ACHARYA N.G RANGA AGRICULTURAL UNIVERSITY

NUTRIENT STATUS AND EXTENT OF THEIR DEFICIENCIES IN MAIZE
matter was oxidised using 30% hydrogen peroxide
drop by drop. The digested material was distilled by
microkjeldahl method with 10 ml of 40% sodium
hydroxide. The ammonia thus released was collected
in 4% boric acid mixed with bromocresol green and
methyl red mixed indicator. This was titrated against
0.02N sulphuric acid and nitrogen content of samples
were calculated (AOAC, 1980)
The powdered leaf sample of 1g was
digested with 10 ml of diacid mixture of nitric acid
and perchloric acid with a ratio of 5:2. The digested
material was diluted making to 25 ml with double
distilled water and filtered. This extract was used for
the estimation of Zn, Cu, Fe and Mn. The extract
was further diluted for analysis of P and K and
accordingly calculated (Wall et al., 1980).
Phosphorus was estimated in the diacid
extract by vanadomolybdate phosphoric yellow
colour method as described by Jackson (1973) and
potassium was estimated with flame photometer
method (Muhr et al., 1965) and expressed in per cent.
The micronutrient contents in diacid extract
were measured with Atomic Absorption
Spectrophotometer of model Varian 240 FS (AOAC,
1980) and expressed in mg kg -1 .
RESULTS AND DISCUSSION
Nitrogen (N)
N content of the leaf samples ranged from
2.01 to 2.97 per cent with an overall mean of 2.47
per cent. The leaf N content was below the critical
level of 2.60 per cent developed by Neubert et al.
(1969), in 110 samples (73%) out of the total 150
leaf samples collected from the major maize growing
tracts of three districts in Telangana region of Andhra
Pradesh. The N content of maize leaf samples of
Nizamabad district ranged from 2.02 to 2.91 per cent
with a mean N content of 2.49 per cent. Seventy
four percent of leaf samples (37) recorded N content
below the critical level out of total 50 samples
collected in the district, with samples of Velupur
mandal containing highest mean N content (2.64%)
and samples of Balkonda mandal containing lowest
mean N content (2.33%). The leaf samples collected
from 9 mandals out of 10 mandals (90%) in the district
were deficient in nitrogen. The N content of maize
tissue samples of Karimnagar district ranged from
2.05 to 2.97 with mean N content of 2.50 per cent.
Thirty five (70%) leaf samples recorded nitrogen
content below the critical level out of total 50
samples collected from the district. samples from
Gollapally mandal had highest mean N content
(2.68%) and Jagitial mandal had lowest nitrogen
(2.25%). The leaf samples in 7 mandals out of 10
mandals had mean leaf N content below the critical
level with the deficiency of seventy per cent. Nitrogen
content of leaf samples in Warangal district ranged
from 2.01 to 2.70 with a mean N of 2.43 per cent
where 38 leaf samples (76%) had N below the critical
level out of 50 samples collected from the district.
Highest N content (2.52%) was recorded in leaf
samples of Geesukonda and Sangem mandals and
lowest mean N (2.25%) was in leaf samples of
Hasanparthy mandal. When mandal wise mean N
contents were observed, all the mandals (100%) had
mean leaf N content below the critical level. The
reported values in this are within the acceptable
ranges as reported in maize by Escano et al. (1981),
Syed et al. (1992), Sumner et al. (1978 and 1981)
and Elwali and Gascho, (1988) and lesser than as
reported by Walworth et al. (1988), Melsted et al.
(1969) and Sumner et al. (1979).
Phosphorus (P)
Phosphorus content of leaf samples as a
whole collected from three districts ranged 0.17 to
0.50 per cent with an overall mean of 0.31 percent.
Eighteen samples out of total 150 samples collected
were deficient (12 PSD) in phosphorus based on the
critical level of 0.25 per cent developed by Melsted
et al.(1969), Neubert et al. (1969) and Jones et al.
(1990). The mean P content in leaf samples was
more in Karimnagar district (0.34%) followed by
Warangal (0.31%) and Nizamabad (0.29%) districts.
The ranges were from 0.17 to 0.50, 0.21 to 0.41 and
0.18 to 0.49 per cent, respectively in Karimnagar,
Warangal and Nizamabad districts. In Nizamabad
district 7 leaf samples were having P below critical
level out of 50 samples collected with the extent of
14 percent deficiency in the district. Samples of
Maakluru mandal had highest mean P value of 0.37
percent and samples of Yellareddy mandal recorded
lower P content of 0.22 per cent. In Karimnagar
district, 10 percent of leaf samples had phosphorus
below the critical level out of 50 samples collected
in the district, with the higher P value (0.43%) in the
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