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Background: Vascular streak dieback (VSD) is an important disease in cocoa and a decrease in nutrient supply is indicated to increase the severity of this disease. This study aimed to analyze the direct and indirect effects of nutrients that play a role in protecting cocoa plants from VSD. Methods: The research location was selected based on criteria such as being a smallholder cocoa plantation area, having 5-10-year-old plants and the presence of VSD disease. A sampling technique for observing disease severity was systematically conducted, with the main sample being farmers' plantations. Cocoa leaf samples were taken from branches at one-third of the plant height, specifically from the upper canopy (leaves 3-4), which were physiologically mature, healthy and dark green. The variables observed were disease severity and cocoa leaf nutrient contents. The influence of N, P, K, Mg, Ca, Fe, Mn, B, Cu and Zn on VSD severity was analyzed using path analysis. Result: The results showed that disease severity was related to nutrient content in the leaves. The cocoa leaf nutrients that have a direct influence on the increase in VSD disease severity are K, Ca, Mn and Cu, while nutrients N, P, Mg, Fe, B and Zn have a direct influence on reducing VSD disease severity. Nutrients N and P have a significant direct influence, whereas nutrient K has a significant indirect influence through its interaction with nutrients N and P in reducing VSD disease severity. [ABSTRACT FROM AUTHOR]

Background: Cowpea [Vigna unguiculata (L.) Walp] is a self pollinated crop, belonging to family fabaceae and sub family papilionaceae. It is an important multipurpose grain legume extensively cultivated in arid and semi arid regions of Sub-Saharan Africa, Asia, Central and South America. The assessment of variability present in any crop species is an essential pre requisite for formulating an effective breeding programme, as the existing variability can be used to enhance the yield level of cultivars after following appropriate breeding strategies. Methods: The present investigation was carried out during the Kharif season of the year 2019. The field experiment was carried out at Pulses Research Station, NAU, Navsari in randomized block design. The study was undertaken on fifty three genotypes of cowpea to know the variability present among genotypes for thirteen traits and correlation and path analysis of yield components. Result: Analysis of variance indicated significant genotypic differences for all the characters under study. The highest GCV was recorded for plant height, pods per plant, pods per cluster, seed yield per plant, straw yield per plant, 100 seed weight and harvest index. High heritability coupled with high genetic advance was exhibited by days to 50 per cent flowering, days to maturity, plant weight, seed yield per plant, 100 seed weight, pod length, pods per cluster and seeds per pod indicating the presence of additive gene action. Seed yield per plant was found to be positively and significantly correlated with pods per plant, pods per cluster, pod length, days to 50 per cent flowering and straw yield per plant or seed yield per plant. The present study has indicated the need for giving due weightage to pods per plant, pods per cluster, seeds per pod, 100 seed weight, pod length with straw yield per plant for improving seed yield in cowpea. [ABSTRACT FROM AUTHOR]

Background: Gossypium hirsutum, the most widely cultivated crop in the world has concurrent importance for both fibre quality and yield. Polygenes regulate cotton output and a variety of factors affect the characteristic. As a result, it is essential to have thorough knowledge of the relationships between different component traits and fibre quality. Thus, the aim of the study was framed to know about the correlation along with cause-and-effect relationship among the economic traits. Mathods: Eight parents and 56 hybrids made up the experimental sample for our study, which were evaluated for 18 economically significant traits. The study was conducted at Department of Cotton, Tamil Nadu Agricultural University, Coimbatore, in 2021-2022. Result: Analysis of variance was highly significant for all the traits studied. The result of correlation revealed that the traits viz., number of bolls per plant, boll weight, number of seeds per boll, upper half mean length and fibre strength had a high magnitude of positive correlation with seed cotton yield at both genotypic and phenotypic levels. Path analysis represented the direct effects of upper half mean length, uniformity index, number of bolls per plant, number of seeds per boll and fibre strength on seed cotton yield. Hence, these traits can be used as selection criteria for yield improvement in cotton. [ABSTRACT FROM AUTHOR]

