Growth, fructification and plastochron index of different branches in the crown of the husk tomato (Physalis ixocarpa Brot.)

Abstract

The husk tomato (Physalis ixocarpa Brot.) is commonly cultivated in Central Mexico for its fruits. The plants of cv. 'Rendidora' show sympodial growth after forming 3-5 internodes in the main axis. From there on, each internode is terminated with a node having one flower bud, one leaf and 2 branches (dichasium type of branching). With the exclusion of the first 3 bifurcations which initiate 4 equal apparent main branches of the plant, each subsequent bifurcation has unequal ramifications: a stronger one which prolongs the apparent main branch, and a weaker one which serves as the origin of an apparent lateral branch. The apparent lateral branches form smaller internodes but these internodes require more time for their growth which is the reason that the plastochron lasts longer in the apparent lateral branches. By forming a smaller number of internodes in the same period of time, the apparent lateral branches reach a lower value of the plastochron index. All apparent lateral branches of a plant produce a greater total number of fruits, but a large proportion of them abscise. Due to this, the harvested fruits come principally from the apparent main branches. The phenology of the husk tomato plant is described. Its short period of development makes possible its cultivation in regions with a limited vegetative period.