TUGAS PLANT-PROTECTION KELAS INTERNASIONAL I WEEDS ON PADDY FIELD AND WAY TO CONTROL

I.                   PREFACE

A.      Background

Food is primary needs for every organism because without that the organism can do their metabolism and metabolism is for keep the organs run well and maintenance every part of body and for build energy for our activities. Food divided into several type like desert (fruit) , meat and the food for source of carbohydrate like rice,potato,wheat,corn and other. The  food for source of carbohydrate is base needs for human because all of us eat that everday. One of the most favorite in Indonesia is Rice from Paddy Field.

Rice is the most main food for Indonesian , like Javanese and Sundanese said that “we not eat if we not eat rice” it means the rice is so important. While the rice so important , in Indonesian still low production of rice and so many problem on paddy crop like pest,unstable price,water source and the problem cause by weeds.Other plant become problem because weeds make competition with main crop(paddy) to get nutrition, water and light. This problem cause decreasing 10%  of paddy yield and make farmer lossing their profit. The decreasing of profit make the farmer in Indonesia won’t to invest their money in paddy cultivation and make the land converting from paddy field to other business like residental business. It make additional problem like decreasing of land conservation, decreasing of green land and decreasing food source.

To overcome the weeds farmer commonly use the chemical herbicides because it so simple and so little knowledge about weed control. Chemical herbicide is efficient to clear the weed but as we know chemical thing have negative effect for environment. The negative effect for environment cause by herbicide is contamination of water quality, can kill other beneficial organism and can accumulate in one place including our body and make the human health decreasing.So the organic weed control is very need to maintain the paddy cultivation and the environment.

B.     The Purpose of Research

The purpose of research about Organic Weed Control in Paddy Field are as follows :

a.       Able to know the Importance of  weed control in paddy field

b.      Able to know several variety of weed in paddy field

c.       Able to know how to control paddy’s weed with organic methods

II.                CONTENT

A.    The Importance of Weed Control in Paddy Field

The importance of weed control in paddy field is for maintain the production of paddy field because rice is very important comodities and have to function for worlds people are as follows :

1.       Rice as a global staple food

Rice, wheat, and maize are the three leading food crops in the world; together they directly supply more than 50% of all calories consumed by the entire human population. Wheat is the leader in area harvested each year with 214 million ha, followed by rice with 154 million ha and maize with 140 million ha. Human consumption accounts for 85% of total production for rice, compared with 72% for wheat and 19% for maize.Rice provides 21% of global human per capita energy and 15% of per capita protein. Although rice protein ranks high in nutritional quality among cereals, protein content is modest. Rice also provides minerals, vitamins, and fiber, although all constituents except carbohydrates are reduced by milling.

 The world average consumption of rice in 1999 was 58 kg, with the highest intake in some Asian countries; Myanmar has the highest annual consumption at 211 kg/person. Rice eaters and growers constitute the bulk of the worlds poor: according to the UNDP Human Development Report for 1997, approximately 70% of the worlds 1.3 billion poor people live in Asia, where rice is the staple food.

Table 1.Rice consumption in several country

To some extent, this reflects Asians large population, but even in relative terms malnutrition appears to affect a substantially larger share of the population in South Asia than in Africa. For these people, rice is the most important commodity in their daily lives. In countries such as Bangladesh, Vietnam, and Myanmar, the average citizen consumes 150-200 kg annually, which accounts for two-thirds or more of caloric intake and approximately 60% of daily protein consumption. Even in relatively wealthier countries such as Thailand and Indonesia, rice still accounts for nearly 50% of calories and one-third or more of protein.

2. The effect of rice on the global economy

Rice is also the most important crop to millions of small farmers who grow it on millions of hectares throughout the region, and to the many landless workers who derive income from working on these farms. In the future, it is imperative that rice production continue to grow at least as rapidly as the population, if not faster. Rice research that develops new technologies for all farmers has a key role to play in meeting this need and contributing to global efforts directed at poverty alleviation.