Background: Tenera oil palm is widely planted as a commercial plantation crop throughout Southern Thailand. The purpose of this study was to evaluate the phenotypic correlation and the direct and indirect effects among bunch yields and vegetative characteristics in commercial tenera oil palms. Methods: The oil yield, fresh fruit bunch, bunch number, average bunch weight, leaf area, leaf dry weight and rachis length were recorded from six commercial tenera oil palm progenies. The data were recorded between January 2019 and June 2020 at The Chaipattana Foundation's oil palm plantation in Trang Province, Thailand. Result: Results show that fresh fruit bunch, average bunch weight and rachis length positively correlated with oil yield (rp=0.90**, 0.50* and 0.53, respectively), while bunch number and rachis length positively correlated with fresh fruit bunch (rp=0.58* and 0.47*, respectively). The path analysis shows that bunch number significantly correlated with fresh fruit bunch (0.58*) and strongly directly affected it (1.11). The fresh fruit bunch significantly correlated with oil yield, (0.90**) and had a strong direct (2.08) and indirect effect (1.20). These results indicate that bunch number and fresh fruit bunch are useful variables for oil yield improvement in further breeding programs of oil palm. [ABSTRACT FROM AUTHOR]

Background: Setaria italica is an essential crop in the developing world and yield levels are low. To improve the yield, the utilization of diverse germplasm in a breeding program is vital. Methods: The present study aimed to characterize 50 genotypes in the first year and out of 50, 10 genotypes in the second year using multivariant traits. Wide variation was observed in both the qualitative and quantitative characteristics. Analysis of variance revealed the presence of significant differences for most symptoms. Higher estimates of GCV were followed for grain yields, followed by panicle lengths and organic outcomes. Higher estimates of PCV were observed for plant height and leaf length, followed by leaf width. Low GCV and PCV were recorded as leaf length, 50% flowering in days. PCV study indicated direct selection based on characters, panicle weight, test weight and strawweight showed a high and positive effect on grain yield per plant in both rainy and summer season indicating the proper relationship between these characters with grain yield per plant, which helps indirect selection for these traits thus in improving the grain yield per plant. Variability in foxtail millet germplasm allows plant breeders to effectively select specific donor lines for genetic improvement of foxtail millet. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken with the objective to estimate the interrelationship of characters for seed yield in early maturing genotypes of pigeon pea (Cajanus cajan L.). The material consisted of twenty-one pigeon pea genotypes among which nineteen were early maturing genotypes received from ICRISAT (The International Crops Research Institute for the Semi-Arid Tropics), Hyderabad and two were local varieties collected from BNCA, AAU (Biswanath Chariali College of Agriculture, Assam Agricultural University), Jorhat. The experiment was conducted during kharif 2017-18 in randomized block design (RBD) with three replications at ICR farm, Assam Agricultural University, Jorhat. The estimates of genotypic correlations, in general, were found higher than the corresponding phenotypic correlation coefficients indicating strong association between two characters but the phenotypic values were lessened by the influence of environment. The seed yield per plant had shown significant positive correlation with plant height, pods per plant, pod length and harvest index both at phenotypic and genotypic level. Pods per plant and pod length had shown high positive direct effects on seed yield per plant at both genotypic and phenotypic level. At genotypic level, days to first flowering exhibited maximum positive direct effect on seed yield per plant. Pods per plant and pod length had shown high direct effects on seed yield/plant and hence direct selection for these traits may contribute towards improvement in seed yield/plant. [ABSTRACT FROM AUTHOR]

An experiment comprising of twenty four diverse Faba bean genotypes were evaluated for genetic variability, correlation and path coefficient analysis for pod yield and its contributing traits. Phenotypic and genotypic coefficient of variation were highest for pod yield per plant (PCV= 55.87% and GCV= 53.90%). Pod yield per plant was significantly and positively correlated with plant height, number of primary branches, pod length, pod width, pod weight and number of pods per plant at genotypic level. Number of pods per plant showed the highest positive direct effect (0.845) on pod yield per plant. Days to fifty per cent flowering, days to first pod picking, plant height, number of primary branches, pod width and number of pods per plant appeared as most important characters and could be considered during selection in Faba bean breeding programmes. [ABSTRACT FROM AUTHOR]

