Digital Commons Network^™

Do Rates Matter? Validation Of Insect Frass Fertilizer Rates In A Vegetable Intensified Push-Pull Technology For Optimal Sustainable Production, Priscilla Mwikali Kimuli, Dennis Beesigamukama, Judy Wambua, Bonoukpoe Mawuko Sokame, Chrysantus Mbi Tanga, Frank Chidawanyika, Sevgan Subramanian, Daniel Munyao Mutyambai

All Peer-Reviewed Publications

Push–pull system intensification with vegetables (VIPPT) has contributed significantly in maintaining good control of lepidopteran pests and parasitic weeds with additional food and nutritional security benefits. However, the impact of integration of different rates of black soldier fly frass fertilizer (BSFFF) in the VIPPT to enhance productivity, has not been explored. This study investigated the effects of different BSFFF application rates on growth performance, pest infestation severity, diversity of natural enemies and yield of kale (Brassica oleracea L. var. acephala) grown under VIPPT in two agroecological zones. Plants were grown in soils amended with five different levels of BSFFF (0, …

Can Fungal Endophytes Suppress Trialeurodes Vaporariorum And The Transmission Of Tomato Infectious Chlorosis And Chlorosis Viruses In Field Conditions?, Marial Makur Zechariah Paweer, Everlyne Samita Namikoye, Shem Bonuke Nchore, Komivi Senyo Akutse

All Peer-Reviewed Publications

Field trials were conducted for two seasons in two experimental sites (Mwea in Kirinyaga and Ngoliba in Kiambu counties of Kenya) to assess the efficacy of fungal endophytes Hypocrea lixii F3ST1 and Trichoderma asperellum M2RT4 in the control of Trialeurodes vaporariorum vector of tomato infectious chlorosis virus (TICV) and tomato chlorosis virus (ToCV) through seeds inoculation. TICV and ToCV’s disease incidence, severity and the yield were also evaluated. All the fungal endophytes successfully colonized all the tomato plant parts, but the highest root colonization was observed in H. lixii F3ST1 compared to the T. asperellum M2RT4 in both seasons. The …

Comparison Of Compositional Characteristics Of Protein Extracted From Spent Hemp Seed Cakes By One-Step Defatting With Organic Solvents Followed By Isoelectric Solubilization Precipitation Using Strong And Weak Acids, Miah Nicole Gathman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Hemp seed cakes (HSC) are the byproduct of pressing hemp seeds for oil and are a significant agricultural waste product, with hundreds of tons produced annually. These nutrient-rich cakes have potential for sustainable applications in animal feed and food products. However, they could offer even greater value to the food industry through further extraction of the lipids and separation of the proteins they contain. Protein is a key nutritional component and companies are seeking cost-effective, time-efficient processes to concentrate protein from underutilized resources like HSC. Hexane (HEX) is a common solvent used in one-step defatting processes but may cause issue …

Microbial And Plant Biodiversity In Appalachian Agroecosystems And Their Implications For Soil Health, Kinsey Reed Close

Graduate Theses, Dissertations, and Problem Reports (ETD)

The sustainability of agricultural landscapes depends on understanding the complex interactions between plants, soil, and microbes. In Appalachia, a region shaped by complex terrain and long histories of human and ecological interaction, small family farms produce hay, livestock, and row crops. These agroecosystems, though often treated as “artificial” by many ecologists, have the potential to support both food production and biodiversity conservation if managed with an understanding of ecological complexity. This dissertation examines how plant and microbial diversity interact with soil and management to influence nutrient cycling, soil health, and long-term resilience in Appalachian agricultural systems. A literature review revealed …

Raman Spectroscopy For Rapid Quantification Of Macronutrients In Heirloom Beans, K. Chandler Williams

Graduate Theses, Dissertations, and Problem Reports (ETD)

Quantification of macronutrients in food requires a large investment in facilities and instrumentation as well as ongoing expenses of labor, reagents, and hazardous waste disposal. These costs pose a significant barrier to determining macronutrient quantities in the thousands of uncharacterized landrace and heirloom crops and discourage traditional crop breeding projects from ensuring that their selected crops maintain desirable macronutrient profiles in addition to target agronomic traits. Our objective was to test whether a hand-held Raman spectrometer—a technology which has found use in plant disease diagnostics but remains largely overlooked in nutrient quantification-- could provide a feasible means for quantifying the …

