Half Bloom Research Articles

Determining the Effect of Growing Media on Growth and Flowering of Rose

The present study aimed to determine the effect of Growing Media on Growth and Flowering of Rose. The study investigation was carried out in the Experimental Farm, Dept. of Horticulture, Assam Agricultural University, Jorhat for the year 2022-2023 with a view to assess the effect of growing media on growth and flowering of rose (Variety Revival). The experiment was carried out in Completely Randomized Design consisting of 9 treatment combination viz., T1 {Sandy loam + Sand + FYM @ 1:1:1 (w/w)}, T2 {Loam soil + Sand + FYM @ 1:1:1 (w/w)}, T3 {Clay loam + Sand + FYM @ 1:1:1 (w/w)}, T4 {Sandy loam + Sand + Vermicompost @ 1:1:1 (w/w)}, T5 {Loam soil + Sand + Vermicompost @ 1:1:1 (w/w)}, T6 {Clay loam + Sand + Vermicompost @ 1:1:1 (w/w)}, T7 {Sandy loam + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, T8 {Loam soil + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, T9 {Clay loam + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, which were replicated three times. The test crop positively responded to the growing media and the highest performance was observed for the treatment T8. Stem girth, number of nodes, intermodal length, leaf area and leaf area index, days taken to bud visibility, bud sprouting, half bloom and full bloom, length of stalk and diameter of bud, number of flowers, number of petals per flower and flowering duration (self-life) and diameter of flower were significantly enhanced by the treatment T8.

Response of Phaius tankervilleae Bl. to Various Nutrient Concentration Levels

To ensure the healthy growth and development of vegetative and reproductive tissues, all plants must obtain a specific amount of inorganic mineral elements from their surroundings.One of the most crucial elements that regulates the growth and development of floral crops is the availability of mineral nutrients in sufficient quantities. The current study was carried out at the Assam Agricultural University's Horticulture Experimental Farm in Jorhat, Assam, during the 2020–2021 academic year utilising a completely randomised design with seven different treatment combinations and three replications. The findings showed that mineral nutrients had a substantial impact on all growth features. The treatment T5 (RDF+ Ca 500 ppm) was the most effective in boosting all growth characteristics, including plant height (56.27 cm) ,leaf count (12.33, leaf length (53.07cm), leaf width (9.67cm), leaf area (469.23cm2), stem diameter (7.07cm), and number of pseudobulbs (2.80).T2 (RDF+ Zn 750ppm) exhibited the shortest days for inflorescence visibility (50.87), bud development (142.80), days to half bloom (146.30), and days to full bloom (148.77), as well as the greatest value for spike length (66.73cm), floret diameter (9.67cm), stalk girth (3.67cm), number of florets per spike (12.93), number of spikes per plant (2. (22.80g). For Physiological characters, treatment T2 (RDF+Zn(750ppm) was best for increasing total chlorophyll content (1.55 mg g-1 fw,), stomatal number (37.13), and stomatal size (5.80 \(\mu\) m2).

Metabolite and Transcriptome Profiling Analysis Revealed That Melatonin Positively Regulates Floral Scent Production in Hedychium coronarium.

