Sand mulching and its relationship with soil temperature and light environment in the cultivation of Lilium longiflorum cut flower

Lilium longiflorum is one of the most important cut flowers both in the world and in Argentina. To plan a commercial crop, it is necessary to understand tools that relate environmental variables to crop growth and development. One of these tools is leaf expansion, which can be determined from the evolution of the leaf area index (LAI). The technique known as sand mulching substantially modifies the soil temperature but can also alter other environmental variables such as light quality. The objective of this work was to determine whether the application of sand mulching affects the growth rate and leaf expansion of a lilium cut flower crop. The experiment was carried out in a greenhouse at the Faculty of Agronomy, University of Buenos Aires, Argentina, where a lilium crop was planted in the soil, adding a 5-cm layer of fine sand over the entire soil surface to reduce soil temperature. Plant height and number of leaves were measured twice a week and the LAI was estimated by spectral reflectance once a week. The cycle length was also recorded, and the accumulation of dry matter was measured at the end of the experiment. The soil temperature was lower in the first month of cultivation, and there were differences in the light environment and in the water status of the crop. Although there were no significant differences in the cycle length or leaf appearance, sand mulching led to differences in the stem growth rate, LAI and final plant height, resulting in a better quality of the product.