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Introduction Bangladesh is an agriculture based country. Agriculture has a great

contribution to the Gross Domestic Product (GDP) of the country. The land

of Bangladesh by birth possesses very fertile in which diversified crops grow

easily. Various types of crops are produced in this country. These crops might

have been categorized into two types such as Food crops and Cash crops. Rice

is the staple food of the people of Bangladesh. There are three types of paddy

namely Aus, Aman and Boro,.(BRRI 2003).

Bangladesh is the 4th largest country in the world with respect to rice area and

production (FAO, 2013). The net cultivable area at present in about 8.50 M

ha and net cultivated area is 7.45 million ha (BBS, 2012). Rice is the staple

food for her people and will continue to remain so in the future. It grows in

all the three crop growing seasons of the year and occupies about 77% (11.42

M ha) of the total cropped area of about 14.94 M ha. At present, rice along

constitutes about 93% of the total food grains produced annually in the

country (BER, 2013). It provides about 62% of the calorie and 46% of the

protein in the average daily diet of the people (HIES, 2010). It also ensures

political stability for the country and provides a sense of food security to the

people.

The necessities of Zn HYV rice varieties are now significant in Bangladesh.

The life span of these HYV aman rice varieties (BRRI Dhan62, BRRI 72 etc.)

are shorter.However, these HYV varieties are capable of to eliminate the

malnutrition due to Zn deficiency (BRRI 2013).

Almost all of the 13 million farm families of the country grow rice. Rice is

grown on about 10.5 million hectares which has remained almost stable over

the past three decades. About 75% of the total cropped area and over 80% of

the total irrigated area is planted to rice. Thus, rice plays a vital role in the

livelihood of the people of Bangladesh.

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Total rice production in Bangladesh was about 10.59 million tons in the year

1971 when the country's population was only about 70.88 millions. However,

the country is now producing about 25.0 million tons to feed her 135 million

people. This indicates that the growth of rice production was much faster than

the growth of population. This increased rice production has been possible

largely due to the adoption of modern rice varieties on around 66% of the rice

land which contributes to about 73% of the country's total rice production.

Half of the global population consumes rice as staple food and poor people in

developing countries solely eat rice and they are rarely accessible to nutrient

rich food sources to supplement rice. In fact, rice is consumed in polished

form (white rice) and it constitutes starch as chief component followed by

proteins, lipids, minerals and negligible levels of vitamins and thus, rice

supplies more energy than essential nutrients leading to micronutrient

deficiency which is also known as “hidden hunger”. The recommended

dietary allowance (RDA) of iron and zinc for human population in the age

group of 25- 50 years are 10-15 and 12-15 mg respectively (FAO/WHO,

2000). In developing countries zinc, iron and vitamin A deficiencies were

reported in human population. Zinc, iron and vitamin-A are the three most

vital micronutrients, deficiency of which hampers children’s natural growth

and decrease their disease prevention capacity. In Bangladesh, over 40 percent

children under five are stunted while an estimated 44 percent children of the

same age group are at risk of zinc deficiency. Each kilogram of rice of BRRI

dhan-62 contained 19 mg of zinc and 9 percent of protein which will ensure

high nutrition and will play a significant role in prevention of diseases; Zinc

also played a vital role in prevention of liver-related diseases. BRRI dhan-62

can be harvested within 105 days. Of the rice varieties of Aman season, BRRI

dhan-62 can be cultivated within a short period. The yield of BRRI dhan-62

is 4.2 tons per hectare of land. The size of rice is medium. The zincenriched

rice variety also outpaced two of the country’s best performing Aman season

early-mature varieties: Bina dhan- 7 and Brri dhan- 33. Crop duration from

seed to seed is 110-120 days for Bina dhan- 7 and Brri dhan- 33 while Brri

dhan- 62 can be reaped in 100 to 105 days.

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Objectives of the Study

Therefore, this study will be carried out with the following objectives:

To observe the response of Zinc on yield and quality of some aman rice

varieties in Patuakhali region.

To evaluate the grainsZn content of the different modern varieties of

aman rice (BRRI dhan 39, BRRI dhan 62, BRRIdhan72,Binadhan 7) in

Patuakhali region.

To find out the interaction effect of different doses of Zinc fertilization

yield and quality of rice in Patuakhali region.

Literature Review Sriramachandrasekharan and Mathan (1988) conducted a field experiment to study

the influence of zinc sources on the growth characters viz., plant height, number of

tillers/hill and root characters. Application of zinc increased plant height, number of

tillers, root length root volume and root weight and root length density. Application

of zincated urea alone or in combination with zincated suphala were on par in regard

to character studied.

