Preferred Cultivars Research Articles

Evaluation of Banana Varieties through Farmer’s Participatory Selection at Teppi, Southwestern Ethiopia

Participatory varietal selection was conducted in Southwestern part of Ethiopia to evaluate the performance of banana cultivars and to identify farmers’ preference and selection criteria in the study area. Seven banana cultivars collected from Melkassa agricultural research center were evaluated in single plot in 2020-2023 main cropping season. Farmers’ evaluation was made at two different stages of the crop, namely at vegetative and at maturity using both direct-matrix and pair-wise ranking methods of selection scheme. Farmers’ set; plant height, disease resistance/tolerance, fruit size and yield as selection criteria to evaluate and identify their preferred cultivars. The results of analysis of variance indicated the existence of highly significant differences among cultivars for all traits measured at 5% probability level. From the previous experiments, the highest mean yield was obtained from the cultivar William I (45.32 t/ha), Dinke-1 (45.1 t/ha), Lady Finger (40.16 t/ha) and Poyo (40 t/ha). Likewise, these three cultivars (William, Dinke-1, and Lady Finger) were identified as farmers preferred cultivars from both pair-wise and direct matrix ranking evaluations. Thus, these cultivars were chosen for their performance in the field and from farmers' evaluation perspective. Moreover, this study indicated participatory varietal selection is a viable method to gain greater insight into farmers’ perceptions, preferences, merits and shortcomings of banana cultivars. Therefore, based on the results of this study, William I, Dinke-1 and Lady Finger cultivars are recommended for multiplication and distribution to farmers in the area and similar agro-ecologies.

Effects of classical and organomineral fertilizer applications on pollen quality and quantity in gemlik olive cultivar

Olive is one of the important plants worldwide in terms of economic and cultural conditions. It is used in fresh consumption, olive oil, cosmetic and pharmaceutic fields and unique numinous plants. Olive can maintain its life for many years even in barren conditions but for an economic cultivation, fertile and preferred cultivars should be used in orchards and optimum maintenance conditions should be provided. At the same time the climate change is also convert the usual behavior of the plants. This study aims to determine the effects of classic and organomineral fertilizers on pollen quality and quantity parameters. In this study, classical fertilizers like Urea+MgSO4 and KNO3+H3BO3+ZnSO4 with Raykat Start, Raykat Growth and Fitomare organomineral fertilizers were sprayed foliarly before flowering on Gemlik olive cultivar and pollen studies were conducted on the flowers formed at full flowering. Within the study, effects of the treatments were evaluated on pollen viability and germination levels, the amount of pollen produced in one flower and the normally developed pollen ratio. As a result of this study, fertilization treatments positively affected pollen quality and quantity with regard to control treatment. In this context, the pollen viability level differed between 74.15% and 89.92%, the pollen germination level between 45.48% and 70.35% and pollen per flower was between 307.238 and 446.761. The lowest data were obtained from control treatments, while the highest were from Raykat group fertilizers. Especially, the 54% increase in pollen germination level with Raykat growth fertilization was one of the most important results of this study. In conclusion, it was determined that the foliar spray of organomineral fertilizers enhanced the pollen properties. Raykat Start, Raykat Growth and Fitomare organomineral fertilizers used in this study significantly increased pollen quality and quantity.

A Countermeasure Strategy against Peramine Developed by Chilesia rudis in the Endophyte-Ryegrass-Herbivore Model.

