AUTECOLOGY AND BIOLOGY OF HANDAL (Citrullus coloynthsis L.) DESERT PLANT

Abstract

The present study was carried out in the desert valley (wadi) Abu Salam (63 Km.) east of Berber city, River Nile State, and in the nursery of the Faculty of Agriculture, Nile Valley University. The autecology and biology of major desert specie, Handal (Citrullus coloynthsis), were studied. The study area (Wadi Abu Salam) was divided into three sections; upper, middle and lower. The soil was classified as sodic soil and contained a high percentage of clay in the upper section, equal percentage of clay and sand in the middle section and high percentage of sand in the lower section. The distribution of Handal plant in the wadi area was investigated. In the first season, it was only detected in the middle section (0.60-0.72 plants/m2). In the second season, the plant was distributed in the three sections of the wadi (1.46-1.66 plants/m2 for the upper section, 0.27-0.49 plants/m2 for the middle section and 0.3-0.4 plants/m2 for the lower sections).The rate of photosynthesis increased during the first stage of growth to reach its maximum (2.2- 2.34 gm/day) during the 8th week from the start of germination, then started to decline till it reached its minimum rate (0.10-0.12 gm/day) at the maturity stage in both seasons. Plant roots growth started at a low rate, then, increased with plant development and became equal after 7 weeks from germination. After that, it decreased until it reached its lowest rate at the stage of maturity.