Effect of Compaction of Soil Effect of Compaction of Soil Surface to Increase Herbicide Surface to Increase Herbicide

Effect in Upland Rice CultivationEffect in Upland Rice CultivationByBy

THAN TOETHAN TOE

DEPUTY SUPERVISORDEPUTY SUPERVISOR

MYANMAR AGRICULTURE SERVICEMYANMAR AGRICULTURE SERVICE

&&

MOHAMMED TAMIZ UDDIN KHANMOHAMMED TAMIZ UDDIN KHAN

AGRICULTURE EXTENSION AGRICULTURE EXTENSION OFFICEROFFICER

BANGLADISHBANGLADISH

IntroductionIntroduction

Weed infestation could be severe in upland rice cultivation and as a result yields may be drastically reduced. Weeds compete with rice plants for nutrition, sunshine and water. And causes serious loss of yield. Weeds also act as an alternate host to many pathogens and insects. Weeds are therefore a major constraint to upland rice cultivation. (Nemoto, 2000) ThereFore controlling weeds is important and this could be done in an economically good way.

MATERIALS AND METHODSMATERIALS AND METHODS

This experiment was set up at the upland field This experiment was set up at the upland field of TBIC. Period of experiment was from 20of TBIC. Period of experiment was from 20 thth April April to 23to 23rdrd July. The variety tested was July. The variety tested was YomenohatamochiYomenohatamochi

Four treatments were established in this experiment. Four treatments were established in this experiment. (Tab.2)(Tab.2)

Tab.2 Treatments: Tab.2 Treatments:  

T-1 No compaction + no herbicide T-1 No compaction + no herbicide -C-H-C-H

T-2T-2 Compaction + no herbicide Compaction + no herbicide +C-H+C-H

T-3T-3 No compaction + herbicideNo compaction + herbicide -C+H-C+H

T-4T-4 Compaction + herbicideCompaction + herbicide +C+H+C+H

Field LayoutField Layout

Randomized block Design with 4 treatments and 2 replications.

Two area of 15x14m each were demarcated as block 1 & Block 2 Respectively.

Each block was made up of four plots measuring 12m2, which had five lines each.

Block 1was covered by net and block 2 was not covered.

Land PreparationLand Preparation

Ploughing and harrowing was completed by the middle of April.

After ploughing and harrowing dig a ditch which has 10 cm depth, alongside the cord by hoe.

Seeding preparationSeeding preparation

Seed selection was by a winnower machine.

the seeds were disinfected with `Benlate – T (Benomial + Thiram) at the rate of 1kg of the chemical to 100kg of seed.

Disinfection was done on the 20th of April.

Fertilizer applicationFertilizer application

N:P:K(50:!00:100) fertilizer was applied on the ditch uniformly as basal at the time of sowing by side dressing method.

Cover the soil on the fertilizer and level. Press the soil by foot on the ditch.

Fertilizer Application was done on the 20th of April. Sulphate of Ammonia, Super phosphate and Potassium chloride were calculated separately,mixed and applied.

Method of sowingMethod of sowing

Direct hill sowing was employed & sow seeds along the trace uniformly.

Seed rate was 50kg per hectare (5g/m2); thus 36gramms per plot of 7.2m2, equivalent of 1290 seeds.

The distance between lines (ridge width) was 60 cm apart and sowing was done on the 20th of April.

CompactionCompaction

After sowing, cover the soil on the seeds for again. Soil surface of T-2 and T-4 plots were compacted by land roller( Weight-22 x 2 Kg, Wide-29.4cm, Diameter-35.4cm ) attached to hand tractor.

Compaction was done on 20th of April.

Herbicide ApplicationHerbicide Application

Herbicide was applied on plots earmarked for herbicide application in the treatment plan.

Herbicide application rate was 4l/ha. Herbicide spray solution was prepared

by mixing 200 litres of the chemical to 100 litres of water per 500m2 and it was on 23rd of April.

Topdressing ApplicationTopdressing Application

Top dressing was applied at 5.8-leaf stage on 29th of May.

LP40 fertilizer was used at the rate of 40 N kg per hectare by side dressing method..

ObservationObservation

Plants establishment was investigated on the 17th of May (28 Days) at leaf age 3~4.

Dry matter weight of rice and weeds were taken and recorded on 4th of June (45Days), 18th of June (59Days), 2nd July (73Days) and 16th July (87Days).

