INFLUENCE OF GREENHOUSE CLIMATIC CONDITIONS ON MUSK-MELON PRODUCTION

• the growth of the plants;
• the level of insertion, on the stem, of male and female flowers;
• the number of female flowers;
• pollination and setting;
• growth of the fruits.

Climate, together with plant nutrition, some growth substances and certain cultural techniques, can interfere with these production factors. Concerning climate, the influence of temperature on the Charentais-type cultivars, Doublon and Vedrantais, was studied in the glasshouses of the Balandran Station. Results were in agreement with those found previously. The temperature differences mainly occure during the night.

On young plants, the warmer treatments (minimum 19°C) are more favorable to growth and give earlier flowering than the cooler treatments (minimum 16°C) and consequently provide an earlier harvest and an equal final yield.

On older plants, after planting, a difference of 3 to 5°C gives, for the higher temperatures, a more vigorous growth and an earlier yield.

Low temperatures promote the formation of female flowers, which are numerous and inserted at a lower level. They increase the number of fruits but reduce their size. Some differences between the reaction of the two cultivars are observed.

Depending on climatic conditions, certain cultural techniques acting on flowering and fruiting may be used. In particular, pruning, management and plant density can, depending on variety, modify climatic effects.