Average Number Of Tillers Research Articles

Yield component Responses to different Planting methods in Fonio under rain fed conditions

Abstract
 Fonio respond differently at different sowing conditions. Field experiment was conducted to assess the respond of fonio grain yield and its components when subjected to different seeding methods under rainfed condition during the growing season of 2021 and 2022. The Randomized complete block design with three replications was adopted for the experiment. The result revealed that planting methods (dibbling, drilling broadcasting and transplanting) used had significant effect on all the yield components and grain yield. Transplanting was on a clear lead with an average number of tillers per plant of 13.8 surpassing dibbling and drilling whose average had no significant difference at 5% probability level. In days to maturity, transplanted crops takes longer (115.1) days for fonio to reach 50% flowering. However, fonio appears to mature earlier when drilling and transplanting methods are adopted. Taller plants, longer spikes, longer panicles, higher number of tillers and higher grain yield were observed when transplanting method was applied in fonio field cultivation. Therefore, transplanting method could be recommended for increased tillers, longer spikes and higher grain yield of fonio under rainfed condition.

Spatial variability of wheat yield using the gaussian spatial linear model

Wheat production has grown over the years and is one of the most important grain food sources for humans. This work analyzed the yield of two varieties of wheat planted in a regular sampling grid in an experimental area in the south of Brazil, using some explanatory variables. For the study of the spatial variability of wheat yield of the COODETEC 101 (CD101) and COODETEC 103 (CD103) varieties, which were cultivated by the farmer in an area of 22.62 ha, 84 samples were defined considering a regular grid of 50 x 50 m. In the sampled sites, the following explanatory variables were collected: average plant height in 60 days - avheight 60 (cm), the average number of tillers in 60 days - avtillers60 (cm), spike length in 120 days - splength (cm) and the wheat variety considered as a dummy variable (CD101 = 0 and CD103= 1). The wheat yield was analyzed using gaussian spatial linear models with different geostatistical models for the parametric form of the variance-covariance matrix. The significance of the parameters to select the explanatory variables were determined by the likelihood ratio test, and also a hypothesis test was presented to confirm that a model that deal with the spatial dependence was required by the data. To assess the global and local influence of some observations, diagnostics techniques based on Cook’s approach were considered. The disregard of potentially influential observations caused changes in the parameters estimates that define the spatial dependence structure, and consequently then in the profitability in sectors of the wheat yield maps. The study of statistical inference and diagnostics on spatial data should be part of all geostatistical analysis

DESEMPENHO AGRONÔMICO DE CULTIVARES DE TRIGO EM RESPOSTA À INOCULAÇÃO (Azospirillum brasilense) E APLICAÇÃO DE NITROGÊNIO

ABSTRACT The objective of this work was to verify the contribution of seed inoculation with the bacterium Azospirillum brasilense to promote growth on yield components in wheat crop. For this, experiments were carried out in different locations (Santa Maria and Cruz Alta, RS, Brazil), sowing times (June and July) and years of cultivation (2013 and 2014). A randomized block design with three replications was used. The treatments were composed by the combination of ten cultivars, three nitrogen managements and two types of inoculation (10 x 3 x 2). Inoculation was carried out with liquid inoculant in the seeds. The components of grain yield were evaluated. The average number of tillers per plant was influenced by seed inoculation (1.63 and 1.72) when uninoculated and inoculated, respectively. On the other hand, the hectoliter mass responded inversely, reducing to 75.7 kg hL-1. Inoculation with A. brasilense increased the grain mass (1%) and had no positive influence on the variables number of ears and spikelets per ear, grain yield and hectoliter weight.

The genotype does not influence the establishment of elephantgrass (Pennisetum purpureum Schum.)