Melatonin is a pleiotropic molecule that regulates a variety of developmental processes. Floral volatiles are important features of flowers that facilitate flower–visitor interactions by attracting pollinators, structure flower–visitor communities, and play defensive roles against plant and flower antagonists. Aside from their role in plants, floral volatiles are an essential ingredient in cosmetics, perfumes, pharmaceuticals, and flavorings. Herein, integrated metabolomic and transcriptomic approaches were carried out to analyze the changes triggered by melatonin exposure during the Hedychium coronarium flower development stages. Quantitative analysis of the volatiles of H. coronarium flowers revealed that volatile organic compound emission was significantly enhanced after melatonin exposure during the half bloom (HS), full bloom (FB) and fade stage (FS). Under the melatonin treatment, the emission of volatile contents was highest during the full bloom stage of the flower. Variable importance in projection (VIP) analysis and partial least-squares discriminant analysis (PLS-DA) identified 15 volatile compounds with VIP > 1 that were prominently altered by the melatonin treatments. According to the transcriptome sequencing data of the HS, FB, and FS of the flowers, 1,372, 1,510, and 1,488 differentially expressed genes were identified between CK-HS and 100MT-HS, CK-FB and 100MT-FB, and CK-FS and 100MT-FS, respectively. Among the significant differentially expressed genes (DEGs), 76 were significantly upregulated and directly involved in the floral scent biosynthesis process. In addition, certain volatile organic compounds were substantially linked with various DEGs after combining the metabolome and transcriptome datasets. Moreover, some transcription factors, such as MYB and bHLH, were also significantly upregulated in the comparison, which might be related to the floral aroma mechanism. Our results suggested that melatonin increased floral aroma production in H. coronarium flowers by modifying the expression level of genes involved in the floral scent biosynthesis pathway. These findings serve as a foundation for future research into the molecular mechanisms underlying the dynamic changes in volatile contents induced by melatonin treatment in H. coronarium.

Transcriptomic Analysis of the Anthocyanin Biosynthetic Pathway Reveals the Molecular Mechanism Associated with Purple Color Formation in Dendrobium Nestor.

Dendrobium nestor is a famous orchid species in the Orchidaceae family. There is a diversity of flower colorations in the Dendrobium species, but knowledge of the genes involved and molecular mechanism underlying the flower color formation in D. nestor is less studied. Therefore, we performed transcriptome profiling using Illumina sequencing to facilitate thorough studies of the purple color formation in petal samples collected at three developmental stages, namely—flower bud stage (F), half bloom stage (H), and full bloom stage (B) in D. nestor. In addition, we identified key genes and their biosynthetic pathways as well as the transcription factors (TFs) associated with purple flower color formation. We found that the phenylpropanoid–flavonoid–anthocyanin biosynthesis genes such as phenylalanine ammonia lyase, chalcone synthase, anthocyanidin synthase, and UDP-flavonoid glucosyl transferase, were largely up-regulated in the H and B samples as compared to the F samples. This upregulation might partly account for the accumulation of anthocyanins, which confer the purple coloration in these samples. We further identified several differentially expressed genes related to phytohormones such as auxin, ethylene, cytokinins, salicylic acid, brassinosteroid, and abscisic acid, as well as TFs such as MYB and bHLH, which might play important roles in color formation in D. nestor flower. Sturdy upregulation of anthocyanin biosynthetic structural genes might be a potential regulatory mechanism in purple color formation in D. nestor flowers. Several TFs were predicted to regulate the anthocyanin genes through a K-mean clustering analysis. Our study provides valuable resource for future studies to expand our understanding of flower color development mechanisms in D. nestor.

Ethylene Induces a Rapid Degradation of Petal Anthocyanins in Cut Vanda 'Sansai Blue' Orchid Flowers.

Ethylene plays a major role in the regulation of flower senescence, including in the ethylene-sensitive Vanda ‘Sansai Blue’ orchid flowers. This cut flower is popular in Thailand due to its light blue big size florets possessing a beautiful shape pattern. In the present study, we further examined the rapid ethylene-induced process of active anthocyanin degradation in cut Vanda ‘Sansai Blue’ flowers, which occurred much before detection of other typical senescence-related symptoms. For this purpose, the cut inflorescences were exposed to air (control), 1 or 10 μl L−1 ethylene for 24 h, or to 0.2 μl L−1 1-methylcyclopropene (1-MCP) for 6 h followed by 10 μl L−1 ethylene for 24 h at 21°C, and the effects of these treatments on various parameters were assayed. While the fading-induced effect of ethylene was not concentration-dependent in this range, the ethylene treatment significantly reduced the flower vase life in a concentration-dependent manner, further confirming the separation of the bleaching process from senescence. Exposure of the inflorescences to 1-MCP pre-treatment followed by 10 μl L−1 ethylene, recovered both inflorescence color and anthocyanin content to control levels. Quantification of total anthocyanin content, performed by HPLC analysis on the basis of cyanidin-3-glocuside equivalents, showed that ethylene reduced and 1-MCP recovered the anthocyanins profile in non-hydrolyzed anthocyanin samples of Vanda ‘Sansai Blue’ florets, assayed at half bloom and bloom developmental stages. The results showed that the ethylene-induced color fading, observed immediately after treatment, resulted from a significant reduction in the levels of the two main anthocyanidins, cyanidin and delphinidin, as well as of other anthocyanidins present in low abundance, but not from changes in the levels of flavonols, such as kaempferol. This anthocyanin degradation process seems to operate via ethylene-increased peroxidase activity, detected at the bud stage. Taken together, our results suggest that the ethylene-induced rapid color bleaching in petals of cut Vanda ‘Sansai Blue’ flowers is an outcome of in-planta anthocyanin degradation, partially mediated by increased peroxidase activity, and proceeds independently of the flower senescence process.