Agricultural population densities on Asia’s rice producing lands are among the highest in the world and continue to increase at a remarkable rate. Rapid population growth puts increasing pressure on the already strained food-producing resources. The aggregate population of the less developed countries grew from 2.3 billion in 1965 to 4.4 billion in 1995. Asia accounted for 60% of the global population, about 92% of the world’s rice production, and 90% of global rice consumption. Even with rice providing 35-80% of the total calories consumed in Asia and with a slowing of growth in total rice area, rice production more than kept up with demand in 2000. The largest producing countriesis China, India, Indonesia, Bangladesh, Vietnam, and Thailand together account for more than three quarters of world rice production.The world’s annual rough rice production, however, will have to increase markedly over the next 30 years to keep up with population growth and income-induced demand for food.

Weeds cause more yield losses in rice field than any other pests. Transplanted crop is affected less by weeds than direct sowing method. Weed management is very important component in rice production. Weeds grow vigorously and compete for resources. The crop weed competition varies with the type of rice culture, variety, cultural practices, like plant density, fertilizer, application, land preparation, time and method of planting, water management etc. Weeds can reduce rice yield varying from 20 to 80 per cent if not controlled even at early stage. However, crop damage is depending upon the intensity of weeds and cultural practices adopted by the farmers. portulacastrum.

B.       Variety of Weeds on Paddy Field

The weeds on paddy field have so much variety, based on morphological characteristic weeds divided into three group there are grass weed, sedges weed and broad leave weeds. About 70 species grasses wedd, 50 species sedges weeds and 20 species broad leave weeds. However just 12 species may be considered as economically important in paddy field in Asia there are Cyperus iria , Cyperus diformis, Echinocloa colona, Echinocloa crus-galli, Eclipta prostata, Fimbrystilis miliacea, Ichaemum rugosum, Leptochloa sinensis, Ludwigia hyssopifolia, Schoenopletus juncoides, Shenoclea zeylanica (IRRI 2014).

1.              Cyperus iria

A tufted annual herb, or occasionally perennial, with fibrous roots, 15-75 yellowish red roots; 10-70cm tall.The Stem: sharply 3 angled, tufted, smooth, 5-80cm high.Leaf: basal, rough to touch in upper part, linear, flaccid, with gradually tapering point and 3-8mm wide; sheath reddish or purplish brown, enveloping the stem at base.Inflorescence: simple or compound umbel composed of numerous erect-spreading 3-10mmlong flattened spikelets.Fruit: three-angled, 1.0-1.5mm nut with slightly concave sides, and shiny dark brown to black.

Pict. 1 Cyperusiria is a tufted weed with a yellowish

brown to greenish crowded inflorescence

This weeds can produce 3,000—5,000 seeds per plant, seedlings emerge immediately after rice is sown; flowers month later and can establish second generation in the same season. Flowers throughout the year.Cyperus rotundus with Cyperus iria can reduce grain yield by 51% because this weeds uptake nitrogen more than paddy (Surajit 1981).

2.      Cyperus diformis

Cyperus diformis or commonly called as Small flower umbrella plantAnnual, fibrous and reddish roots; up to 100cm tall.Stem: tufted, smooth and erect, triangular and 2-3mm thick; slightly winged.Leaf: three to 4 basal leaves; sheaths united at base, lower ones straw-colored to brown; blades flaccid and linear, 15-45 cmlong.Inflorescence: umbellate and subtended by two leaf-like bracts; rays 15-cmlong, some with long peduncle, some without stalk; spikelets numerous, crowded in masses about 2-5mmlong, each spikelet composed of 10-30 flowers.Fruit: brownish nut, elliptical to slightly obovate, about 0.6mmlong and lightly pitted.

Pict. 2 Inflorescensce of Cyperus diformis

Grows well in flooded or moist fertile soils and common in lowland rice. Also found on poorer sandy or clay soils in fallow lands but cannot tolerate deep flooding. Has a short life span; propagates by seeds and produces seeds throughout the year. Produces large quantities of seed and can complete life cycle in about 30 days. A dominant weed in direct-seeded rice when it occurs in high plant densities; forms dense mats of vegetation in the young crop and can cause rice yield losses of 12-50%.Alternate host of Xanthomonascampestris (Kern 1974).