The Effect Of Thidiazuron Treatment On The Growth Of Vanda Limbata Blume In Vivo, Novika Ditasya Putri, Nintya Setiari, Yulita Nurchayati, Sri Widodo Agung Suedy

Makara Journal of Science

Vanda limbata is one of the most popular ornamental orchids. Currently, its growth is slow, making it necessary to improve its cultivation techniques. One of the possible ways to achieve this is to use plant growth regulator (PGR) treatment. Thidiazuron (TDZ) is a cytokinin used to increase the growth of V. limbata. This study aimed to determine the effect of TDZ concentration on the growth rate of V. limbata. The study involved cultivating V. limbata on planting media and spraying it with TDZ at various concentrations. This research uses a CRD (Completely Randomized Design) single-factor, which is TDZ concentration at …

Phosphorus Buffering Determines How Soil Properties And Rainfall Influence Wheat (Triticum Aestivum) Yield Response To Phosphorus Fertiliser, Craig Scanlan, Raj Malik, Gustavo Boitt, Mark Gherardi, James Easton, Zed Rengel

Grain and Other Field Crops Research Articles

Context

Current decision support systems (DSS) for phosphorus (P) fertiliser were developed using data from historical cropping systems. An understanding of how soil properties and rainfall influence wheat (Triticum aestivum) response to P fertiliser in current systems is required to optimise P management. Aims

The aims of this study were to: (1) assess the soil properties that have the greatest influence on relative yield; (2) examine how rainfall conditions influence relative yield; and (3) examine whether there were interactive effects between rainfall and soil properties on relative yield. Methods

Forty P rate-response field experiments were completed in Western …

Farmers’ Decision Processes About Biocontrol Innovation Adoption: Dynamics Surrounding Push-Pull Technology In Western Kenya, Olufemi Samson Adesina, Stephen Whitfield, Susannah M. Sallu, Steven M. Sait, Jimmy Pittchar

All Peer-Reviewed Publications

Smallholder farmers in sub-Saharan Africa (SSA) face increasing challenges from pests and climate change, among other issues. In response to these challenges, international agricultural research for development (R4D) investment is often focused on developing and scaling up techniques and technologies that bolster resilience. However, such approaches are often technocentric and follow linear assumptions of innovation diffusion and adoption, which overlook the complex realities that influence smallholder farmers’ dynamic decisions and engagement with novel techniques. This study used qualitative ethnographic methods to explore the experiences, knowledge construction, motivations, and decision-making of farmers in Western Kenya regarding the extensively researched push-pull technology …

Impacts Of Gibberellin Application On Citrus: An Overview From Seed Germination To Fruit Quality Enhancement, Siti Auliya Rahma, Rahmat Budiarto, Syariful Mubarok, Supatida Abdullakasim

Jurnal Kultivasi

Gibberellins are key plant hormones, and their application in citrus plants is frequently reported. This review aims to provide an overview of the application of gibberellic acid (GA3) in citrus cultivation, emphasizing their effects on growth, flowering, fruit quality, and ripening. Citrus fruits often face challenges like irregular fruit set, size inconsistency, and environmental stress, impacting yield and profitability, with exogenous gibberellin application as a potential solution. Applying gibberellins can accelerate citrus seed germination and seedling growth, enhance vegetative growth, inhibit flowering, delay fruit ripening, and improve fruit quality. However, the efficacy of gibberellins varies across species and conditions, highlighting …

Agronomic Biofortification Of Calcium In Pak Choy (Brassica Rapa Subsp. Chinensis) Via Hydroponic Nutrient Film Technique, Regina Septiani Zahro, Khavid Faozi, Zulfa Ulinnuha, Agus Sarjito

Jurnal Kultivasi

Pak choy is rich in calcium, magnesium, phosphorus, iron, and vitamin K, all essential for health. Pak choy requires a proper balance of nutrients for optimal growth. In a hydroponic system, any imbalance in nutrient levels can negatively impact plant growth and reduce the nutritional value stored in the tissues. Selecting suitable varieties and providing appropriate calcium treatment can help increase calcium content and enhance productivity. This study aims to determine the effect of calcium concentration on growth, yield, and Ca content and the most responsive varieties to increased calcium concentration. The research design used was a Split Plot Design …