Maji and Bandyopadhyay (1990) studied the response of rice to zinc in coastal saline

soils. They used two levels of zinc (6.8 and 13.6 kg/ha) and reported that a

decreasing trend in dry matter was observed with higher doses of zinc.

Gill and Hardeep (1978) reported that application of zinc sulphate at 20 kg/ha

increased the productive tillers, panicle lengths and number of grains per panicle in

rice. Whereas, Patel (1979) observed that application of 0-25 kg ZnSO4/ha increased

1000 grain weight, number of effective tillers per plant, fertile spikelets per panicle

and panicle lengths.Uddin et al. (1981) found that with increase in the levels of

ZnSO4 application number of effective tillers, plant height, panicle length, number

of grains per panicle and 1000 grain weight was increased. Saravanan and

Ramanathan (1986) reported that 25 kg ZnSO4/ha is the optimum rate for rice grown

on Cauvery delta clay loam soils.

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Ilangovan and Palaniappan (1987) reported that soil application of six per cent Zn-

DAP enhanced the grain yield significantly over no Zn (control). Four, five and six

per cent Zn-DAP recorded higher yield over soil application of ZnSO4 @ 25 kg/ha,

foliar application of ZnSO4 @ 0.5 per cent sprayed on 30 and 45 days after planting

and seedling root dipping in two per cent ZnO suspension.

Ingle et al. (1997) reported that application of 15 kg Zn/ha through zinc sulphate

with N, P, K (100:50:50) fertilizers gave the highest grain and straw yields of paddy

and was found significantly superior over control and other treatments.

Kumar et al. (1998) studied the effect of Zn application on yield attributing

characters and yield of rice. Application of 25 kg ZnSO4/ha in transplanted field or

spraying standing crop with 0.5 per cent ZnSO4 solution three weeks after

transplanting or dipping seedling roots in 2 per cent ZnO suspension were equally

effective in correcting zinc deficiency. Zinc application in transplanted field in

general improved yield attributes like number of panicles, test weight, panicle length

and fertile spikelets significantly.

Kaur et al. (1985) opined that zinc concentration in all the plant parts increased up

to 30 days after transplanting and decreases thereafter with rate of decrease being

much faster from 30 to 45 days than from 45 to 60 days.

Saravanan and Ramanathan (1988) conducted a field experiment with seven levels

of ZnSO4 (0, 12.5, 25.0, 37.5, 50.0, 62.5 and 75 kg/ha) to study the effect of zinc

application on its availability and yield of rice. They observed that the uptake of Zn

by rice increased with the increased level of Zn application. Similar observations

were made by Ingle et al. (1997).

Kumar and Singh (1979) conducted a field experiment to study the effect of different

doses and methods of zinc application on zinc status of rice plants. Maximum zinc

content under all the treatments was observed at active tillering stage. With

advancement in age, the zinc concentration in plant declined. Zinc application in

nursery gave maximum concentration of zinc in the treatment of root dipping in ZnO

suspension irrespective of zinc application in transplanted field at all the stages.

Under transplanted condition, the similar trends were observed with little variations.

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Discussion

Methodology

Experimental site:

The experiment will be conducted at the Field Laboratory of the Department of

Agronomy, Patuakhali Science and Technology University, Dumki, Patuakhali.

Season:

The experiment will be conducted during July to November, 2016

Experimental material:

Treatment:

Factor-A: Different Zn doses (Without Zn, 1 Kg, 2Kg, and 3Kg)

Factor-B: Varieties:

1) BRRI dhan39 2) BRRI dhan62

3) BRRI dhan72

4) Binadhan-7

Replication: 3

Plot no.4×4×3=48

The Experiment were conducted at PATUAKHALI SCIENCE AND TECHNOLOGY

UNIVERSITY farm, Dumki, Patuakhali under the ecological zone of Ganges tidal

floodplain, AEZ-13 during Kharif season, July to November of 2016 to examine the

Performance of Variety and Zinc level on the yield of different Rice varieties on the

Coastal region of Bangladesh. The unit plot size will be 4m×2.5m = 10m2 . The land will be

ploughed with a rotary plough and power tiller for four times. Ploughed soil willbe then brought

into desirable fine tilth and leveled by laddering. The weeds will be cleaned properly. The final

ploughing and land preparation will be done on 3 July, 2016. In this experiment manures and

fertilizers will be used according to BARI. Sowing will be done on 5 July, 2016 in rows 30 cm

apart. Seeds will be sown continuously in rows at a rate of 8 kg/ha. The optimum plant population,

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60 plants/ m2will be maintained by thinning excess plant at 15 DAS. The plant to

plant distance will be maintained as 5 cm. No. of seedling/hill 3; spacing 20×20. One

weeding with khurpi will be given on 25 DAS. Different intercultural operations and

protection measures will be done when necessary

Seedbed Preparation and seed soaking:

Seedbed preparation was done 26 June, 2016. The Length and wide for

the seedbed were maintained respectively 45m, 1.5m . Seed soaking was

done 23 June, and seed sowing Date 27 June, 2016. Seed rate of rice 40

kg/ha. Germination Percentage of BRRI dhan39, 62 , 72 and BINA Dhan

7 were almost 90%.

