Selection Of Varieties Research Articles

Multi environmental evaluation for selection of stable and high yielding sugarcane (Saccharum officinarum L.) clones based on AMMI and GGE biplot models

The present study was aimed to evaluate the G x E (genotype x environment) interaction using AMMI and GGE biplot analysis to identify sugarcane (Saccharum officinarum L.) genotypes that combine high yield and stability in multi-location trials. Twelve advanced clones generated in the sugarcane breeding programs along with three standards (Co 86032, CoC 671 and Co 09004) were evaluated for cane and sugar yield using randomized complete block design with three replicates over two plant crops and one ratoon during 2019 to 2021 across two years and locations. Data was collected on yield traits and sugar quality characters. Stability parameters were determined. The data was also investigated using GGE biplot and the AMMI models. The results of combined analyses of variance exhibited significant differences among genotypes at the three test environments and when locations were combined. The GE interaction was also significant for all the traits, indicating inconsistency of performance of the genotypes over the locations and seasons. Pooled data analysis of 15 genotypes indicated the superiority of Co 15017 and CoN 15071 for CCS yield across six environments. Two clones, Co 15017 and CoSnk 15102 recorded higher mean cane yield as compared with three standards across the six experimental conditions. Multivariate (AMMI and GGE biplot) statistical analysis indicated that CoSnk 15102 exhibited higher and more stable commercial cane sugar yield and cane yield per hectare, indicating this genotype’s suitability across the test locations. The results of such multi-environmental trials with the elucidation of GE interaction using AMMI and GGE are of great significance in guiding the selection and recommendation of stable and superior varieties in sugarcane production zones.

БИОХИМИЧЕСКИЕ И ТЕХНОЛОГИЧЕСКИЕ ОСОБЕННОСТИ СОРТОВ, ФОРМ И КЛОНОВ ВИНОГРАДА СЕЛЕКЦИИ ФГБНУ СКФНЦСВВ

The current area of research is a comprehensive study of varieties, forms and clones of local breeding for a reasonable selection of modern varieties. The aim of the study was to study the biochemical and technological characteristics of varieties, forms and clones of grapes bred by NCFSCHVW in the edaphoclimatic conditions of the Kuban. The objects of research were varieties, forms, clones of the NCFSCHVW breeding (9 white-berry, 11 dark-berry and 4 control varieties), as well as fresh grape must and dry wine materials obtained from them. Wine materials were prepared according to classical technologies for low-oxidized white wines and red wines with a «floating cap». The mass concentrations of sugars and titratable acids were determined in the must. Physicochemical and organoleptic characteristics, indicators, composition of aroma-forming components and individual organic acids were determined in wine materials. A complex of phenolic substances, vitamins and vitamin-like substances was studied in red wine materials. It was established that the must of the studied samples had moderate mass concentrations of sugars and titratable acids: white berry 19.1-22.5 g/100 cm3 and 7.6-8.3 g/dm3 , respectively; dark berries 20.2-24.4 g/100 cm3 and 6.8-8.0 g/dm3 , respectively. It was noted that the group of Tana forms was distinguished by a higher volume fraction of ethyl alcohol of 11.8-12.5 % vol. In a sample of dry wine material Tana 95, a higher content of esters (89.8 mg/dm3 ) was noted, among red ones – in wine materials Tana 33 (116.8 mg/dm3 ), Kurchanskiy (100.1 mg/dm3 ) and Cabernet Kuban (105.2 mg/dm3 ). The mass concentration of higher alcohols in dry wine materials from the white berry forms of Tana (295.9-349.8 mg/dm3 ) exceeded the classic varieties and proto-clones from the Chardonnay and Riesling lines (192.6-264.4 mg/dm3 ). Vladimir stood out by the amount of phenolic substances (3603 mg/dm3 ), Tana 85 distinguished according to the accumulation of anthocyanins. Kurchanskiy, Vladimir and Tana 85 were isolated according to the amount of vitamins and vitamin-like substances.

Transcriptome-Based WGCNA Analysis Reveals the Mechanism of Drought Resistance Differences in Sweetpotato (Ipomoea batatas (L.) Lam.).