Potential Propagation Seedling Of Ramie (Boehmeria Nivea) From Various Types Of Stem Cuttings, Taufiq Hidayat Rahman Side, Mayasari Yamin, Sri Mulyani, Agung Pangestu Aji, Luthfi Ayunawati

Jurnal Kultivasi

Ramie is a fiber-producing plant that can replace cotton as a raw material for the textile industry. In general, ramie plants are reproduced using rhizomes, but it takes a long time, around two years, to be used as a source of planting material. Therefore, other sources of explants besides rhizomes are required, such as stem cuttings. Explants from stem cuttings are quickly available and only need 2-3 months to be used as planting material. This study aims to determine the potential of effective stem cuttings that can be used as planting material for the propagation of ramie seedlings. The research …

Maize Hybrids’ Genetic Variability Based On Qualitative And Quantitative Traits, Slamet Bambang Priyanto, Herawati, Suwarti, Ayyub Ar Rahman, Nining Nurini Andayani, Abdul Fattah, Muhammad Azrai

Jurnal Kultivasi

Genetic variability was a prerequisite to doing a plant breeding program. A broad genetic variability allows plant breeders to select a desired genotype. This research aims to assess the maize hybrid's genetic variability based on qualitative and quantitative traits. This research was conducted in the Bone district, south Sulawesi, from November 2022 to March 2023. Fifteen maize hybrids were arranged in a randomized complete block design with three replications. The variables observed are qualitative and quantitative traits. Principal component (PCA) and cluster analyses assessed the genetic variability. The result indicated that based on a loading factor greater than 0.70, the …

Assessment Of Drought Tolerance In Mung Bean [Vigna Radiata (L.) Wilczek] Through Phenology, Growth, Protein Yield, And Cluster Heatmap Analysis, Rafiqul Islam, Jamil Hossain, Shamsul Huda, Mohammad Golam Azam, Faruk Hossain, Aktar Uz Zaman, Safiqul Moula, Nasir Uddin Ahmed, Jamal Hossain, Ayman El Sabagh, Mohammad Sohidul Islum

The Philippine Agricultural Scientist

Mung bean [Vigna radiata (L.) Wilczek] cultivation is challenging under the changing climate as less precipitation during the summer season, which is becoming increasingly common, results in soil moisture deficiency and affects production especially at the early growth stages. Hence, this study was conducted to assess the phenology, growth, and protein yield traits of mung bean related to drought tolerance. Eight mung bean genotypes were grown in pots inside a rain-out shelter under well-watered (WW) and water-deficit (WD) conditions. These genotypes included four water stress-tolerant genotypes: G-1 (BARI Mung-8), G-2 (BMX-010015), G-3 (BMX-08010-2), and G-4 (BMX-08009-7), as well as four …

Morphological And Physiological Changes Of Katuray (Sesbania Grandiflora) During Seed Maturation [Research Note], Alangelico San Pascual, Lucille Elna De Guzman, Maurice Gravidez, Elijah Estante

The Philippine Agricultural Scientist

Katuray (Sesbania grandiflora), whose flowers are consumed as steamed vegetables, is an important green manure crop in the Philippines. Understanding different processes leading to seed maturity can aid in determining S. grandiflora’s seed quality, preventing premature harvesting for seed increase, ensuring efficient propagation and production of seedlings, and breeding new varieties of this crop. Multiple flowers were tagged, and three to five pods were collected five days after anthesis (DAA) and at a five-day interval thereafter until 100% germination was achieved. Seed size, moisture content (MC), dry weight, germination percentage, and embryo development were observed and recorded. Seed length was …

Effect Of Integrated Crop–Livestock Systems On Soil Properties And Microbial Diversity In Soybean Production, Namita Sinha, Brett R. Rushing, Aniruddha Acharya, Shankar Gaapathi Shanmugam

Faculty Publications - Biological Sciences

Integrated crop and livestock systems (ICLSs) have been considered an important management-based decision to improve soil health by carbon sequestration. A two-year study (2019–2021) at CPBES in Newton, MS, was conducted to evaluate the effect of an ICLS on soil microbial diversity in the southeastern region of the USA, representing agroclimatic conditions that are warm and humid. Amplicons targeting bacterial 16S rRNA genes and fungal ITS2 regions were sequenced. Taxonomic assignment and characterization of microbial diversity were performed using QIIME2®. Soil fungal diversity pattern showed significant difference (alpha diversity, p = 0.031 in 2020 and beta diversity, p = 0.037 …