This study investigated whether genotype influences the establishment of Pennisetum purpureum Schumach. The experimental design was a randomized complete blocks with four treatments and eight replications (n=8). The treatments were four genotypes of P. purpureum, two classified as tall sizes: P. purpureum cv. Elephant B and cv. IRI 381; and two as dwarf types: P. purpureum cv. Mott and Taiwan A-146 2.37. They were planted in a tropical wet and dry region of Brazil. Tall genotypes showed superior field sprouting rates (p < 0.05), ranging between 95-99%, while dwarfs varied between 88-90%, however, Elephant B and IRI 381 produced a much lower average number of tillers (31 and 32 linear m-1, respectively), than Taiwan A-146 2.37 and Mott (56 and 41 linear m-1, respectively) (p < 0.05). Dwarf genotypes produced lower biomass yields (p < 0.05), but this was genotype-dependent and did not impact on their establishment. The levels of non-structural carbohydrates (NSC) (>10%) in the planted stems were associated with satisfactory field sprouting of the elephantgrass genotypes. Despite some variations between the genotypes in terms of sprouting, tillering, and growth rates, the kind of genotype had no major significance on the establishment of the elephantgrass.

Effect of Fish Amino Acid Application on Growth and N-uptake in Plants Rice Using The System of Rice Intensification Method

Rice is the main rice crop which is used as the staple food of most Indonesians. Rice production in Indonesia cannot be separated from inorganic fertilizers which have a bad impact on the environment, so it is necessary to carry out a revolution, one of which is the SRI method. The addition of FAA organic matter originating from fish sorted by fishermen which have no selling price is used as a substitute for inorganic fertilizers. This study aims to determine the effect of FAA application on growth and N uptake in rice plants using the SRI method and to determine the best dose of the effect of FAA application on growth and N uptake in rice plants using the SRI method. This research was conducted in December 2019 - April 2020 at the Greenhouse of the Agroecotechnology Department, Faculty of Agriculture, Lambung Mangkurat University, Banjarbaru. The design used was a one-factor Completely Randomized Design (CRD), with treatment f0 (control / without FAA application), f1 (1 mL FAA / L), f2 (3 mL FAA / L), f3 (5 mL FAA / L) , and f4 (7 mL FAA / L). The treatment was repeated 5 times, to obtain 25 experimental units. Observation parameters in the study were plant height, number of tillers, and N uptake of rice leaves. The results showed that the application of FAA with a dose of 1 mL FAA / L was able to increase the height of rice plants by 5.5%, produced an average number of tillers of 14 tillers, and was able to increase nitrogen uptake by 9.6% in rice plant leaves.

Effect of Soil Organic Ameliorants with Carbonized Rice Hull on the Growth and Yield of Shallot Onion (Allium ascalonicum L) on Salt Affected Soil

A pot experiment was conducted to test the potential of different soil organic ameliorants in salt affected soils reclamation; to test the effect of soil organic ameliorants on the growth and yield of shallot onion (Allium ascalonicum L.) planted in salt affected soil; determine the most effective soil organic ameliorants on salt affected soil Treatments prepared were; T1- Control Salt affected soil (1.57 kg/pot-1), T2- Vermi-cast (197.40 g/pot-1) with CRH (30 grams/pot-1),T3- Guano dung (39.40 g pot-1 with CRH (30 grams/pot-1), T4- Dried Goat Manure (115.40 g/pot-1) with CRH (30 grams/pot-1), T5- Dried Chicken Dung (94.94 g pot-1) with CRH (30 grams/pot-1), T6- Dried Cattle Manure (214.30 g/pot-1) with CRH (30 grams/pot-1). The study was laid out using Randomized complete block design with treatments and three replications. All organic ameliorants applied to the salt affected soil significantly improved on average bulb diameter, average height, average number of leaves, average bulb fresh weight, average number of tillers and average yield per hectare. It can be concluded that application of organic ameliorants is effective means to address the problem in saline affected soils.