Exploitation of the symbiotic relationship between endophytic fungi and ryegrass is a crucial technique for reducing the incidence of insect pests. This is primarily due to the production of alkaloids, such as peramine, by the fungi. This alkaloid has been reported as both a deterrent and toxic to a variety of insects. However, insects have developed various strategies to counteract plant defenses. One of the most studied methods is their ability to sequester toxic compounds from plants. In this study, we examined the feeding preferences and adaptation to peramine in Chilesia rudis, a native Chilean larva. Using a no-choice assay, we assessed larval feeding preferences and mass gain on seven experimental lines and two commercial cultivars of endophyte-infected and non-infected ryegrass. Pupal development time and adult performance were evaluated post-assay. Additionally, we measured peramine content in larval carcasses, feces, and ryegrass leaves. Jumbo was the most preferred cultivar with 32 mm2 of leaf tissues consumed. The longest pupal development time was observed in L161 and ALTO AR1, both at 28 days. Wing length in adults was greatest in the Jumbo and L163 cultivars, measuring 1.25 cm and 1.32 cm, respectively. Peramine concentrations were detected in the bodies of C. rudis. In conclusion, this larva can adapt to endophyte-infected ryegrass and develop counter-adaptation mechanisms to mitigate the effects of peramine.

Equine relative preferences regarding selected cool-season grass hays

Horse preferences for cool season grass cultivars under grazing has been described. However, preference for cool-season grass cultivars as hays has not been widely evaluated in horses, particularly the new varieties of Tall Fescue with novel endophytes designed to produce less ergovaline, the compound to which fescue toxicosis is attributed. First cutting hay was harvested in 2019 and 2020 from seven cool season grasses: Tall Fescue v. KY 31; Tall Fescue v. Bronson, endophyte free; Tall Fescue v. Texoma MaxQ, novel/non-toxic endophyte; Meadow Fescue v. Preval; Festulolium v. Spring Green; Perennial Ryegrass v. Elgon; and Orchardgrass v. Crown Royal. First cutting yield was determined on a dry weight basis. Sub-samples were analyzed for forage quality parameters and ergovaline concentrations. The effect of cultivar on mean hay yields was analyzed using a one-way ANOVA, and since the F-Value was significant (< 0.001) the least significant differences were further determined to compare yield differences among the cultivars. All three Tall Fescue cultivars, Meadow Fescue, and Festulolium had significantly greater yields than the Perennial Ryegrass and Orchardgrass (P < 0.05). All samples tested for ergovaline were below the reporting threshold of the laboratory. Subsequently, tillers of the Tall Fescue cultivars were evaluated for endophyte presence. Endophyte was detected in only 3.3 % and 16.7 % of v Bronson and Texoma MaxQ tillers, respectively. No endophyte was detected in v KY 31. To evaluate preference four mature idle horses (6 ± 1.08 yrs) were fasted 30 min prior to being in the test stalls for 30 min. First choice and weight consumed were recorded. Preference testing occurred within harvest year. Equine preference data were analyzed within year using a one-way ANOVA pairwise comparison with the Tukey-Kramer adjustment for multiple comparisons. Both forward and backward stepwise regression modelling were used to investigate proximate analyses values as potential predictors of cultivar consumption by the horses during the preference tests. The best performing model explained 36 % of the variation in cultivar consumption. Based on amounts consumed horses had similar preferences each year; the overall rank of the cultivars was very similar with only the two least preferred cultivars transposed from 2019 to 2020. Horses most preferred the lowest yielding cultivars (Perennial Ryegrass and Orchardgrass). Despite low ergovaline and endophyte content in the Tall Fescue varieties, adult horses preferred hay of other cultivars. Festulolium is an option for hay producers that balances both yield and horse preference.

Integrate analysis of metabolome and transcriptome of three Fragaria × ananassa cultivars to stablish the non-volatile compounds of strawberry flavor

The flavor attribute of Fragaria × ananassa Duch. would decide consumers’ selection of preferred strawberry commercial cultivars. The roles of volatile compounds in strawberry aroma have been well-studied while knowledge regarding the non-volatile compounds is limited. Some non-volatile compounds which are involved in consumers preference of strawberry have been reported, contributions of non-volatile compounds for strawberry flavor remain ambiguous. This study explored the strawberry flavor influences of essential non-volatile compounds by comparing biosynthesis pathways of cultivars exhibiting distinct flavor characteristics. The widely targeted metabolome generated global profiles of three cultivars including 521 known non-volatile compounds. The differential accumulation analysis and precise quantification of soluble sugars, organic acids, polyphenols and free amino acids (FAAs) predicted fructose, citric acid, kaempferol and pelargonin-3-glucoside were key compounds involved in the sweetness, acidity and astringency of strawberries. Further, the conjoint analysis of metabolites and 824 differentially expressed genes revealed that flavonoid biosynthesis, phenylpropanoid metabolism and citrate cycle pathways decided the content difference of key flavor compounds. Within these pathways, several structure genes were predicted as potential regulators of organic acids, flavonoids and umami-taste FAAs. These findings would be helpful in identification of non-volatile compounds and genes responsible for strawberry flavor.