Leveraging Within-Field Spatial Variability To Optimize Soybean Yield, Seed Quality, And Profitability, Marina Marly Dalla Betta

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Optimizing yield and seed quality in soybean production is critical for both profitability and meeting market demands. However, within-field variability in soil properties poses a challenge in determining optimal management strategies to maximize soybean yield, seed quality, and profitability. This work aimed to evaluate the spatial variability of soybean fields to optimize soybean seeding rates, seed quality, and profitability. Two case studies were used to carry over this research. The first study looked at the optimal economical site-specific soybean seeding rates using 11 on-farm precision experiments across Nebraska. The second study looked at the protein and oil variability within 22 …

Induced Systemic Resistance Against Nematodes By Plant Growth-Promoting Microbes In Potatoes, Cole Grannan

Master's Theses

Biofertilizers consist of plant growth-promoting microorganisms that establish symbiotic relationships with plant roots and stems. These beneficial microbes play a crucial role in enhancing plant defenses against various threats including insects, nematodes, and microbial pathogens. The purpose of this study was to investigate the effectiveness of two fungal biofertilizers (an endophytic strain of Beauveria bassiana (BA) and a mixture of arbuscular mycorrhizal (AM) fungi), specifically their ability to induce systemic resistance against plant- parasitic nematodes (PPNs) in potatoes (Solanum tuberosum cv. Masquerade) under controlled greenhouse conditions. The study utilized soil collected from Colorado State University’s San Luis Valley (SLV) Research …

Evaluating The Duckweeds Lemna Minor And Spirodela Polyrhiza As Alternative Aquatic Hosts For The Spread Of The Bacterial Wilt Pathogen, Ralstonia Solanacearum, Irelynn Smith

Honors Theses

Ralstonia solanacearum is a plant pathogen that causes bacterial wilt disease in major crops such as tomatoes and potatoes. Recently, this bacterium was discovered in floating pennywort (Hydrocotyle ranunculoides) and Pennsylvania smartweed (Polygonum pennysylvanicum), two previously unsuspected aquatic plants. Duckweed is an aquatic plant with a high level of resilience and short doubling time. Common duckweed (Lemna minor) has previously demonstrated its capability as a versatile high-yield infection model for other types of pathogenic bacteria. Given this newfound branch of aquatic hosts and the fact that duckweed is a common pond weed previously identified in several ponds located nearby infected …

Genetic Diversity And Population Structure Of Tomato (Solanum Lycopersicum) From The Usda-Grin Germplasm Collection, Ibtisam Alatawi, Haizheng Xiong, Hanan Alkabkabi, Kenani Chiwina, Qing Luo, Kai-Shu Ling, Yuejun Qu, Renjie Du, Ainong Shi

Horticulture Faculty Publications and Presentations

The genetic diversity and population structure of tomato (Solanum lycopersicum) were investigated to support breeding strategies and germplasm conservation. A total of 276 accessions from the USDA-GRIN collection were analyzed using single-nucleotide polymorphisms (SNPs) generated through genotyping by sequencing (GBS). After stringent filtering, 5162 high-quality polymorphic SNPs were retained for analysis. Population structure analysis revealed three distinct genetic groups (Q1, Q2, and Q3) among the accessions. Accessions from the USA, Asia, and Central and South America were assigned to all three groups, while accessions from Europe and Oceania were predominantly clustered within Q2. Genetic diversity indices, including major …

The Diverse Effects Of Continual Organic Inputs On Soil Biogeochemical Properties And Microbial Communities In Sandy Ultisols Under Organic Production, Zhine Wang

All Dissertations

The objectives of this study were to understand how continual organic amendment inputs improve Nitrogen (N) cycling, microbial diversity and functional traits. Fully crossed factorial experiments were designed to test four cover crop treatments (cereal rye, hairy vetch, mixture of the rye and vetch, and no cover crop fallow) and two levels of manure compost application (with manure application and blank control) in organic vegetable production from 2020 to 2023. Cover crop biomass, soil chemical and biological properties were analyzed for the distribution and availability of soil labile N (Chapter 2), the abundance of N-cycling genes (Chapter 3), the structure …

