| Abstrakt: |
Optimization is a management approach to improve yield and resource efficiency and decrease environmental pollutions in saffron agroecosystems. Response-surface methodology (RSM) is defined as a set of statistical techniques used to optimize a product. In this work, spraying cow manure and leaf with Dalfard on saffron using RSM is optimised. An experiment was conducted using a central composite design with 13 treatments and two replications at the Agricultural Research Field of the Ferdowsi University of Mashhad during two growing seasons of 2015-2016 and 2016- 2017. The treatments were allocated based on low and high cow manure levels (0 and 100 t.ha-1, respectively) and leaf spraying concentration with Dalfard ® (0 and 10 ppm, respectively). Flower yield, daughter corm yield and quality criteria were calculated as dependent variables and changes of these variables were evaluated by a regression model. Lack-of-fit test was used to evaluate the quality of the fitted model. The adequacy of the model was tested by analysis of variance. The quality of the fitted models was determined using the determination coefficient (R2). Finally, the optimum levels of cow manure and leaf spraying concentration were calculated based on economic scenario. The results showed that the effect of linear component was significant on quality characteristics of stigma. The effect of square component was significant on dried weight of stigma, mean diameter of daughter corms, number of daughter corms per m2, mean weight of daughter corms and crocin content. Interaction effect of full quadratic component was significant on flower yield criteria. Lack of fit test had no significant effect on the studied traits. This indicates that the full square model is satisfactory. The maximum observed value for number of daughter corms was recorded for 50 t cow manure per ha+ no leaf spraying (with 41.38 corms.m-2). The highest observed value for dried stigma yield was related to 100 t cow manure per ha+ no leaf spraying (with 156.33 mg.m-2). The maximum observed amounts for quality criteria such as picrocrocin, crocin and safranal were calculated for 100 t cow manure per ha+ 10 ppm leaf spraying (with 89.91 E1%257, 180.98 E1%440 and 40.15 E1%330, respectively). Dried weight of stigma, number of daughter corms and crocin content were considered in the economic scenario. Thus, estimated cow manure and Dalfard concentration levels were 92.67 t.ha-1 and 1.2 ppm, respectively. In general, it seems that resource use optimization based on Response-surface methodology may be a suitable cropping approach for sustainable production and improvement of yield flower, corm yield and quality characteristics of saffron. [ABSTRACT FROM AUTHOR] |
