Physiological Determinants for Pod Yield of Peanut Lines

Changes in leaflet shape and seeds per pod modify crop growth parameters, canopy light environment, and yield components in soybean

The number of seeds per unit area is an important yield component in soybean [Glycine max (L.) Merr.]; however, the mechanisms responsible for the regulation of this yield component are not well understood. Field experiments were conducted at Lexington, KY (3 yr), and at Taian, China (1 yr), to investigate the relationship between net canopy photosynthesis and seeds per unit area using genotypes with differences in individual seed growth rates (SGR). At Lexington, shades (30 and 63% reduction in insolation) were placed over plots from growth stage Rl until maturity to create differences in canopy photosynthesis. Planting dates (early and late) and row spacing (wide and narrow) were used at Taian to create differences in canopy photosynthesis. Crop growth rate (CGR) was measured between growth stage Rl and RS as an estimate of net canopy photosynthesis. Yield, seeds per m2, and SGR were also measured. Within each genotype, there was a linear relationship between CGR and seeds per m2 across treatments and years. Within an experiment, seeds per m2 at a constant CGR was inversely related to genotypic differences in SGR. A partitioning coefficient (γ) was estimated by dividing the total sink demand (seeds per m2 ✕ SGR) by CGR. There were no apparent genotypic differences in γ however, γ decreased linearly as CGR increased. The data suggest that the model proposed by Charles‐Edwards, which describes seeds per m2 as a direct function of canopy photosynthesis and a partitioning coefficient and an inverse function of assimilate flux to individual seeds, accurately describes the regulation of seeds per m2 in soybean.

The experiment studied the genetic variability of production and some productivity elements in peanuts grown on sandy soils at Research Development Station Plant Culture Sands Dabuleni during 2018-2020. Several genotypes of local and foreign peanuts were studied. The highest coefficient of variation was recorded at number of secondary branches per plant, number of immature pods, number of mature pods, number of gynophores forming pods, pod production and grain weight per plant. Pod yield per plant showed a highly significant and positive correlation with number of pod-forming gynophores, number of mature pods per plant, grains weight per plant, and days to 50 percent flowering. The number of mature pods per plant was positively correlated with pod yield per plant. Therefore, the number of branches per plant, the height of the main stem, the number of pods per plant, the weight of pods per plant, the number of days to 50 percent flowering, the percentage of shelling and the number of days to maturity are the most important characters that would could be used in selection to increase production.

The use of the surrogate traits with simple inheritance as selection criteria for drought tolerance should speed up the selection programs. The objectives of this study were to investigate the responses of released cultivars of peanut to end of season drought for traits related to drought tolerance and agronomics traits and to identify the released cultivars with tolerance to end of season drought. Ten peanut genotypes and two water regimes (field capacity; FC and 1/3 available water; 1/3 AW) were laid out in a split plot design with four replications for two years. The data were recorded for SPAD chlorophyll meter reading (SCMR), Specific leaf weight (SLW), biomass, pod yield, harvest index (HI), number of mature pods, 100-seed weight and number of seeds per pod. Drought increased SCMR and SLW and reduced biomass production, pod yield and seed size, whereas harvest index and number of pods per plants were not significantly affected. Maintaining high pod yield and number of pods per plant depended solely on high potential under well-watered conditions, whereas maintaining high biomass production and seed size and harvest index was dependent on both high potential and low reduction. SCMR and SLW were well associated and they had high correlations with biomass and pod yield. SCMR seemed to be more stable than SLW and it is recommended to be used as a surrogate trait for drought tolerance in peanut. The released cultivar KKU 60 was identified as drought tolerant by SCMR and SLW and by pod yield

Effects of micronutrients [molybdenum (Mo), boron (B), iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu)] on seed yield and yield components (seed yield per unit area, fertile shoots per unit area, number of racemes per shoot, number of pods per raceme, number of seeds per pod and 1000-seed weight) of alfalfa were investigated in the northwest region of China, over two seasons (2003–2004) on a torrifluvent soil and a site of 1720 m altitude. After two years study, it demonstrated that molybdenum and boron were more critical for alfalfa seed production. Molybdenum increased seed yield by 27–47%, the number of racemes per shoot by 38–55%, the number of pods per raceme by 100–133%, the number of seeds per pod by 48–61% and 1000-seed weight by 24%, and boron increased seed yield by 22–35%, fertile shoots per unit area by 17–35%, the number of racemes per shoot by 38–64%, the number of pods per raceme by 100%, the number of seeds per pod by 41–52% and 1000-seed weight by 16%. Iron, manganese, and copper had any effect on yield components, but they had no effect on seed yield. Zinc had no positive effect on seed yield and yield components. Among seed yield components, the number of pods per raceme was the most important factor to determine alfalfa seed yield. Results from this study will be used to recommend further evaluation of molybdenum and boron across a number of environments around the world and as a basis for developing recommendations to the alfalfa seed production industry.

