Parameter estimation validity and relationship robustness: A comparison of telephone and internet survey techniques

With the expansion of telecommunication and online technologies for the purpose of survey administration, the issue of measurement validity has come to the fore. The proliferation of automated audio services and computer-based survey techniques has been matched by a corresponding denigration of the quality of traditional phone survey data, most notably as an outcome of falling response rates. This trend, combined with the introduction of screening technologies and answering machines, represents a barrier to the proper execution of survey research. Whereas the question was once, “can technology-assisted surveys achieve the same level of validity as traditional phone surveys?”, the question now becomes, “what are the relative advantages and disadvantages of technology-assisted and phone surveys?” Each has its own challenges and opportunities, and this paper begins to explore these. The present study provides further insight into the validity of telephone and Internet survey data, and explores whether or not the robustness of relationships between variables varies by survey mode. Study data were provided by two surveys, the first of which was conducted in a metropolitan area of the Midwestern US, with interviews of 505 adults using a computer-aided telephone-interviewing (CATI) system. The second was a national survey of 2172 respondents conducted over the Internet by a commercial research firm that sends requests to a diverse set of potential respondents, who logged onto the survey site to participate. Results suggest that weighting in an attempt to achieve parametric matching does seem to increase robustness of relationships and, in this age of poor response rates, this seems to demand an increased use of parametric weightings. Implications of study findings for telematic survey practitioners are discussed

Effect of Organic and Chemical Fertilizer Applications on Yield And Chlorophyll Content of Yedikule Lettuce (Lactuva Sativa L.) Plant

This study was conducted in Erciyes University Agricultural Research and Application Land in 2020 to determine the effects of organic and chemical fertilizers applied from the base to the Yedikule lettuce plant on plant yield and plant chlorophyll content. In the study, solid worm manure (100 kg da-1) was preferred as organic fertilizer, while 15 - 15 - 15 compound bottom fertilizer was preferred as chemical fertilizer. Seedlings of lettuce plants were planted with 16 plants in each plot, with a row spacing of 25 cm and a spacing of 50 cm between rows. In the study, the chlorophyll content of plant leaves (SPAD) was examined, as well as the yield parameters of plant height (cm), plant width (cm) and plant fresh weight (g/plant). As a result of the examination, it was determined that chemical fertilizer application had a positive effect on the fresh weight of the plant, and organic fertilizer application had a positive effect on the chlorophyll content

Effects of rootstocks on storage and shelf life of grafted watermelons

Watermelon fruits from non-grafted or grafted ‘Crimson Tide’ (CT) and ‘Crisby’ (CR) onto Ferro, RS841, Argentario and Macis rootstocks were compared for their postharvest quality during storage at 7 °C for 21 days and additional 7 days at 21 °C. Non-grafted and grafted CT and CR fruits did not exhibit chilling injury (CI) symptoms, but the 1-2% of fungal decay occurred after shelf life period following storage. Watermelons grafted on Ferro and RS841 rootstocks had higher flesh firmness thicker rind, lower ripening rating, more intense (higher C*) brighter red (lower h° value) color and higher lycopene content after shelf life period following storage, compared to non-grafted fruits. All of the fruit tested by the panelists received high taste scores of >7.9 out of 8.5 at the beginning, but the scores decreased to >6.8 out of 7.7 at the end of shelf life period. Watermelons could successfully be kept for 21 days at 7 °C and additional 7 days at 21 °C. Watermelons grafted on Ferro and RS841 rootstocks had higher postharvest quality, compared to the non-grafted fruits for both cultivars

Farklı kabak türlerinin ve karpuzun tuz stresi altında bitki gelişimi ve element içerikleri