Additionally rice plants suffered severely Additionally rice plants suffered severely from drought damage that eventually made from drought damage that eventually made them to wither away. ( Total precipitation them to wither away. ( Total precipitation recorded between the period of June 22recorded between the period of June 22ndnd ~ August 21~ August 21stst was only 30mm. ) However was only 30mm. ) However we didn’t irrigate between crop season we didn’t irrigate between crop season because we expected plants drought because we expected plants drought tolerance ability. Finally the rice plants tolerance ability. Finally the rice plants produced only white panicles produced only white panicles and therefore no further observations and therefore no further observations were done and so yield data was not were done and so yield data was not taken.taken.

ResultResultEstablishmentEstablishment

Establishment percentages recorded ranges between 11.5 % ~ 33.6 %. (Tab.3,4)

It was observed that seed emergence was three times higher on compacted plots.

Compaction plots showed seed emergence of 30.2%,33.6% while plots without compaction recorded 11.5%, 12.8%.

Tab.3. Percentage of Germinated seeds Tab.3. Percentage of Germinated seeds in 170 grains seeded/min 170 grains seeded/m22

Grains/mGrains/m22 % % -C-H-C-H T1T1 21.721.7 12.812.8+C-H+C-H T2T2 57.157.1 33.633.6-C+H-C+H T3T3 19.619.6 11.511.5+C+H+C+H T4T4 51.351.3 30.230.2

Tab. 4 Germination Percentage on Tab. 4 Germination Percentage on

differend concept of plotsdifferend concept of plots

Avg

Without Compaction

12.8(T1) 11.5 (T3) 12.2

With Compaction

33.6(T2) 30.2(T4) 31.9

Without Herbicide

12.8(T1) 33.6(T2) 23.2

With Herbicide

11.5(T3) 30.2(T4) 20.9

WeightWeight

Tables 3&4 shows that compaction is effective to seed establishment.

It was also observed that combination of herbicide and compaction was not effective to weed control.

This was indicated by the dry matter weight per meter square of both rice and weeds taken throughout the growing period. (Tab.5)

Tab. 5 Dry Matter Weight (g/mTab. 5 Dry Matter Weight (g/m22) of ) of Rice plants and WeedsRice plants and Weeds

Days after Sowing

45 59 73 87

Rice -C-H 1.3 3.7 4.9 3.2

+C-H 4.7 13.7 16.1 13.5

-C+H 0.5 7.3 38.3 127.8

+C+H 6.8 40.0 103.3 251.2

Weed -C-H 46.3 199.0 479.4 658.1

+C-H 70.2 233.9 500.7 782.5

-C+H 0.1 7.0 15.8 358.5

+C+H 0.4 17.7 64.7 204.9

Tab. 4 Germination Percentage on Tab. 4 Germination Percentage on

differend concept of plotsdifferend concept of plots

Avg

Without Compaction

12.8(T1) 11.5 (T3) 12.2

With Compaction

33.6(T2) 30.2(T4) 31.9

Without Herbicide

12.8(T1) 33.6(T2) 23.2

With Herbicide

11.5(T3) 30.2(T4) 20.9

DiscussionDiscussion

In table 3,4 the number of seeds that germinated was highest in T-2 and T-4.T-1 and T-3 followed in that order. This table shows that where compaction was applied the effect was good but was better where it was without herbicide. T-1, which was without herbicide achieved higher germination than T-3.

Plots with compaction plus herbicide, it could Plots with compaction plus herbicide, it could be seen that rice growth in terms of dry matter be seen that rice growth in terms of dry matter weight/mweight/m22 was higher than that of weeds. (Tab.5) was higher than that of weeds. (Tab.5) It possible for the rice to grow faster. With It possible for the rice to grow faster. With compaction plus herbicide application was compaction plus herbicide application was effective throughout the growing period but effective throughout the growing period but without compaction plus herbicide was only without compaction plus herbicide was only effective at the initial stages of growth. (0~73 effective at the initial stages of growth. (0~73 DAS) At later stages (87 days and beyond), the DAS) At later stages (87 days and beyond), the weeds were able to compete favourably with the weeds were able to compete favourably with the rice and over shadowed it. In other situation dry rice and over shadowed it. In other situation dry matter weight of weeds were higher than that of matter weight of weeds were higher than that of rice.rice.

ConclusionConclusion

In term of germination, compaction is very effective whiles herbicide application could reduce germination.

Compaction is absolutely effective for germination in upland rice cultivation whereas herbicide applied before germination and establishment may reduce the emergence rate.

Herbicide in upland rice cultivation should be applied after seedling emergence and establishment between 10-14 days after sowing.