Thicker Stem Diameter Research Articles

Response of Sunflower (Helianthus Annuus L) to Plant Spacing

Agriculture is an important sector of Sudan economy and is the backbone of growth, poverty reduction, and sustainable development. Sunflower has become an important crop for both farmers and consumers in Sudan, fits well in the local cropping system and is considered the most important cash crop of the country. The experiment was conducted in the Experimental Farm, University of Kassala (New Halfa) of Sudan, to investigate the influence of cultivars and planting Spacing on plant growth and yield of Sunflower (Helianthus annuus L). It consisted of two cultivars (pannar-735 and Damazin-1) and three plant spacing’s (10 cm, 20 cm and 30 cm). Treatments were arranged in a factorial randomized complete block design (RCBD), in three replications. The results revealed, the cultivar, pannar- 735, early flowering, significantly highest hundred seed weight, seeds number per disc, seed yield (g/plant) and final yield (3.00 ton/ha). The Intra-row spacing of 30 cm had a thicker stem diameter, a highest number of seeds per head, 100-seed weight, seed yield per plant and final seed yield (3.34 ton/ha). The study revealed that the sunflower hybrid pannar-735 and plant spacing 30 cm apart is the best for New Halfa Eastern of Sudan.

Killing two enemies with one stone? Genomics of resistance to two sympatric pathogens in Norway spruce.

Trees must cope with the attack of multiple pathogens, often simultaneously during their long lifespan. Ironically, the genetic and molecular mechanisms controlling this process are poorly understood. The objective of this study was to compare the genetic component of resistance in Norway spruce to Heterobasidion annosum s.s. and its sympatric congener Heterobasidion parviporum. Heterobasidion root- and stem-rot is a major disease of Norway spruce caused by members of the Heterobasidion annosum species complex. Resistance to both pathogens was measured using artificial inoculations in half-sib families of Norway spruce trees originating from central to northern Europe. The genetic component of resistance was analysed using 63,760genome-wide exome-capture sequenced SNPs and multitrait genome-wide associations. No correlation was found for resistance to the two pathogens; however, associations were found between genomic variants and resistance traits with synergic or antagonist pleiotropic effects to both pathogens. Additionally, a latitudinal cline in resistance in the bark to H. annosum s.s. was found; trees from southern latitudes, with a later bud-set and thicker stem diameter, allowed longer lesions, but this was not the case for H. parviporum. In summary, this study detects genomic variants with pleiotropic effects which explain multiple disease resistance from a genic level and could be useful for selection of resistant trees to both pathogens. Furthermore, it highlights the need for additional research to understand the evolution of resistance traits to multiple pathogens in trees.

Effect of Nitrogen Fertilizer Rates and Plant Density on Straw, Fiber Yield and Anatomical Manifestations of Some Flax Cultivars

Two field experiments were carried out at the Experimental Farm at Gemmeiza Agriculture Research Station, Agricultural Research Center, Egypt, during two successive winter growing seasons of 2018/2019 and 2019/2020 to study the response of three flax cultivars, i.e. Sakha 3, Giza 11 and Giza 12 to three nitrogen fertilizer rates (30, 50 and 70 kg N/fed) and three plant densities (1500, 2000 and 2500 seeds/m2) and their effect on straw and fiber yield and its related traits as well as anatomical manifestations for flax stem at middle region. The experimental design was laid out using split-split plot design in four replications. Flax cultivars were distributed in the main plots, whereas nitrogen fertilizer rates were arranged at random in sub-plots and plant densities treatments were assigned at random in sub-sub plots. The sub-sub plot area was 9 m2. Sakha 3 cultivar significantly produced the maximum total plant height, technical stem length, total fiber percentage, fiber yield/plant, fiber yield/fed, fiber length and fiber fineness in both seasons. Meanwhile, the highest No. of basal branches/plant, straw yield/plant and straw yield/fed in both seasons were recorded with Giza 12 cultivar. Meanwhile, Giza 11 cultivar gave the thickness stem diameter in both seasons. Increasing nitrogen fertilizer rates from 30 to 70 kg N/fed caused significant increases in all straw and fiber yield and its related traits of flax, except fiber fineness was significantly decreased with increasing nitrogen rates in both seasons. Increasing plant densities from 1500 to 2500 seeds/m2 caused markedly increment in total plant height, technical stem length, straw yield/fed, total fiber percentage, fiber yield/fed, fiber length and fiber fineness during both seasons. On the other hand, No. of basal branches/plant, stem diameter, straw yield/plant and fiber yield/plant were significantly decreased by increasing plant densities during both seasons. The first order interactions between treatments Sakha 3 X 70 kg N/fed, Sakha 3 X 2500 seeds/m2 and 70 kg N/fed X 2500 seeds/m2 as well as the second order interaction between treatments Sakha 3 X 70 kg N/fed X 2500 seeds/m2 were significantly recorded the highest total plant height, technical stem length, fiber yield/fed and fiber length as compared with the others interactions in both seasons. While, the maximum fiber yield/fed were recorded from the first order interactions between treatments Sakha 3 X 70 kg N/fed, Sakha 3 X 2500 seeds/m2 and 70 kg N/fed X 2500 seeds/m2 as well as the second order interaction between treatments Sakha 3 X 70 kg N/fed X 2500 seeds/m2. Data illustrated an increase in each of total cross section area, cortex area, fiber area, xylem area, fiber index per plant, cortex % and xylem % in all flax cultivars under study (Sakha 3, Giza 11 and Giza 12) as affected by fertilized flax plants with 70 kg N/fed and plant density at 1500 seeds/m2. It could be concluded that Sakha 3 cultivar and fertilizing by 70 kg N/fed with plant density of 2500 seeds/m2 to maximizing fiber yield/fed and quality.

