The effects of indole-acyl esters (ID), NH 4 NO 3 (N), and KH 2 PO 4 (P), on the mitigation of the toxic effects of Cd and Pb and their concentration in Jatropha curcas L. from contaminated soils was investigated. The concentrations of ID, N, and P were optimized (0.1 mL·L -1 , 7 mM, and 2.5 mM, respectively) and they were applied in various combinations to the contaminated soils of potted plants of J. curcas. The results showed that ID together with the N and P fertilizers, increased plant biomass and improved the mitigating effects of the N-P treatments on Cd and Pb toxicity. Plants growing under ID-N-IP treatments had high whole plant biomasses, high concentrations of P, N, Pb and Cd in whole plants, as well as enhanced activities of superoxide dismutase (SOD) and peroxidase (POD). These results point to the phytoremediation ability of J. curcas. We propose a new methodology that can be utilized to study the effects and interactions of multiple factors on plant growth.

This paper attempts to disclose the effects of main agronomic traits and physiological indices on potato yield, under different agronomic measures. Four-factor five-level orthogonal test plan was designed by the strategy of quadratic orthogonal rotation combination (QORC). The test data were subjected to multiple regression analysis of variance (ANOVA), correlation analysis, and path analysis. The main results are as follows: Based on correlation, the main agronomic traits can be ranked as yield per plant> plant height> stem diameter> emergence rate> number of tubers per plant> leaf area index> number of main stems; the physiological indices can be ranked as net photosynthetic rate> intercellular carbon dioxide concentration> transpiration rate> chlorophyll content. Based on direct effect over potato yield, the main agronomic traits can be ranked as yield per plant> leaf area index> stem diameter> plant height> emergence rate> number of tubers per plant> number of main stems; the physiological indices can be ranked as net photosynthetic rate> intercellular carbon dioxide concentration> chlorophyll content> transpiration rate. Based on the direct contribution to the potato yield, the main agronomic traits can be ranked as yield per plant> stem diameter> plant height> leaf area index> emergence rate> number of tubers per plant> number of main stems; the physiological indices can be ranked as net photosynthetic rate> intercellular carbon dioxide concentration> transpiration rate> chlorophyll content. To ramp up potato yield, priority should be given to enhance yield per plant and net photosynthetic rate. On the population, the plant height and stem diameter must match leaf area index in terms of planting density. Under high photosynthesis, the potato yield could be increased by reducing transpiration rate and intercellular carbon dioxide concentration.