Deficit irrigation effects on yield and yield components of grain sorghum

Development of sustainable and efficient irrigation strategies is a priority for producers faced with water shortages. A promising management strategy for improving water use efficiency (WUE) is managed deficit irrigation (MDI), which attempts to optimize yield and WUE by synchronizing crop water use with the crop’s reproductive stages. In comparison, deficit irrigation (DI) is applied at a fraction of the full (FI) irrigation requirement. Soil water use and grain yield of grain sorghum [Sorghum bicolor (L.) Moench] were evaluated in the High Plains of Texas, USA under three irrigation strategies: FI, DI, and MDI from 2010 to 2012. Grain yields of FI sorghum averaged 3.7 Mg ha−1 greater (p < 0.001) than DI sorghum in all years. However, MDI yields averaged 1.6 Mg ha−1 more than DI yields, which was significant in 2010 and 2012 (p ≤ 0.006). The WUE of FI sorghum was significantly greater than MDI in 2012 (p = 0.003) and DI in 2010 and 2012 (p ≤ 0.001) demonstrating that limiting water did not reduce WUE in two of the three years. Results suggest that WUE’s of grain sorghum are not compromised under MDI compared with FI in most cropping seasons. While FI provides the greatest opportunity to reduce production risks through increased yield, if irrigation water is limiting, MDI provides less risk than DI due to its ability to maintain yield and WUE. Yield was stabilized in all years by increasing seed panicle−1 under MDI, which was supportive of concentrating irrigation water between growing point differentiation and half bloom to maintain ovules.

Productivity and essential oil quality assessment of promising accessions of Ocimum basilicum L. from north India

The essential oil of Ocimum basilicum L. finds an extensive use in food-flavour, fragrances and cosmetics. In order to explore promising genotypes of Ocimum basilicum for quality production of essential oils, a field experiment was conducted to assess the productivity and essential oil quality of two accessions of Ocimum basilicum (OB-1G and OB-5P) in comparison of an existing prevalent variety of Ocimum basilicum (CIM-Soumya) in the subtropical agroclimatic conditions of north India. Yield and quality attributed were assessed in different harvesting stages (half bloom, full bloom, and seed setting stages) of two cropping seasons (spring-summer and rain-autumn). Significant variations in respect of the essential oil content, fresh herb yield, essential oil yield, methyl chavicol content and methyl chavicol yield were noticed among the investigated O. basilicum taxa. Methyl chavicol (56.1–89.7%) and linalool (1.0–33.7%) were the major constituents of the essential oils. The essential oils of O. basilicum accessions possessed significantly higher content of methyl chavicol (OB-1G: 80.7–89.7%; OB-5P: 81.6–88.9%) as compared with check variety (CIM-Soumya: 56.1–67.6%). Consequently, Significantly higher methyl chavicol yield (96.8kgha−1) was found in OB-1G, followed by 91.3kgha−1 in OB-5P; with lowest (84.9kgha−1) in check variety. All examined taxa produced significantly higher methyl chavicol at full bloom stage in rain-autumn cropping season as compared with spring-summer season. Moreover, the accessions, OB-1G and OB-5P produced 14.0% and 7.5% more methyl chavicol, respectively as compared with the check variety.