An experiment was conducted with the objective of determining the magnitude of association between seedling vigour index and its component characters. Fifty rice genotypes were evaluated in completely randomized design with three replications. Correlation coefficient analysis of vigour index showed positive and significant association with total seedling length, root length, total seedling dry weight, root dry weight, shoot length, germination percentage and first leaf area under normal condition. Germination percentage, total seedling length, root length, shoot length and first leaf area showed strong and significant positive association with seedling vigour index under cold condition. Thus, these traits could play pivotal role in developing cold tolerant rice. Separation of correlation coefficients into direct and indirect effects of component traits for vigour index revealed that the traits total seedling length and root dry weight exerted maximum positive direct and indirect effect respectively on vigour under normal condition. Under cold stress the traits shoot length and root length exerted maximum positive direct and indirect effects respectively for vigour index. These characters, therefore, are required to be considered during selection for vigour improvement in rice under normal and cold condition in rice. [ABSTRACT FROM AUTHOR]

An experiment was conducted in fifty seven pigeonpea genotypes to study the variability, correlation and path coefficient in pigeonpea at Department of Pulses, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore during kharif, 2015. The highest GCV was recorded for number of secondary branches/plant (111.73) followed by number of pods/plant (40.73). Heritability in broad sense ranged from 94.66 (pod size) to 99.93 (number of pods per plant). High genetic advance were observed for number of secondary branches/plant (230.00), number of pods per plant (83.88), single plant yield (80.89) and number of racemes (60.41) indicating the prevalence of additive gene action for inheritance of these traits. Character association studies indicated that number of racemes, number of secondary branches, number of primary branches per plant, clusters per plant, pods per plant, pod length, seeds per pod, and 100 seed weight were strongly associated with seed yield. Path coefficient analysis revealed that days to 50 per cent flowering and number of pods per plant had high positive direct effect on seed yield. Pod size had moderate direct effect on seed yield. Hence due emphasis should be given on number of pods per plant for improvement of seed yield in pigeonpea. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken to study the extent of interrelationship and direct and indirect effect of component characters on seed yield in a set of 20 genotypes of greengram. The material was evaluated in randomized block design with three replications during the Kharif, 2017. Observations were recorded for 13 quantitative characters. Correlation coefficient analysis revealed that seed yield per plant exhibit significant positive correlation with number of pods per plant, biological yield per plant, harvest index, plant height, number of seeds per pod, pod length, number of clusters per plant, seed index. Harvest index, biological yield per plant, number of pods per plant, seed index, number of seeds per pod, plant height and number of clusters per plant exhibited positive direct effect accompanied by significant positive correlation with seed yield. Thus priority should be given to these characters during selection for greengram yield improvement. [ABSTRACT FROM AUTHOR]

Fifty three germplasm of chickpea were undertaken to determine relationships among yield and some yield components using direct (variability, heritability, and genetic advance) and indirect selection parameters (correlation and path coefficient analysis). The present investigation was carried out at the Agriculture Research Farm of Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during the rabi season of 2011-12. Significant genetic variations were observed among the genotypes for days to flower, days to maturity, plant height, number of branches plant-1, number of pods plant-1, 100-seed weight and seed yield plant-1. Correlation studies revealed that seed yield was positively and significantly correlated with number of primary branches, number of secondary branches and number of pods plant-1. The path coefficient analysis based on seed yield, as a dependent variable, showed that pods plant-1 had the greatest direct effect on seed yield (0.81) followed by number of secondary branches. Both correlation and path analysis indicated that pods plant-1 and number of secondary branches were the major direct contributors to seed yield. [ABSTRACT FROM AUTHOR]