Sweetpotato (Ipomoea batatas (L.) Lam.) is a globally significant storage root crop, but it is highly susceptible to yield reduction under severe drought conditions. Therefore, understanding the mechanism of sweetpotato resistance to drought stress is helpful for the creation of outstanding germplasm and the selection of varieties with strong drought resistance. In this study, we conducted a comprehensive analysis of the phenotypic and physiological traits of 17 sweetpotato breeding lines and 10 varieties under drought stress through a 48 h treatment in a Hoagland culture medium containing 20% PEG6000. The results showed that the relative water content (RWC) and vine-tip fresh-weight reduction (VTFWR) in XS161819 were 1.17 and 1.14 times higher than those for the recognized drought-resistant variety Chaoshu 1. We conducted RNA-seq analysis and weighted gene co-expression network analysis (WGCNA) on two genotypes, XS161819 and 18-12-3, which exhibited significant differences in drought resistance. The transcriptome analysis revealed that the hormone signaling pathway may play a crucial role in determining the drought resistance in sweetpotato. By applying WGCNA, we identified twenty-two differential expression modules, and the midnight blue module showed a strong positive correlation with drought resistance characteristics. Moreover, twenty candidate Hub genes were identified, including g47370 (AFP2), g14296 (CDKF), and g60091 (SPBC2A9), which are potentially involved in the regulation of drought resistance in sweetpotato. These findings provide important insights into the molecular mechanisms underlying drought resistance in sweetpotato and offer valuable genetic resources for the development of drought-resistant sweetpotato varieties in the future.

Genome-Wide Association Study of Starch Properties in Local Thai Rice.

Rice (Oryza sativa L.) is the main source of energy for humans and a staple food of high cultural significance for much of the world's population. Rice with highly resistant starch (RS) is beneficial for health and can reduce the risk of disease, especially type II diabetes. The identification of loci affecting starch properties will facilitate breeding of high-quality and health-supportive rice. A genome-wide association study (GWAS) of 230 rice cultivars was used to identify candidate loci affecting starch properties. The apparent amylose content (AAC) among rice cultivars ranged from 7.04 to 33.06%, and the AAC was positively correlated with RS (R2 = 0.94) and negatively correlated with rapidly available glucose (RAG) (R2 = -0.73). Three loci responsible for starch properties were detected on chromosomes 1, 6, and 11. On chromosome 6, the most significant SNP corresponded to LOC_Os06g04200 which encodes granule-bound starch synthase I (GBSSI) or starch synthase. Two novel loci associated with starch traits were LOC_Os01g65810 and LOC_Os11g01580, which encode an unknown protein and a sodium/calcium exchanger, respectively. The markers associated with GBSSI and LOC_Os11g01580 were tested in two independent sets of rice populations to confirm their effect on starch properties. The identification of genes associated with starch traits will further the understanding of the molecular mechanisms affecting starch in rice and may be useful in the selection of rice varieties with improved starch.

Genotype and agronomic management interaction to enhance wheat yield and water use efficiency in the Mediterranean rainfed environment of Morocco: I. Field data analysis

