Effect of Potassium Chlorate Effect of Potassium Chlorate Concentration on Flower Initiation of Concentration on Flower Initiation of

Longan (Longan (Dimocarpus longanDimocarpus longan Lour.) Lour.) in Soi Dao District, Chanthaburi. in Soi Dao District, Chanthaburi.

Benjaporn TangsukkasemsanBenjaporn TangsukkasemsanFaculty of Agricultural Technology,Faculty of Agricultural Technology,

Rambhai Barni Rajabhat University, Chanthaburi, Thailand.Rambhai Barni Rajabhat University, Chanthaburi, Thailand.

ChanthaburiChanthaburi

LocationLocation Eastern part of ThailandEastern part of Thailand 245 km from Bangkok245 km from Bangkok Area : 6,338 kmArea : 6,338 km22

IntroductionIntroduction

Longan (Dimocarpus longan Lour.) , cultivar “Daw”

an economic crop of Thailand Fresh eaten preserved: canning / dried canning / dried

ProductsProducts

longan require a period of cool longan require a period of cool and dry climatic conditions for and dry climatic conditions for induction of flowering induction of flowering

northern provinces i.e : Lumpun, northern provinces i.e : Lumpun, Chiang Mai and Chiang Rai. Chiang Mai and Chiang Rai.

longan growers have discovered longan growers have discovered an alternative method of floral an alternative method of floral induction in the absence of induction in the absence of suitable climatic conditions. suitable climatic conditions.

application of chlorate compound : application of chlorate compound : potassium chlorate or sodium potassium chlorate or sodium chloratechlorate

Chanthaburi

Plantation and YieldPlantation and Yield1996 -20071996 -2007

YearYear Planting Planting Area (acre)Area (acre) 

Harvested area Harvested area (acre)(acre) 

total Yield total Yield (ton)(ton)

Average Average yield/Acreyield/Acre  

1996 4,102 1,965 1,979 1007

1997 3,982 1,907 1,918 1005

1998 4,238 2,611 6,301 2412

1999 4,999 3,649 0 0

2000 5,648 4,294 19,047 4360

2001 8,062 4,294 19,273 4487

2002 11,058 5,460 27,051 4955

2003 12,620 6,930 34,813 5025

2004 19,378 9,948 49,782 5000

2005 32,462 20,724 104,467 5040

2006 33,130 21,813 103,798 4757

2007 33,462 26,789 129,867 4847

Suggestion rateSuggestion rate

Subhadrabandhu and Subhadrabandhu and Yapwattanaphun, (2000): Cultivar Yapwattanaphun, (2000): Cultivar 'Daw' requires 8 g/m² of potassium 'Daw' requires 8 g/m² of potassium chlorate as soil drench chlorate as soil drench

Somchai Ongprasert and Winai Somchai Ongprasert and Winai Wiriya-Alongkorn (2007) : 200 mg of Wiriya-Alongkorn (2007) : 200 mg of potassium chlorate per liter of potassium chlorate per liter of standard nutrient solution standard nutrient solution

C. Sritontip et. al. : soil drenched with C. Sritontip et. al. : soil drenched with KClOKClO33 at 5 g/m at 5 g/m-2 -2 of canopy of 4-5 year- old- of canopy of 4-5 year- old-

longan trees longan trees Mike A. Nagao and Elodie B. Ho-a. (2000) : Mike A. Nagao and Elodie B. Ho-a. (2000) :

application of 250 – 500 grams of KClOapplication of 250 – 500 grams of KClO33

around the canopy around the canopy Li XiangHong (2004) :130 g/mLi XiangHong (2004) :130 g/m2 2 seven-year-seven-year-

old trees of longan cultivars Chuliang and old trees of longan cultivars Chuliang and Shixia Shixia

Chanthaburi growers Chanthaburi growers practicepractice

soil drenchsoil drench 200 grams/tree for the 4-year- old- 200 grams/tree for the 4-year- old-

trees trees By the following years, the amount of By the following years, the amount of

potassium chlorate used was double. potassium chlorate used was double. Shortening longan tree lifeShortening longan tree life

The purposes of the study was to The purposes of the study was to determine the suitable amount of KClOdetermine the suitable amount of KClO33

which were able to initiate flower which were able to initiate flower buds buds

of 7- year- old - longan tree. of 7- year- old - longan tree.

Materials and Method Materials and Method

completely randomized design completely randomized design 6 treatments and 5 replications. 6 treatments and 5 replications. Treatment:Treatment: 200 gm /50 L water/tree 200 gm /50 L water/tree 400 gm/50 L water/tree 400 gm/50 L water/tree 600 gm/50 L water/tree 600 gm/50 L water/tree 800 gm/50 L water/tree 800 gm/50 L water/tree 1000 gm/50 L water/tree1000 gm/50 L water/tree 1000 gm/30 L water /tree (control) 1000 gm/30 L water /tree (control)

experimental unitsexperimental units

Thirty longan trees Thirty longan trees seven-year- oldseven-year- old Fifty healthy vegetative shoots/tree Fifty healthy vegetative shoots/tree The potassium chlorate was applied on The potassium chlorate was applied on

June 13, 2007. June 13, 2007.