Site Position, Tillage, And Soil Depth Effects On Soil Properties In A Furrow-Irrigated Rice Field On A Silt-Loam Soil, Hannah Nobles, Kristofor Brye, Diego Della Lunga

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The fundamental agronomic shift from conventional agricultural methods to conservation agriculture relies on understanding soil nutrient stratification with depth and under different tillage treatments. Assessment of nutrient stratification in the dynamic conditions of furrow-irrigated rice (Oryza sativa) systems in eastern Arkansas is absent. The objective of this study was to evaluate the effects of tillage [i.e., conventional tillage (CT) and no tillage (NT], site position (i.e., up-, mid-, and down-slope), soil depth interval (i.e., 0-10 and 10-20 cm), and their interaction on the difference (i.e., end of the season minus beginning of the season) in select soil chemical …

Broad-Spectrum Resistance To Fungal Foliar Diseases In Wheat: Recent Efforts And Achievements, Amira M.I. Mourad, Asmaa A.M. Ahmed, P. Stephen Baenziger, Andreas Börner, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum spp.) is one of the most important cereal crops in the world. Several diseases affect wheat production and can cause 20-80% yield loss annually. Out of these diseases, stripe rust, also known as yellow rust (Puccinia striiformis f. sp. tritici), stem rust (Puccinia graminis f. sp. tritici), leaf rust (Puccinia recondita), and powdery mildew (Blumeria graminis f. sp. tritici) are the most important fungal diseases that infect the foliar part of the plant. Many efforts were made to improve wheat resistance to these diseases. Due to the continuous advancement in …

Efficacy Of Banana Fibre Paper For The Management Of The Root-Knot Nematode, Meloidogyne Incognita, On Potato (Solanum Tuberosum) In Kenya, Dorris W. Kamau, Wanjohi Waceke, Laura Cortada, Onesmus Mwaura, Tahira Pirzada, Tim L. Sit, Eric Davis, Dick Guenther, Reny Mathew, Lokendra Pal, Saad Khan, Solveig Haukeland, James Kisaakye, Charles Opperman, Danny Coyne

All Peer-Reviewed Publications

Globally, potato (Solanum tuberosum) is a key staple food crop. In Kenya, it is the second most important food crop after maize. Among the various constraints to potato production are plant-parasitic nematodes. In particular, root-knot nematodes (Meloidogyne spp.) are a significant impediment to potato production, suppressing yield and reducing the quality of harvested tubers. The current study was undertaken to evaluate the efficacy of a lignocellulose fibre matrix (banana paper) either impregnated with a chemical or drenched with a biologically-based nematicide for the management of root-knot nematodes on potatoes, in Kenya. The experiment was conducted in both field and pot …

Disentangling Genotype And Environment Specific Latent Features For Improved Trait Prediction Using A Compositional Autoencoder, Anirudha Powadi, Talukder Zaki Jubery, Michael C. Tross, James C. Schnable, Baskar Ganapathysubramanian

Department of Agronomy and Horticulture: Faculty Publications

In plant breeding and genetics, predictive models traditionally rely on compact representations of high-dimensional data, often using methods like Principal Component Analysis (PCA) and, more recently, Autoencoders (AE). However, these methods do not separate genotype-specific and environment-specific features, limiting their ability to accurately predict traits influenced by both genetic and environmental factors. We hypothesize that disentangling these representations into genotype-specific and environment-specific components can enhance predictive models. To test this, we developed a compositional autoencoder (CAE) that decomposes high-dimensional data into distinct genotype-specific and environment-specific latent features. Our CAE framework employed a hierarchical architecture within an autoencoder to effectively separate …

Industrial Hemp Biomass Negatively Affected By Herbicide Drift From Corn And Soybean Herbicides, Milos Zaric, Bruno Canella Vieira, Barbara Houston, Guilherme Sousa Alves, Samuel E. Wortman, Julie A. Peterson, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