Fig: Seed Germination and seed soaking

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Land preparation and Transplanting of Rice:

Land preparation is important to ensure that the rice field is ready for planting. A

well-prepared field controls weeds, recycles plant nutrients, and provides a soft soil

mass for transplanting and a suitable soil surface for direct seeding. Land

preparation covers a wide range of practices from zero-tillage or minimum tillage

which minimizes soil disturbance through to a totally 'puddled' soil which actually

destroys soil structure. 15-16 July, 2016 Land was prepared for rice transplanting.

27m

.5m

2.5

Fig: Land Layout in RCBD Experimental Design

Here, after 4 ploughing , the whole land is prepared with above Randomized

Complete Block Design along with three replication .

R1

V1T1 V4T1

V2T2 V3T3

V4T3 V1T3

V4T4 V2T4

V3T4 V2T1

V4T2 V1T2

V2T3 V3T2

V1T4 V3T1

R3

V1T4 V4T2

V2T4 V3T3

V4T4 V1T3

V4T1 V2T2

V3T2 V2T1

V4T3 V1T1

V2T3 V3T4

V1T2 V3T1

R2

V1T3 V4T4

V2T1 V3T1

V4T1 V1T2

V4T2 V2T2

V3T2 V2T4

V4T3 V1T1

V2T3 V3T4

V1T4 V3T3

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Ligand:

Treatment

A. Variety

V1= BRRI dhan39

V2= BRRI dhan62

V3= BRRI dhan72

V4= Binadhan-7

B. Zinc Fertilizer

T1 =0 kg/ha

T2=1 kg/ha

T3=2 kg/ha

T4=3 kg/ha

C. Replication

R1=Replication 1

R2=Replication 2

R3=Replication 3

Now,

Plot Size =10 m2 (4m×2.5m)

Drainage = 50cm

Total Width:

(2.5m×8)+(.5m×2)+(.4m×7)=20m+1m+2.4m

=23.8m ≤24m

Total Length:

(4m×6)+(.4m×5)+(.5m×2)

=24m+2m+1m=27m

Plot to Plot distance = 40cm =0.4m

Total Plot =48

Plant to Plant Distance = 20cm

Row to Row Distance = 20 cm

Replication to Replication = 50cm =0.50m

Experimental Type = RCBD

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In 17 July, 2016 at the seedling age 20 days, transplanting is done with plant to

plant distance 20 cm , along with row to row distance 20 cm .

Fig : Transplanting of seedling of rice at the ages of 20 days

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Intercultural Operation:

Fertilizer Application:

Essential fertilizer with recommended dozes was applied during Final Land

preparation. However, organic matter was applied through decomposition of

manure, organic waste and other natural resources.

Amount of Fertilizer during land preparation was.

TSP = 6.4 kg

Gypsum = 5.6 kg

Mop = 3.2 kg

Urea fertilizer was applied through basal doses at 15 DAT .

Urea= 10 kg .

Zinc Fertilizer has been applied according to the treatment before flowering,

Heading and finally after flowering through foliar application .

Fig: Foliar application of zinc fertilizer

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Irrigation/Water Management:

Rice is typically grown in bunded fields that are continuously flooded up to 7−10

days before harvest. Continuous flooding helps ensure sufficient water and control

weeds. Lowland rice requires a lot of water.

On average, it takes 1,432 liters of water to produce 1 kg of rice in an irrigated

lowland production system. Total seasonal water input to rice fields varies from as

little as 400 mm in heavy clay soils with shallow groundwater tables to more than

2000 mm in coarse-textured (sandy or loamy) soils with deep groundwater tables.

Around 1300−1500 mm is a typical amount of water needed for irrigated rice in

Asia. Irrigated rice receives an estimated 34−43% of the total world’s irrigation

water, or about 24−30% of the entire world’s developed fresh water resources.

Worldwide, water for agriculture is becoming increasingly scarce. Due to its semi-

aquatic ancestry, rice is extremely sensitive to water shortages.

