The experiment was conducted in split plot factorial based on
randomized complete block design with three replications at
Research farm of University of Zabol in 2013. The result of
chemical analysis of the field soil is given in Table 1.
Drought stress consisted of three levels 75% (control), 50%
(mild stress) and 25% of field capacity (severe stress) as main
plots, and factorial combinations of three triple superphosphate
fertilizer (CaH
4
P
2
O
8
) levels (0, 150, and 300 kg ha
)
and two zinc sulfate fertilizer (ZnSO
4
H
O) levels (0 and
30 kg ha
1
2
) as subplots (the fertilizers were applied before
planting time). Generally 18 treatments were used with three
replications. In order to increasing in germination percentage,
the seeds were mixed with soft sawdust in ratio of 1 (seed) to 2
(sawdust) (the ratio is based on weight). The seeds were sown
at 20 cm apart in rows 40 cm wide, on first half of March 2013.
Drought stress levels were determined by the Time Domain
Reflectometry (TDR) (Imko, Germany). Water suitable for
irrigation was obtained from a deep well in the area. The normal
cultural practices of growing chamomile plants were followed
until harvest. The success of chamomile cultivation as
a commercial venture lies in how efficiently and effectively
one can collect the flowers at the right stage during the peak
flowering season extending over a period of 3–6 weeks. Flower
plucking is a selective process as flowers in all stages, namely,
buds, semi-opened buds, flowers in all stages of bloom appear
on the plants. Flowering will be observed on plants here and
there all over the field and these flowers are plucked at the
appropriate stage (Singh et al., 2011). So flowers were selectively
collected on 27 April, 30 April, 4 May, 8 May, and 12
May 2013. Fresh flowers weighted immediately after each collection
and after the final collection, total weight of the harvested
flowers were considered as a fresh flowers yield. A
sample of the harvested fresh flowers were used for the assessment
of carbohydrate (0.2 g of fresh leaf tissue), prolin (0.2 g
of fresh leaf tissue) and carotenoid (0.1 g of fresh leaf tissue).
1