Individual Pod Weight Research Articles

Determination of Green Pod Yield Components in French Bean (Phaseolus vulgarisL.) through Correlation and Path Coefficient Analyses

Twenty genotypes including few released cultivars of French bean (Phaseolus vulgaris L.) were evaluated to determine genetic variability, heritability, genetic advance as per cent of mean, correlations among yield and economically important traits and direct and indirect effects of these traits on overall yield. Field trial was conducted during Rabi 2011–12. A high phenotypic (34.20) and genotypic (34.03) coefficients of variations were recorded for number of pod per plant followed by green pod yield, pod weight and pedicel length. Phenotypic coefficients were higher than their respective genotypic correlations in most of the cases indicating that genotypic correlations are stronger, reliable and free from environmental effects. A significant positive correlation between green pod yield and economic traits like number of pods per plant, pod length, individual pod weight and number of seed per pod was estimated which indicates that improvement in these traits could lead to increase in pod yield. Path analysis revealed that number of pods per plant had maximum direct effects on green pod yield followed by pod weight, pod thickness and seed length thus, in improvement programmes, emphasis should be given on these traits to improve green pod yield. The traits like plant height, number of pods per plant, pod length and individual pod weight are important dependable yield contributing traits and need due weight age while formulating selection strategies for genetic improvement of French bean.

The effect of soil temperature on source–sink economy in peanut ( Arachis hypogaea)

Information on the effects of air temperature on the peanut's biomass allocation, water status and gas exchange is common, but we lack information on the effects of soil temperature in the field on the same features. The aim of this study was to determine the effect of soil temperature on the source–sink balance in peanut. Soil temperature ( T soil; 12, 18, 25, 32 and 40 °C) was controlled independently of air temperature (26/20 °C, day/night) with thermostatic water baths. Higher T soil significantly shortened the times to flowering, podding and maturity. Sink (individual pod weight) size increased as T soil fell from 40 to 18 °C. The highest total biomass was produced at soil temperatures of 25, 32 and 40 °C, but the highest pod yield was obtained at 25 and 32 °C. The ratio of pod to total biomass increased almost linearly with decreasing soil temperature to 18 °C. The root-to-shoot ratio was minimum at T soil=25 °C. The concentrations of chlorophyll- a (Chl- a) and Chl- b, CO 2 assimilation rate ( A), quantum yield ( Y Q) and water-use efficiency ( E WU) were highest at 32 °C during pre-flowering and flowering stages and at 25 °C during subsequent pod filling stage. Leaf water potential ( Ψ leaf), hydraulic conductivity ( g h), transpiration rate ( E) and stomatal conductance ( g s) increased with increasing soil temperature. The intercellular CO 2 concentration ( C i) did not respond to T soil. A was positively correlated with Chl- a ( r=0.73, P<0.001) and g s ( r=0.74, P<0.001), and E with g s ( r=0.77, P<0.001). The increased source potential at moderately higher T soil (25–32 °C) in association with the greater sink strength at moderately lower T soil (18–25 °C) indicates that modification of field soil temperature through management practices could improve peanut production by achieving an optimum balance between vegetative and reproductive growth.

Variability, heritability and genetic advance of some quantitative characters over the seasons in soybean

Genetic variability parameters like genotypic coefficient of variation (GCV) plienotypic coefficient of variation (PCV), heritability (h) and genetic advance as per cent of mean (GAM) were studied using the 196 soybean germplasm lines for six plant growth, four yield attributing and ten pod characters in three seasons. Genetic variability parameters for plant growth characters indicate high GCV for degree of indeterminate growth habit. plant height and branches per plant. Estimates of GCV were moderate for days to flower initiation, days to flower termination, whereas low for days to maturity. Heritability and genetic advance as percentage of mean were high for all the plant growth characters (except moderate GAM for days to maturity). With regard to seed yield and yield attributing characters, high estimates of variability parameters were observed in all the three seasons. GCV was high for some of the pod characters viz. individual pod weight, seed to pod shell ratio and pod shattering. but was moderate for seeds per pod, moisture content of pods at physiological maturity, pod length, pod thickness and pod shattering, whereas moderate for seeds per pod, moisture content of pods at physiological maturity, seed to pod shell ratio, pod width and P.T:PW. The pod characters vic. individual pod weight, seed to pod shell ratio, pod thickness, PT.PL and pod shattering expressed high GAM. whereas seeds per pod, moisture content of pods at physiological maturity, pod length, pod width: expressed moderate GAM.

Differential resource allocation in seed and vegetable types of cluster bean [cyamopsis tetragonoloba (L.) Taub.

Selection for vegetable and seed types in cluster bean has necessitated a change in the resource allocation pattern between the seed and pod features. In the vegetable types where selection has been primarily for the pod characteristics, several features such as pod length, individual pod weight, pod coat weight (also referred to as packing cost), packing cost per unit seed weight, packing cost per unit seed number and packing cost per unit pod length indicate a substantial allocation of resource to the pod than the seed. In the seed types, the allocation is biased to seed biomass per se. Though the seed number per pod was same in the vegetable and seed types, the correlation between the seed number per pod with pod length, pod weight, individual seed weight and packing cost was negative for vegetable type, while, it was positive in the seed types. Z transformation considering packing cost per seed weight and seed number per pod, and pod weight to seed weight and packing cost per unit seed number segregated the two types into distinct quadrants. The two contrasting allocation patterns may also represent alternate strategies of cluster bean against seed predators in the wild habitats.

