Plant Nutrition :: Plant Growth Regulators

APPLICATIONS IN AGRICULTURAL AND HORTICULTURAL CROPS

GROWTH REGULATORS IN AGRICULTURAL CROPS

Crop	Chemical/ Dosage	Response
Rice	Kinetin, GA3 and Triacontanol (1000 ppm)	Grain filling and partitioning. Delayed senescence
Cotton	IAA, NAA (30 ppm), CCC (cycocel)	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)	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)	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

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

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.