MULTIPLE REGRESSION AND CORRELATION ANALYSIS OF EARLINESS AND POTENTIAL PRODUCTION TRAITS OF FIVE COTTON VARIETIES (Gossypium barbadense L.) GROWN UNDER DIFFERENT ENVIRONMENTS

Abstract

The present experiments were carried out at the Farm of the Faculty of Agriculture, El Fayoum University, in the summer seasons of 2010 and 2011 in a split plot design with five replicates, to investigate the effects of different sowing times, as an indication of different climatic environments i.e. micro-environments on earliness, yield and its components in some Egyptian genotypes.The obtained results indicated that the studied plant characters were significantly affected by microenvironments. However, its effect was not observed in some earliness measurements i.e. node number of the first sympodium, the period between the first bud and the first flower appearance, the period between the first flower appearance and the first boll opening and mean maturity date. Early sowing recorded the highest values of the studied characters. While, delayed sowing to the 1 st of April significantly decreased the values of the characters. Significant differences among varieties were found in all the studied traits over the three environments except the period among the first bud initiation and the first flower appearance and the period between the first flower appearance and the first boll opening. Giza 90 gave the highest seed and lint cotton yields. The results obtained clearly indicated that the treatment combination comprising early time on the first of March with the variety Giza 90 proved to gave the highest values of seed and lint cotton yields.It could be concluded that earliness traits were able to result in a linear regression model for all the five tested genotypes. At least two of these traits were included in the yield per feddan model of the five varieties. Consequently, this way of estimating earliness could be favored over the other methods used regardless of the variety studied.