Durum wheat (Triticum turgidum subsp. durum), considered better drought tolerant, is the most cultivated wheat in Morocco and in the Middle East and North Africa (MENA) region. The region, including Morocco, predominantly has rainfed production systems, declining water supply, and increasing trends and effects of rainfall variability and climate extremes leading to poor crop yield and yield stability. The objectives of this study were to understand major factors determining wheat yield and water use efficiency (WUE); assess the interaction of genotype × environment × management on crop yield and field- and crop-water use efficiencies; and determine the water-limited yield gaps of genotypes under different agronomic management practices in the Mediterranean climate of Morocco. Four years (2015/16–2018/19) of on-station experiments investigating genotype (ten genotypes including seven advanced line and three commercial varieties), seeding time (17 November vs. 29 December), and water management (rainfed vs. supplementary irrigation), was conducted at Merchouch research station, Morocco. The results showed that durum wheat yield mostly varied due to year (rainfall) by 43%, followed by water management × year (23%), year × seeding time (15%), and genotype (7%), with the highest yield (7.15 t ha−1) observed in 2018 (wet year) and the lowest in 2019 (dry year). Across years, not only the rainfall amount but also its distribution during the crop growing season caused yield variability. In low-rainfall years, supplementary irrigation (28–166 mm) increased yield by 2.12–3.27 t ha−1 compared to rainfed conditions. The significant (p < 0.01) year × seeding time × genotype effect on grain yield and WUEs indicates that the response of genotype and seeding time varied with rainfall amount and distribution as the water-limited yield gap in rainfed conditions appeared to be more than 2 t ha−1. In both supplementary irrigated and rainfed systems, the machine learning model showed the effect of different climatic (rainfall and temperature) and management (seeding time, genotype, and irrigation) factors determining yield, yield attributes, and WUEs. The total rainfall remained the most important factor explaining variation in rainfed wheat yield followed by the temperature at flowering, mid- and early-season rainfall, and genotype in order of importance. Similarly, seasonal rainfall was the most important factor explaining variation in grain yield followed by early-season rainfall, days to flowering, temperature at flowering, irrigation amount, seeding time, and genotype in supplementary irrigated durum wheat. Our study clearly shows that yield is highly related to rainfall in rainfed drylands, and the selection of high WUE variety and crop management practices are the key to improving the resilience and sustainability of durum wheat in Morocco and similar production environments in the MENA region.

Estimation of the productivity of rice samples under severe field drought

Drought is one of the most important factors hindering the cultivation of rice, resulting in large yield losses, and limiting productivity growth. The purpose of the current study was to determine the drought resistance of rice varieties and samples of various origins under conditions of periodic irrigation with periods of prolonged soil aridity and high air temperature, to identify drought-resistant plants for the selection of upland varieties. There have been studied 68 varieties and samples of upland rice when grown on irrigated and flooded areas (Proletarsk, Rostov region). There has been established that varieties and samples under drought conditions and sufficient water supply formed different grain productivity, which in 2020–2021 with a lack of water amounted to 63.7 % of the norm, and in 2022 to 30.1 %. There has been found that the correlation of rice productivity under dry conditions with that under full moisture supply was weak negative (r = –0.22±0.12), and with the drought resistance index (DRI) it was high positive (r = 0.95±0.04). The values of quantitative traits under drought conditions have changed significantly in comparison with the control. Such traits as plant height (95.7 %), panicle length (73.1%), panicle density (58.7 %), number of harvested plants per 1 m2 (87.3 %), plant weight (42.3 %), panicle weight (25.1 %), total number of spikelets (54.5 %) and grains per panicle (32.4 %), 1000-grain weight (70.4 %) have decreased. Such traits as number of productive stems per 1 m2 (115.2 %), tilling capacity (126.1 %), the number of empty spikelets per panicle (205.1 %) and the percentage of empty grains (339.1 %) have increased. There have been identified such 9 varieties and samples with DRI from 51.1 to 93.7 % as ‘Kontro’, ‘An-Yun-Ho’, ‘Chan-Chun-Man’, ‘Hong-Mo’, ‘8323’, ‘8338’, ‘8337’, ‘ZULK 8’, ‘ZULK 9’, which formed maximum productivity in dry conditions (3.95–5.51 t/ha).

Improving Crop Health, Performance, and Quality in Organic Spring Wheat Production: The Need to Understand Interactions between Pedoclimatic Conditions, Variety, and Fertilization