3.      Echinochloacolona

A tufted annual grass, up to 60—cm tall.Stem: reddish purple or green, ascending to erect, without hairs.Leaf: linear, 10-15cmlong,basal portion often tinged with red;liguleabsent.Inflorescence: simple, ascending racemes, green to purple, about 5-15cmlong; spikeletssubsessile 1-3mmlong.

	Pict 3. Echinochloacolona closely "mimics" rice and can be a severe competitor (IRRI).

 

Echinochloacolona flowers throughout the year and is propagated by seeds. Seeds have a short dormancy period.Can be present in large numbers and responsive to nutrients. Prefers moist but unflooded conditions and is a problem mainly in upland and rainfed lowland rice fields rather than in flooded fields.It closely "mimics" rice in the vegetative growth stage and is a severe competitor of rice.It is a host of diseases such as tungro and rice yellow dwarf. It can be used as a palatable fodder for milking animals and water buffalo (Galinato 1999).

4.      Echinochloa crus-galli

Annual, erect, tufted or reclining at base; up to 200cm tall.Stem: culms rooting at lower nodes, cylindrical, without hairs, and filled with white spongy pith.Leaf:linear with a broad round base and narrow top; blade 10-40cmlong; ligule absent.Inflorescence: loose green to purplish, 10—25—cm—long comprising compound racemes; spikelets more or less elliptical and pointed, usually slightly hairy; awns, if present, green to purplish, 2—5—mm—long.

Pict 4. Echinochloa crus-galli has loose green to purplish inflorescence (IRRI).

Propagates by seed. Flowers throughout the year and can produce seeds within 60 days.Echinochloa crus-galli prefers moist to wet land; easily grows in direct-seeded rice fields and wastelands. It is a common weed in swamps and aquatic places. 

A serious weed of lowland rice due to its rapid growth, competitive ability, and capacity to multiply rapidly. The young shoots are eaten in Java and it is used for reclaiming saline lands in Egypt. Serves as feed for animals in grasslands and wastelands (Holm et al. 1977).

5.      Eclipta prostrate

A prostrate or reclining to erect, often branched, annual or perennial herb, 30-100cm tall.Stem: cylindrical, green or purplish, rooting at basal nodes, and often covered with long white hairs.Leaf: oblong to lance-shaped, opposite, sessile or short-stalked, with more or less coarse hairs; margins entire or slightly toothed, up to 2-16cmlong.Inflorescence: terminal and axillary, about 1cm across, white or cream, on peduncles to 7-cm long.Fruit: achene, densely warted, either brown or black, 2-3mm—long.

Pict 5. Ecliptaprostrata is a prostrate or reclining to erect herb with white or cream inflorescence (IRRI).

Widespread and adapted to a range of environments. Found in poorly drained wet areas, saline conditions, along streams, in drains and canals of irrigated lowland rice paddies, in waste areas, and in upland fields.A single plant can produce as many as 17,000 seeds; germination affected by light, moisture level, pH, and temperature, but seeds have no dormancy.A common weed of rainfed lowland rice in the Philippines, Indonesia, and India, and other crops, including sugarcane, flax, taro, papaya, banana, soybean, vegetables, and cotton.Ecliptaprostrata is an alternate host of root-knot nematodes (Meloidogyne spp.). 

6.      Fimbristylismiliacea

Annual or perennial, without hairs, strongly tillering, with fibrous roots and up to 80-90cm high.Stem: slender, erect, densely tufted, compressed, and smooth; strongly angled at the top and flattened at the base; 20-70 cm tall.Leaf: stiff and thread-like; on flowerless stems: in 2 rows and with flattened sheaths; no prominent midribs; on flowering stems: only linear leaf sheaths; basal leaves have overlapping leaf sheaths; ligule absent.Inflorescence: 6-10 cmlong, compound umbel with 6-50 spikelets; spikelets reddish brown, 2-4mmlong and either round or acute at apex.Fruit: straw-colored or pale ivory nut, 0.2-0.3mmlong.

