Yield In Non-stress Conditions Research Articles

Effects of Foliar Application Chitosan and Salicylic Acid on Physiological Characteristics and Yield under Deficit Irrigation Condition

Drought stress is recognized as one of the most important factors reducing crop yields worldwide. Many studies are underway on the foliar application of different compounds to mitigate the effects of drought stress on plants. This experiment was designed to investigate the effects of foliar application of chitosan and salicylic acid on yield and its components under drought stress conditions in potatoes. The experimental design was split-plot with three replications based on a completely randomized design. The main plots and the sub-plots were 12 by 6 m and 6 by 3 m, respectively. The main plots represented three levels of irrigation (100%, 80%, and 60% of available soil water). Treatments in sub-plots included control treatment, 0.5 g/l salicylic acid, 2 g/l chitosan, and combined treatment with chitosan and salicylic acids. The results showed a direct relationship between reduced irrigation and reduced yield. As drought stress increased, yield, yield component parameters, and the physiological indices of the crop declined. Under stress conditions, the biological yield was increased by the application of chitosan and salicylic acid. The highest yield in non-stress conditions was 45,717 kg/ha; for foliar application of 0.5 g/l salicylic acid and 2 g/l chitosan, the highest yield was 45,683 kg/ha.

Grain yield and drought tolerance indices of maize hybrids

Drought is one of the major abiotic stress factors limiting crops production in Oltenia area, Romania. In order to study the response of six maize hybrids to drought stress, the trials were conducted in research field of ARDS Simnic – Craiova, during 2017-2018 (non-stressed conditions) and 2018-2019 (drought stress). Six tolerance indices including: abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI), Stress tolerance index (STI), mean productivity (MP), relative drought index (RDI) and golden mean (GM), were utilized on the basis of grain yield. Results from analysis of variance showed that there is a significant difference in 1% of probability level among hybrids in terms of grain yield and tolerance indices. The yield in non-stress conditions (Yp) showed significant positive correlations with ATI, SSPI, STI and MP, and negative correlation with RDI and GM. The yield in drought conditions (Ys) showed significant positive correlation with RDI and GM, and negative correlation with ATI and SSPI. None of the tolerance indices used could identify the high yielding hybrids under drought and non-stress conditions. Based on the ranking method, the hybrids ‘Felix’ and ‘P 9903’ were the most droughts tolerant. Therefore, they hybrids are recommended to be grown under drought prone areas and to be used as parents for breeding of drought tolerance in other cultivars.

Assessment of salinity indices to identify Iranian wheat varieties using an artificial neural network

In arid and semi-arid regions of the world, including Iran, soil salinity is one of the major abiotic stresses. One of the ways to achieve high performance in these areas is to use salt-tolerant varieties of wheat. Iran is known as one of the places where the D-genome originated and evolved. In order to evaluate the salt tolerance of Iranian genotypes based on the eight indices using analysis of variance, regression and an artificial neural network (ANN), 41 Iranian wheat varieties (Trticum aestivum L.) were planted in a randomised complete block design with three replications under two saline irrigation conditions, 0.631 and 11.8 dS m−1, in Kerman, Iran. Significant differences between the varieties were observed, and the significant two-way interaction of environment × varieties in combined analysis and non-significant correlation, 0.07, between the yield in two environments (yield in non-stress conditions, Yp, and yield in stress conditions, Ys) indicates the existence of genetic variation among varieties and the different responses of the varieties in both the environments. The indices of tolerance, geometric mean product (GMP), mean product (MP), harmonic mean (HM) and stress tolerance index (STI) were calculated based on grain yield evidence of positive significant correlation with Yp and Ys. Based on the ANN results, yield stability index (YSI), MP, GMP and STI were the best indices to predict salinity-tolerant varieties. The varieties selected based on these indices, such as Bolani, Sistan, Ofogh, Pishtaz, Karchia and Arg, produced high yield in both the environments. These results show that bread wheat originating from Iran has salt tolerance potential and can also be used in studies related to salinity tolerance mechanisms.

Cycocel Priming and Foliar Application Affect Yield Components of Rapeseed (Brassica Napus L.)

ABSTRACT A factorial based on RCBD experiment was conducted to evaluate the effects of priming and foliar spray of cycocel on rapeseed yield components. Treatments were included; seed priming (0, 600, 900, 1200, 1500 μM) and foliar spray (0, 600, 1200 μM) with cycocel at development stage of flower buds. The results revealed that seed priming with cycocel significantly increased emerged plant number per plot, silique dry weight in the main stems and branches, plant dry weight, branches number, silique number in the main stems and branches, seed number in branches, 1000 seeds weight, and seed yield in non-stress conditions. Foliar application with cycocel also increased plant dry weight, 1000 seeds weight in branches, harvest index and seed yield. Moreover, interaction effect of priming and foliar application of cycocel increased plant dry weight and 1000 seeds weight with branches. CCC foliar application during the early stages of reproductive stage went to elevated plant dry weight and 1000 seeds weight in auxiliary branches and, also increased harvest index and grain yield. Mean comparison and interaction effects of traits also revealed that, appropriate levels of CCC had the meaningful effects on any agronomic and physiological trait. However, the most meaningful impact in most traits was traced in case with primed seed with 900 and 1500 μM CCC. Overall, owing to the present data, CCC priming under both normal and harsh conditions may raise the germination related traits, seedling establishment, plant growth and ultimately may goes to increased yield.