Response of M5 wheat (Triticum aestivum L.) mutant to low altitude growing condition

This study aims to study the adaptability of wheat mutant lines in the lowlands and determine the growth and production of the mutant lines. The research was conducted from September to December 2017 at Teaching Farm, Faculty of Agriculture, Hasanuddin University, Makassar, South Sulawesi Province. The study was carried out in the form of experiments arranged based on Randomized Block Design and further tested using orthogonal contrast. The treatments given were five M5 mutant genotypes and two convergent breeding genotypes. Three wheat varieties Dewata, Munal, and Selayar were used as comparisons. The results showed that the convergent breeding line (CB 145) showed good genetic traits on plant height parameters and the number of empty floret. Dewata, Munal, and Selayar varieties showed more average number of tillers (6.00 tillers) and 100 heavier grain weight (4.07 g) compared to the mutant genotypes. Dewata variety showed good genetic characteristics on panicle length parameter (6.50 cm) and grain weight per panicle (0.34 g). CB 169 genotype showed good genetic characteristics on the parameter number of grain per panicle which only produced the number of seeds per panicle (8.33 seeds).

The Combination of Piper Caninum Blume Leaf Extract and Compost Fertilizer for Pressing Blast Disease and Improving Growth of Bali Red Rice (Oryza Sativa Linn)

Blast disease is a spotting disease on the leaves that attacks rice, rice grains become empty and finally causing a significant loss in rice production. Many factors that cause blast disease include the continuous use of synthetic fertilizers and pesticides which could decrease soil fertility resulting in a decrease in rice yield. One way to restore soil fertility and increase rice production is to use organic methods such as using biopesticides and compost. The purpose of this study is to obtain the most appropriate formulation between biopesticides, P. caninum BL. leaf extract and compost to suppress blast disease and improve results in red Bali rice cultivation. This research was conducted in the field in Senganan Village, Penebel, Tabanan Bali, a flat area of about 300m above sea level. The experiment was carried out using a randomized block design (RBD) with 4 set of different treatments. The mixture of 40% compost and 2% piper caninum Bl. leaf extract was found to be the most effective formulation to suppress blast disease by 57.17% when tested in a 0.2-hectare paddy field. The significant reduction of blast disease and the use of organic fertilizer have improved the growth of red rice as shown by the average number of tillers (12.9) and leaves (60.5 strands) after 12 weeks of transplant. The yield of the rice after 3 months of cultivation was 5.51 ton / ha, an increase by 2.40%. The morphology of the ripen grain of F4 treated clamps were studied and EDX analysis showed only carbon and oxygen are the major elements and trace amount of potassium and magnesium were detected. The crystalline nature of the rice is shown by the presence of polyhedral shape of starch with the size between 3 and 6 µm in the endosperm area. The silicon was only observed in the hull layer. At an optimal extract concentration, the yield was increased significantly by 77%. However, above the optimal concentration of the extract toxic behaviour was observed in both the growth and reduction of yield. This may be due to the toxicity nature of the many active components that were present in the extract. Therefore, further study is necessary to understand the mode of action and side effects that enable to assist in the modelling work for cultivation management and practices.

Assessing the contribution of ethaboxam in seed treatment cocktails for the management of metalaxyl-resistant Pythium ultimum var. ultimum in Pacific Northwest spring wheat production

Hard red spring wheat is an important crop in the Pacific Northwest and is a component of a 3-year crop rotation involving soft white winter wheat; cool season pulse crops such as pea, lentil and chickpea; and canola. Pythium root rot and damping-off have long been observed as an annual problem, particularly in spring planted crops. As such, a seed treatment that includes metalaxyl is very common. Recently, an increase in the incidence of Pythium damping-off highlighted that there is an emerging population of Pythium spp. that are resistant to traditional seed treatments containing metalaxyl. The use of alternative chemistries to manage Pythium root rot and damping-off has gained regional interest to increase crop health and improve yields. The effectiveness of ethaboxam was evaluated along with two other seed treatment cocktails in controlling metalaxyl-resistant Pythium in replicated field experiments of spring wheat over three growing seasons in northern Idaho. Emergence, seedling characteristics, plant height, yield and test weight were assessed. The addition of ethaboxam to metalaxyl-containing seed treatment blends consistently increased emergence and yield of spring wheat compared to seed treatment blends containing metalaxyl only. First leaf length, an indirect measure of early season Pythium damage, was longest in seed treatments containing ethaboxam and the average number of tillers was lower, likely due to increased emergence, than non-treated seed. These results indicate that ethaboxam can improve disease control in spring wheat production when applied as a seed treatment in combination with metalaxyl, specifically in the presence of metalaxyl-resistant Pythium spp.