Pict 6. Fimbristylismiliacea is a slender tufted herb with compound reddish brown inflorescence (IRRI).

Propagates by seeds; flowers year-round and produces 10,000 seeds per plant; seeds can germinate immediately after reaching maturity.In rice fields, seedlings appear soon after rice is sown; flowers in about 1 month and capable of producing a second generation in the same season. Germinates where flood water is shallow or absent and seedlings may emerge throughout the entire growing period of rice. A serious and widespread weed of rice.An alternate host of diseases Rhizoctoniasolani, Thanatephoruscucumeris, and Xanthomonascampestrispv. oryzae, insects Creatonotusgangis Linnaeus, Leptocorisaacuta (Thunberg), and Mythimnaseparata (Walker), and nematodes Hirschmanniella sp. and Meloidogyne spp. 

7.      IschaemumrugosumSalisb.

An erect or ascending annual or perennial; up to 100—cm tall.Stem: often purplish, usually has hairs at nodes, cylindrical.Leaf: blades 10—30—cm—long, glabrous or with scattered hairs on both surfaces; compressed sheaths rather loose and green or purplish, with hairs on margins; ligule membranous and fused with auricles.Inflorescence: paired terminal spikes that are often strongly pressed against one another, thus appearing like a single spike. At maturity, it separates into two spike-like racemes. Spikelets paired, one is sessile, the other pedicelled; sessile spikelet yellowish green, up to 6—mm—long, first glume prominently transversely wrinkled; awns spiral at base, dark colored. 

Pict 7.Ischaemumrugosum has paired terminal spikes (IRRI).

Propagates by seeds. Seeds do not germinate while submerged though, after emergence, they can grow easily under flooded conditions.Ischaemumrugosum is found in wet conditions, especially in direct-seeded rice fields.Ischaemumrugosum is a serious weed in lowland direct-seeded rice, where it emerges later than many weeds in the crop and is favored by shallow flooding.

Also an alternate host of Chaetocnemabasalis (Baly), Cicadulinabipunctata (Melichar), Hysteroneurasetariae (Thomas), Leptocorisaacuta (Thunberg), NisiacarolinensisFennah, Orseoliaoryzae (Wood-Mason), Pseudococcussaccharicola Takahashi, Sesamiainferens (Walker), and Tetraneuranigriabdominalis (Sasaki), and diseases caused by tungro virus. It is also a host of the nematode Meloidogynesp.(Catindig 1995)

8.      Leptochloachinensis

A tufted and smooth annual or perennial; up to 120—cm tall.Stem: slender, hollow, erect or ascending from a branching base, rooting at lower nodes, smooth and without hair, typically 10-20 nodes, and can reach as high as 50-100cm.Leaf: smooth, linear, 10-30cmlong; ligule an inconspicuous membrane 1-2mmlong and deeply divided into hairlikesegments.Inflorescence: narrowly ovate, loose panicle, main axis 10-40cmlong, and with many spike-like slender branches; racemes slender, each with two rows of spikelets, spikelets 2-3.2mmlong, purplish or green and 4-6 flowered.

Pict 8. Leptocholachinensis has a slender stem and loose inflorescence

Propagates by seeds or vegetatively by rootstocks. Germination does not occur when seeds are submerged in water.

Leptocholachinensis is a serious weed of rice. Its ability to withstand waterlogged conditions as well as drained, moist conditions makes it a problem weed in rice. It is an alternate host of diseases caused by Ephelisoryzae, Pyriculariaoryzae, and Rhizoctoniasolani.

9.      Ludwigiahyssopifolia

An erect annual herb, 15-150cm tall and minutely hairy during early stage of growth.Stem: often 3 to 4 angled, green or purplish, and with white spongy pneumatophores arising from submerged roots.Leaf: lance-shaped, petioled, and up to 9cmlong.Inflorescence: solitary flowers, borne at axils of leaves; 4 yellow petals, elliptic, up to 3mmlong.Fruit: finely hairy, almost cylindrical, 1.75-2.5cmlong capsule.