Organic wheat production systems have lower yields compared with intensive conventional production and often do not achieve the grain protein content and quality thresholds set by millers and bakers. In contrast, organic production methods were reported to result in higher concentrations of nutritionally desirable micronutrients and lower concentrations of the toxic metal Cd in wheat grain and wholegrain flour. However, although N-availability and variety characteristics are known to affect both gain yields and bread-making quality, the exact reasons for the yield gap and differences in grain processing and nutritional quality between organic and conventional spring wheat production in the UK are poorly understood. The overall aim of this study was therefore to determine to what extent changes in variety choice and fertilization regimes may reduce the yield gap and improve processing quality without affecting nutritional quality in organic spring wheat production. To achieve this aim, we compared crop health, yield, grain processing, and nutritional quality parameters in spring wheat produced using (i) six contrasting spring wheat varieties grown with a standard fertilization regime and (ii) one variety widely used by organic farmers (Paragon) with nine different fertilization regimes in (iii) three UK sites/farms with contrasting pedoclimatic conditions. Significant differences in foliar disease severity, grain yield, and quality parameters were detected between six contrasting spring wheat varieties when grown under organic management regimes. Specifically, the varieties Paragon and Tybalt were identified as the best-performing varieties with respect to foliar disease resistance and grain yield under organic farming conditions and also produced high processing and nutritional quality across the three UK sites. However, the highest grain yields were obtained by Paragon at the Gilchester site and Tybalt at the Sheepdrove and Courtyard sites, while the highest protein contents were produced by Tybalt at the Gilchester site and Paragon at the Sheepdrove and Courtyard sites, which suggests that there is a need for site-specific wheat variety selection in the UK organic sector. Although organic fertilizer input type and level also affected wheat performance, differences between fertilization regimes were smaller than those observed between the five contrasting varieties, which suggests that improvements in spring wheat breeding/selection have a greater potential for increasing crop yield and quality in the organic sector compared with changes to fertilization practices. Overall, results suggest it is feasible to breed/select spring wheat varieties that combine high protein, vitamin E, and micronutrients with low toxic metal (Cd, Pb) concentrations when produced under organic farming conditions. These findings also support the hypothesis that differences in variety choice by organic and conventional farmers have contributed to the differences in nutritional quality between organic and conventional wheat products reported in previous studies.

Genotype-by-environment interaction for grain yield and quality traits in durum wheat: Identification of ideotypes adapted to the Spanish region of Castile and León

Understanding how environmental conditions affect grain yield and quality in the Mediterranean basin, characterised by high interannual climate variations, is essential for the successful selection of durum wheat varieties better adapted to local agro-environments. We evaluated the effects of the genotype-by-environment interaction on grain yield and quality traits in a multi-environment field trial, across five consecutive growing seasons, to identify the varieties with consistently specific and broader adaptation to prevailing and limiting conditions in the Spanish region of Castile and León. Fourteen commercial varieties were tested in thirteen environments, including different management practises (irrigation, late sowing and nitrogen fertilisation). AMMI, Finlay-Wilkinson and GGE models were used to study the genotype-by-environment interaction, showing that the environment was the main factor affecting yield and grain quality traits. The genotypic and genotype-by-environment interaction effects were also significant for most traits. We identified the varieties with higher grain yield and quality or greater stability across environments. However, there are no varieties that perform better for all traits. We found the yellow pigment concentration as heritable trait, while δ13C, grain yield and vitreousness had the lowest genetic control. We conclude that the Castile and León region is a suitable agro-environment for durum wheat under current and limiting climatic conditions, although the selection of varieties and management practises is necessary to maximise profitability depending on the final end-use of the grain. This study provides relevant information for future durum wheat breeding programmes that take into account crop's stability and resilience to multiple environmental factors.

Varietal effects on Greenhouse Gas emissions from rice production systems under different water management in the Vietnamese Mekong Delta

AbstractRice production accounts for 15% of the national Greenhouse Gas (GHG) emissions and Vietnam aims at reducing emissions from rice production by focusing on changing farming practices. However, the potential for mitigation through the selection of different rice varieties is still poorly understood. A two‐year field screening of 20 rice varieties under continuous flooding (CF) and alternate wetting and drying (AWD) irrigation was conducted in the Vietnamese Mekong Delta (VMD), Vietnam, employing the closed chamber method for assessing GHG emissions. The results confirmed that varietal variation was the largest for methane (CH4) emissions under CF. Across the varietal spectrum, CH4 emissions were more important than nitrous oxide (N2O) (accounts for less than 2% of the CO2e) with the lowest emitting variety showing 243 kg CH4 ha−1 and the highest emitting variety showing 398 kg CH4 ha−1 emissions as compared to 0.07 kg N2O ha−1 and 0.76 kg N2O ha−1 emissions, respectively. Under AWD, CH4 emissions were generally strongly reduced with the varietal effect being of minor importance. Compared with IPCC default values, the data set from the two seasons yielded higher Emission Factors (EFs) under CF (2.92 and 3.00 kg ha−1 day−1) as well as lower Scaling Factors (SFs) of AWD (0.41 and 0.38). In the context of future mitigation programs in the VMD, the dry season allows good control of the water table, so varietal selection could maximize the mitigation effect of AWD that is either newly introduced or practised in some locations already. In the wet seasons, AWD may be difficult to implement whereas other mitigation options could be implemented such as selecting low‐emitting cultivars.

