Effect of Some Growth Regulators Under Different Planting Dates on Growth and Yield of Cotton

Abstract

This study was carried out at the Experiment and Research Station, Faculty of Agriculture, Cairo University, Giza in two growing seasons (2010 and 2011) to study the effect of three sowing dates; (25 March, 25 April, and 25 May) and some growth regulators i.e.,(Indole acetic acid (IAA) at the rates of 50, 100 and I50 ppm, Naphthalene acetic acid (NAA) at the rates of 10, 20 and 30 ppm and Mepiquate chloried (Pix) 50, 100 and I50 ppm) on Egyptian cotton cultivar (Giza 92). A split-plot design with three replicates was used, sowing dates were allocated in the main plot while growth regulators in the sub plot. Obtained results could be summarized as follows:-Sowing date had significant effect on growth characters, yield, yield components and technological properties. Whereas, delayed sowing date tended to increase significantly the plant height, no. of days to 1 st bud, 1 st flower and 1 st open boll. Planting cotton in 25 March was superior in the no. of sympodial branches / plant, seed index, earliness percentage, seed cotton yield /feddan and fiber properties such as fiber length, uniformity ratio, fiber elongation, fiber strength, micronaire reading, brightness and yellowness.Growth regulators significantly affected all growth and yield characters under study. Use of 50 ppm PIX was superior in the no. of days to 1 st bud, 1 st flower and 1 st open boll, seed index, earliness percentage and seed cotton yield /feddan, while 30 ppm NAA was superior in plant height. Fiber properties were not significantly affected by growth regulators in all characters under study in both seasons.The interaction between sowing dates and growth regulators significantly affected in most characters under study whereas, the use of 50 ppm PIX and planting in 25 March or 25 April was superior in the no. of sympodial branches / plant, no. of open bolls / plant, seed index, earliness percentage and seed cotton yield /feddan in the first season, while in the second one the use of 50 or 100 ppm PIX with sowing in 25 March gave the best reading in yield and yield components.

Effect of Different Levels of Organic Matter and Genotypes on Seed Yield and Fiber Quality in Cotton (Gossypium hirsutum L)

“…It is difficult to raise organic matter beyond 4.5%. Biovita (sea weed) is a rich source of organic matter that has significant impact on yield components and seed cotton yield but has not much significant impact on quality of cotton i.e., GOT%, staple length, fineness and fiber strength (Elayan, 2008;Abdallah and Mohamed, 2013). Studies suggested that application of farm yard manure improves fiber yield by way of improved GOT (Desouza et al, 2023).…”