To effectively and efficiently use water and maximize rice yields, the following good

water management practices can be done:

Fig : Water management in rice field

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Weed Management:

Weeds are the cause of serious yield reduction problems in rice production

worldwide. Losses caused by weeds vary from one country to another, depending

on the predominant weed flora and on the control methods practised by farmers. Two

examples give an idea of the dimensions of the problem. In China, 10 million tonnes

(Mt) of rice are lost annually due to weed competition (Ze Pu Zhang, 2001); such a

quantity of rice is sufficient to feed at least 56 million people for 1 year. In Sri Lanka,

a country considered self-sufficient in rice, weeds are the major biotic stress in rice

production and account for 30 to 40 percent of yield losses (Abeysekera, 2001).

Weed control in overpopulated areas of Asia has mainly been carried out through a

combination of water management and hand-weeding, but the latter is becoming less

common in areas with an increasing labour shortage problem; furthermore, this

method affects transplanting. For these reasons, many farmers in several regions of

the world, including Asia, have shifted from transplanting to direct seeding rice; less

labour is required but herbicides must be used for weed control. Farmers are then

faced with no option other than the application of herbicides, despite their lack of

knowledge concerning the proper use of these chemicals.

Herbicide-based weed management is becoming the most popular method of weed

control in rice. However, while herbicide application certainly controls several

weeds, it does not eliminate others, thereby provoking a weed shift of tolerant

species. In some areas it is believed that herbicide use will solve all weed problems.

Experience shows, however, that although herbicide use alleviates the problem of

labour for weeding, incorrect use of herbicides may bring about other environmental

problems. The advent of herbicide-resistant species is an increasingly worrying

problem for farmers, extension workers and policy-makers in many rice-producing

areas in Asia and Latin America.

The only way to avoid these problems is the implementation of improved weed

control within the context of integrated pest management, with particular emphasis

on the weed ecobiology of the prevailing species. This is an important prerequisite

for achieving the expected yield growth in rice production and obtaining the

necessary reduction in weed stand, including weed seed bank.

Weed control is important to prevent losses in yield and production costs, and to

preserve good grain quality. Specifically, weeds

decrease yields by direct competition for sunlight, nutrients, and water

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increase production costs e.g., higher labor or input costs

reduce grain quality and price

For example, weed seeds in grain can cause the buyer price to be reduced.

Fig : Before And After weed Management

Pesticide and Fungicide Application:

The consumption of rice accounts for 1% to 18% of the daily consumption of

cereals (according to consumption data presented in Table 2 3). There is a

production of rice in southern EU. However, about two-thirds of the rice consumed

in the EU is imported. Most EU imports come from Thailand, India and Pakistan.

Some of the rice produced in the EU, in particular round or medium-grain japonica

rice, is exported . As mentioned earlier, the EU imports rice from countries outside

the EU. It is therefore of interest to gain knowledge on use patterns not only within

the EU but also from the countries exporting rice to the EU.

Fungicides prevent rice diseases which can result in severe damage to the crop in

terms of both quality and quantity. Globally 8.4 % of fungicides market share is for

rice (Collins, 2007). Synthesizing and characterizing a new molecule to be used as

fungicide involves several steps. Initially the new lead molecule is tested in-vitro for

its efficacy against the target pathogen and then it is characterized under field

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condition to ascertain its efficacy against the target disease and to finalize the most

effective dose/rate that can be used for the control of the target disease.

Benzimidazole [FRAC CODE – 1]: This group fungicide was introduced for plant

disease control in the 1960s and early 1970s as foliar fungicides, seed treatments and

for use in post-harvest applications. They possess unique properties not seen before

in the protectants. These included low use rates, broad spectrum and systemicity

with post-infection action that allowed for extended spray interval. All these

qualities made them very popular with growers but also subject to misuse, such as

poor spray coverage and curative spraying. These fungicides are single site inhibitors

of fungal microtubule assembly during mitosis, via tubulin-benzimidazole-

interactions (Smith, 1988). The current ranking of global sales is: carbendazim,

thiophanate, thiabendazole.

Data Collection:

1. Plant height(cm)

2. Leaf Area index(LAI)

3. Days to first flowering

4. Days to 50% flowering

5. Days to maturity

6. Number of total tillers per hill

7. Number of effective tillers per hill

8. Number of non-effective tillers per hill

9. Panicle length (cm)

10. Number of grains per panicle

11. Number of sterile spikelet’s per panicle

12. 1000 grain weight (g)

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13. Grain yield (t ha-1)

14. Straw yield (t ha-1)

15. Biological yield (t ha-1)

16. Harvest index(%)

17. Zinc-use efficiency

Conclusion:

Zn deficiency is a critical problem in flooded rice, causing rice grains with low Zn content

to contribute to human Zn deficiency (Impa and Johnson-Beebout, 2012). Water

management and Zn fertilization are important agricultural practices for rice plants, both

of which were proved through impacting soil conditions to affect Zn uptake by rice (Gao

et al., 2011; Impa and Johnson-Beebout, 2012). In order to obtain high grain yield and Zn

content in rice grain, optimization of Zn source fertilizer and water management should be

assessed.