Reproductive development and yield components in indeterminate soybean as affected by post-flowering photoperiod

A simple crop physiological model was employed to study the yield basis and environmental effects on 31cowpea genotypes of early, medium and late maturities. The tests were carried out at four sites in northern Ghana between 1992 and 1994. Genotypic variations observed for pod yields (Y), reproductive duration (RD), crop growth rates (CGR) and partitioning coefficients (p) were wide. Pod yields averaged 2032, 2170 and 1983 kg ha-1 for the early, medium and the late lines, respectively. The interaction effects of years with genotypes were quite substantial for pod yield and all the other physiological parameters. Partitioning coefficient was more stable than pod yields in the medium and late lines as shown by the non-significant interactions of genotype W location effects. Regression of pod yields and partitioning coefficients with their respective environmental means also showed the latter to be more stable. Plant breeders may, therefore, put selection pressure on p when developing cowpea varieties for the Guinea and Sudan savanna agro-ecological zones, because of its relative stability compared with pod or grain yields. Pod yields correlated with p in all the maturity groups. CGR correlated better with Y for medium and late lines than the early genotypes. This indicates good possibilities for identifying lines which canproduce both haulms for livestocks and pods for human consumption in the medium and late lines. (Ghana Journal of Agricultural Science, 1997, 30(1): 15-22)

Cluster bean is a multipurpose legume crop grown in arid and semiarid regions for feed, fodder, and vegetable purpose. In the present study, seven genotypes of cluster bean were evaluated to estimate vegetable pod yield and guar gum properties under Coimbatore conditions. The experiment was laid out in Randomized Block Design with five replications. Observation on 14 characters viz., plant height (cm), days to first flowering, days to 50% flowering, number of flower cluster per plant, number of pods per cluster, number of pods per plant, pod length (cm), fresh pod weight (g), dry pod weight (g), fresh pod yield per plant (g), dry pod yield per plant (g), seed yield per plant (g), guar gum in seed (%) and protein content in seed (%) were recorded. The results of present investigation showed that CT CBE 002 outperformed all other genotypes studied in terms of plant height (156.34 cm), total number of clusters (16.44.), number of pods per cluster (6.78), number of pods per plant (99.64), seed yield per plant (29.61 g), guar gum percent (30.56 %), and seed protein content (22.13%). Pod weight was found to be the highest in MDU 1(6.62 g). CT CBE 001 was found to have the maximum pod yield per plant (343.12 g) and pod length (15.16 cm) and had the earliest days to first flowering (27.00 days) and days to 50% flowering (39.80 days).

This study was conducted at the University of Cukurova, Faculty of Agriculture research area in 2018 and 2019 in Adana, Turkey. The objective of this study was to determine the effect of plant density on pod yield and some agronomic characteristics of different growth type peanut varieties (Halisbey and NC-7) in main crop growing condition. In this research; five different intra-row spacing (5, 10, 15. 20 and 25 cm) were used in single row planting pattern. The experimental design was a split plot with three replications. Pod number and pod weight per plant, 100 seed weight, shelling percentage, oil and protein content, pod and kernel yield per hectare characteristics of varieties were investigated. As a result; pod number and weight per plant and 100 seed weight values were decreased when the plant density was increased, but shelling percentage, pod and kernel yield and protein percentage values were increased. The oil content was not affected by the plant density. The highest pod yield (6652 kg ha-1 ) was obtained when the seeds planted at 5 cm inter-row spacing (28.5 plants m-2 plant density). The highest pod yield was obtained from Halisbey variety.

The objective of this study was to determine the effect of different sowing dates on pod yield and some agronomic characteristics of the ‘Virginia’-type peanut cultivar ‘Halisbey’, and to determine the optimal sowing date in the Mediterranean region. This study was conducted in 2018 and 2019 at the Experimental Research Farm of Agricultural Faculty, Cukurova University in Adana, Turkey. The seeds were sown on seven dates: March 28, April 8, April 18, April 28, May 8, May 18 and May 28 each year. The experiment included a randomized complete block design with three replications. The plants were harvested 160 days after sowing, starting on September 8 every year. Pod number and pod weight per plant, 100 seeds weight, shelling percentage, oil and protein content, pod and kernel yield per hectare were investigated. As a result, pod number and weight per plant, 100 seeds weight, shelling percentage, pods and kernel yield values were found to be the highest at the experimental variant with May 8 sowing date. While the oil content decreased by delaying the sowing date, the protein content was increased. According to a two-year average, the highest pod yield (8136 kg ha-1) and kernel yield (5711 kg ha-1) were also obtained at the experimental variant with May 8 sowing date.