Orchards closer to forest patches produced fewer malformed fruits and more commercial fruits: The importance of legitimate floral visitors

Mexico is the main mango exporter worldwide, making ‘Ataulfo’ one of the most preferred cultivars. However, fruit production has been drastically diminished due to the high incidence of malformed fruits, known as nubbins. One of the possible causes of this is the lack of pollinators, which are necessary to set developed fruits. Since many pollinators depend on forest patches, the proximity of mango orchards to these is expected to decrease the incidence of nubbins. However, no study has evaluated the effect of distance from forest patches on the production of malformed fruits in any mango cultivar. The present study evaluates the incidence of nubbins and the production of commercial fruits, as well as the richness, composition, and frequency of visits of legitimate floral visitors (i.e., those that contact both reproductive parts of the flowers) over two consecutive years on ‘Ataulfo’ mango orchards located at different distances from tropical dry forest patches. Our results indicate that mango orchards located closer to forest patches were visited more frequently and by more species of legitimate floral visitors, showed less incidence of nubbins, and had greater production of commercial fruits than those located further away from the forest patches. Moreover, we found that older mango trees and the absence of exotic honeybees are also key factors to increasing fruit production. Our results highlight the importance of the conservation of tropical dry forest patches to ensure the provision of pollination services and to maintain or increase the production of mango orchards.

Yellow Leaf Disease Resistance and Melanaphis sacchari Preference in Commercial Sugarcane Cultivars.

Sugarcane yellow leaf disease (YLD) caused by sugarcane yellow leaf virus (ScYLV) is a major threat for the sugarcane industry worldwide, and the aphid Melanaphis sacchari is its main vector. Breeding programs in Brazil have provided cultivars with intermediate resistance to ScYLV, whereas the incidence of ScYLV has been underestimated partly due to the complexity of YLD symptom expression and identification. Here, we evaluated YLD symptoms in a field assay using eight sugarcane genotypes comprising six well-established commercial high-sucrose cultivars, one biomass yield cultivar, and a susceptible reference under greenhouse conditions, along with estimation of virus titer through RT-qPCR from leaf samples. Additionally, a free-choice bioassay was used to determine the number of aphids feeding on the SCYLV-infected cultivars. Most of the cultivars showed some degree of resistance to YLD, while also revealing positive RT-qPCR results for ScYLV and virus titers with non-significant correlation with YLD severity. The cultivars IACSP01-5503 and IACBIO-266 were similar in terms of aphid preference and ScYLV resistance traits, whereas the least preferred cultivar by M. sacchari, IACSP96-7569, showed intermediate symptoms but similar virus titer to the susceptible reference, SP71-6163. We conclude that current genetic resistance incorporated into sugarcane commercial cultivars does not effectively prevent the spread of ScYLV by its main aphid vector.

Use of retrotransposon based iPBS markers for determination of genetic relationship among some Chestnut Cultivars (Castanea sativa Mill.) in Türkiye.