Water-saving management was shown to be more effective in improving grain yield, Zn

concentration and accumulation in rice grain than CF conditions. Thus, AWD represents

not only a promising rice production system but also a strategy for Zn biofortification. Zn

fertilization significantly increased grain yield and Zn concentration, and maximum Zn

accumulation was observed with ZnSO4 fertilization under AWD. Moreover, Zn

fertilization reduced the phytic acid content and molar ratio of phytic acid to Zn in polished

rice, and consequentially enhanced the Zn bioavailability in the rice grain. According to

the current results, AWD regime combined with ZnSO4 fertilization was recommended in

rice production systems to obtain higher yield, Zn concentration and bioavailability in

grain. Our field data supported research conclusions from several greenhouse studies,

which showed that granular Zn Fertilizer source might influence the growth and

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Zn nutrition of the crop grown immediately following Zn fertilization. Zinc fertilizer

source affected early season rice growth and Zn nutrition, but not grain yield, only for the

rice crop grown immediately after fertilization. The residual benefits of Zn fertilization on

rice growth, Zn nutrition, and grain yield were not affected by Zn fertilizer source, but were

affected by Zn application rate. Apparently, the chemical reactions between Zn fertilizers

and soil are sufficiently complete by 1 yr after fertilization so that soil properties, rather

than fertilizer properties, control the residual Zn availability to plants, which can be

accounted for through soil testing. The selection of an appropriate Zn source is most critical

only for the crop to be grown the same year that Zn fertilizer is applied.

Field and greenhouse research studies are usually conducted on Zn-deficient soils, however

they may not always represent the most Zn-deficient soils or duplicate other environmental

(i.e., cool temperatures) and pest induced (i.e., inhibited root growth and root pruning)

stresses that can occur in commercial production fields. Thus, the fertilizer sources or

source and rate combinations that provide superior nutrient availability should be

recommended so that maximum crop growth and yield potential can be realized.

Reference:

SRIRAMACHANDRASEKHARAN, M.V. AND MATHAN, K.K., 1988,

Influence of Zinc sources of the yield components, dry matter production

and yield of rice (Var. IR-60). Madras Agricultural Journal, 75(5-6): 200-

203.

MAJI, B. AND BANDYOPADHYAY, B.K., 1990, Response of rice to soil

and foliar application of micronutrients in coastal saline soils of Sunderbans,

West Bengal. Journal of the Indian Society of Coastal Agricultural

Research, 8(1): 47-49.

GILL, R.S. AND HARDEEP, S., 1978, Effect of Zinc Sulphate on the grain

yield performanceof tall and dwarf varieties of rice. Indian Journal of

Agronomy, 23: 375-376.

UDDIN, M.J., BHUIYA, Z.H., HOQUE, M.S. AND RAHUMAN, L., 1981,

Effects of rates and methods of zinc application on rice. Madras

Agricultural Journal, 68(4): 211-216.

ILANGOVAN, R. AND PALANIAPPAN, S.P., 1987, Studies on the sources

and methods ofapplication of zinc to low land rice. Madras Agricultural

Journal, 74(10-11): 421-425.

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INGLE, S.N., BORKAR, D.K., CHAPHALE, S.D. AND THAKRE, S.K.,

1997, Effect of sources and levels of zinc on yield and nutrient uptake by rice.

Journal of Soils and Crops, 7(2): 157-159.

KUMAR, B., SINGH, S.B. AND SINGH, V.P., 1998, Effect of different

methods of zinc application on yield attributes and yield of rice. Journal of

Soils and Crops, 8(2): 112-115.

KAUR, N.P., NAYYAR, V.K. AND TAKKAR, P.N., 1985, Zinc

requirement of rice varieties of different growth stages. Indian Journal of

Agricultural Sciences, 55(7): 485-486.

SARAVANAN, A. AND RAMANATHAN, K.M., 1986, Response of

lowland rice to zinc fertilizer. International Rice Research Newsletter, 11(2):

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KUMAR, V.P. AND SINGH, G.B., 1979, Effect of different doses and

methods of zinc application on rice plant nutrition. Oryza, 16(2): 222-227.