Assessing Soil Organic Carbon Pool for Potential Climate-Change Mitigation in Agricultural Soils—A Case Study Fayoum Depression, Egypt

It is essential to assess the soil organic carbon pool (SOCP) in dry environments to apply appropriate management techniques that address sustainable development. A significant opportunity for sustaining agricultural output and reducing climate change is the storage of soil organic carbon in agricultural soil. The goal of this study was to measure the spatial variability of SOCP content, and determine the effects of soil texture, changes in land use, and land cover on SOCP in surface soil samples. The study additionally investigated the relationships between SOCP and other characteristics, including the normalized vegetation index (NDVI) and land surface temperature (LST), as well as the effects of increasing soil organic carbon on the amount of greenhouse gases. To accomplish this goal, 45 soil surface samples were collected to a depth of 30 cm at the Fayoum depression in Egypt, and analyzed. The soil samples were representative of various soil textures and land uses. The average SOCP concentration in cultivated regions is 32.1 and in bare soils it is 6.5 Mg ha−1, with areas of 157,112.94 and 16,073.27 ha, respectively. According to variances in soil textures, sandy soils have the lowest SOCP (1.8 Mg ha−1) and clay loam soils have the highest concentrations (49 Mg ha−1). Additionally, fruit-growing regions have the greatest SOCP values and may therefore be better suited for carbon sequestration. The overall average SOCP showed 32.12 Mg C ha−1 for cultivated areas. A rise in arable land was accompanied by a 112,870.09 Mg C rise in SOCP. With an increase in soil organic carbon, stored carbon dioxide emissions (greenhouse gases) would be reduced by 414,233.24 Mg CO2. We should consider improving fertilization, irrigation methods, the use of the multiple cropping index, decreasing desertion rates, appropriate crop rotation, and crop variety selection. The research highlights the significance of expanding cultivated areas towards sustainable carbon sequestration and the climate-change-mitigation potential.

Performances of 34 shallot accessions in Lembang highland

Identification of the appearance of shallot accession is needed in the selection of new superior varieties of shallots. Therefore, performance identification of shallot accessions from various parental backgrounds was carried out. Thirty-four shallot accessions were planted on open land in Lembang highlands (1250 m asl) from May to September 2022. The performance of shallot plants was observed starting from percentage of flowering, number of tillers, plant fresh weight, bulb dry weight, weight loss, bulb number, weight, height and diameters of bulbs and cloves. The data were analysed descriptively. The results showed that there were 11 accessions with 100% flowering percentage, 10 accessions with more than 5 tillers per plant, 5 accessions with weight loss potential of less than 40%, 3 accessions with more than 10 bulbs per plant, 6 accessions with bulb weight more than 10 grams, 11 accessions with bulb diameter more than 2.5 cm and 6 accessions with clove diameter more than 2.5 cm. There were 2 accessions that have a combination of superior traits, namely accessions BLK and C89.

The effect of varieties of true shallot seed and paclobutrazol concentrations on growth and production of shallot plant