Forty nine genotypes of wheat were evaluated for 12 quantitative and one quality traits during 2010-11. The experiment was conducted in randomized complete block design with three replications at Crop Research Centre, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut. The mean, range, genotypic and phenotypic coefficient of variation, heritability in broad sense, genetic advance, correlation and path analysis were analyzed. Plant height, number of productive tillers per plant, spike length, 1000 grain weight, biological yield per plant and harvest index were significant and positive correlated with grain yield per plant. The phenotypic and genotypic path coefficients exhibited high positive direct contribution of number of productive tillers per plant, plant height, harvest index and 1000 grain weight towards grain yield. The positive indirect effect of plant height on grain yield was registered via days to maturity, number of spikelets per spike, 1000 grain weight and biological yield per plant. Number of productive tillers per plant revealed contribution on grain yield via number of grains per spike, 1000 grain weight, biological yield per plant and harvest index revealing that indirect selection of these characters would be effective in improving grain yield per plant. Higher genotypic coefficient of variance along with high heritability and genetic advance for grain yield per plant, plant height, number of spikelets per spike, number of grains per spike and 1000 grain weight would also be of great use for indirect selection for improvement in yield per plant. [ABSTRACT FROM AUTHOR]

Fifty diverse paddy genotypes were evaluated under low land submerged field condition at two different locations i.e. Hingalganje (North 24 Pgs, West Bengal) and Baruipur (South 24 Pgs, West Bengal) during the kharif seasons for three consecutive years of 2011, 2012 and 2013 for the study of association between yield and yield components under submerged condition where the water depth was more than 50 cm at least for two weeks at the vegetative stage of crop. On the basis of mean performances genotypes viz., Mahananda, Sabita, Nagalmuda, Lakshmikajal, Purnendu and Jaladhi II performed better for seed yield than the tolerant checks. High broad sense heritability along with high genetic gain over mean was also observed for plant height, grains/panicle, test weight, and seed yield. Fertile grains per panicle, panicle length and test weight (1000 seed weight) are consistently highly positively correlated with the seed yield. These yield attributes were the major contributing traits for seed yield in rice under submergence in the set of genotypes under study. [ABSTRACT FROM AUTHOR]

The present investigation was carried out in the Department of Horticulture, Faculty of Agriculture, Annamalai University, during the period 2014 - 2015 to asses the extent of genetic variability, heritability, correlation and path coefficient analysis of 60 genotypes of brinjal for yield and shoot and fruit borer tolerance. The experiment was laid out in randomized block design with three replications. The maximum phenotypic and genotypic variation was noted for fruit yield per plant followed by fruit weight, fruit girth, number of fruits per plant and shoot and fruit borer incidence. High heritability along with high estimates of GCV, genetic advance and genetic gain were observed for fruit yield per plant, fruit weight, number of secondary branches per plant and shoot and fruit borer incidence. Among the sixteen morphological characters studied, number of long styled flowers per plant, number of short styled flowers per plant, number of fruits per plant, fruit weight, days to first harvesting and shoot and fruit borer incidence showed positive direct effect. For fruit weight, fruit girth and number of fruits per plant were observed positive and significant correlation. It is suggested that the greater emphasis should be given for selection of these characters. [ABSTRACT FROM AUTHOR]

In the present investigation the level of diversity in 44 potato germplasm was assessed using principal component analysis (PCA) and cluster analysis and interrelationships among ten different quantitative characters was also worked out. A variation of 94.52 per cent was recorded due to first seven principal components on various genotypes. The first PC had high positive weight for plant height, average tuber weight and tuber yield per plant and second was more related to number of shoot per plant, number of tuber per plant and tuber yield per plot. The forty-four potato germplasm were grouped into eleven well distinct clusters. Genotypes belonging to cluster IV, II, IX and VIII were found diverse and best in all respect. Positive and significant correlation of tuber yield observed for plant height followed by number of shoots per plant, average weight of tuber, tuber yield per plant and marketable yield per plot. Path analysis revealed that marketable yield per plot, tuber yield per plant, number of tuber per plant and plant height had highest positive direct effect on tuber yield. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during kharif season 2013 to estimate the correlations and path coefficients for ten quantitative characters among 72 cowpea germplasm. Seed yield per plant had positive significant correlation with days to 50% flowering, plant height, primary branches per plant, pods per plant, pod length, seeds per pod and 100-seed weight at both genotypic and phenotypic levels. Path coefficient analysis revealed that primary branches per plant and 100-seed weight had high direct positive effect on seed yield per plant at both genotypic and phenotypic levels. Pod length, days to maturity, 100 seed weight and pod wall proportion had high positive direct effects on seed yield per plant at only genotypic level. Correlation and path analysis indicated that for increasing seed yield in cowpea direct selection should be carried out for higher values of primary branches per plant, pods length, days to maturity and 100 seed weight. [ABSTRACT FROM AUTHOR]