Result :Result : Days flowering shoots observedDays flowering shoots observed

KCLOKCLO33 concentration concentration daysdays nsns

200 gm/ 50 l water/tree 200 gm/ 50 l water/tree 35.46 35.46

400 gm/ 50 l water/tree 400 gm/ 50 l water/tree 29.3529.35

600 gm/ 50 l water/tree600 gm/ 50 l water/tree 32.62 32.62

800 gm/ 50 l water/tree800 gm/ 50 l water/tree 37.25 37.25

1000 gm/ 50 l water/tree1000 gm/ 50 l water/tree 39.96 39.96

1000 gm/ 30 l water/tree1000 gm/ 30 l water/tree 33.83 33.83

Result :Result :

Percentage of flowering shootPercentage of flowering shoot KCLOKCLO33 concentration concentration flowering shootflowering shoot ( (%%))nsns

200 gm/ 50 l water/tree 200 gm/ 50 l water/tree 52.0052.00

400 gm/ 50 l water/tree 400 gm/ 50 l water/tree 53.2053.20

600 gm/ 50 l water/tree600 gm/ 50 l water/tree 72.8072.80

800 gm/ 50 l water/tree800 gm/ 50 l water/tree 54.8054.80

1000 gm/ 50 l water/tree1000 gm/ 50 l water/tree 48.4048.40

1000 gm/ 30 l water/tree1000 gm/ 30 l water/tree 69.2069.20

Yield of logan: Yield of logan: Mean indexMean index

KCLOKCLO33 concentration concentration Mean indexMean index

#1#1nsns #2#2 ns ns #3 #3 nsns #4#4 ns ns #5#5 ns ns

200 gm/ 50 l water/tree 200 gm/ 50 l water/tree 3.83.8 2.22.2 3.03.0 1.61.6 2.02.0

400 gm/ 50 l water/tree 400 gm/ 50 l water/tree 1.41.4 4.04.0 3.03.0 1.21.2 2.42.4

600 gm/ 50 l water/tree600 gm/ 50 l water/tree 2.62.6 2.22.2 3.83.8 1.41.4 2.22.2

800 gm/ 50 l water/tree800 gm/ 50 l water/tree 2.02.0 3.03.0 3.23.2 1.41.4 2.02.0

1000 gm/ 50 l water/tree1000 gm/ 50 l water/tree 2.82.8 1.41.4 4.24.2 1.61.6 2.02.0

1000 gm/ 30 l water/tree1000 gm/ 30 l water/tree 2.02.0 2.82.8 4.04.0 1.41.4 2.02.0

yield index 1 = noneyield index 1 = none

2 = yield 1-20 %2 = yield 1-20 %

3 = yield 21-40 %3 = yield 21-40 %

4 = yield 41-60 %4 = yield 41-60 %

5 = yield 61-80 %5 = yield 61-80 %

6 = yield 81-100 %6 = yield 81-100 %

Yield of logan: Yield of logan: mean weight per tree (kg)mean weight per tree (kg) KCLOKCLO33 concentration concentration Mean weight /tree (kg)Mean weight /tree (kg)

#1#1nsns #2#2 ns ns #3 #3 nsns #4#4 ns ns #5#5 ns ns totaltotal

200 gm/ 50 l water/tree 200 gm/ 50 l water/tree 25.8025.80 13.8413.84 12.7012.70 4.504.50 4.464.46 61.3061.30

400 gm/ 50 l water/tree 400 gm/ 50 l water/tree 4.764.76 43.5043.50 26.0426.04 3.203.20 3.323.32 80.8280.82

600 gm/ 50 l water/tree600 gm/ 50 l water/tree 15.0015.00 14.0214.02 26.2026.20 2.002.00 8.408.40 65.6265.62

800 gm/ 50 l water/tree800 gm/ 50 l water/tree 8.728.72 20.4020.40 21.0021.00 2.842.84 6.726.72 59.6859.68

1000 gm/ 50 l water/tree1000 gm/ 50 l water/tree 13.4413.44 3.083.08 31.2031.20 3.803.80 3.183.18 54.7054.70

1000 gm/ 30 l water/tree1000 gm/ 30 l water/tree 9.309.30 20.9020.90 35.1035.10 2.282.28 7.187.18 74.7674.76

conclusionconclusion

the average flower initiation period was the average flower initiation period was 29-40 days.29-40 days.

The application of 600 grams of The application of 600 grams of KClOKClO33/ 50 liters of water/tree give the / 50 liters of water/tree give the

highest percent of flowering shoot.highest percent of flowering shoot. Not only flower initiation period but also Not only flower initiation period but also

percent of flowering shoot were non-percent of flowering shoot were non-significant.significant.