Effect of harvest stages, cultivars and drying methods on weight and quality of dry Dutch rose flowers

Investigation was carried out during the years 2013-14 and 2014-15 at Department of Horticulture, Post Graduate Institute, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola to evaluate drying techniques and to find out suitable desiccant, for Dutch roses. Minimum dry flower weight (2.46, 2.39 and 2.42g), decrease in flower weight, diameter of dry flower, minimum reduction in diameter of flower was observed when half bloom stage flowers dried by embedding in silicagel as compared to tight bud stage for the same during both the years (2013-14 and 2014-15) and which was further confirmed in pooled result.A half bloom harvest stage flowers of Gold Strike dried by embedding in silicagel recorded maximum per cent loss of moisture (71.35,75.68 and 73.58 %), per cent reduction in diameter of flowers (13.58, 16.37 and 14.97 %), whereas it was found minimum in tight bud harvest stage flowers of a cultivar Bordo. Among two stages of harvest half bloom harvest stage flowers embedding in silicagel recorded maximum sensory scores for colour, texture and appearance of dried flowers.

Morphological characterization and extent of genetic variation in rose (Rosa hybrida L.)

An experiment was laid out in a randomized block design (RBD) with three replications to evaluate 10 genotypes of rose for various vegetative and floral traits to ascertain genetic parameters such as variability, heritability, genetic (GCV) and phenotypic (PCV) coefficient of variations and genetic advance. Morphological characterization was done for different morphological traits and genetic diversity of rose species based on morphological characters. The mean performance of cultivars for quantitative traits revealed that cv. First Red exhibited maximum for most of the growth, flower as well as physiological characters viz., plant height (137.38 cm), internodal length (7.31 cm), stem girth (1.03 cm), bud length (3.59 cm), stalk length (42.00 cm), flower diameter (9.18 cm), number of petals per flower (43.33), self life (17.33 days), vase life (12.33 days), number of flowers per plant per year (168.50). It also took minimum days to bud sprouting from bud visibility (13.83 days) and half bloom (14.83 days) which was desirable. High heritability coupled with high genetic advance was observed in the character number of flowers per plant per year which indicated that apparently this character was more governed by additive gene effect.

Cloning and expression profile of 1-deoxy-D-xylulose 5-phosphate reductoisomerase gene from an oil-bearing rose

The components of rose essential oil are mainly monoterpene alcohols, predominantly synthesized through the methylerythritol 4-phosphate (MEP) pathway in plants. 1-Deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) is specified to be a first committed enzyme of the MEP pathway. In order to understand better the role of DXR in the rose essential oil biosynthesis at the molecular level, the full-length cDNA of DXR sequence (designated as RhDXR) was isolated from an oil-bearing rose hybrid Rosa cv. Zizhi and characterized, and the expression profile of it was investigated. Essential oils of rose cv. Zizhi and the other five oil-bearing roses were distilled to evaluate the relationship between the expression of DXR gene and oil yield rate. The full-length cDNA of RhDXR was 1915 bp in length, comprised an open reading frame of 1419 bp, encoding an enzyme of 472 amino acids. A comparative analysis with DXRs of selected species from bacteria to higher plants revealed three conserved domains: a conserved cleavage site for plastids, an extended Prorich region, and a highly conserved NADPH oxidase-binding motif existing in the N-terminal region, like in other higher plant species. The relative expression levels of the DXR gene were determined in various tissues: receptacle, leaf, sepal, pistil, stamen, and petal (in the order of decreasing expression level), and at different flowering stages (flower bud, flower in half bloom, and flower in full bloom). Six cultivars could be classified into two groups according to flower color, and within each group there was a positive correlation between the expression level of DXR gene and oil yield rate.