Environmental effects on seed development and hardseededness in Stylosanthes hamata cv. Verano. II. Moisture supply and illuminance

The effects of variation in moisture supply and of level of illuminance during seed formation on the development of hardseededness and on the seed production of Stylosanthes hamata cv. Verano were studied in two glasshouse experiments. Verano plants were grown in pots containing 1.6 kg soil and were watered daily to field capacity until early flowering (43 days after seedling emergence). From day 43 to day 116, the plants were watered every 1, 2, 3 or 4 days. Leaf water potential immediately before rewatering varied from c. -20 to -28 bars in the 4-day treatment. Yields of seed pods were 5.8, 4.6, 3.8 and 3.8 g in the I-, 2-, 3- and 4-day treatments respectively. Severe water stress greatly reduced inflorescence density, had lesser negative effects on frequency of blooming, floret number, seed setting and proportion of florets forming a lower (beakless) articulation, and increased individual pod weight. Watering treatment had transitory and inconsistent effects on hardseededness. Seed production of Verano plants grown after flowering under shades with 30,40 or 59 % transmission or no shade was reduced by low level of illuminance, mainly because of effects on floret number per inflorescence; the proportion of florets forming a lower articulation and individual pod weight (but not seed setting) was also reduced by shading. The seed moisture content at different harvest occasions appeared to influence hardseededness, but shading had no consistent effect.

Effect of Temperature Treatment on Peanut Vegetative and Fruit Growth1

Abstract Two studies were conducted in growth chambers to evaluate the effects of temperature on the vegetative and reproductive growth phases of peanuts (Arachis hypogaea L., cv. Florigiant). Temperature regimes in the first study ranged from 34/30 to 18/14°C day/night and in the second from 34/30 to 22/18°C. The experiments were conducted for 61 and 110 days, respectively. In the first study, the plants were kept vegetative by clipping the pegs. Dry weights of leaflets, petioles and stems, leaf area, and number of flowers were measured. The same measurements plus fruit weights were made in the second study. Early growth, as determined by accumulation of top dry weight, was optimum at a weighted mean temperature of 27.5°C and essentially no growth occurred at 15.5°C. When plants were grown at the optimum temperature for four weeks and then subjected to different temperatures, the treatments had much less effect on top weight during subsequent growth and the optimum temperature decreased somewhat relative to that for early growth. Total fruit weight and individual pod weight were greatest at 23.5°C. Also, the rate of increase in pod weight was greatest at 23.5°C. During early growth the optimum temperatures for development of leaf area and for rate of flowering were above 28°C while in later stages the optimum for rate of flowering decreased to about 26°C.

Genetic Variability, Heritability And Correlation Study In Hyacinth Bean

Forty four hyacinth bean genotypes were studied to estimate the variability, heritability, genetic advance and correlation coefficients. There was a large variation among the genotypes for all the characters among which the number of pods per plant had highest (122 to 425). Green pod yield per plant varied from 0.46 kg to 3.45 kg indicating the presence of high yielding genotypes. High genotypic coefficient of variation was obtained for 100-green seed weight, pod yield per plant, number of pods per plant and harvesting duration. The highest heritability was observed for days to first flower (98.39%) followed by days to first harvest (96.1 %).The pod yield per plant also exhibited high heritability of 77.9% with highest genetic advance (68.28) indicating the possibility of selection to improve this traits. Yield of green pods showed highly significant and positive association with number of pods per plant (r=0.71**), individual pod weight (r=0.54**) and harvesting duration (r=0.198*), which indicates the importance of these characters during selection for high yielding genotypes in hyacinth bean. Keywords: Genetic variability; heritability; hyacinth bean. DOI: http://dx.doi.org/10.3329/bjar.v36i2.9262 BJAR 2011; 36(2): 351-356

Physico-morphological variation in hyacinth bean [&lt;i&gt;Lablab purpureus&lt;/i&gt; (L.) Sweet

Forty-four hyacinth bean genotypes were evaluated for different qualitative and quantitative characters during July 2005 to February 2006 at Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur. The genotypes showed considerable variations for most of the morpho-physical traits. Shape, size and colour of vein, leaf, petiole, stem, flower, pod and seed varied among the genotypes. Days to first flower ranged from 47.6 to 136.3 days indicating the presence of early variety. Individual pod weight varied from 1.47 (HB042) to 12.3g (HB009). The genotype HB027 produced the maximum number of pods/ plant (425) closely followed by HB001 (385). Similar trend was observed for pod yield/plant. The genotype HB027 produced the highest pod yield/plant (3.45kg) followed by HB001 (3.35kg). 100-green seed weight ranged from 4.0g to 73.33g, which indicated the presence of bold seeded genotypes. Among the genotypes, HB027 and HB007 produced very bold green seed and higher green pod yield/plant, therefore, they can be selected for both pod and green seed production purpose. Keywords: Physico-morphological; hyacinth bean DOI: 10.3329/bjar.v35i3.6450Bangladesh J. Agril. Res. 35(3) : 431-438