Agriculture - - Contents -

The in­ter­na­tional trade of roselle ca­lyces has in­creased steadily, with 15,000 tons/year in the world mar­ket. Ger­many and the USA are the top im­porters. In the Philip­pines, there is very lit­tle pub­lished in­for­ma­tion on both the ar­eas in which roselle is cul­ti­vated, or on the pro­duc­tion lev­els of roselle, al­though some por­tions of Metro Manila, Visayas, and Min­danao have dried ca­lyces, wines, and other pro­cessed prod­ucts in lo­cal mar­kets and even on­line.

USES AND NU­TRI­TIONAL VALUE The leaves and ca­lyces serve as a sour­ing agent (mostly as a sub­sti­tute for vine­gar) for some pop­u­lar Filipino dishes such as ‘sini­gang na isda’ and ‘sinaing na tulin­gan’. In the Ilo­cos re­gion, roselle seeds are grilled, ground, and brewed for cof­fee.

Roselle ca­lyx is used in jams, jel­lies, sauces, syrup, ge­latin, and wines. The ca­lyx is also used for mak­ing a re­fresh­ing bev­er­age called ‘ja­maica’ in Mex­ico. Dried ca­lyx is used for tea, jelly, mar­malade, ice cream, sher­bet, but­ter, pies, tarts, and other desserts.

Roselle stems are used for fuel and fiber while the whole plant is used to treat var­i­ous ail­ments; the plant it­self is con­sid­ered or­na­men­tal. Roselle leaves have high lev­els of polyphe­nol com­pounds (chloro­genic acid and its iso­mers, quercetin and kaempferol gly­co­sides), which may con­trib­ute to its an­tiox­i­dant prop­er­ties and anti-in­flam­ma­tory ac­tiv­i­ties.

Roselle in­fu­sions are a very pop­u­lar drink in many parts of the world. Its phy­to­chem­i­cal com­po­si­tion is as­so­ci­ated with anti-ox­i­dant, anti-hy­per­ten­sive, an­tidi­a­betic, and anti-atheroscle­rotic (clog­ging or hard­en­ing of the ar­ter­ies caused by ac­cu­mu­la­tions of fatty de­posits, usu­ally choles­terol) ef­fects.

NU­TRI­ENT MAN­AGE­MENT Roselle re­quires min­i­mal man­age­ment and pro­duc­tion in­puts. Fer­til­izer ap­pli­ca­tion (usu­ally com­post or other or­ganic in­puts at the rate of 0.51.0 kilo­grams or kg/ per square me­ter or m2) can be done as basal or side-dress­ing once or twice dur­ing the veg­e­ta­tive stage and once dur­ing the re­pro­duc­tive stage.

It has a deep root sys­tem, which con­trib­utes to its drought tol­er­ance. It can com­pete well against weeds, though higher ca­lyx yields can be ob­tained if weed­ing is prac­ticed.

PRO­DUC­TION MAN­AGE­MENT Va­ri­eties: There are many cul­ti­vars or lines of roselle based on phe­no­typic vari­a­tions in plant height, color of leaves and ca­lyx, size of ca­lyx, yield and taste of the ca­lyx. How­ever, there are still no rec­om­mended va­ri­eties for leaf, ca­lyx or fiber pro­duc­tion.

Prop­a­ga­tion and plant­ing: It can be prop­a­gated through seeds and stem cuttings. For leafy veg­eta­bles, seeds can be di­rectly sown or trans­planted 2 weeks af­ter sow­ing in 5me­ter or m x 1m plots with 50 cen­time­ter or cm x 20-40 cm plant­ing dis­tance and 2-3 plants/hill.

Plant­ing dis­tance for ca­lyx pro­duc­tion should be wider, up to 100 cm apart. It is im­por­tant to note that tim­ing of plant­ing is a crit­i­cal as­pect, es­pe­cially in ca­lyx pro­duc­tion. Since roselle is a pho­tope­riod (i.e. change in day length) sen­si­tive plant, plant­ing should be done by Oc­to­ber so that flow­er­ing will com­mence dur­ing the cold months.

PEST MAN­AGE­MENT Dis­eases com­monly ob­served in roselle in­clude leaf spot, caused by Cer­cospora hi­bisci, and pow­dery mildew ( Oid­ium abel­moschi). Roselle with green leaves ap­pear to be more sus­cep­ti­ble than the red leaf types. Phy­toph­thora spp. causes stem burn and the sud­den wilt­ing of the plant. Spray­ing roselle with com­post tea can re­duce downy mildew in­fes­ta­tion and other dis­eases.

In­sect pests can dam­age the leaves; these in­clude the flea bee­tle (Poda­grica spp.), ca­lyx (cot­ton boll­worm lar­vae, Earias bi­plaga/ in­su­lana), cot­ton stainer ( Dys­der­cus su­per­ti­tio­sus) and stem (spi­ral bor­ers, Agrilus acu­tus). Spray­ing the plants with a soap so­lu­tion in­fused with hot pep­per can help re­duce in­sect pests.

HAR­VEST­ING AND PRO­CESS­ING For leaf pro­duc­tion, leaves can be har­vested 8 weeks from trans­plant­ing, and this is usu­ally done 2-3 times dur­ing the veg­e­ta­tive stage. For ca­lyx pro­duc­tion, ca­lyces can be har­vested 10-14 days af­ter flow­er­ing, or when the ca­lyx snaps off eas­ily by hand.

Sep­a­rate the ca­lyx from the fruit, ei­ther man­u­ally or through the use of a cork borer prior to dry­ing in the shade for 2-3 days. Yields of up to 1 ton or t/hectare or ha of ca­lyces have been re­ported in Su­dan.

PO­TEN­TIAL Aside from its po­ten­tial as a veg­etable crop, roselle is gain­ing at­ten­tion nowa­days from the food, bev­er­age, and phar­ma­ceu­ti­cal in­dus­tries be­cause of its po­ten­tial as a nat­u­ral food prod­uct and as a col­orant to re­place some syn­thetic dyes. The ca­lyx has big po­ten­tial in the mar­ket, es­pe­cially if pro­cessed (dried, jams, jel­lies, wines, health drinks, etc.).

RECIPES • Sinaing na tulin­gan with roselle leaves: Mix gar­lic, onion, ground black pep­per, ginger, and wa­ter in a pot. Place roselle leaves un­der tulin­gan and let it boil for 30 min­utes. • Roselle juice/tea: Steep 5-7 dried ca­lyces or 2-3 fresh ca­lyces in boil­ing wa­ter for 5 min­utes or un­til the red color comes out. Serve warm or with rice.

For more in­for­ma­tion, please con­tact Dr. Rodel G. Maghi­rang, Crop Science Clus­ter-In­sti­tute of Plant Breed­ing, Col­lege of Agri­cul­ture, Univer­sity of the Philip­pines Los Baños, 4031 Col­lege, La­guna, or email rgmaghr@ya­

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