Effect of Transplanting Zones and Dates on Pre-imaginal Populations, Parasitism and Attacks of Major Insect Pests of Rice on the Rice-Growing Area of la Vallée du Kou (Bobo-Dioulasso)

Lepidopterous stem borers cause extensive damage in irrigated rice in Burkina Faso and regularly compromise the harvest of the dry season rice in the rice-growing area of la Vallee du Kou in western Burkina Faso. Yield of losses of 40% were observe during the dry season. The study conducted during the wet season in 2015 examined the effects of areas and of transplanting dates on the evolution of population of stem borer's damage and of parasitism. Rice irrigation area of la Vallee du Kou was divided into three areas within which 12 farmers were selected on the basis of three dates of transplanting rice; they were total 36 for the days three transplanting dates. According to agronomic evaluation, the transplantation dates are influence by the number of tillers and by the number of panicles. The maximum average number of tillers was observed in the second area within the first date of transplantation. Otherwise the second area and the second date recorded the highest number of panicles. Entomological observations were carried on every 7 days from the 21th day to 91th day after rice transplanting in each of the 36 fields. Late transplanting (August) are the most exposed to Orseolia oryzivora attacks. The genus Chilo spp, Maliarpha and Diopsis spp were the most important pests in rice plants on the perimeter of la Vallee du Kou. Periods of greatest damage were observed in tillering. They were responsible for the deadhearts damage, for white panicles and for the highest rates. These damages were recorded during the first date of rice transplanting. Parasitism associated with the genus Chilo was observed in the first transplanting date. The hectare average yields were most important in the second transplanting date of within the third area. These results on the pre-imaginal populations are important data. These data can be taken into account to improve the development of a strategy to fight against the major insect pests of rice plants. All these elements are linked to the climatic variations.

Experience with the system of rice intensification for sustainable rainfed paddy farming systems in India

ABSTRACTPrinciples of the System of Rice Intensification (SRI), an agroecological methodology for improving rice crop performance, were introduced in the Dharwad district of Karnataka, India, in 2008 by an NGO wanting to improve the sustainability of rainfed paddy-farming systems. Farmer field schools enabled 82 farmers to adopt and adapt SRI practices in the initial season. SRI’s alternative practices were found to contribute to healthier roots and more productive tillers, the average number of tillers per plant on farmers’ SRI and control plots being 19 and 7, respectively. SRI was found to require 87% less seed than with traditional methods; yet, it gave 40% more yield per unit area in a drought year. The economic returns per hectare were 76% greater. There was some early evidence of soil-fertility improvement, but this can only be assessed over longer periods of time. Three years after introduction, over 3,000 farmers had continued adopting SRI practices in the district. In another 3 years, the number using these new methods had reached almost 29,000 in Dharwad and neighboring districts.

Development of a Biological Phosphate Fertilizer to Improve Wheat (Triticum Aestivum L.) Production in Mali

