Melhoramento da batata doce

Florescimento e frutificação

Resumo

1 — The Author reports some works it has been done on sweet potato in order to collect data for their improvement through plant selections and hybridizations.

2 — For cross pollination the Author describes his observations, the emasculation preferably beeing done at 4 p.m. and the pollination next evening.

3 — Flowering seems to be a limitant problem everywhere sweet potato grows. In the climatic conditions these works are been conducted, blossom, as a whole, is as luxuriant as it can be, Bagging were done on 66 varieties and 1513 bagged. flowers (selipollinated) set 152 seeds (Quadro H).

4 — Seventy five sib matings were done on the variety “Cinco Bicos” and no seeds were formed. Interspecilic crosses with Ipomea nihil were made, and on 42 crosses only one fruit was collected (3 seeds). Nihil as male seems to be unlunctional.

5 — These seeds did germinate, however. 1596 seeds of 3 vears old resulting from open pollination were taken for germination and only 38 (2%) germinate. ay

6 — Although no satisfactory datas are recorded so far, to the Author it seems that cross pollination is the main responsible for seeds setiing, as the evidence tends to show that natural self pollination is very scarce.