Environmental Effects on Clonal Female and Male Carica papaya L. Plants 

 -  Scientia Horticulturae, 32(3-4), p.221-232, 1987 .
<br/><br/> Clonal male and female papaya plants were grown under six different environments for a year, cut back, and active re-growth studied for another 18 months. A very hot (36/28°C)regime caused rapid plant growth, tall spindly plants, smaller fruits which matured soonest, poorer pollen viability, and plants with the lowest carbohydrate reserves which failed to re-grow. The coolest regime (20/12°C)resulted in very slow growth (4-5 vs. 9-10 leaves per month). Night temperatures of about 12 ° C appeared to be critical in causing sex reversal from staminate to elongatatype hermaphrodite flowers, but shorter day lengths also play a role. Ovule development appeared normal under all environments when pistillate flowers developed, and ovules formed in flowers initiated during the cold winter months can be fertilized with viable pollen. Pollen viability was best at intermediate to hot temperatures with wider diurnal temperature fluctuations. High night temperatures lead to reduced carbohydrate (mainly starch)reserves, which are higher in the base than the tops of the stems. Carbohydrate levels were higher during the slower re-growth phase, especially in male plants. Fruit development time varied from 170 to 312 days, being faster, with more elongated fruits, the hotter the environment. While the largest fruits were produced under 40 
<br/><br/><label>Subjects--Topical Terms: </label><br/>CARBOHYDRATES<br/>ENVIRONMENT<br/>FRUIT DEVELOPMENT<br/>OVULES<br/>PAPAYA CLONES<br/>POLLEN<br/>SEX REVERSAL