Drought stress resistance indicators of chickpea varieties grown under deficit irrigation conditions

The aim of this study was to determine the drought stress resistance of three chickpea cultivars (Inci, Hasanbey and Seçkin) grown under water deficit conditions and to discuss the use of yield, crop water stress index and chlorophyll index values as drought stress tolerance indicators in breeding studies. Three drought stress levels, (full irrigation = no stress - I100, deficit irrigation = moderate stress - I50, and no irrigation = severe stress - I0) were used as irrigation treatments. The highest seed yield (1,984 kg ha−1) in severe stress conditions was recorded for the Inci cultivar with a low crop water stress index (CWSI) (0.50) and high chlorophyll index (33.60 SPAD). The lowest seed yield (1,783.66 kg ha−1) in I0treatment was noted for the Seçkin cultivar which had a high CWSI (0.58) and low chlorophyll index (32.88 SPAD). The highest seed yield (2,566.33 kg ha−1) in full irrigation was recorded for the Inci cultivar which had a low CWSI (0.19) and high chlorophyll index (44.39 SPAD), while the lowest seed yield (2,328.00 kg ha−1) in I100 treatment was recorded for the Seçkin cultivar which had a high CWSI (0.26) and low chlorophyll index (42.12 SPAD). The seed yield of the Hasanbey cultivar in both severe stress (1,893 kg ha−1) and full irrigation (2,424.00 kg ha−1) conditions was between Inci and Seçkin varieties. The chlorophyll index and yield had a significant positive (r = 0.877) correlation, while a significant negative (r = −0.90) relationship was determined between CWSI and yield. Seed yield of the Inci cultivar in I0and I100treatments and water use efficiency revealed that the Inci cultivar is resistant to drought stress. Therefore, the Inci cultivar can be used in drought stress tolerance studies. In addition, the CWSI and chlorophyll index values can be employed as resistance indicators in chickpea breeding studies to determine the drought resistant chickpea cultivars

Yield, Quality and Water Use Efficiencies of Silage Maize as Effected by Deficit Irrigation Treatments

The present study was carried out to investigate the effects of different water deficit levels applied through growing season on silage yield, quality and water use efficiency (WUE) of main crop silage maize under semi-arid climate conditions during the years 2014 and 2015. Irrigation treatments were set as 100% (I100), 70% (I70) and 35% (I35) supply of depleted water within 0-90 cm effective root zone in 7-day intervals. Applied irrigation water quantities in I100(control) treatment of the first and second year (in 8 irrigations) were respectively observed as 693 and 666 mm. Plant water consumptions in control treatment were respectively measured as 770 and 738 mm. Silage yield was 10650 kg da−1 in the first year and 10600 kg da−1 in the second year. The silage yield obtained from I70 treatment with 30% water deficit was statistically placed in group (B) following I100 (control) treatment. The water deficits over 30% resulted in significant decreases in silage yield and quality. The correlation coefficient between ETa and dry matter was respectively identified as (r: 0.78), (r: 0.87) in 2014 and 2015 and the correlation coefficient between plant water consumption (ETa) and protein content was respectively identified as (r:0.81), (r:0.80) and the correlations between ETa and quality parameters were found to be positive and highly significant. There were significant linear correlations between ETa and kernel yield (Y). Yield response factor (ky) of experimental years were respectively calculated as 0.74 and 1.06. Irrigation water use efficiency (IWUE) values varied between 3.80-5.10 kg da−1 mm and water use efficiency (WUE) values varied between 3.62 and 4.42 kg da−1 mm

Defining Irrigation Scheduling Based on Crop Water Stress Index and Physiological Parameters for Hybrid Corn in Semi-Arid Climate

The goal of this study is to determine the crop water stress index (CWSI) and irrigation scheduling based on CWSI values, as well as to examine the correlations between CWSI, physiological parameters and grain yield of hybrid corn P31A34 in semi-arid climate conditions. In 2014 and 2015, the upper limit (UL) temperatures at which plants were entirely exposed to water stress were 1.178°C and 2.38°C, respectively. When the corn grain yield began to decline, the CWSI threshold value was 0.34, indicating the yield limit. Grain yield, crop water consumption, crop water stress index, chlorophyll content, water use efficiency and leaf area index were found to have negative correlations (p ≤ 0.01) with CWSI values in both years of the study. The findings revealed that in semi-arid climate conditions, a maximum of 30% water deficit could be used during the growing period of the corn compared to full irrigation (I100) for water savings and that a water deficit greater than 30% results in considerable grain yield losses. In areas with limited water resources, the moderate water deficit (I70) may be a viable alternative to the I100