Thermal sum of potato plants and tuber sprouting

Abstract

This study aimed to determine the thermal sum of the different stages of development of potato plants to better understand its relationship with tuber sprouting. The potato clones SMIJ461-1, SMINIA793101-3 and SMINIA97145-2 and the cultivar Macaca were evaluated in spring and autumn crop seasons in Santa Maria and Julio de Castilhos, RS. Emergence (EM), tuber initiation (TI) and onset of senescence (OS) of the plants were determined and the accumulated thermal sum (aTS) was calculated in each phase. After harvesting, tubers were stored at 20oC for 15 days for curing and then stored at 10 or 20°C to quantify the percentage of sprouted tubers and the number of sprouts per tuber at 0, 30, 60 and 90 days of storage. The experiment was a factorial of four potato clones and two growth conditions, season and storage temperature, in a random design with four replications of 20 tubers. The environmental conditions of Julio de Castilhos in the spring resulted in a greater aTS from EM and TI to OS than those of Santa Maria, meaning that different crop locations and even seasons should be considered for making inferences about tuber sprouting based upon aTS. The management of storage temperature can promote or retard tuber sprouting, but its effect depends on the potato clone. Based upon combined correlation estimations, the aTS between EM-OS or between TI-OS is a good estimator for potato tuber sprouting.

Thermal and photoperiodic requirements of the seedling stage of three tropical forest species

“…Of the studies on the influence of air temperature and the photoperiod on plant growth, most have been carried out on agricultural crops, like strawberry (Tazzo et al 2015), sunflower (Souza et al 2016), rice (Steinmetz et al 2017), potato (Bisognin et al 2017), grape (Pedro Júnior and Hernandes 2018), lettuce (Tezza and Minuzzi 2019), and arugula (Barreiros et al 2021) and focused on germination, seedling establishment, budding, flowering, fruiting, and ripening. However, studies of this nature on tropical forest species are still scarce and have focused only on those of commercial interest, such as Eucalyptus at the seedling Freitas and Martins 2019) and flowering stages (Rawal et al 2015), and some Brazilian forest species at the germination (Daibes et al 2019) and seedling stages (Martins et al 2022c).…”