The aim of this study was to reveal the genetic relationships among some economically important chestnut cultivars for Türkiye by using retrotransposon-based inter primer binding site (iPBS) markers. In this study, a total of 19 iPBS markers were used to determine the genetic relationships among 11 chestnut cultivars (Castanea sativa Mill.). In the study, chestnut cultivars named Hacıömer, Osmanoğlu, Sarıaşlama, Erfelek, Kemer, Işıklar, Şekerci, Siyah Bursa, Tülü, Bouche De Betizac and Marigoule were the preferred cultivars utilised. Using the online marker efficiency calculator (iMEC), some indices of polymorphism, such as the mean heterozygosity, polymorphism information content, marker index and discriminating power, were determined. In addition, the size ranges of alleles, number of average alleles, number of total alleles, number of polymorphic alleles, and polymorphism rate were determined at a successful level. The chestnut cultivars of Hacıömer and Şekerci were determined to be the most similar cultivars with a similarity coefficient value of 0.924, and they formed a subgroup together with the chestnut cultivars Osmanoğlu and Erfelek, showing close similarity with these two cultivars. The use of iPBS markers in chestnuts in Türkiye was carried out for the first time in this study. The power of iPBS markers to evaluate the genetic relationship for our preferred chestnut cultivars was revealed. For this reason, it has emerged that it will be useful in the molecular characterization of both genotypes in natural chestnut populations and chestnut breeding materials such as varieties and cultivars in chestnut breeding programs.

Maximizing Total Sugar Recovery from Low Severity Pretreatment-Hydrolysis of Sweet Sorghum Bagasse Through Cultivar Selection and Process Optimization

The nature of a sweet sorghum cultivar influences the recovery of sugars from the bagasse during pretreatment. The sugars recovered are used in applications for conversion to high-value products such as alcohols, organic acids, and other fuels and chemicals. The severity of the pretreatment used plays a crucial role in the yield and quality of the sugars that can be recovered. Therefore, a strategic approach was taken to lower the severity of the pretreatment process to a combined severity factor (CSF) value of 0.48, whilst maintaining a high level of total-sugar recovery (i.e. 68% (w/w) and higher). This was achieved by screening 23 sweet sorghum cultivars for high-performance characteristics at low-severity conditions and optimizing the pretreatment process conditions. The pretreatment conditions included time, temperature, and acid concentration ranges of 5 to 60 min, 150 to 210 oC, and 0.00–0.96% (w/w) H2SO4, respectively. Cultivar AP6 was identified as the best performer, producing the highest total sugar yield of 78.17%. A reduction in total by-product formation from 4.79 to 2.79 g/100 g biomass was also observed. Three preferred cultivars selected for pilot scale pretreatment using steam explosion resulted in maximum total sugar recoveries that exceeded 80% (w/w). Cultivar selection provides an opportunity to utilize sweet sorghum bagasse that will liberate sugars at desired yields while reducing the generation of by-products by implementing low severity pretreatments.

Attraction of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) to the semiochemical volatiles of stored rice materials

AbstractIn order to explore the influence of stored cereal volatiles on the behavior of Sitophilus oryzae, the olfactory responses of adult rice weevils to the volatiles of different rice cultivars [Red brown rice (RBR), Daohuaxiangmi (DHXM), Baishuigongmi (BSGM), Yashuixinmi (YSXM), and white glutinous rice (WGR)] were studied using electroantennography (EAG) and behavioural bioassays in different types of olfactometers. S. oryzae showed significantly different preferences for these rice cultivars, in the order RBR &gt; DHXM = YSXM ≥ BSGM &gt; WGR. Furthermore, 26 components were identified in the volatile profile of RBR. Nonanal (29.37%), hexanal (16.08%), and 1-octen-3-ol (8.83%) were the most abundant compounds. EAG recordings showed that the antennae of S. oryzae were able to perceive these three compounds in a dose-dependent manner. The compounds elicited significant EAG responses at various concentrations, with the strongest responses at 100 μg μL−1. S. oryzae had a significant positive behavioural response to nonanal, hexanal, and 1-octen-3-ol at various concentrations, with the most attractive being 50, 100, and 100 µg µL−1, respectively. The olfactory preferences of S. oryzae, based on a comparison of these compounds at their optimal concentrations, were nonanal &gt; 1-octen-3-ol = hexanal. These results indicated that the volatiles of the preferred rice cultivar (RBR) were perceived by the peripheral olfactory system of S. oryzae adults and individually elicited positive chemotaxis. These findings offer new insights into the mechanism of host preferences of stored-grain pests. Nonanal showed the greatest potential for use as a novel monitoring and control tool against this storage-beetle pest.