The present investigation was carried out at Horticultural College and Research Institute, Venkataramannagudem, West Godavari Dist. (Andhra Pradesh). The experimental material comprised of 12 genotypes of Lablab purpureus collected from IIPR Kanpur and AICRP on pigeon pea Bangalore. A wide range of variability was reported in most of the characters. The highest genotypic coefficient of variation was recorded for number of pods per plant followed by pod yield per hectare and lowest in days to first pod harvest. Higher heritability estimates coupled with high genetic advance as per cent of mean were observed for all the characters except days to first harvest and pod width. Correlation coefficient analysis revealed that number of secondary branches per plant, number of inflorescences per plant, number of pods per inflorescence, number of pods per plant, number of seeds per pod, pod width, days to last harvest and 100 seed weight had the significant positive correlation with marketable green pod yield per plant. Path analysis revealed true relationship between yield and number of secondary branches per plant, number of pods per inflorescence and number of pods per plant and direct selection for these traits will be rewarding for yield improvement as correlation was due to direct effect of the characters. Hence, selection based on these characters could be effective in developing high yielding varieties of dolichos bean for coastal Andhra Pradesh. [ABSTRACT FROM AUTHOR]

Studies on correlation among different component traits in rabi redgram with seed yield and their simultaneous path coefficient analysis from the data recorded on fifteen genotypes indicated that seed yield per plant had significant positive relationship with pods per plant, harvest index, plant height, secondary branches per plant, days to flowering, days to maturity and primary branches per plant. Path coefficient analysis revealed maximum positive direct effect of pods per plant followed by harvest index, days to flowering and pod length on seed yield per plant. [ABSTRACT FROM AUTHOR]

Genetic variability, characters association and path analysis between grain yield and its contributing characters were studied using sixteen genotypes of wheat under rainfed conditions. Highly significant differences among genotypes for all the characters were observed. High phenotypic and genotypic coefficient of variation coupled with high heritability and genetic advance as percent of mean were reported for grain yield, biological yield, days to 50% flowering, spikelets per spike, effective tillers per plant and days to maturity indicating predominance of additive gene effects in controlling these characters. Seed yield had significant and positive correlation with days to maturity, plant height, effective tillers/plant, 1000-grain weight and biological yield. Path coefficient analysis revealed positive direct effect of days to 50 % flowering, plant height, spike length, number of seeds per spike, biological yield and harvest index on seed yield. These characters were considered as most important for selection and improvement of seed yield in rainfed wheat breeding programme. [ABSTRACT FROM AUTHOR]

Field and laboratory experiments were carried out at Punjab Agricultural University, Ludhiana to screen suitable parameters for thermotolerance in wheat cultivars. Four wheat cultivars namely PBW-502, PBW-343, WH-542 and PBW-509 were sown at six dates at weekly interval starting from 30th October to 4th December. The growing degree days were accumulated more under 30th October sowing (1815.82) than 4th December (1502.89). The path coefficient analysis revealed that the direct effect of grain weight (P57= 0.3815) followed by number of spikes m-2 (P27= 0.3483) on yield was more as compared to number of grains spike-1 (P47= 0.0744). These results showed that thermal use efficiency, grain filling period, spikes m-2, grainspike weight ratio, test weight can be used as an index for screening thermotolerance in wheat cultivars. [ABSTRACT FROM AUTHOR]