MODELLING AND FIELD PLOT TECHNIQUES IN COTTON (G. barbadense L.) TRIALS

Abstract

PART I: The relative contribution of yield components as estimated by different statistical methods Two field experiments were carried out during the two successive seasons of 2009 and 2010 at the Agricultural Research and Experiment Station, Faculty of Agriculture, Cairo University, Giza, Egypt. The main objectives of the present investigation are to study: The relative efficiency of lattice design relative to randomized complete blocks design for yield and yield components in cotton trials, The relationship between yield, yield components and some fiber characteristics to determine the most important characters that can be used as selection criteria for yield and quality improvement in some Egyptian cotton by using four statistical procedures including; multiple linear regression, stepwise regression, cluster analysis and factor analysis, Evaluate sixteen Egyptian cotton varieties for yield and their components and Determine the optimum plot size and number of replications. The genetic materials used in this experiment included sixteen Egyptian cotton (Gossypium barbadense L.) varieties sex of them were Extra-long staple (over 1 3/8 inch) [Giza45, Giza70 Giza 87, Giza 88, Giza 92, and Pima S6]. While the other varieties were long staple (1 1/8 – 1 3/8 inch) [Giza 75, Giza 80, Giza 83, Giza 85, Giza 86, Giza 89 Giza 90, Giza 91, Sea Island, and Dandara]. Seeds of all varieties were obtained from Cotton Research Institute, Agriculture Research Center, Giza, Egypt. 124 A balanced lattice design 4×4 with five replications was used in both seasons. The size of each plot was 5.4 m2 (1.8×3 m). Each plot was three rows 3.0 m long and 0.6 m wide. Hills were 20 cm apart to insure 15 hills per row. Hills were thinned to keep a constant stand of two plants per hill at seedling stage. Seeds were sown by hand on the first of April in both seasons. All cultural practices i.e., irrigation, fertilization and pest control were applied as usual for the ordinary cotton production. 1. Studied characters To record field observation on individual plant basis, 10 guarded plants were randomly chosen from each three rows (plot) on which the following characters were determined. a. Number of fruiting branches per plant b. No. of dry bolls c. No. of opening bolls d. Lint cotton yield per plant (in grams) e. Seed cotton yield per plant (in grams) f. Lint cotton yield per plot (in grams) g. Seed yield per plot (in grams) h. Lint percentage (L %) i. Seed cotton yield per fed. (Kantar) j. Fiber length at 2.5% k. Uniformity ratio l. Micronaire reading m. Pressly