Online Survey of Consumer Preferences for Poinsettia Cultivars

New introductions necessitate ongoing studies to keep producers updated about current trends. Consumer preference study results for poinsettia cultivars may interest breeders, wholesale producers, and retail consumers. An online consumer preference survey, conducted from 15 December 2020 to 19 January 2021, was posted in the Qualtrics software platform. Email distribution lists and Facebook were both used to promote the online survey. The survey link was accompanied by a description introducing the project’s purpose and expressing gratitude for participation. Qualtrics automatically collected participants’ data. The survey was closed, and the data were collected on 19 January 2021 from 792 respondents. This study aimed to identify consumer preferences for traditional red, white, or pink poinsettia cultivars and novelty selections. The topmost preferred poinsettia cultivars are “Princettia Queen Pink”, “Winter Rose Dark Red”, “Ice Punch”, “Christmas Mouse”, “Princettia Pure White”, and “Princettia Hot Pink”. The color of poinsettia cultivars did not significantly affect the respondents’ willingness to pay. However, pot size substantially impacted their willingness to pay for poinsettias. Respondents were willing to pay USD 4.89, 8.13, 12.11, and 17.14 per pot for the 4-, 6-, 8-, and 10-inch potted poinsettias, respectively. Some of the socioeconomic characteristics of the respondents influenced their decisions on how much they were willing to pay for poinsettias.

Assessment of Natural Fruit Ripening and Fruit Quality of Three Elite Durian Cultivars for Overland Export

The study aimed to assess the natural fruit ripening duration, fruit quality, and consumer preference of 3 elite durian cultivars-‘Monthong’, ‘Musang King’, and ‘Ocee’-after harvest. From the day of harvest at maturity stage until the second day of the fresh fruits emitted aroma; ‘Monthong’ took 9 days for full ripening measured by the natural fruit ripening duration value significantly (p &lt; 0.05) longer by 4 days than of ‘Musang King’ and ‘Ocee’. This value indicated that the longer ripening duration, the longer storage life was. The flesh weight, percentage of flesh weight, and flesh thickness most significantly influenced fruit quality. ‘Monthong’ had significantly higher flesh weight, percentage of flesh weight, and thicker flesh (p &lt; 0.05) than ‘Musang King’ and ‘Ocee’. A questionnaire and interview guide were used to compare the sensory qualities (flesh smell and flesh taste) of the durian cultivars by 50 Thai consumers through smelling (mild, moderate, strong) and eating the flesh. Consumer preference was determined by eating the flesh and smelling each cultivar by the same 50 consumers and then chose the durian cultivar they mostly prefer. Consequently, consumers mostly preferred ‘Monthong’ (54 %) over ‘Musang King’ (28 %) and ‘Ocee’ (18 %) due to its mild aroma, mildly sweet taste, crispy but soft golden-yellow flesh. In conclusion, the significantly longer natural fruit ripening duration (or long storage life) of ‘Monthong’ plus its higher flesh weight, higher percentage of flesh weight, more flesh thickness, and consumers’ high preference are good indicators of its export quality-suitable for shipping fresh overland especially to China, top importer of Thailand. ‘Musang King’ and ‘Ocee’ had short ripening duration (or short storage life); ergo, poor export quality. Shipping by land, sea, and air, including packaging technology development, should then be studied further for the benefit of export market. HIGHLIGHTS The natural fruit ripening duration of ‘Monthong’ cultivar was significantly longer than ‘Musang King’ and ‘Ocee’ The longer storage life of ‘Monthong’ cultivar, due to its higher flesh weight, percentage of flesh weight, and flesh thickness, is a good indicator of an export quality suitable for shipping fresh fruit overland By means of smelling and eating the durian flesh by 50 Thai consumers, ‘Monthong’ was recorded to be the most preferred cultivar due to its mild aroma, mildly sweet taste, crispy outer but soft inner and golden-yellow colored flesh GRAPHICAL ABSTRACT