Cloning and Expression Profile of 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase Gene from an Oil-Bearing Rose

The components of rose essential oil are mainly monoterpene alcohols, predominantly synthe� sized through the methylerythritol 4�phosphate (MEP ) pathway in plants. 1�DeoxyDxylulose 5�phosphate reductoisomerase (DXR) is specified to be a first committed enzyme of the MEP pathway. In order to under� stand better the role of DXR in the rose essential oil biosynthesis at the molecular level, the fulllength cDNA of DXR sequence (designated as RhDXR) was isolated from an oilbearing rose hybrid Rosa cv. Zizhi and char� acterized, and the expression profile of it was investigated. Essential oils of rose cv. Zizhi and the other five oilbearing roses were distilled to evaluate the relationship between the expression of DXR gene and oil yield rate. The fulllength cDNA of RhDXR was 1915 bp in length, comprised an open reading frame of 1419 bp, encoding an enzyme of 472 amino acids. A comparative analysis with DXRs of selected species from bacteria to higher plants revealed three conserved domains: a conserved cleavage site for plastids, an extended Pro� rich region, and a highly conserved NADPH oxidasebind ing motif existing in the Nterminal region, like in other higher plant species. The relative expression levels of the DXR gene were determined in various tissues: receptacle, leaf, sepal, pistil, stamen, and petal (in the order of decreasing expression level), and at different flowering stages (flower bud, flower in half bloom, and flower in full bloom). Six cultivars could be classified into two groups according to flower color, and within each group there was a positive correlation between the expression level of DXR gene and oil yield rate.

Efficiency of salicylic acid delay petal senescence and extended quality of cut spikes of Gladiolus grandiflora cv ‘wing’s sensation’

Gladiolus (Wing’s sensation) is one of the popular cut flowers that demonstrates postharvest problems which cause shorter vase life and loss of quality. In this research, effect of salicylic acid (SA) continuous treatment on the quality and vase life of cut Gladiolus cv ‘wing’s sensation’ flowers over four developmental stages (bud stage; half bloom; full bloom; senescence) were investigated. This research was conducted in a split plot in time experiment based on completely randomized design with 3 replications. The flowers were treated in different concentrations of SA (50, 100, 150 and 200 mg/L). Results showed that the SA delayed flower senescence and leakage of ion in petals, as well as decreased fresh weight loss and lipid peroxidation. In addition, these treatments also increased antioxidant enzyme activities of peroxidase (POD) and maintain protein content. The (150 mg/L) SA treatment was the most effective on vase life of cut gladiolus flowers. Moreover, the results showed that the postharvest application of SA (150 mg/L) maintain higher spike fresh weight, antioxidant enzyme, stability of membrane and leading to delay in petal senescence. Key words: Antioxidant enzymes, cut flower, lipid peroxidation, salicylic acid.

Carotenoid bioaccessibility from whole grain and decorticated yellow endosperm sorghum porridge

Sorghum is a staple crop and a potential dietary source of carotenoids in semi-arid regions of Africa, but information on the bioavailability of these pigments is limited. This study aimed at exploring the effects of agronomic manipulation on sorghum carotenoid contents at selected stages of kernel development and maturation and assessing carotenoid bioaccessibility from matured yellow-endosperm sorghum varieties (P88 and P1222), by comparing porridge made from sorghum whole and decorticated milled grains. Carotenoid content of sorghum milled fractions ranged from 2.90 to 7.22 mg/kg in P88 unbagged decorticated flour, at 50 and 30 days after half bloom (DAHB) respectively, to 9.87–13.69 mg/kg in bagged decorticated bran fractions in P88, at 50 and 30 DAHB respectively. Maize milled fractions were significantly ( P < 0.05) higher in carotenoid content than all sorghum products. Bagging increased sorghum carotenoid content by 8–184% vs. unbagged panicles. Carotenoid bioaccessibility was generally higher from sorghum (63–81%) compared to maize (45–47%). Micellarization of xanthophylls (75%) was more efficient than carotenes (52%) in sorghum, while they were similar in maize (40–49%). These results suggest that the higher bioaccessibility of sorghum carotenoids combined with efforts to enhance sorghum carotenoid content may allow for sorghum to provide similar levels of bioaccessible carotenoid pigments as common yellow maize.

Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills

Rosa damascena Mill. is an important aromatic plant for commercial production of rose oil, water, concrete and absolute. The rose water and rose oil produced under the mountainous conditions of Uttarakhand were investigated for their chemical composition. The major components of rose water volatiles obtained from the bud, half bloom and full bloom stages of cultivar ‘Ranisahiba’ were phenyl ethyl alcohol (66.2–79.0%), geraniol (3.3–6.6%) and citronellol (1.8–5.5%). The rose water volatiles of cultivar ‘Noorjahan’ and ‘Kannouj’ also possessed phenyl ethyl alcohol (80.7% and 76.7%, respectively) as a major component at full bloom stage. The essential oil of cultivar ‘Noorjahan’ obtained from two different growing sites was also compared. The major components of these oils were citronellol (15.9–35.3%), geraniol (8.3–30.2%), nerol (4.0–9.6%), nonadecane (4.5–16.0%), heneicosane (2.6–7.9%) and linalool (0.7–2.8%). This study clearly showed that the flower ontogeny and growing site affect the composition of rose volatiles. The rose oil produced in this region was comparable with ISO standards. Thus, it was concluded that the climatic conditions of Uttarakhand are suitable for the production of rose oil of international standards.

Characterization of Carotenoid Pigments in Mature and Developing Kernels of Selected Yellow-Endosperm Sorghum Varieties

Sorghum is a critical source of food in the semiarid regions of sub-Saharan Africa and India and a potential source of dietary phytochemicals including carotenoids. The objective of this study was to determine the carotenoid profiles of sorghum cultivars, selected on the basis of their yellow-endosperm kernels, at various developmental stages. Following extraction from sorghum flours, carotenoids were separated by high-performance liquid chromatography (HPLC) with diode array detection. Total carotenoid content in fully matured yellow-endosperm sorghum kernels (0.112-0.315 mg/kg) was significantly lower (p < 0.05) than that in yellow maize (1.152 mg/kg) at physiological maturity. Variation in total carotenoids and within individual carotenoid species was observed in fully mature sorghum cultivars. For developing kernels, large increases in carotenoid content occurred between 10 and 30 days after half bloom (DAHB), resulting in a peak accumulation between 6.06 and 28.53 microg of total carotenoids per thousand kernels (TK). A significant (p < 0.05) decline was noted from 30 to 50 DAHB, resulting in a final carotenoid content of 2.62-15.02 microg/TK total carotenoids. (all-E)-Zeaxanthin was the most abundant carotenoid, ranging from 2.22 to 13.29 microg/TK at 30 DAHB. (all-E)-Beta-carotene was present in modest amounts (0.15-3.83 microg/TK). These data suggest the presence of genetic variation among sorghum cultivars for carotenoid accumulation in developing and mature kernels.

Decline in ascorbate peroxidase activity – A prerequisite factor for tepal senescence in gladiolus

Flower senescence was studied in Gladiolus cv. "Snow Princess" over five arbitrarily divided developmental stages (stage 1, half bloom; stage 2, full bloom; stage 3, beginning of wilting; stage 4, 50% wilting; stage 5, complete wilting) in terms of changes in fresh weight, antioxidant enzymes (superoxide dismutase, SOD; ascorbate peroxidase, APX; glutathione reductase, GR) activities and membrane integrity. A significant decrease in tepal fresh weight was observed over the senescence period (after stage 2). Membrane integrity was studied by measuring lipid peroxidation [in terms of thiobarbituric acid reactive substances (TBARS) content] and membrane stability index (MSI) percentage. Maximum TBARS content was recorded in stage 4 (50% wilting). This increase in lipid peroxidation over the senescence period was in close association with high degree of membrane deterioration expressed as decrease in membrane stability index percentage. A significant decrease (two and half-fold) in MSI% in stage 5 (as compared to stage 1) indicates complete membrane deterioration. Progressive increase in endogenous H2O2 level was recorded over senescence period. Maximum H2O2 content (19.7+/-1.4 micromol g(-1) DW) was recorded at stage 5 (complete wilting). Three different patterns were observed in antioxidant enzymes behavior over the senescence period. APX activity was declined significantly as, the flower entered stage 3 (beginning of wilting) from full bloom condition (stage 2). Progressive and significant increase in SOD activity was measured as a function of time. Maximum SOD activity (24.2+/-0.8 U mg(-1) DW) was recorded in stage 5 (three-fold increase over stage 1). GR activity initially increased up to stage 4 (50% wilting) and declined significantly thereafter (approximately seven-fold). An increase in endogenous H2O2 level during senescence may be the result of a programmed down-regulation of APX enzyme activity, which seems to be the prerequisite factor for initiating senescence process in gladiolus tepal.