The increasing demand for shallots is inversely proportional to the quality of the current production. Efforts to improve and increase quality of production are selection of good varieties and add plant regulatory substances has also become the focus of many researchers in their effect on plant growth. Therefore, research was carried out on the effect of the varieties and also plant regulatory substances namely paclobutrazol on the growth and production of shallot plants. This research was carried out at the Teaching Farm, Faculty of Agriculture, Hasanuddin University from August to November 2021. This research was carried out as a factorial experiment in a split plot design, as the main plot, namely the botanical seed varieties of shallot (v) consists of 3 varieties, namely the Lokananta varieties (v1), Maserati varieties (v2), and Sanren varieties (v3), as a sub-plot, namely the concentration of paclobutrazol consists of 4 levels, namely 0 ppm (k0), 100 ppm (k1), 200 ppm (k2) and 300 ppm (k3). The research results showed that the interaction of the Sanren varieties with paclobutrazol concentration of 100 ppm gave the best results on the weight of fresh stover per plant (26.04 g), weight of dry stover per plant (19.23 g) and production per hectare (9.20 ton/ha). The Sanren varieties gave the best results on chlorophyll a (387.23 μmol.m−2), chlorophyll b (187.12 μmol.m−2), total chlorophyll (564.14 μmol.m−2) and number of tubers (1.81). Paclobutrazol concentration of 100 ppm gave the best results on plant height (43.07 cm) and number of leaves (6.24 strands), while paclobutrazol concentration of 200 ppm gave the best results on tuber diameter (23.13 mm) and paclobutrazol concentration of 300 ppm gave the best results on the number of tubers (1.54).

Genetic variation among cocoa (Theobroma cacao L.) families for resistance to black pod disease under field and laboratory conditions

The laboratory detached black pod test method has been suggested as the most economical and effective screening procedure to complement field black disease resistance selection. General combining ability and association between black pod disease incidence under field and laboratory conditions among 24 cocoa F1 families were investigated over a 7-year period. The 24 F1 families were derived by crossing three seed garden parental clones with eight GU clones as males in a 3 x 8 North Carolina II (NC II) mating design. The 24 families together with four standard varieties planted in a randomized complete-block design with four replicates of 25 trees per plot were monitored for percentage black pod disease incidence (PBDI). Selfed pods from the 24 NC families and four standard varieties were arranged in a completely randomized design with four replicates of five pods each in the laboratory and subsequently inoculated with Phytophthora megakarya isolates. Percentage detached pod disease incidence (PDDI) was determined after seven days of incubation. Family effects was significant (p < .01) for PBDI and PDDI, and the association between them was positively and moderately correlated (r = 0.71; p < .01). Broad-sense heritability was high but narrow-sense heritability was low for both traits. General combining ability effects of eight of the 11 parental clones and specific combining ability effects of 17 of the 24 crosses were consistent (positive or negative) for PDDI and PBDI. Results from the study indicate that there is a considerable association between both traits, and clones GU 125/C and GU 255/V and their corresponding crosses PA 150 × GU 255/V, T60/887 × GU 125/C, and PA7/808 × GU 255/V had favorable effects for resistance to black pod disease expression. It is concluded that the detached black pod test represents a suitable method to support the field selection of black pod-resistant cocoa varieties.

Superior sweet oranges for varietal diversification of tropical rainfed orchards

Citrus orchards in northeastern Brazil are mostly rainfed and comprised basically of ‘Pera CNPMF D-6’ sweet orange budded on ‘Rangpur’ lime, for the drought tolerance and productivity imparted by this rootstock. Therefore, the selection of new varieties is needed to broaden the genetic basis of citrus cultivated in this region. Accordingly, this study compared vegetative, productive, and fruit quality traits of eight sweet orange scions grafted on ‘Rangpur’ lime over eleven years under the tropical rainfed conditions of northeastern Brazil. ‘Kona’ trees excelled in yield performance associated with bulk canopy, precocity, sweet fruit with intermediate acidity, and high vitamin C contents in spite of proneness to alternate yields and low ratio (maturity index). ‘Valencia Montemorelos’ and ‘Rubi’ trees, in turn, had high yield performances coupled with intermediate canopies, sweet fruit, intermediate acidity (‘Rubi’) and vitamin C contents, low propensity for yield fluctuation (‘Valencia Montemorelos’), and high precocity (‘Rubi’), albeit low ratio. Overall, our results emphasize ‘Kona,’ ‘Valencia Montemorelos,’ and ‘Rubi’ as superior sweet orange varieties for diversification of tropical rainfed orchards for their outstanding yield performance and good fruit quality.

Peculiarities of the protein complex of seeds of pea (Pisum sativum L.)