Varietal differences of japonica rice: Intrinsic sensory and physicochemical properties and their changes at different temperatures

In this study, changes in the physicochemical and sensory properties of seven japonica rice cultivars mainly consumed in Korea were investigated at different storage temperatures. Our results showed no distinct varietal differences in recovery properties, moisture, protein, and amylose contents. In contrast, storage conditions had a considerable effect on physicochemical properties, such as germination rates, seed viability, guaiacol oxidation, fatty acid values, adhesiveness, and all sensory attributes. The results indicated that higher temperatures led to more rapid degradation rates and oxidative reactions. Sindongjin and Samkwang were the most preferred cultivars immediately after harvest. However, they had low storage stability, owing to poor sensory and physicochemical properties, such as germination rates, seed viability, and fatty acid values. Unkwang, the only early maturing variety, had the highest storage stability despite showing the lowest physicochemical and sensory qualities immediately after harvest. Nevertheless, the differences in these cultivars were insignificant. In particular, the varietal differences in physicochemical and sensory properties were negligible when the refrigeration temperature was maintained. Therefore, we suggest that control of storage conditions increases the rice quality more than selection for cultivar types because high-quality japonica rice cultivars are already standardized.

Morphological characterization of Amaranthus cruentusL. mutant lines derived from local and preferred Amaranthus cultivar

Amaranthus species are of underutilized orphan crops grown in tropical and sub-tropical regions of the world. Benin’s most appreciated Amaranthus cruentus L. «local» cultivar is susceptible to saline stress. This study aimed to create genotypes agronomically, at least, as good as the «local» cultivar and useful for further saline tolerance breeding using mutation breeding. The morphological diversity among 19 gamma-irradiated A. cruentus mutant lines and «local» cultivar (control) were investigated, through a randomized complete block design with three replications, using 18 phenotypical traits (12 quantitative and 6 qualitative). The results show that among the six qualitative traits, only terminal inflorescence shape was discriminant. However, permutation analysis of variance revealed significant variability in quantitative traits: leaf width (CV=19%), Branches length (CV=47%), plant height (CV=25%), stem diameter (CV=29%), number of branches (21%) number of leaves (CV=25%). Multivariate analysis of quantitative traits showed the first two principal components contributing to 78.30% of observed variability. Correlation analysis revealed the significance of number of leaves, number of branches, plant height and leaf width for selecting better genotypes for biomass production. Mutant lines L1, L2, L6, L16, L18 and L23 showed high performances for traits cited above and could, therefore, be a good source of genes.

Optimizing the spatial distribution of roots by supplemental irrigation to improve grain yield and water use efficiency of wheat in the North China Plain

Soil moisture affects the yield and water use efficiency (WUE) of winter wheat (Triticum aestivum L.) by regulating the spatial distribution of roots. Therefore, appropriate supplemental irrigation (SI) schemes are essential to achieve high yield and high WUE of wheat by constructing a reasonable root structure. In this study, field experiments were conducted the North China Plain (NCP) from 2018 to 2020. Based on the soil moisture management at sowing on a consistent basis, four SI regimes were set up: no irrigation after seedling emergence (W0), SI at jointing (W1), SI at jointing and anthesis (W2), and SI at regreening, jointing, and anthesis (W3). The results showed that although the grain yield of wheat increased with the SI frequency, the WUE decreased with increasing SI amount. SI at jointing and anthesis significantly increased WUE without reducing or slightly reducing the grain yield. The grain yield and WUE in 2018–2019 were significantly higher than those of the corresponding treatments in 2019–2020, and the yield of Bainong 4199 was higher than that of Zhoumai 18. The grain yield and WUE in 2018–2019 were significantly higher than those of the corresponding treatments in 2019–2020. The root length density (RLD) in the 0–20-cm soil layer increased with increasing SI frequency, but the proportion of RLD in the 40–60-cm soil layer decreased. The average RLD in the 0–60-cm soil layer and grain yield of Bainong 4199 were significantly greater than that of Zhoumai 18. Correlation analysis showed that the grain yield and WUE was positively correlated with the RLD in the 0–20-cm soil layer, and reached a very significant level with RLD in the 0–20-cm soil layer between rows. W2 and W3 in terms of root vigor and the grain filling rate 30 days after anthesis were significantly higher than W1 and W0 and also increased the contribution of post-anthesis dry matter to grain, resulting in an increase in grain weight. These results demonstrated that SI at jointing and anthesis could optimize the spatial distribution of roots, maintain higher root activity and filling rate at the late stage, increase accumulation and translocation of post-anthesis dry matter, and finally improve the yield and WUE. Therefore, we propose that Bainong 4199 was the preferred cultivars for this experiment，under sufficient soil moisture conditions before sowing, SI at jointing and anthesis is the optimal irrigation scheme for wheat on the NCP.