Critical period for seed number determination in soybean as determined by crop growth rate, duration, and dry matter accumulation

The present investigation was carried out in the experimental field of Technical College of Agriculture, University of Halabja, in 2022 summer season to determine correlation coefficient and path analysis results for yield and its components in cowpea. Twenty-eight genotypes of cowpea used in the Completely Randomized Block Design (CRBD) in three replicates to evaluate ten quantitative characters included pods yield /plant, number of pods /plant, pod length, the number of seeds /pod, the number of branches /plant, 100 grains weight, plant height, average harvest duration, grain index and grain yield /plant. Among the studied traits, pods yield /plant, pod length, the number of pods /plant, 100 grains weight, number of branches /plant, the plant height and average harvest duration showed highly significant and positively association to grain yield /plant with 0.922, 0.432, 0.787, 0.394, 0.309, 0.515 and 0.560 respectively. Pods yield /plant, with 0.785 recorded the highest value of positive direct effect on the grain yield, and followed by the character number of pods /plant with 0.142. The characters number of brunches /plant with -0.060 showed the maximum negative value of direct effect in total grain yield. The pods yield /plant via the number of pods per plant confirmed the highest value of positive indirect effect with 0.654, and the pods yield /plant via the average harvest duration followed it with the value of 0.484. The highest value of negative indirect effect was -0.033 recorded by the average harvest duration via the character number of brunches /plant. The results of those character association work aid in understanding how various characters contribute to overall yield, breeders can use this knowledge to increase yield by increasing yield-contributing traits directly or indirectly.

A field experiment was conducted at Oilseeds Research station, Latur during rabi 2017-18 to evaluate twenty four genotypes of groundnut for genetic variability, character association and path analysis for ten characters under both stress and non stress conditions. Results revealed high phenotypic correlation coefficients (PCV) and genotypic correlation coefficients (GCV) for kernel yield and pod yield per plant and GCV were higher than PCV suggesting strong inherent association under both conditions. High heritability accompanied with high genetic advance as per cent of mean was recorded for kernel yield and pod yield per plant under non stress condition and kernel yield, pod yield, number of pods per plant and SCMR under stress condition. Pod yield exhibited highest positive and significant association with number of pods per plant, number of seeds per pod, kernel yield per plant, test weight, harvest index and SPAD Chlorophyll Meter Reading (SCMR) at both genotypic and phenotypic level under non stress condition. Path coefficients among the characters showed that kernel yield per plant, number ofseeds per pod and harvest index exerted highest positive direct effect on pod yield per plant under non stress and stress conditions.

Vegetable cowpea or Yard long bean [Vigna unguiculata var. sesquipedalis L. (Walp)] is a warm season leguminous crops grown especially for vegetable purpose along the west coast of India. In Goa, pole type varieties are preferred over bushy types as they offer multiple harvests with comparatively longer pods. There is wide variability found for different morphological and other traits in the local types cultivated in the state of Goa. Exploration of genetic variability in the available germplasm is a prerequisite for initiation of any successful breeding programme. Twenty nine genotypes of vegetable cowpea including three improved varieties collected from different parts of Goa state were evaluated for twelve quantitative characters including yield. High variability was observed for pod yield/plant, number of pods/plant and pod length. The high variability for pod yield per plant is apparent as the pod yield ranged from 315.25 to 2070.45 g/plant with an average of 827.48 g per plant. Pod yield depends on number of pods per plant, pod length and pod weight. Number of pods per plant ranged from 36.65 to 147.80. Pod weight depends on pod length, number of seeds per pod and hundred seeds weight. Wide variation was observed for all these characters in the present study. The GCV value was maximum for pod yield per plant (g) followed by pod weight (g) and number of pods per plant. Low values of GCV were observed for days to first flowering, days to first harvest and number of seeds per pod. In the present study, the twenty nine genotypes could be grouped into fourteen clusters based on genetic distance. High coefficient of variation was observed for pod yield per plant, pod weight, number of pods per plant and pod length indicating their significant contribution in determining the inter cluster distances.

Leaf spot and rust are two important diseases on groundnut. Both diseases are frequently found at the same time that influence the growth and reduce the yield of groundnut. This study was conducted to evaluate thirteen groundnut genotypes resistance to leaf spot and rust disease. The experiment was conducted using a split plot design and three replications, with inoculated and uninoculated treatment as main plot, and groundnut genotypes as the sub plot. Disease assessment was conducted by counting number of pustules per leaf, the number of spots per leaf, rust disease intensity, the intensity of leaf spot disease, and leaf area index. Yield components including stover weight, number of pods per plant, number of empty pods, number of chipo pods, and weight of pods per plant were recorded for both inoculated and uninoculated plants. The result showed that leaf spot disease developed earlier than rust disease. Only one genotype was susceptible to rust and the other 12 genotypes were very susceptible, whereas all genotypes tested were very susceptible to leaf spot. The intensity of rust and leaf spot diseases was negatively correlated with yield (r = - 0.1 – (0.4)). Rust and leaf spot diseases reduced the yield components including stover weight (73.2%), number of pods (68%), and weight of pods (72.5%). The number of empty pods and chipo pods were increase to 81% and 56.4% respectively.