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The purpose of this study was to improve irrigation water use and cotton yield using real-time crop evepotranspiration based on the FAO-56 Penman-Monteith and canopy cover using surface drip and subsurface drip irrigation. The experiments were conducted Southeast Anatolia Region of Turkey, during 2016 and 2017. The experimental design was split-plots in randomized blocks using three replications. The main plots were surface drip irrigation (SDI), subsurface drip irrigation (SSDI-30 cm) and SSDI-40 cm. Sub-plots were three different irrigation levels based on real crop evapotranspiration (ETc), 0.75×ETc, 1.00×ETc and 1.25× ETc. There were significant differences (657 kg ha -1 ) between the seed cotton yield of SDI (3667 kg ha -1 ) and SSDI with a 40-cm lateral depth (4323 kg ha -1 ). Irrigation water and crop consumptive water use were 552 and 589 mm for the SSDI-40 cm recommended treatment, respectively. According to the projection using the results for cotton cultivation area in the study region, SDI and SSDI could save water about 37 and 42% compared to furrow irrigation, respectively. Net income based on unit area in SDI and SSDI was higher 20 and 69% than it in furrow irrigation, respectively. Irrigation scheduling based on real crop evapotranspiration (1.0×ETc) was more appropriate for water saving and increasing water productivity (0.84 kg m -3 ). The use of drip irrigation systems (especially SSDI) is significantly important to improve cotton yield, water use and economic contribution considering possible water shortage, decreasing water resources, farmers conditions, irrigation schemes, regional and national incomes.

Methyl jasmonate (MEJA), a volatile organic compound, can induce plant defenses, thereby contributing to repelling insect pests and attracting their natural enemies. In 2013 and 2014, the influence of three exogenous MEJA doses (0.88, 1.76, and 3.55 mM) under field conditions was investigated on the abundance of the cotton pests Thrips tabaci Lindeman (Thysanoptera: Thripidae), Empoasca decipiens Paoli (Hemiptera: Cicadellidae), and Aphis gossypii Glover (Hemiptera: Aphididae), as well as of the predators Coccinella septempunctata L. (Coleoptera: Coccinellidae), Aeolothrips intermedius Bagnall (Thysanoptera: Aeolothripidae), and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). The MEJA treatments were performed at three cotton plant growth stages: 6-8 true leaves-early squaring, square bud, and boll forming. The abundances of A. gossypii, T. tabaci, and E. decipiens varied considerably among strata and growing seasons and between experimental years, but overall they were lower on MEJA-treated cotton plants than on control plants. The population density of A. intermedius and C. septempunctata did not differ between MEJA-treated and control plants, whereas the intermediate MEJA concentration had an attractive but inconsistent effect on C. carnea. Most of the insect pests and predators showed a preference for specific plant strata. The abundance of T. tabaci was higher in earlier plant growth stages, whereas A. gossypii and E. decipiens were more abundant in later growth stages. Our results demonstrate the deterrent effects of MEJA-induced cotton plants on sucking pests and suggest that MEJA could be exploited as a non-toxic pest management tool. Possible mechanisms underlying the effectiveness of MEJA-mediated cotton plant responses to insect pests are discussed. K E Y W O R D S cotton, elicitor, generalist predators, jasmonate, sucking insect pests, plant growth, Thrips tabaci, Empoasca decipiens, Aphis gossypii, Coccinella septempunctata, Aeolothrips intermedius, Chrysoperla carnea INTRODUC TION Cotton, Gossypium hirsutum L. (Malvaceae), is planted annually on approximately 500 000 ha in Turkey and constitutes a significant cash crop (TUIK, 2019). Cotton plants suffer from damage by a wide range of economically important insect pests for most of the growing season in Turkey. Among important sucking insect pests are onion thrips, Thrips tabaci How to cite this article: Tonğa A, Şeker K, Çakmak S, Temiz MG & Bayram A (2022) Cotton treatment with methyl jasmonate at different growth stages reduces the population of sucking insect pests and marginally increases their associated predators Entomologia

Determination of the effect of Cotton wilt disease (Verticillium dahliae Kleb.) on seed contentThe study was carried out to determine the effect of Cotton wilt disease (Verticillium dahliae) on seed content, the experiment set up in randomized blocks design methods with four replications in Dicle University, Agricultural Faculty Research Area that is naturally infested with the pathogen in Diyarbakır in 2014. Stoneville 468 (Moderately tolerant) and Beyaz Altın 119 (Moderately susceptible) cotton varieties are used in the study. The land prepared for sowing and cotton seeds were sown in the 23th of May, 2014. Necessary agricultural practices were performed until the harvest. During the harvest, the stem of plants were cut 5-6 cm above ground level for each plot and the disease severity was recorded according to 0-3 disease scales. Also, in Diyarbakır and Batman, 5 farmers field were checked in the same way and the plants were evaluated according to the 0-3 scale respectively. During the harvest 40-50 g cotton seeds were brought to the laboratory for each character. After ginning, cotton seeds were treated with sulfuric acid to delint at the laboratory. After that delinted seeds were grinded with a mixer for seed content analysis. The prepared samples were stored at -18⁰C in a deep freeze. The samples were kept in a pastor oven at 70 0 C for 24 hours for their humidity to stabilize. Then the seed contents were analyzed by "Nor-XDS Rapid Content Analyser" device. According to 0-3 disease scale, protein content, oil content, ash content, starch content and cellulose content of seeds were found to be significantly different at the farmers' fields and research area and moisture content were not determined differently at the farmers field, but were found differently in research area.

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Verticillium wilt disease in cotton is a soil-borne disease that causes significant yield losses, and it is therefore important to identify disease-resistant genotypes. Current study was carried out in the experimental field of the Faculty of Agriculture, Dicle University (Diyarbakir) in the year 2020 to determine the tolerance levels of some cotton genotypes which contain different characteristics to wilt disease (Verticillium dahliae Kleb.). The experiment area has been naturally infected with Verticillium wilt pathogens. A total of 124 cotton genotypes, including four controls (DP-499, Edessa, ST-468, ES-1), were arranged in five blocks according to the Augmented Design. The indices of stem cross-section and the leaf-disease severity were found significant. The leaf-disease severity varied between 0.12-3.09 at 50-60 % at boll opening period, whilst stem cross-section values ranged between 0.36-2.30. Moreover, a positive correlation was found between the indices. In conclusion, G7, G12, G21, G22, G23, G41, G51, G55, and G101 were determined as tolerant genotypes to Verticillium wilt in terms of examining two parameters.

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