Sensitivity and Recovery of Tomato Cultivars Following Simulated Drift of Dicamba or 2,4-D

Tomato (Solanum lycopersicum L.) plants are commonly injured by the off-target movement of synthetic auxin herbicides. A greenhouse and a field trial were conducted to determine the relative tolerance of eight fresh market tomato cultivars to drift-simulating rates of dicamba or 2,4-D. Tomato cultivars included ‘BHN 589’, ‘Celebrity’, ‘Florida 91’, ‘Mountain Merit’, ‘Primo Red’, ‘Red Deuce’, ‘Red Morning’, and ‘Skyway’. Dicamba (3,6-dichloro-methoxybenzoic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) were applied at 2.8 g ae ha−1 and 5.3 g ae ha−1-D, respectively. By 14 weeks after treatment (WAT), herbicide-treated plants of each cultivar produced less total and marketable yield than their respective nontreated control in the greenhouse trial. For most cultivars, dicamba-treated plants had less marketable yield than 2,4-D-treated plants in the greenhouse. Herbicide treatments also reduced total and marketable yields of each cultivar when compared with their control in the field study at 14 WAT, except for ‘Mountain Merit’. The severity of yield loss from herbicide treatments was cultivar-dependent. Field-grown ‘Skyway’ plants treated with dicamba produced the lowest marketable yield. In contrast, herbicide-treated plants of ‘Florida 91’ produced high marketable yields in the field, but ‘Red Deuce’ plants receiving 2,4-D were also highly productive. Herbicide residue in fruit sampled the third week of the harvest was nondetectable. Because the type of auxin herbicide drift is often unanticipated, ‘Florida 91’ may be the preferred cultivar for cultivation among those tested to maximize tomato production in the field.

Molecular genetic characterization of Amaranthus cruentus L. mutant lines derived from local and preferred Amaranthus cultivar

Molecular genetic characterization of Amaranthus cruentus L. mutant lines derived from local and preferred Amaranthus cultivar

Evaluation of Genetic Variations and Agronomic Performance of Some Cultivars of White Yam (Dioscorea rotundata) in Obio Akpa, Nigeria

Field experiments were conducted in 2020 and 2021 at Teaching and Research Farm of Akwa Ibom State University, Ikot Ekaideh, Obio Akpa Campus, Oruk Anam Local Government Area of Akwa Ibom State to assess Genetic Variability and the Agronomic Performance of ten different cultivars of White Yam (Dioscorea rotundata). The experiments were laid out in a Randomized Complete Block design (RCBD) and replicated three times. Data analysis was done using statistical software (SPSS 20 version). Results indicated differences for some of the traits studied. However, there was a significant difference (P&lt;0.05) for the number of tubers, the weight of tubers, stem number plant, and sprout length. The genetic variability assessment indicated that the phenotype of Variation (PCV) was higher than the Genotypic Coefficient of Variation (GCV) in all the traits, which suggests the influence of the environment on the study genotypes. Moderate heritability and genetic advance values were recorded for sprout length, plant vigor at 8 weeks, plant vigor at 16 weeks, plant vigor at 32 weeks, and number and weight of tubers suggesting that these traits as a good selection for improvement. However, high heritability and Genetic Advance value were recorded for sprout length suggesting the selection for improvement on this trait will be successful. Hence, cultivar TDR110180, TRD 1401593, TDR 1401785, and TDR 1100128 tend to be the preferred cultivars of white yam for improvement as they exhibited the longest sprout length, maximum mean number, and weight of yam tuber and were earliest to attend plant vigor at 8, 16 and 32 weeks after planting respectively.

