Kassem,, M., Namich, A. (2003). RESPONSE OF GIZA 83 corros CULTIVAR TO SEQUENTIAL APPLICATIONS OF GIBBERELLIC ACid (GA3) AND MEPIQUATCHLORIDE (PIX). Journal of Plant Production, 28(3), 1611-1620. doi: 10.21608/jpp.2003.242481
M. M. A. Kassem,; Alia A. M. Namich. "RESPONSE OF GIZA 83 corros CULTIVAR TO SEQUENTIAL APPLICATIONS OF GIBBERELLIC ACid (GA3) AND MEPIQUATCHLORIDE (PIX)". Journal of Plant Production, 28, 3, 2003, 1611-1620. doi: 10.21608/jpp.2003.242481
Kassem,, M., Namich, A. (2003). 'RESPONSE OF GIZA 83 corros CULTIVAR TO SEQUENTIAL APPLICATIONS OF GIBBERELLIC ACid (GA3) AND MEPIQUATCHLORIDE (PIX)', Journal of Plant Production, 28(3), pp. 1611-1620. doi: 10.21608/jpp.2003.242481
Kassem,, M., Namich, A. RESPONSE OF GIZA 83 corros CULTIVAR TO SEQUENTIAL APPLICATIONS OF GIBBERELLIC ACid (GA3) AND MEPIQUATCHLORIDE (PIX). Journal of Plant Production, 2003; 28(3): 1611-1620. doi: 10.21608/jpp.2003.242481
RESPONSE OF GIZA 83 corros CULTIVAR TO SEQUENTIAL APPLICATIONS OF GIBBERELLIC ACid (GA3) AND MEPIQUATCHLORIDE (PIX)
Cotton Research Institute, Agricultural Research Center, Giza.
Abstract
This investigation was carried out at Mallawi Agric. Res. Station, Minia Governorate during 2001 and 2002 seasons to study the response of Giza !b cotton cultlvar to the application of gibberellic acid (GAJ) and mepiquat chloride (pix applied in sequential foliar applications as follows:
1· Control. 2· Spraying GAJ at seedling stage (SES) + pix at ear1y floweqpg stage (EFS). 3· Spraying GAJ at squaring stage (SaS) + pix at EFS 4- Spraying GA3 twice at SES and sas + pix at EFS. The used concentration of both GA3 and pix was 50 ppm.
However, results showed that the application of GA:! once at SES 0 at sas with sequent spray of pix at EFS positively influenced growth characters; pia t height, number of nodes per stem and number of sympodia per plant. producing vigorous but balanced plants with greater both fruiting capacity and reproductive eflicien~ through enhancing number of total fruiting sites, nowers, open bolls and total bolls !per plant along with reducing fruil shedding% leading to a significant increase in sead cotton yield per feddan.
The appucanon of GA:! twice at SES and sas + pix at EFS enhanced plant growth and Its fruiting capacity by increasing significantly plant height, numbej of main stem nodes, number of sympodia, lotal fruiting sites, flowers and total bolls ~er plant but it failed to increase seed cotton yield due to the Significant increase in umopened bolls per plant and delaying crop maturity associated with this treatment.
The results of chemical constituents of leaves obtained from treat d cotton planls showed that application of GAJ once at SES or at sas and then sprayi g pix at EFS increased significantly chlorophyll (a, b and total). carotenoides, carbohydrate contents (reducing sugars, non-reducinq sugars and total soluble sugars) and phenolic compounds.
Gibberellic acid and mepiquat chloride treatments had no significant effects on internode length, number of days from sowing to either first flower or first open boll, boll weight, tint % and fiber quatity. Only in 2002 season, seed index was sigmificantly increased by the treatments included one spray of GAJ at sas or two sprays of GAJ, followed by spraying Pix al EFS.