Tilemsi Rock phosphate Tilemsi (TRP), is a good and inexpensive alternative to imported phosphate fertilizers. Thiobacillus thioparus, Thiobacillus thiooxidans and Thiobacillus ferooxidans, are known for their ability to oxidize soil sulfur and sulfides and influence the solubilization of inorganic phosphates. These bacteria have also a good potential to improve plant growth. In order to improve wheat response to fertilization with TRP, we describe in this work, the isolation from agricultural soils and the selection of different Thiobacillus strains with high TRP-solubilizing activities. Initially, 91 acidifying bacteria were selected, but after 10 subcultures on agar and in liquid media, only four bacteria were chosen for their strong P-solubilizing activities. No Thiobacillus ferrooxidans, was isolated from tested agricultural soils. A significant correlation was observed between acid production by isolated strains and phosphate solubilization. In a field trial in Koygour (Dire), wheat (Triticum aestivum cv. Tetra) was inoculated with selected strains of Thiobacillus and fertilized with the TRP or diammonium phosphate (DAP). The growth and yield parameters measured were the plant the tillers per plant, panicles per plant, percentage of fertile tillers (number of tillers with panicles/total number of tillers), panicle length, grain per panicle, grain yield calculated at 13% moisture, and 1000 grain weight. Yield increase relative to control and yield relative efficiency were also calculated. BioTRP1, with yield of 2840kg/ha grain, increased grains and straw yield at 45.64 and 73.81%, respectively with the highest relative yield efficiency. BioTRP1 is the only treatment not significantly different from the Di-ammonium phosphate. At harvest, average number of tillers was 18 for treatment 5 and a bit lower for di-ammonium phosphate with 17.8. Percentage of fertile tillers was 92% and 90% for the di-ammonium phosphate and the BioTRP1 treatments respectively. Panicle length was more than double for di-ammonium phosphate and BioTRP treatments compared to control. The number of grains/panicle was also highest for di-ammonium phosphate and BioTRP1 with 54 and 51 grains/panicle respectively. The di-ammonium phosphate, the BioTRP1 and control were significantly different and showed the maximums and minimum weights of 28; 27 and 20g for 1000 grains of wheat. BioTRP2 and BioTRP3, formulated with Thiobacillus thiooxidans AHB411 and Thiobacillus thiooxidans AHB417, also caused yield increases of 33.33 and 11.97% respectively. The choice of Thiobacillus thiooxidans AHB 436, and the formulation of BioPNT will be discussed

Genetic variability of seed yield and seed yield components of autochthonous Lolium perenne L. populations

The aim of this study was to examine genetic variability, heritability and correlation of seed yield components and seed yield of progenies of autochthonous populations and cultivars of perennial ryegrass, and that on the basis of these results distinguish genotypes that would be later used in the creation of new local cultivars of perennial ryegrass. Research was carried out on experimental fields and laboratories of the Agricultural Institute of Republic of Srpska in Banja Luka in 2007. and 2008., on 6 natural populations of perennial ryegrass collected in Bosnia and Herzegovina and two cultivars, Maja and Calibra as standard. Following parameters were analyzed: number of generative tillers per plant, time of flowering, spike length, number of spikelets per spike, seed yield per spike and plant and 1000 seed weight. Analysis of the results of the number of generative tillers per plant indicates a statistically significant difference in the studied populations and cultivars of perennial ryegrass. The highest average number of tillers per plant was found in the cultivar Maja (193.8), and the least number was detected in population Dragocaj (78.9), so statistical differences were highly significant. The longest period to beginning of flowering was determined in cultivar Calibra (56.5 days) and the shortest in population Laminci (43 days). The average length of spike of perennial ryegrass in the studied population was 22.78 cm and was significantly lower than cultivar Maja. Statistically significant differences between populations and variety Maja in the number of spikelets per spike were detected. The average seed yield per spike of studied populations was in level with cultivar Maja and 37.5% higher compared with variety Calibra. In the studied populations of perennial ryegrass seed yield ranged from 5.21 g (Dragocaj population) to 15.40 g (Kupres population). Weight of 1000 seeds was highest in the variety Calibra (2.60 g) and lowest in population Maglajani (1.94 g). Proportion of genetic to phenotypic variance for time of flowering, the number of generative tillers, seed yield per spike and plant and 1000 seed weight indicate that the variability of these traits in this collection of genotypes, largely derived from plant genotype. In this investigation, the presence of a highly significant positive genetic correlation was found between time of flowering and spike length (0.98), time of flowering and 1000 seed weight (0.97), number of generative tillers and seed yield per plant (0.91) and spike length and 1000 seed weight (0.98).

