The main commercial variety of coffee is the Coffea arabica specie, however, it is very susceptible to damage caused by nematodes, for this reason scions of the C. arabica specie are used on ro-busta (Coffea canephora) rootstocks to improve tolerance to these microorganisms, because they modify the organoleptic, nutraceutical and nutritional characteristics. The objective of this work was to assess the effect of five roasting degrees on commercial beans (light, medium light, medi-um, medium, medium dark and dark) in two varieties of Coffea arabica species (Colombia and Costa Rica) and their respective scions on C. canephora of the Romex variety. The scion of the Co-lombia variety with the medium dark roast had the highest concentration of caffeine, while the coffee beans of the Costa Rica variety with the light roast grade had the highest concentration of chlorogenic acid (5-CQA), while the highest acrylamide content was found in the scion of the Co-lombia variety with the medium light roast beans and nutritional content differs considerably between varieties, however, there is similarity between roasting degrees. The degree of roasting, variety and scion of coffee influences the organoleptic, nutraceutical and nutritional content of the coffee infusion.

Grafting is an effective way to increase plant tolerance to biotic and abiotic stressors, it is widely used in watermelon production. However, grafting is labor intensive due to the additional time is required, such as the management of rootstock regrowth. This study used a new grafting tool to destroy (remove) the epidermis of pumpkin and bottle gourd rootstock cotyledon base during grafting, we called this a new grafting method. Compared with the traditional grafting (100%), the new grafting method had significantly lower rate of rootstock regrowth (2-23%), higher watermelon scion dry weight and leaf area. In addition, the time used for the new hole insertion and one cotyledon grafting method to destroy (remove) the epidermis of rootstock cotyledon base (4.2 s/plant, 4.2 s/plant) is significantly shorter than the time required to remove the rootstock regrowth manually in the traditional grafting (9.3 s/plant, 8.8 s/plant). Thus, this study developed a new grafting method for watermelon to inhibit rootstock regrowth and enhance scion growth, and this new method is cost-effective for grafted watermelon seedlings.