Pict 9. Ludwigiahyssopifoliais an erect herb with yellow flowers (IRRI).

Widespread, growing in wet places, shallow pools and ditches, margins of canals and in lowland rice fields.Can produce approximately 250,000 seeds per plant; seeds released gradually and they remain floating in water up to 16 days before they sink. Seeds do not germinate under submerged conditions or when buried in soil. Seeds germinate in temperatures of 10—40º C.Can be a serious rice weed on both clay-loam and clay soils; in lowland rice fields.

10.  Schoenoplectusjuncoides

Found in lowland rice, shallow ponds, streams, and drains.Emerges directly from seeds in puddled rice fields; in swampy areas where tillage is minimal, seedlings emerge from vegetative buds. Seed germination increases under anaerobic conditions.In competition with rice, about 1,500 seeds are produced per plant.

Pict 10.Schoenoplectusjuncoides is a tufted erect herb with ovoid to oblong inflorescence (IRRI).

Can be a major weed in lowland rice fields.( Azmi 1993).

11.  Sphenocleazeylanica

An erect, branched herb, 7-150cm tall.Leaf: simple and spirally arranged light green; blades oblong to lance-shaped, narrowed at the tip, 10cmlong, borne on short stalks.Inflorescence: green, cylindrical, 7.5cmlong and dense terminal spike; flowers densely crowded, white to greenish, sessile.Close-up of inflorescence (IRRI).Fruit: a flat, 4-5mmdiameter globular capsule.Seed: yellowish brown, 0.5mmlong.

Pict 11. Sphenocleazeylanica is an erect branched herb (IRRI).

Reported to cause yield loss of 25—50% in rice. Young plants and tips of older plants are steamed and eaten as a vegetable in Indonesia (Moody 1989).

C.    Organic Weeds Control

1.      Land preparation

Land preparation is frequently overlooked as a method of weedcontrol. Typically, two tillage operationsare required to achieve a weed-free seedbed:

1)    Plowing

Incorporatesweeds into soil, often to a depth of 10 to 15 cm.

Pict 12. Plowing

2)    Harrowing

Early harrowing destroys weeds and encouragesweed seeds to germinate. Later harrowing destroys weeds that havegerminated since the previousharrowing. Greaternumbers of harrowing reduce seedstocks inthe soil and,consequently, reduces weedinfestations.

Pict 13. Harrowing

2.      Preventative weed control

It is easier to prevent the introduction orgermination ofweeds than to control them after they are already established. Seven possible methods of preventive weed control exist:

1.  Use “clean” seeds that have no weed seeds in them.

2.  Keep the riceseedling nursery freeof weeds and make sure weedsare not transplanted with seedlings.

3.  Keep bunds and irrigation canals freeof weeds.

4. Keep tools andmachinery clean so that seeds are nottransportedfrom field to field.

5.  Keep livestock out of rice fields.

6.  Prevent weeds in the areafrom producingseeds.

7. Prevent entryof water-carried vegetativepropagulesofweeds that are perennial.

3. Water management

Water management has always been aneffective and very important method ofcontrolling weeds  in rice. Many weeds cannotgerminate under flooded conditions. Proper leveling of paddies results in evendistribution of water duringearlyflooding, which is essential to effective herbicide application.

Pict 14. Water system

In general, weed densities decrease aswater depth increases. Even as little as 1 to 2 cm of waterreduces weeddensities. Continuous flooding usually results in abundant aquatic species but can be useful for controlling grasses and some sedges. Few weeds occur whena field is floodedto a depth of 15 cm.

4. Flooding

Flooding is effective only when the area issubmerged from time of planting until the crop forms a continuous canopy. If the water level drops within thisperiod, thenconditions become favorable for seedgermination or regrowth of some weed species.