Identification and characterization of the major mitochondrial Fe transporter in rice

The uptake, translocation, and compartmentalization of Fe are essential for plant cell function and life cycle. Despite rapid progress in our understanding of Fe homeostasis in plants, Fe transport from the cytoplasm to mitochondria was, until recently, poorly understood. The screening of 3,993 mutant lines for symptoms of Fe deficiency resulted in the identification and characterization of a major mitochondrial Fe transporter (MIT) in rice. MIT was found to localize to mitochondria and to complement the growth of a yeast strain defective in mitochondrial Fe transport. The knock-out of MIT resulted in a lethal phenotype, and in knock-down plants, several agronomic characteristics were compromised, such as plant height, average number of tillers, days to flower, fertility, and yield. Changes in the expression of genes involved in Fe transport suggested a disturbance of cellular Fe transport. Furthermore, the mitochondrial Fe concentration and the activity of the mitochondrial Fe-S enzyme aconitase were significantly reduced compared with wild-type plants. The identification of MIT is a significant advance in the field of plant Fe nutrition and should facilitate the cloning of paralogs from other plant species.

Insect resistance and risk assessment studies of advanced generations of basmati rice expressing two genes of Bacillus thuringiensis

Advanced generations of different transgenic lines of indica basmati rice (Basmati-370) expressing two unrelated Bt genes, cry1Ac and cry2A were evaluated for resistance to Yellow Stem Borer (YSB) and Rice Leaf Folder (RLF) under field conditions compared to control lines over three years (2003-2005). Homozygous lines were selected and analyzed for insect resistance, morphological, physiochemical properties and risk assessment studies. After artificial infestation of target insects, the transgenic plants showed significant resistance. Data were recorded in terms of dead hearts and white heads at vegetative and flowering stage respectively. Transgenic lines showed up to 100 and 96% resistance against yellow stem borer at vegetative and flowering stages, respectively. Natural damage of rice leaf folder was also observed during the year 2005. The transgenic plants were 98% more resistant as compared to untransformed control plants. Variations in some morphological characteristics, e.g., the average number of tillers, plant height and maturity were also observed. Transgenic lines produced 40% more grains than control plants. All these characteristics were stably inherited in advanced generations. The transgenic lines had no significant effect on non-target insects (insects belonging to orders other than Lepidoptera and Diptera) in field or under storage conditions. Chances of pollen-mediated gene flow were recorded at a rate of 0.14%.

Novel indica basmati line (B-370) expressing two unrelated genes of Bacillus thuringiensis is highly resistant to two lepidopteran insects in the field

We report the first field trials of indica basmati rice expressing two Bt genes, cry1Ac and cry2A simultaneously. Different transgenic lines were sown under field conditions for two consecutive years (2001 and 2002). Artificial infestation of yellow stem borer (YSB, Scirpophaga incertulas) and natural infestation of rice leaf folder (RLF, Cnaphalochrocus medinalis) were studied. Transgenic lines showed up to 100% and 98% resistance against YSB at vegetative and flowering stages, respectively, with 98% additional resistant against RLF as compared with the control. Variation in some morphological characteristics, e.g., the average number of tillers, plant height and maturity, were also observed. Transgenic lines produced up to 59% more grains than control plants under artificially augmented conditions, while up to an 8% increase was recorded under natural infestations. All lines expressed high level of Cry proteins when compared with commercially released cultivars of Bt cotton, maize and potato. It was also observed that although toxin titer substantially decreased with increasing age of the plants, it remained well within the limits necessary to kill the target insects. It was also observed that the transgenic lines released Bt toxins from roots into Murashige and Skoog basal medium, hydroponic cultures and soil, which could be detected through sandwich ELISA. On the basis of these results these lines seem good candidates to be released as the first commercial cultivars of Bt indica basmati rice.

