MM2.4: Physiological manipulation of cotton plant morpho frame for enhanced productivity under varied agro-climatic conditions

About 70 percent cotton cultivation in India is under rain fed conditions. Cotton suffers from various biotic and abiotic stresses right from the germination to maturity. The growth during the seedling establishment phase has a role to play in yield realization. A good plant frame would provide sufficient space for holding and catering the needs of the reproductive parts during the later part of growth. Under Coimbatore condition, the crop experiences initial water logging followed by sucking pests. Both these stresses causes considerable damage to the plant leading to stunted growth. This leads the plants to either premature death or reduced boll load. Relatively little is known about hormonal control of cutout but based on established effects of the hormones, it is speculated that auxin, cytokins and Gibberellines promote growth and delay cutout... ABA , on the other hand promotes cutout as it inhibits growth and prolongs bud dormancy. Ethylene increases boll abscission and may restrict growth, but may not induce dormancy. Various growth regulators have been applied in cotton in attempts to set more bolls, limit vegetative growth or terminate fruiting. When boll load is limited by carbohydrate supply, exogenous modification of hormonal balance to increase boll set may be futile. More bolls may be set, but will be of smaller size and plant growth is terminated prematurely. Therefore, a plant type with a good morpho frame would sustain more boll load with synchronous boll development and boll burst. This will help in enhanced yield and effective harvesting in one or two picking.

OBJECTIVES

• To Study the growth and development of the cotton plant from germination to maturity.
• Effect of growth regulators on the physiological and biochemical changes and quality parameters of cotton lint.
• Formulate a growth regulator mixture to alter the plant frame to produce maximum yield and also amenable to mechanical harvest.

Name of the Lead Center: CICR (RS), Coimbatore

Co-operating Centers: CICR, Nagpur UAS, Dharwad, NAU, Surat, ANGRAU, Lam, IISS, Bhopal