MSc

The demand of cashew (Anacardium occidentale L.) for export and local
consumption is increasing in the country and there is a gap of 7 lakh tonnes in the
production to meet the requirement. Due to pressure on land, the possible way to
increase production is to increase productivity by adopting improved varieties. Hybrid
vigour was well exploited in cashew. Cashew Research Station, Madakkathara has
developed many hybrids through hybridization programmes which are maintained in
the farm. In the present study 19 hybrids of stabilized yield along with 11 cross
parents and check variety Poornima were evaluated for yield and quality traits during
the year 2020-2021.
Qualitative and quantitative parameters including those of growth,
inflorescence, apple, nut, yield and biochemical attributes revealed a spectacular array
of variations among the tested genotypes. Among hybrid population, upright and
compact canopy with intensive branching habit, yellowish red flush colour and
pyramid shaped loose inflorescence were predominating. Early flowering from
October was recorded in 13 cashew hybrids and four parents. Cluster bearing habit
was observed in hybrids H03-113/1 (4.65 fruits), H03-55/10 (4.55 fruits) and H03-
53/9 (4.10 fruits). The apple weight varied from16.83 g (H03 55/10) to 137.49g
(Priyanka). Nut weight of more than 10g was observed in hybrids H03-21/10, H03-
97/2, H03-36/8, H03-110/1, H03-52/6, H03-52/7, H03-52/5, HO3-95/4 and H03-
18/17 and these can be represented as bold nut hybrids. The average kernel weight
varied from 1.62g (H03-55/10) to 4.19g (H03-95/4). Nut yield above 18 kg/tree was
recorded in hybrids, H03-92/3 (20.2 kg), H03-52/5(21.5kg), H03-36/8(22.10 kg),
H03-110/1(23.40 kg), H03-97/2 (24.50 kg), H03-21/10 (25.20 kg) and in parent,
Amrutha (21.3kg) and check variety, Poornima (20.0 kg).
In biochemical analysis, TSS ranged from 13.150Brix (H03-18/17) to
17.40Brix (H03-53/9). Vitamin C content ranged from 107.5 to 220.15mg/100ml.
Lowest tannin content was shown by hybrid H03-55/11(0.085%), H03-92/3(0.09%)
and H03-55/10(0.09%). The hybrids H03-57/4, H03-110/1, H03-113/1, H03-52/5 and
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H03-21/10 and parents, Dhana, Madakkathara-1, Vridhachalam-3, and K-22-1 were
less susceptible to TMB.
Nut yield per tree was found to possess significant positive correlation with
nut weight, kernel weight, apple weight, number of bisexual flowers and shelling
percentage. In the principal component analysis 85.92% of total variability was
explained by the first three components with an eigen value greater than one. The
characters like yield per plant, apple weight, shelling percentage, kernel weight, nut
weight and bisexual flowers contributed more towards diversity. Eight hybrids viz.,
H03-21/10, H03-97/2, H03-36/8, H03-110/1, H03-52/6, H03-52/7, H03-52/5 and
H03-95/4 were placed in the first quadrant along with check variety Poornima.
Magnitude of heterosis was calculated for 19 hybrids over mid parent (relative
heterosis), better parent (heterobeltiosis) and standard variety (standard heterosis).
The above eight hybrids along with H03-18/17 exhibited better heterosis.
The hybrids, H03-36/8, H03-97/2, H03-110/1, H03-21/10 and H03-52/5 which
exhibited heterosis and nut weight above 10g, tree yield above 18kg, kernel weight
above 2.5g and shelling per cent above 28 were selected as promising types. Hence
these hybrids may be recommended for commercial cultivation. Further studies
should be undertaken with different traits for exhaustive evaluation for
commercialization. The hybrids H03-52/6, H03 -52/7, H03-95/4 and H03-18/17
having good yield and quality traits can be utilized for crop improvement
programmes.