5. Crop production Practices

1)      Planting method

Transplanting is primarily done for good weedcontrol. Planting seedlingsgives the crop a 14- to 21-daygrowth advantage over the weeds, andallows continuous floodingat greater depths. Plus, with rice in neat rows, hand weeding, or the use of mechanical weeders, is much simpler.

2)        Cultivars

cultivars may differ in how competitive they are against weeds. Cultivars with greaterseedling vigor, greater leaf areadevelopment, greaterearlyheight growthrates, and greatertillering ability are probably most competitive.

3)        Plant density

the closerthe plants aresown, the more competitive they are against weeds. Greater plant densities may allow the crop canopy to closesooner, reducing weedgermination and growth.

4)      Time of fertilizer application

weeds also require nutrients, and application of nitrogen and phosphorous stimulatesweed growth. In unweeded plots, weedgrowth increases asnitrogen levelincreases, resulting in yield reductions.Fertilizers should be applied when theyare mostbeneficial to the crop, not when they would increase weedcompetition. Early to mid-seasonapplication ofnitrogen often benefits the rice crop, but if weeds are present, then weed competition may also increase. Therefore, weeds should be controlled before nitrogen application.

6. Controlling Weeds - Direct Method

1) Hand weeding

Handweedingis most useful on annual weeds and certain perennial weeds thatusually do not regenerate from underground parts. It is a practical method of removing weeds within rows and hills where a cultivating implement cannot be used, but requires more labor thanother direct weedcontrol methods. Handweedingof young weeds at the two-leaf to three-leaf growthstages is extremely difficult. Therefore, hand weeding isgenerally delayed until weeds are large enough to be grasped easily.

III.             CONCLUSION

After we learn about Weed in Paddy Field , there are some conclusion :

1.                  Paddy is very important comodities because rice is global staple food and paddy is very big business.

2.                  Control of weed are so important to maintain the quality and quantity of paddy field. Control of weed is for prevent yield losses.

3.                  There are so many weed in Paddy cultivation but classified into three group based on Morphology there are grass, sedges and broad leave weeds.

4.                                     The main weeds for paddy is Cyperus iria , Cyperus diformis, Echinocloa colona, Echinocloa crus-galli, Eclipta prostata, Fimbrystilis miliacea, Ichaemum rugosum, Leptochloa sinensis, Ludwigia hyssopifolia, Schoenopletus juncoides, Shenoclea zeylanica .

5.                  Control of weed have so many way  there are indiret metod with  Land Preparation , water management, flooding and crop  production practices and direct method like hand weeding , mechanical weeding.

BIBLIOGRAPHY

Azmi M, Bakar B, Mansor M. 1993. Weed communities in principal rice-growing areas in penisular Malaysia. MARDI Report 165:1-16.

Caton BP, Mortimer M, Hill JE. 2004. Weeds of rice in Asia. Los Baños (Philippines): International Rice Research Institute. 116 p.

Holm LG, Plucknett DL, Pancho JV, Herberger JP. 1977. The world's worst weeds: distribution and biology. Honolulu Hawaii (USA): The University of Hawaii Press. 609 p.

Galinato MI, Moody K, Piggin CM. 1999. Upland rice weeds of South and Southeast Asia. Manila (Philippines): International Rice Research Institute. 156 p.

Kern JH. 1974. Cyperaceae. Flora Malesiana Ser. 1 7(3): 435-753.

Moody K. 1981.Major weeds of rice in South and Southeast Asia. Manila (Philippines): International Rice Research Institute. 79 p.

Moody K. 1989. Weeds reported in rice in South and Southeast Asia. Manila (Philippines): International Rice Research Institute. 442 p.

Moody K, Munroe CE, Lubigan RT, Paller Jr. EC. 1984. Major weeds of the Philippines. Weed Science Society of the Philippines. College Laguna (Philippines): University of the Philippines at Los Baños 328 p.

Pancho JV, Obien SR. 1995. Manual of ricefield weeds in the Philippines. Muñoz, Nueva Ecija (Philippines): Philippine Rice Research Institute. 543 p.