CORRELATION AND PATH COEFFICIENT ANALYSIS IN SORGHUM (SORGHUM BICOLOR L. MOENCH)

A study undertaken with 40 sorghum types revealed the high positive and significant association of plant height, peduncle thickness, leaf number, grain number, grain weight and straw yield with grain yield both at phenotypic and genotypic level. Among the inter-correlations, the positive association of straw yield with days to half bloom, leaf number and plant height was significantly positive. Significant negative associations were observed for panicle length.with grain weight and peduncle thickness. The path coefficient analysis indicated the high direct effects of grain number and grain weight on yield. Plant height, leaf number, peduncle thickness and straw yield had positive indirect effects on grain yield through grain number, but the indirect effects of grain weight and whorl number were negative on grain yield, through number of grains.

AN APPRAISAL OF GENETIC DIVERSITY IN PROSO MILLET (Panicum miliaceum L.)

Mahalanobis D Statistic was used to estimate the genetic diversity among 50 types of proso millet (Panicum miliaceum L.). The types grouped themselves into as many as 15 clusters indicating wide genetic variability among them. Geographic distribution was not related to genetic diversity pointing to the availability of wide genetic variability in the types from the same geographic region. The clusters XII and XIV were highly divergent from the others. The type MS. 5201 in cluster XIV was superior in yield of grain and straw, panicle length and rachis number while MS. 1452/1 in cluster II was superior for panicle number. The type MS. 4955 in cluster VII recorded the lowest number of days to half bloom. When these types which are highly divergent are utilized in a crossing programme, a large spectrum of recombinants are likely to be unleashed. The rank total analysis disclosed that yield of grain and straw and panicle length contributed most to genetic divergence.

Relationship between agronomic and silage quality traits of forage sorghum cultivars (1988)

Results from two trials evaluating 11 forage sorghums as silage crops indicated that silage quality traits of voluntary intake, digestibility, and crude protein content were linearly associated with the agronomic characteristics of days to half bloom and plant height. Intake was negatively associated with plant height (r = -.49); digestibility was negatively associated with days to half bloom (r = -.39) and plant height (r = .49); and crude protein was negatively associated with days to half bloom (r = .51) and plant height (r = -. 71). Within the same cultivar, but between years, voluntary intake varied by as much as 30 percent, digestibility by 13 percent, and protein content by 12.5 percent. Forage sorghums were also compared to grain sorghum and corn hybrids.

Effect of maturity at harvest on yield, composition, and feeding value of forage and grain sorghum silages (1987)

In the last 2 years, three trials were conducted to determine the influence of hybrid and stage of maturity at harvest on silage yield, composition, and nutritive value for 15 forage and nine grain sorghum hybrids. Agronomic data, such as days to half bloom, plant height, and whole-plant dry matter (OM) and grain yields, were also obtained. In Trial 1, Pioneer 947, Acco Paymaster 351, and DeKalb 25E forage sorghum hybrids had different whole-plant OM and crude protein (CP) contents. Whole-plant OM increased, whereas CP generally decreased with advancing maturity. Hybrid affected both DM intake and CP digestibility. Results indicated that the late-dough stage of maturity optimized both yield and nutritive value. In Trials 2 and 3, grain sorghums reached the late-dough stage in fewer days than forage sorghums. The whole-plant DM and CP contents and grain yields differed considerably among the forage sorghums, and all were lower than values for the grain sorghum hybrids. However, Whole-plant DM yields were generally higher, but much more variable for the forage than for the grain sorghums. These results substantiate that large variations exist among forage sorghums and between grain and forage sorghum hybrids. Sorghums with higher DM and grain content should be favored and harvested at the late-dough stage for silage.