Aim. To investigate the features of the protein complex of pea seeds (Pisum sativum L.) of varieties of Ukrainian and foreign breeding of different morphotypes for use at the selection of varieties of food direction. Methods. Standard and developed in Laboratory of Plant Biochemistry methods of plant biochemical analysis (Kjeldahl method, spectrophotometric methods, electrophoresis). Statistical analysis of research results was carried out using the programs Libre Office Calc (GNU Lesser General Public Licensev3), “Imagel”. Results. The study of the content of protein, 11S and 7S globulins, their ratio in the seeds of peas of Ukrainian and foreign varieties showed the presence of reliable varietal differences according to the studied characteristics depending on their morphotype. Using electrophoretic and densitometric analyses, varietal differences in the intensity of bands, the presence or absence of some components in the electrophoretic spectra of 11S and 7S globulins, which affect the nutritional value of pea seeds, were established. Conclusions. The obtain results shown that it will be possible to select genotypes of food direction using the studied biochemical characteristics of evaluation.

Analysis of Extreme Rainfall and its Impacts of Rice Production in Krishnagiri District

Extreme rainfall in Krishnagiri district can have significant implications for agriculture and the overall socio-economic landscape of the region. Krishnagiri district, located in Tamil Nadu, India, experiences a monsoon-driven climate, making it susceptible to both deficient and excessive rainfall. Extreme rainfall events have significant impacts on rice production, affecting planting, growth, yield, and grain quality. Excessive rainfall delays planting, causes waterlogging, and reduces crop establishment. Water stress, hindered root growth, and nutrient leaching impact growth and development, lowering plant height, tiller production, and leaf area. Lodging, disease susceptibility, and nutrient loss reduce yield. Fungal diseases, grain sprouting, and post-harvest losses affect grain quality. To mitigate these impacts, strategies like improved drainage, crop diversification, suitable variety selection, and water management should be employed. Early warning systems and supportive policies are crucial for adaptation and resilience in rice production. During the growth and development stages, excessive rainfall can hinder the progress of rice crops. Waterlogged soils deprive plants of oxygen, leading to water stress and hampering root growth, nutrient uptake, and photosynthesis. This, in turn, results in stunted plant height, reduced tiller production, and decreased leaf area, ultimately affecting the overall growth and health of the crop.The impact of extreme rainfall on rice yield is significant. Heavy downpours can cause lodging, where plants bend or collapse due to weak root systems unable to support the weight of the crop. Lodging reduces the crop's ability to photosynthesize effectively and makes it more susceptible to diseases and pests. Additionally, excessive rainfall can leach essential nutrients from the soil, diminishing their availability for the rice plants and ultimately leading to lower grain yield.. Key words: extreme rainfall, Rice production,Krishnagiri District

Impact of waterlogging on fruit crops in the era of climate change, with emphasis on tropical and subtropical species: A review

Incidents of flooding in tropical and subtropical fruit trees have increased as a result of climate change. Because of flooding, the anaerobic conditions of the rhizosphere increase the conditions for phytotoxicity and infection by pathogenic fungi and bacteria. Due to oxygen depletion in waterlogged soils, growth, functions of the roots and of the entire plant are impaired. The decrease in the photosynthetic rate is considerable because of the reduced functional leaf area because of chlorosis, necrosis, leaf drop and stomatal closure, as well as chlorophyll degradation. Plants have developed different morphological, physiological, and biochemical adaptations to survive hypoxic stress. Some fruit trees form an aerenchyma in roots for the diffusion of oxygen from the aerial parts. Induced aerenchyma-containing adventitious roots, rapidly elongate stems into deeply flooded soils; or they form hypertrophied lenticels, like some mango varieties. Measures for better adaptations and tolerance of tropical fruit trees to climatic impact include the following: adaptations of the cultivated terrain, selection of varieties, rootstocks more tolerant to hypoxic stress, pruning to reestablish the balance of the aerial part/roots, and foliar applications (e.g., of glycine betaine or hydrogen peroxide (H2O2)). Mycorrhizal colonization of roots can increase tolerance to waterlogging, while the application of fertilizers, such as CaO or MgO, can improve the redox potential of flooded soils. We present results of studies on this problem for the following fruits: yellow passion fruit (Passiflora edulis f. flavicarpa) and purple passion fruit (P. edulis f. edulis), cape gooseberry (Physalis peruviana), lulo or naranjilla (Solanum quitoense), tree tomato (Solanum betaceum), citrus (Citrus spp.), guava (Psidium guajava), papaya (Carica papaya), and mango (Mangifera indica).

