International Journal of Horticulture, 2016, Vol.6, No.21, 1-8
2
Materials and Methods
Under cashew hybridization programme, sixty genotypically and phenotypically different hybrids comprising ten cross combinations e.g., Cross A–RP-1X Kalyanpur
Bold Nut, Cross B-RP-1xVTH-711/4, Cross C–RP-2xKankadi, Cross D–M-44/3xVTH 711/4, Cross E–RP-1xKankadi, Cross F–RP-2xVTH711/4, Cross
G-RP-2xKalyanpur Bold Nut, Cross H-M-44/3xKalyanpur Bold Nut, Cross I-Vittol- 44/3xVTH 711/4 and Cross J-BPP-30/1xKalyanpur Bold Nut were developed in
the year 2001 using eight parents (having desirable traits such as bold nut type, profuse flowering, cluster bearing, high shelling percentage (>28%) and nut
yield>2ton/ha). These cashew hybrids are designated in terms of alphabetical letters followed by numerical numbers to refer cross combination and hybrid clone
number. The nuts of different crosses were collected at full maturity and seedlings were raised in the nursery as per standar d package of practices. After attaining
desired growth, the seedlings were planted in the main field with a spacing of 4 mx4 m in the year 2002. The experimental materials included 71 cashew nut test
genotypes comprising above 60 experimental hybrids, eight parents and three standard checks (BH 6, BPP 8 and BH 85) laid out in an augmented design with three
blocks (to accommodate 20 hybrids and all parents and checks in each block) for evaluation and selection of promising hybrid(s) over two years (2011 and 2012).
Observations on vegetative, yield and yield attributing traits were recorded wherever applicable, as per the standard descriptor of cashew (Swamy et al., 1998) and
pooled over two years. The data were subjected to statistical method of analysis of variation following Panse and Sukhatme (1985) and coefficient of variation as per
(Burton, 1952).
Results
and Discussion
The knowledge of genetic variability is imperative for efficient sampling and utilization of genetic resources. With a quest to identify genetic worth and breeding
potential of a set of cashew hybrids as compared to their parents and three standard checks, their overall mean values along with range, phenotypic variance and
co-efficient of variance for nut yield and its thirteen component traits (Table 1). In the present investigation, major emphasis was laid on identification of superior
high yielding genotypes. Many often direct selection based on per se grain yield led to missing of valuable breeding materials which otherwise have potential
genotypic worth for some specific traits. The genotypes which represent the favourable extreme boundary of the range variation may occur at very little frequency,
but these would provide the necessary base for the desired direction of selection. Some of the genotypes which have merit in relation to specific traits (Table 2).
Table 1 Estimates of genetic variability for nut yield (kg/plant) and its component traits in cashew
Para-meters
PHT
TG
CS
(E-W)
CS
(N-S)
FL/ m
2
NPF
NSF
TF
SR
NW
KW
AW
N/P
NY
(kg/plant)
Mean
4.12
59.38
4.03
4.20
16.68
79.65
359.75
439.47
0.22
7.84
2.40
62.43
4.76
2.78
Range
2.77
- 4.97
46.43
-73.5
3.27
- 4.68
2.96
-5.22
12.6
- 22.9
15.41
- 233.4
222.07
- 526.57
268.3
- 723.0
0.063
-0.56
5.32
-12.8
1.56
-3.88
30.7
-149.8
2.22
-8.02
1.59
-4.34
σ
2
P
0.19
36.04
0.11
0.16
4.89
1638.9
4871.94
9070.8
0.01
1.49
0.17
369.54
1.53
0.49
CV (%)
10.64
10.11
8.10
9.64
13.25
50.83
19.40
21.67
42.48
15.57
17.05
30.79
26.02
25.30
*CD
0.05
0.57
5.66
0.551
0.447
2.82
14.79
93.81
98.95
0.07
0.58
0.19
5.086
1.091
0.462
Note:* CD(0.05) between test variety and check variety mean,
σ
2
P
-
Phenotypic variance, PHT-Plant height(cm), TG-Trunk girth(cm), CS(E-W): E-W canopy spread(m), CS(N-S):
E-W canopy spread(m), FL/ m
2
-Flowering laterals/m
2
, NPF-No. of perfect flowers/m
2
, NSF-No.of staminate flowers/m
2
, TF-Total no. of flowers/m
2
, SR-Sex ratio, NW-Nut
weight(g), KW-Kernel weight(g), AW-Apple weight(g), N/P-No. of nuts/panicle, NY-Nut yield(kg/plant)