Foliar Diseases and the Associated Fungi in Rice Cultivated in Kenya

We conducted a survey to assess the occurrence and severity of rice blast and brown spot diseases on popular cultivars grown in the Busia, Kirinyaga, and Kisumu counties of Kenya in 2019. Working with agricultural extension workers within rice production areas, we interviewed farmers (n = 89) regarding their preferred cultivars and their awareness of blast disease, as this was the major focus of our research. We scored the symptoms of blast and brown spot and assessed the lodging, plant height, and maturity of the crops (days after planting). Furthermore, we collected leaf and neck tissues for the assessment of the prevailing fungal populations. We used specific DNA primers to screen for the prevalence of the causal pathogens of blast, Magnaporthe oryzae, and brown spot, Cochliobolus miyabeanus, on asymptomatic and symptomatic leaf samples. We also conducted fungal isolations and PCR-sequencing to identify the fungal species in these tissues. Busia and Kisumu had a higher diversity of cultivars compared to Kirinyaga. The aromatic Pishori (NIBAM 11) was preferred and widely grown for commercial purposes in Kirinyaga, where 86% of Kenyan rice is produced. NIBAM108 (IR2793-80-1) and BW196 (NIBAM 109) were moderately resistant to blast, while NIBAM110 (ITA310) and Vietnam were susceptible. All the cultivars were susceptible to brown spot except for KEH10005 (Arize Tej Gold), a commercial hybrid cultivar. We also identified diverse pathogenic and non-pathogenic fungi, with a high incidence of Nigrospora oryzae, in the rice fields of Kirinyaga. There was a marginal correlation between disease severity/incidence and the occurrence of causal pathogens. This study provides evidence of the need to strengthen pathogen surveillance through retraining agricultural extension agents and to breed for blast and brown spot resistance in popular rice cultivars in Kenya.

In vitro evaluation of marker assisted conversion of adapted sorghum varieties into Striga hermonthica resistant versions

Striga has long been recognized to infest staple food crops like sorghum in Ethiopia. This study was designed to introgress Striga-resistance genes into popular and farmer-preferred varieties through marker-assisted backcrossing and to assess resistance based on Striga germination stimulant activity inagar-gel assay (aga). The experiment was arranged in completely randomized design with four replications. Genotypes performance, heritability and genetic advance were analyzed and Germination rate was measured. The progeny showed significant genetic variation for maximum germination distance (mgd), germination rate (gr), and germination index (gi). The mean mgd ranged from 0.0 mm to 29.45 mm and gr ranged from 0.0% to 72.38%.Of the 118 backcrossed lines, 22.9% showed less than 10 mm of mgd and gr of &lt;30%, revealing provision of low germination stimulant/strigolactones production (lgs). There were significant positive (r = 0.4-0.81) correlations showing the roles of these parameters as selection criteria in breeding for resistance. The existence of higher heritability (h2b = 77-83%) and genetic advance (ga = 62-93%) for the germination parameters indicated possibilities for improving resistance against Striga through selection. Genotypes that carry different qtls showed different capacity of producing Striga germination stimulants in the aga. The combined effect of two qtls (lgs2_SBI-05_60404021 and lgs_3_60629027) at a time showed lower Striga germination stimulant activity and better field resistance indicating existence of possible cumulative effects. Thus, the study showed that marker-assisted backcrossing for transfer of lgs qtls from donor into popular and farmers preferred cultivars has the potential to enhance tolerance/resistance to Striga in sorghum.