usahakan penyiraman pada pagi hari dan / atau sore hari, tergantung kebutuhan.
11. Jaga tanaman alfalfa dari gulma minimal  60 hari setelah tanam, setelah itu gulma dapat biarkan saja karena pembersihan gulma akan memerlukan banyak tenaga dan biaya.
12. Hama dan penyakit tanaman alfalfa cukup banyak, maka dalam perawatanya di anjurkan untuk bertanya pada penyuluh lapangan atau dinas pertanian setempat.

Note:

• Selain penanaman cara diatas, ada juga penanaman dengan cara biji langsung ditebar diatas permukaan tanah yang telah diolah ( dosis kapur dan pupuk hampir sama). Kemudian di ratakan dengan mengunakan semacam sapu dari jerami.
• Dengan cara tebar langsung  akan menghemat waktu dan ongkos penanaman tetapi agak susah dalam membersihkan gulma karena berbaur dengan tanaman alfalfa muda yg gampang tercabut ( sukar untuk di tanam kembali / mati) pada saat membersihkan gulma.
• Baca tulisan lainya di blog kami, ttg alfafa untuk melengkapi informasi ini
  
• Dengan membaca dan menerapkan tulisan ini, maka sukses atau tidak  adalah tanggung jawab anda.

)* Kandungan hara dari pupuk kandang padat/segar

No	Sumber Pupuk Kandang	Persentasi (%)
		Kadar Air	Bahan Organik	N	P2O5	K2O	CaO	Rasio C/N
1	Sapi	80	16	0,3	0,2	0,15	0,2	20-25
2	Kerbau	81	12,7	0,25	0,18	0,17	0,4	25-28
3	Kambing	64	31	0,7	0,4	0,25	0,4	20-25
4	Ayam	57	29	1,5	1,3	0,8	4,0	9-11
5	Babi	78	17	0,5	0,4	0,4	0,007	19-20
6	Kuda	73	22	0,5	0,25	0,3	0,2	24

Sumber: Pinus Lingga (1991)

Production of agarwood fragrant constituents in Aquilaria calli and cell suspension cultures

By Yukie Okudera, Michiho Ito*

Calli and suspension cell culture were established from Aquilaria species whose resinous portion was called agarwood and used as medicine and incense. Four different strains of calli were analyzed for fragrant compounds such as sesquiterpenoids and chromone derivatives which were the major components of agarwood. Main sesquiterpenoids detected from calli were  a-guaiene,  a-humulene and  d-guaiene, and those of chromone derivatives were phenylethylchromones(AH3, AH4, AH5, AH6). Amount of these compounds differed among the four strains, indicating that Aquilaria plants may have variation in capacity for fragrant compound production. Incubation temperature analysis was also done from 20°C to 40°C and resulted that cell growth was the best at 25°C, whereas the amount of fragrant compounds was largest at 20°C.

Salicylic acid (SA) and methyl jasmonate (MJ) were added to calli and suspension cell culture respectively in order to induce production of fragrant compounds. Both SA and MJ apparently induced production of three sesquiterpenoids, aguaiene,  a-humulene, and  d-guaiene at early stage of treatment of SA or MJ, but did not induce that of chromone derivatives directly. Further studies of time course of chromone production and cell viability suggested that cell death may take part in chromone production, and that phenylethylchromones would be produced via oxydoagarochromones (OACs). These results indicate that sesquiterpenoids are synthesized in living cells, but chromone derivatives may be produced from debris of dying cells. 

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Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
* E-mail: michihoi@pharm.kyoto-u.ac.jp Tel & Fax: +81-75-753-4506

Satoimo (Colocasia esculenta) can be used as an alternative food source

By Ahmad Suhendra

Satoimo ( Sato-imo) is the name given to taro root that grows wild and is cultivated in Japan. Its name means village potato. Common taro has a long rootstock with a shape similar to a sweet potato, whereas Satoimo is smaller and roughly rounded, with tapered ends. The taste and texture of the different varieties is similar. Taro Satoimo is rich in Hyaluronic Acid (HA), a substance produced naturally within our bodies in abundance when we are young. It promotes strong joints and produces natural collagen.[1]  It also contains potassium , phosphorus, Vitamins B1, B2 and C and Rich in fibers.[2] Taro is closely related to Xanthosoma and Caladium, plants commonly grown as ornamentals, and like them it is sometimes loosely called elephant ear.[2]

Generally, commercial taro producers apply a variety of fertilizers for improved yields. Nitrogen at 100 kg N/ha is often applied as urea or ammonium sulphate, in split applications at 5, 10 and 15 weeks after planting (WAP). Where necessary, 25 kg/ha phosphorus is applied at planting as superphosphate. If potassium is low, 100 kg/ha is split, with one application at planting and the other at 10 WAP. Compound NPK fertilizer (13:13:21) is recommended at 400 kg/ha, with half applied at planting and the other half at 10 WAP. Where available, poultry manure can be used at 10 tonnes/ha, applied two weeks before planting.[1]

Table.1 Proximate Composition of the Taro Corm on Fresh Weight Basis[3]
Component	Content
Moisture	63-85%
Carbohydrate	13-29%
Protein	1.4-3.0%
Fat	0.16-0.36%
Crude fiber	0.6-1.18%
Ash	0.6-1.3%
Vitamin C	7-9 mg/100 g
Thiamine	0.18 mg/100 g
Riboflavin	0.04 mg/100 g
Niacin	0.9 mg/100 g

The main economic parts of the taro plant are the corms and cormels, as well as the leaves. The fresh weight composition of the taro corm is shown in Table 1. The fresh corm has about two-thirds water and 13-29 % carbohydrate. The composition of the carbohydrate fraction is shown in Table 2, indicating that the predominant carbohydrate is starch. The starch itself is about four fifths amylopectin and one-fifth amylose. The amylopectin has 22 glucose units per molecule, while the amylose has 490 glucose units per molecule. The starch grains are small and therefore easily digestible. This factor makes taro suitable as a specialty food for allergic infants and persons with alimentary disorders.

Table.2 Percentage Composition of Taro Corm Carbohydrate[3]
Carbohydrate	Percentage(%)
Starch	77.9
Pentosans	2.6
Crude fiber	1.4
Dextrin	0.5
Reducing sugar	0.5
Sucrose	0.1

The taro leaf, like most higher plant leaves, is rich in protein. It contains about 23% protein on a dry weight basis. It is also a rich source of calcium, phosphorus, iron, Vitamin C, thiamine, riboflavin and niacin, which are important constituents of human diet.

Ref:

1. FAO: Taro cultivation in Asia and the Pacific, 1999
2. http://shizuokagourmet.wordpress.com/2009/12/26/vegetables-facts-and-tips-15-tarosato-imo/
3. Onwueme,I.C.(1994).Tropical root and tuber crops-production, prespectives and future prospect. FAO Plant Production and Protection Paper 126,FAO,Rome.228p
4. http://en.wikipedia.org/wiki/Taro