Crop
Chemical/ Dosage
Chemical
Response
Rice
Kinetin, GA3 and Triacontanol (1000 ppm)
GA3
Grain filling and partitioning. Delayed senescence
Cotton
IAA, NAA (30 ppm), CCC (cycocel)
30 ppm
Increase grain yield Decrease boll shedding Increase photosynthetic rate and yield Increase number of bolls, boll weight and lint yield
Sunflower
Benzyl adenine (BA) (250 ppm) GA+BA(150ppm)
Increase yield and Achenes weight and number
Groundnut
Mepiquat chloride (125 ppm) (2,3,4-D-chlorophynoxy triethyl amine)
25 ppm
Increased grain yield and chlorophyll synthesis and decrease chlorophyllase activity Stimulation of assimilate transport in germination
Sugarcane
Ethephon Glyphosine
Reduced growth rate and regulate ripening
Tapioca
Ethrel (250 ppm) CCC (1000 ppm)
Ethrel
Early tuberisation Increase the weight of storage roots
Pigeonpea
Ethrel (40 ppm) and GA3 (20 ppm) CCC(0.64 mM)
Increase grain yield Respond well for RWC, chlorophyll and stomatal conductance
Carrot and Potato
GA3 (50 ppm)
Induction of flowering in long day and seed setting
PLANT GROWTH REGULATORS IN RIPENING OF FRUITS
| Crop | Chemical | Dose | Response |
| Mango | Ethephon | 1000 ppm | Accelerated fruit ripening and improves surface colour |
| Citrus | Ethrel | 1000 ppm | Induce yellow colour with in seven days |
| Banana | Ethrel | 1000 ppm | Accelerated ripening by two days |
| Papaya | Ethephon + NaOH | 2000 ppm | Ripening within 24 hours |
| Sapota | Ethephon + NaOH | 500 ppm | Ripening within two days |
Dose
Banana
| Crop | Chemical | Dose | Time of spray and number of spray | Response |
| Coconut | 2,4-D | 30 ppm | One month after opening of spathe, through micro sprayer | Fruit setting percentage increased to 32.5% against 23% in control |
| Banana | 2,4-D | 25 ppm | Within a week after opening of last bud | Prevents seediness in poovan |
| Mandarin orange | 2,4-D or NAA | 20 ppm, 100 ppm | Spray at flowering. | Increase fruit set |
| Thompson seedless | GA3 | 25 ppm | Dip cluster at calyptra falling stage | Increase fruit set |
| Pine –apple | Planofix 10 ppm +2% urea 0.04% sodium carbonate +20 ppm ethrel | 50 ml/plant applied in to the crown 200 to 300 ppm | At 35-40 leaf stage Sprayed during fruiting | Induced uniform flowering to increase the fruit size |
| Snake gourd Bitter gourd Bottle gourd | Ethrel | 100ppm | 4 times 10 –15 days after sowing at weekly intervals | Increase in yield |
| Ribbed gourd Pumpkin | Ethrel | 250ppm | 4 times 10-15 days after sowing at weekly intervals | Increase in yield |
| Sweet potato | Ethrel | 250ppm | At fortnight interval from 15 days after planting | Increased tuber yield |
Coconut
2,4-D
One month after opening of spathe, through micro sprayer
Fruit setting percentage increased to 32.5% against 23% in control
Within a week after opening of last bud
Prevents seediness in poovan
Mandarin orange
2,4-D or NAA
20 ppm, 100 ppm
Spray at flowering.
Increase fruit set
Thompson seedless
Dip cluster at calyptra falling stage
Pine –apple
Planofix 10 ppm +2% urea 0.04% sodium carbonate +20 ppm ethrel
50 ml/plant applied in to the crown 200 to 300 ppm
At 35-40 leaf stage Sprayed during fruiting
Induced uniform flowering to increase the fruit size
Snake gourd Bitter gourd Bottle gourd
100ppm
4 times 10 –15 days after sowing at weekly intervals
Increase in yield
Ribbed gourd Pumpkin
250ppm
4 times 10-15 days after sowing at weekly intervals
Sweet potato
At fortnight interval from 15 days after planting
Increased tuber yield
Note: 1% - 1 gram dissolved in 100ml (made up to 100 ml) 1ppm – 1 mg dissolved in 1 litre (made up to 1 lit.)
Source: Dr. P.Jeyakumar, Associate Professor (Crop Physiology), Dept. of Fruit Crops, HC & RI, TNAU, CBE.
Related Links
http://www.ikisan.com/links/ap_regulators.shtml
http://en.wikipedia.org/wiki/Plant_hormone