Crimson Tide karpuz [Citrullus lanatus (Thunb.) Matsum. and Nakai] çeşidi ve karpuza anaçlık potansiyeli olan 7 farklı kabak genotipi [Cucurbita maxima, C. moschata, Luffa cylindrica, Benincasa hispida, Lagenaria siceraria (Skp ve Birecik) köy çeşidi ve L. siceraria melezi (FRGold)] 30 gün tuzlu (0, 4, 8, 12 ve 16 dS m-1) koşullarda yetiştirilerek tuz stresine tepkileri belirlenmiştir. Bitki ana gövde uzunluğu, kök kuru ağırlığı, yaprak ve gövde kuru ağırlığı, bitki kuru ağırlığındaki azalma, yapraklardaki Na+, Ca2+ ve K+ konsantrasyonu, Ca2+/Na+ ve K+/Na+ oranları belirlenmiştir. Kabak genotipleri tuzlu koşullarda incelenen bütün parametrelere farklı tepkiler vermişlerdir. L. cylindrica ve B. hispida hariç bütün kabak genotipleri tuz stresinden karpuza göre bitki gelişimi açısından daha az etkilenmişlerdir. İyon regülasyonu bakımından kabak genotipleri ve karpuz arasında önemli farklılıklar tespit edilmiştir. Tuz uygulaması ile birlikte yapraktaki Na+ konsantrasyonu yükselmiştir. L. cylindrica’nın yapraklarında Na+ birikimi önemli bir artış gösterirken, en düşük Na+ içeriği Birecik ve C. maxima’da belirlenmiştir. Tuz stresi altında, B. hispida ve L. cylindrica, karpuz ve diğer kabak genotiplerinden daha fazla Na+ biriktirmişlerdir. Ca2+/Na+ and K+/Na+ oranları tuz uygulaması ile birlikte önemli derecede azalmıştır. Azalma genotipe göre değişmiştir. Yüksek bitki kuru ağırlığına sahip olan genotipler, yüksek Ca2+/Na+ ve K+/Na+ oranlarına sahip olmuşlardır. Bitki büyüme parametreleri ile Ca2+/Na+ ve K+/Na+ oranları arasında önemli pozitif korelasyonlar bulunurken, Na+ içeriği ile önemli negatif korelasyon tespit edilmiştir. Cucurbita ve Lagenaria türleri tuz stresine, L. cylindrica, B. hispida ve karpuza göre daha yüksek tolerans göstermiştir.The watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] cultivar Crimson Tide and 7 different gourd genotypes [Cucurbita maxima, C. moschata, Luffa cylindrica, Benincasa hispida, Lagenaria siceraria landraces (Skp and Birecik), and L. siceraria hybrid (FRGold)] with rootstock potential for watermelon were grown under saline conditions (0, 4, 8, 12, and 16 dS m–1) to investigate the responses of the gourd genotypes and watermelon to 30 days of salt stress. Plant main stem length, shoot dry weight, root dry weight, reduction in shoot dry weight, concentration of Na+, Ca2+, and K+ in the leaves of the genotypes, and Ca2+/Na+ and K+/Na+ ratios were investigated. Plant length, and shoot and root dry weight of the plants significantly decreased as salinity stress increased. Gourd genotypes responded significantly differently to all investigated parameters under saline conditions. All genotypes had better growth performance than watermelon, except for L. cylindrica and B. hispida. The gourd genotypes and watermelon showed significant differences under saline conditions, with respect to ion regulation. Sodium concentration in the leaves of all the genotypes increased in response to salt application. There was a remarkable increase in Na+ concentration in the leaves of L. cylindrica, whereas the lowest Na+ concentration was observed in Birecik, and C. maxima, B. hispida, and L. cylindrica accumulated more Na+ than watermelon and the other gourd genotypes did under saline conditions. Ca2+/Na+ and K+/Na+ ratios were significantly reduced by salt treatment and the degree of decrease was dependent on genotype. Genotypes with higher Ca2+/Na+ and K+/Na+ ratios produced more dry weight. Significant positive correlations were observed between plant biomass parameters, and Ca2+/Na+ and K+/Na+ ratios, whereas strong negative correlations were observed between Na+ concentrations and shoot and root dry weight of the genotypes. Cucurbita and Lagenaria species were more tolerant to salinity stress than L. cylindrica, B. hispida, and watermelon