The first crop was planted at the start of the rainy season, thereby ensuring that plants were provided with adequate water to support early growth.
During this trial total rainfall for the first 6 months was about 970 mm (Fig. 1). This crop is referred to as ‘without initial water stress’.
The growing period of the plant extended through two rainy seasons separated by a period of comparative drought between the 7th and 9th month (Fig.1).
Roots were harvested at the end of the first rainy season (6 months), mid dry period (8
months), the onset and middle of the second wet season (10 and 12 months).
The second crop was planted later, immediately after the rainy season.
The total precipitate for the first 6 months was only 158 mm (Fig. 1).
The plants were not provided with sufficient water for growth and, therefore,
subjected to water stress for the first 6 months of their development; we refer to this crop as ‘with initial water stress’.
Plants were subsequently grown through two wet periods (Fig. 1).
Roots were harvested at the end of the early drought (6 months), late drought (10 months) and after the rainy periods (8 and 12 months).