Influence of low night temperatures on sweet pepper flower quality and the effect of repeated pollinations, with viable pollen, on fruit setting

SummaryThe effects of night temperatures on the functioning and fertility of flower parts and, thereby, on fruit set and fruit shape in sweet pepper (Capsicum annum L.) were studied. In cv. Mazurka style length was positively, and the ovary diameter was negatively, correlated with the decrease in night temperatures. The functioning of the flower female organs was also affected by low (14°C or less) night temperatures, and the number of viable pollen grains per flower was markedly reduced and their germinability was impaired. Fruits which set under low night temperatures were deformed (and generally seedless), whereas under higher night temperatures most of the fruits were of the normal, blocky type. The male and female flower organs of cv. 899 were less sensitive to low temperatures than those of cv. Mazurka, so that all the fruits of cv. Mazurka which had set under low night temperatures were small and seedless (flattened) or pointed, while more fruits of cv. 899 were larger, seeded and of better shape. ...