8 pages, via Online journal, The use of tomato (Solanum lycopersicum) grafting is gaining traction across the United States, but small-scale growers face the challenge of creating optimum postgrafting healing conditions. The practice of blocking light for a period of 2 to 4 days while maintaining high humidity is commonly recommended for healing grafted tomato transplants; however, research is exploring alternatives to this practice. The present study investigated a low-input healing method for grafted tomato transplants with a specific focus on light and the use of propagation heat mats to regulate substrate and healing chamber air temperatures during the 7-day healing process. We hypothesized that 4 days of light exclusion and the use of propagation heat mats would improve grafted tomato transplant survival and growth. ‘Cherokee Purple’ was used as the scion and ‘RST-04-106-T’ was used as the rootstock. The whole plot factor was heat [propagation mats set at 80 °F (heat) or no propagation mat (no heat)] and the subplot factor was light exclusion (0, 4, or 6 days of dark). The highest survival rate among treatments was 97% in 0 days of dark with no heat treatment; survival decreased to 84% in 4 and 6 days of dark with no heat treatments. The plant survival rate was 96% with 0 days of dark and heat treatment; however, the survival rates were 63% and 45% for the 4- and 6-day dark treatments, respectively. The scion stem diameter was largest for transplants grown in 0 days of dark, but there was no difference in stem diameter due to heat treatments. There were no differences among scion or rootstock biomasses due to heat or light treatments. These results demonstrate that propagation mats set at 80 °F to regulate the substrate temperature were detrimental to grafted transplant survival under extended periods of light exclusion. However, this finding creates the basis to explore lower levels of substrate temperature modification. Our work also indicates that light exclusion may not be necessary for healing grafted tomato plants regardless of root-zone temperature treatments. Future work should examine the interactions of various substrate and air temperatures under full light conditions and their effects on grafted tomato transplant survival and growth. This work contributes to the ongoing research of how to optimize low-input healing methods that may be readily adopted by small-scale tomato growers.
18 pages, Recent studies cast doubt on the ability of abstract experiments to predict decision-making in the field. Thus, scholars have argued for more ‘realism’ by introducing context to field experiments. Yet, such realism may work against the induced values of monetary incentives in economic experiments. It is an open question whether contextual framing works best with or without inducing values, through methods such as the use of monetary incentives. Using a sample of 146 German farmers, we compare experimentally the predictive power of a framed lottery in an agricultural context vs. using an abstract version. For one half of the sample, lotteries are incentivised; for the other half, they are hypothetical. Although risk preferences differ between treatments, all four lottery tasks correlate poorly with farmers’ real-world use of risk management instruments such as harvest or hail insurance. Subjects who start with an agricultural framing are willing to take significantly greater risks in the lotteries. More generally, our findings cast doubt on the ability of lottery tasks to predict risk-taking in the field.