Binomial Sequential Sampling Methods for Cereal Aphids in Small Grains

Seventy-one samples of 200 to 400 tillers each were taken from small grain fields. An equation used to relate the proportion of infested tillers to the mean number of aphids per tiller fit the data well ( r 2 = 0.98). Although the equation was developed from pooled counts of four species of cereal aphids ( Schizaphis graminum (Rondani), Sitobion avenae (F.), Rhopalosiphum padi (L.), and R. maidis (Fitch)), it described the relationship between the proportion of infested tillers and mean number of aphids per tiller adequately for each species individually. When predictions from the equation were compared with independent data, the predicted and actual numbers of aphids per tiller were similar. Required sample sizes for estimation of the mean number of aphids per tiller with fixed average levels of precision (standard error /mean) were determined. Required sample sizes to achieve a precision level of 0.15 ranged from a low of approximately 110 tillers for intermediate aphid populations to >500 tillers for low and high aphid populations. A truncated sequential sampling plan was developed. Using this plan, from 25 to 100 tillers are inspected for the presence or absence of cereal aphids. The average number of tillers inspected to arrive at a control decision ranged from 25 to 76 tillers depending on aphid population density. The frequency of decision errors was high (approximately 0.9) for populations near the action threshold (12.5 aphids/tiller), but was otherwise acceptable.

EFFECTS OF 14MeV NEUTRONS IN HETEROZYGOTIC EINKORN WHEAT

Heterozygotic einkorn wheat seeds were subjected to γ-rays and 14MeV neutrons and the effect of neutrons on the frequency of somatic mutation and fertility in X1 were examined. Up to 900rad of neutrons had no apparent effect on germination rate. Survival rates were slowly decreasing with increasing dosage. A similar tendency was also observed in the average number of tillers, but it was not marked.Somatic mutation rate was calculated on spike basis. An almost linear relation of the mutation curve was observed between mutation frequency and neutron dosage.Very high mutation rate or high RBE values in 14MeV neutrons was obtained in this experiment like in the previous experiment, for instance somatic mutation rate in the γ-ray 8600rad lot was 0.18 and that of neutron 324rad lot was 0.39. RBE value of neutron was very high in higher plants in general.Decrease of fertility was marked with increasing dosage. When the fertility was compared between mutated and non-mutated tillers (including the main stalk) within each individual, average fertility in the former was lower than in the latter. These facts support the view that most of somatic mutation arises from chromosome aberrations.Average number of mutated tillers per individual roughly increased with increasing dosage, as the result of repeated occurrence of the same kind of mutation within the same individual.

Studies on the tillering in genus Allium. VI

In this paper, the mechanism and mode of the tillering of Chinese leek were studied using var. “Oba-Nira” under natural conditions. 1. The mechanism of the tillering of Chinese leek is similar to that of the welsh onion with the exception of the following single point mentioned in 2. 2. The 1st and 2nd leaves of the tiller are usually formed on the phyllotaxy plane of the mother plant, however the 3rd and subsequent leaves are not formed on this plane. Soon after the commencement of tillering bud formation, the phyllotaxy plane of the mother plant changes its direction unmethodically. Namely, while the phyllotaxy planes of tiller and mother plant are on the same plane at first, later they become separated from each other. 3. In a plant which has fully developed in tillerings, the tillers are arranged in a circle or elliptical group. In this case, there is no rule as to the arrangement of these tillers. 4. The indications of flower bud differentiation are quite similar to those of the welsh onion. The initial stages of involucre formation becomes discernible in middle June, and flower cluster development progresses rapidly until the flowers commence to bloom in early or middle August. Soon after the beginning of involucre formation, a new vegetative axillary bud is formed at the base of the primordium of the flower cluster stalk. This bud developes in parallel with the flower cluster and grows into a perfectly developed mature plant. 5. Under natural conditions, the first tiller of seedling appeared at the 6th or 7th node of the main plant, and the percentage of appearance at the 6th node was 71.4 and that at the 7 th node was 28.6. Most of the 2nd and subsequent tillers appeared at the 1st, 2nd or 3rd node after the preceding tiller had occurred, and the frequency of appearance at the 2nd node was the highest. 6. The average number of tillers coming from a seedling in a growing season was 23.6, and that of differentiated leaves was 150.5. 7. At times, the development of a tillering bud was so slow that the tiller appeared from the leaf sheath of preceding node too late to be normal. These abnormal tillerings were frequently observed in the late stage of the growing season. No examples of other types of abnormal tillerings were observed in Chinese leek.