No abstract

No abstract

The study aimed to identify early‐stage traits of cotton for heat tolerance using multitrait approach reflecting field yield performance. Seedling growth and physiological response of 16 cultivars to high temperature were investigated at three different developmental stages and four heat stress conditions in a climate chamber. Some traits such as hypocotyl dry weight, leaf pigment contents and cellular respiration were significantly correlated with previously known yield of ten cultivars grown in the hot field conditions. Sixteen cotton cultivars were classified for their heat tolerance by principle component analysis (PCA) using yield‐correlated physiological traits. As a result, we showed that heat tolerance classification of cultivars based on PCA significantly coincided with the yield results of cultivars grown in hot field. As a conclusion, yield‐correlated physiological traits determined in the study may facilitate selection of heat‐tolerant cotton genotypes at early stage. In addition, yield‐correlated early‐stage traits can be used in phenotyping for QTL and association mapping studies to develop selection markers for heat tolerance.

No abstract

No abstract

The present study was conducted to investigate the effects of different soil compaction levels (non-compacted control, low compaction, high compaction), irrigation management practices (conventional furrow and alternate furrow) and nitrogenous fertilizer levels (60, 90, 120 kg ha^–1) on vegetative characteristics (dry biomass production, plant height, number of branch and number of pod per plant, height of the first pod, leaf area index, stem diameter), physiological characteristics (leaf relative water content, leaf chlorophyll content and leaf temperature) and root development through 0 -80 cm soil profile of soybean grown in Harran Plain of Turkey. Experiments were conducted in Sanliurfa Province of Turkey in split-split plots experimental design with 3 replications during the years of 2006 and 2007. Irrigation program was created by using KanSched simulation model. The amount of applied irrigation water in conventional and alternate furrow systems in 2006 and 2007 were measured as 435.61 and 291.59 mm, and 429.51 and 271.72 mm, respectively. While the highest yield (947.8 kg ha^–1) was observed in control treatment of the year 2006, conventional furrow system had the highest yield (2099.3 kg ha^–1) in the year 2007. Soil compaction, irrigation and nitrogenous fertilization in general had significant effects on entire vegetative characteristics investigated in the present study. Increasing compaction levels yielded decreasing plant height, stem diameter and leaf area indexes. Biomass production increased with increasing nitrogen doses. Results indicated that negative impacts of soil compaction in agricultural fields due to traffic and various other reasons could be eliminated with proper irrigation and fertilization implementations.

Cotton fiber color is determined by the effect of fiber reflectance (Rd) and fiber yellowness (+b), which are important standards for determining cotton price. This study was conducted to determine effects of different sowing times on fiber color components in widely grown four cotton (Gossypium hirsutum L.) varieties in 2015 and 2016 under Harran Plain double crop conditions. The experiments were conducted on the experimental area of Agricultural Faculty of Harran University at Eyyübiye Campus. Seeds of cotton cultivars were sown according to sowing dates with completely randomized split plot experimental design with three replications. Sowing dates (June 1 st , June 10 th and June 20 th) were kept in main plot and varieties (Stoneville 468, BA 119, DP 499 and PG 2018) were in sub plot. Four cotton varieties (Stoneville 468, BA 119, DP 499 and PG 2018), which are certified for Harran Plain, were used as plant material. As the result of the study, the fiber color of Şanlıurfa province, where all varieties are in the light and white class according to the HVI color scale, but white color is changing from standard 2 to standard 3 and standard 4 grade. All the varieties used in the experiment were affected by sowing time in terms of fiber color and whiteness of color was found to be dulled with the delay in the sowing time. For this reason, early and late harvests should not be mixed and should be stored separately.

The interest in organic cotton (colored) has been increased due to high contamination and environmental pollution during fabric dying process. However, detailed studies are needed to determine the genetic and yield related traits. Eight different cotton genotypes (3 green, 3 brown and 2 white) with known fiber color values were used in the current study to record combining ability and heterosis for fiber colour and quality traits. An 8×8 half diallel hybrid population containing 28 F1 hybrids was analysed in the experimental area of GAP Agricultural Research Institute, Şanlıurfa, Turkey. The study including parents and hybrids was established in a randomized complete block design with three replications. The main aim was to examine the genetic structure for studied traits in the populations developed and detecting F1 hybrid vigour. Finding appropriate parent and hybrid combinations for breeding studies was the second major aim of the study. Sufficient variations were noted for the studied traits in hybrid population formed. Genetic parameters such as general and special compatibility abilities, heterosis and heterobeltiosis values were recorded in the formed population. Fiber length (mm), fiber fineness (micronaire), fiber strength (g tex-1), fiber uniformity (%), fiber color values L* (brightness), a* (red-greenness) and b* (yellow-blueness) values were recorded. It was noted that additive genetic effects were important for fiber length, fiber fineness, fiber strength, L*, a* and b* traits.