The establishment of industrial hemp (Cannabis sativa L.) fields near row crops has raised concerns about the potential adverse effects of herbicide drift on hemp production. This study examined hemp susceptibility to drift of herbicides registered for use in corn and/or soybeans. Herbicide solutions (2,4-D, dicamba, glufosinate, glyphosate, imazethapyr, lactofen, mesotrione) were applied separately in the wind tunnel (3.6 m s⁻¹ airspeed), simulating drift scenarios, with conventional TP95015EVS (TP) and air inclusion AI95015EVS (AI) flat fan nozzles calibrated to deliver 140 L ha⁻¹ carrier volume at 230 kPa. Mylar cards and hemp plants (20–25 cm tall) were placed …

Towards An Ideal Seed Coating, J M. Scott

IGC Proceedings (1977-2023)

Coated pasture seeds have been formulated in the past based largely on "trial and error" with relatively few objective criteria being employed to define desirable formulations, A description of desirable propelties of various layers of seed coatings and of the seeds themselves is presented.

Lolium Endophyte Viability: Effect Of Seed Storage, M P. Rolston, J R. Crush, M D. Hare, K K. Moore

IGC Proceedings (1977-2023)

The effects of seed storage on the endophyte Acremonium lolii in ryegrass (Lolium perenne L.) were evaluated over 7 years. The long• term effects of 4 seed moisture contents (SMC) 8.6-13.1 %: tempemture (ambient, 5, O, -15°C) 'aitd packaging types: calico, polyethylene fi,Jm. 9-140 µm, and aluminium-polyethylene (AIP) on endophyte viability were assess·ed. • Endophyte viability was maintained by lower seed moisture content and low temperatures. In ambient warehouse conditions endophyte viability declined to zero in 12 months in calico bags,' but was maintained for 3 years at 8.6% SMC in AIP: • Endophyte viability was maintained for …

Effect Of Dormancy-Releasing Treatments On Germination Of Bahiagrass Seed, J. Jeffrey Mullahey, D S. Fisher

IGC Proceedings (1977-2023)

Low seed germination and dormant seed in bahiagrass (Paspalum nonatutum Flugge.) necessitate high seeding rates for successful pasture establishment. A study of dormancy-releasing treatments and age of seed on germination of bahiagrass was conducted in an incubator at the Southwest Florida Research and Education Center near Immokalee, Florida. Five seed treatments (Crop-Start (Solid Matrix Seed Priming, Kamterter Products Inc., Lincoln, NB), potassium nitrate (KNO3), heat/humidity, palea removed, and a check), 2 cullivars (Pensacola, Tifton 9) of bahiagrass and 2 ages (10 and 16 months) of seed were used. A significant (P<0.05) age ·x treatment interaction occurred for all response variables. Based on total germination at 28 days, % dormant seed and rate of germination, Crop-Start and heat/humidity were consistently the best treatments. Additional research on germination with dormancy-releasing treatments is needed to study the Interaction of seed age and bahiagrass cultivar.

Weed Seed Contamination: Use Of A Seed Testing Database To Identify Processing Limitations, J S. Rowarth, M P. Rolston, A A. Johnson

IGC Proceedings (1977-2023)

A computerised database maintained by the Official Seed Testing Station of New Zealand provided the opporlunity to survey weed seed contamination in clover and grass seed-lots. Broad-leaf weeds such as Slierardia arvensis, Stellaria ,nedia and Chenopodium album were the major contaminants in Trifolium repens seed-lots. In grass seed-lots the main contaminants were seeds of other grasses such as Bromus hordaeceus, Vulpia spp. and Holcus lanatus. Weed seeds were found to be a major reason for downgrading or rejection from certification of clover and grass seed-lots in New Zealand; this reflects strict quality control measures.

An Investigation In To The Effect Of Some Factors On The Germination Of Erodium Seeds, Myrna Johnston, Alfredo Olivares, Gladys Fernandez

IGC Proceedings (1977-2023)

Erodiurn seeds present variable dormancy in and even within each species. Thus, it is important to know the factors that determine this variation as related to the persistence of its species. E. rnoschatmn and E. rnalacoides seeds were collected at the end of the annual cycle at La Rinconada de Maipli (33°28'S and 7S050'W). Effects of seed sour.ce (collecting in 1986, 1988 and 1990), age (keeping seeds under laboratory conditions) and maternal factors (cutting plants at early flowering) were analysed. Seeds were tested for germination capacity and germination rate at a constant temperature of 15°C on Petri dishes provided with …