Does acclimation in distinct light conditions determine differences in the photosynthetic heat tolerance of coffee plants?

Worldwide coffee production is threatened by climate change, which highlights the importance of heat tolerance studies. Here we tested the hypothesis that photosynthetic heat tolerance in coffee varieties changes according to acclimation to distinct light conditions. Furthermore, we tested if heat tolerance is associated with the habitat of origin of the coffee species. We evaluated heat tolerance using chlorophyll fluorescence in varieties of Coffea arabica (Mundo Novo and Catuai Amarelo) and C. canephora (Conilon) grown in a common garden under two conditions: high (HS) and low (LS) sunlight. Leaf traits associated with leaf cooling were evaluated in plants grown in LS and HS and associations of heat tolerance with these traits were determined. The varieties tested had high photosynthetic heat tolerance, with temperatures above 54 °C leading to a 50% reduction in Fv /Fm (T50 ). The heat tolerance of each Coffea variety was unaffected by growth in distinct light conditions. Leaves of plants grown in LS were larger and had a lower fraction of the leaf area occupied by stomata (nast ). Heat tolerance was positively associated with leaf size and negatively with nast . C. canephora exhibited higher heat tolerance than C. arabica. The limited plasticity of heat tolerance in response to acclimation under distinct light conditions contradicts the prediction that plants acclimated to HS would have higher photosynthetic heat tolerance than those acclimated to LS. Our results on heat tolerance among Coffea species/varieties in HS and LS indicate the possibility of selection of varieties for better acclimation to ongoing climate changes.

USE OF IMAGE FOR CLASSIFICATION AND IDENTIFICATION OF FOREST SEEDS QUALITY

Seeds are essential inputs in agriculture and forestry, being the viability, crucial criteria for determining their quality. Image processing and analysis methods were explored to assess seed quality. The vigor of seeds is vital for the establishment of crops, being defi ned as their ability to germinate and grow in diff erent environments, often inhospitable. Conventional methods, such as germination tests, tetrazolium and the accelerated aging test, have their limitations to determine aspects of predictions and vigor, promoting the search for non-destructive and automated approaches. Image analysis, including near-infrared spectroscopy (NIR) and hyperspectral imaging (HSI), is an eff ective tool for evaluating various seed characteristics such as size, color and shape. Equipment such as GroundEye® allows for accurate and quick analysis of seed quality. Image analysis has expanded rapidly, off ering alternative options to ensure the determination of seed quality of forest and agricultural species, with the potential to revolutionize the selection of plant varieties and increase productivity.

Breeding dryland legumes for diverse needs: Using multi‐location trials and participatory variety selection to develop farmer‐preferred groundnut (Arachis hypogaea) and pigeon pea (Cajanus cajan) varieties

AbstractAgriculture in Sub‐Saharan Africa is primarily smallholder‐based, employing up to 60% of the workforce and accounting for 14%–23% of GDP. The smallholders grow crops for domestic and off‐farm markets, necessitating crop variety attributes for which trait mismatches may limit adoption. Indeed, improved variety adoption is varied and limited, especially for self‐pollinated crops, in part due to the mismatch in characteristics of commercialised varieties. The international research community leads breeding of varieties for under‐invested crops, especially legumes. These varieties are often resilient and productive, but the dynamisms in target agri‐food systems may limit their relevance. Gaining a better understanding of the trait profiles that crop value chain actors consider will increase their adoption. This study combined multi‐location trials and participatory variety selection (PVS) of pigeon pea and groundnut across different environments to evaluate the efficacy of both processes in the breeding of desired varieties. The present study shows improvement in the new materials regarding performance and preference by farmers. Additionally, PVS showed that men prioritised productivity and market‐enhancing traits, whereas women ranked food security traits highest.