Effect of Bacillus subtilis and Bacillus amyloliquefaciens culture on the growth and yield of off-season potato (Solanum tuberosum L.)

A study was carried out in order to investigate the effect of microbial fertilizer application on off-season potato (Solanum tuberosum L. cv. Universia) under field conditions in early spring and late autumn in 2016. The experiment included Control (C, no application), Standard Fertilizer Application (SFA), Microbial Fertilizer Application (MFA) and SFA+MFA treatments. An equal mixture of three strains of Bacillus subtilis VKPM B-10641(DSM 24613), Bacillus amyloliquefaciens VKPM B-10642 (DSM 24614) and Bacillus amyloliquefaciens В-10643 (DSM 24615) was applied at 1x109 cfu/ml to tubers before planting and to plants at flowering stage in MFA and SFA+MFA plots. Treatments affected the plant growth parameters. SFA plots produced the highest tuber yields in both seasons. MFA plots had earlier emergence time (40 days), higher number of stems per plant (3), higher number of leaves per plant (37.2), thicker stem diameter (10.15 mm), higher above ground biomass yields (5.42 t/ha), higher single tuber weight (104.21 g) and higher tuber yields (22.06 t/ha) compared with control plots (42 days, 2.2, 31.2, 9.15 mm, 4.40 t/ha, 90.88 g and 20.14 t/ha respectively). Tuber yield in MFA plots (26.56 t/ha) was equal to SFA plots (26.81 t/ha) in warmer autumn planting. Combination of SFA and MFA produced lower tuber yields (21.72 t/ha) than SFA treatment (26.81 t/ha). In conclusion, Bacillus subtilis and Bacillus amyloliquefaciens gave comparable tuber yields to chemical fertilizer application in warmer autumn plantings, but lower tuber yields in colder spring conditions warranting further experiments with cold tolerant psychrophilic bacterial strains for off-season potato production.

Traits Affecting Low Temperature Tolerance in Tomato and Its Application to Breeding Program

It is essential to develop tomato (Solanum lycopersicum L.) cultivars with tolerance to low temperature (LT) for reducing production cost and increasing fruit quality in winter. This study was conducted to investigate the effects of LT on 40 tomato accessions for establishing selection criteria to select accessions with LT tolerance. Tomato plants were grown in two polyethylene film greenhouses with night temperature set-points of 10℃ and 15℃. LT significantly affected the photosynthetic parameters as well as both vegetative and reproductive growth in tomato. There was a significant difference in plant height between plants grown in 10℃ and 15℃. Leaf length and width were also significantly lower in 10℃. The stem diameter was generally lower in 10℃ but 12 accessions in 10℃ had thicker stem diameter than those in 15℃. The retarded growth was due to lower photosynthetic rate in 10℃ than 15℃. Significant delay in flowering was observed among tomato accessions in 10℃. For the number of flowers, 62.5% showed the increase but 37.5% did the decrease in 10℃ among 40 tomato accessions, showing genotype specific interaction with LT. Accessions with small fruits showed reduced fruit set in 10℃; however, it was not obvious among accessions with large fruits. Interestingly, 75% of accessions showed increased chlorophyll contents in 10℃ compared to 15℃. An accession ‘VI037163’ was selected for LT tolerance based on good performance in six out of seven traits considered such as plant height, leaf length, stem diameter, chlorophyll contents, days to flowering, the number of flowers and fruit set.

Bark in Woody Plants: Understanding the Diversity of a Multifunctional Structure

Most biological structures carry out multiple functions. Focusing on only one function to make adaptive inferences overlooks that manifold selection pressures and tradeoffs shape the characteristics of a multifunctional structure. Focusing on single functions can only lead to a partial picture of the causes underlying diversity and the evolutionary origin of the structure in question. I illustrate this discussion using bark as a study case. Bark comprises all the tissues surrounding the xylem in woody plants. Broadly, bark includes an inner and mostly living region and an outer, dead one. Of all plant structures, bark has the most complex anatomical structure and ontogenetic origin involving two (and often three) different meristems. Traditionally, the wide diversity in bark traits, mainly bark thickness, has been interpreted as the result of the selective pressures imposed by fire regime. However, recent research has shown that explanations based on fire regime cannot account for salient patterns of bark variation globally including the very strong inner bark thickness-stem diameter scaling, which is likely due to metabolic needs, and the very high intracommunity variation in total, inner, and outer bark thickness, and in inner:outer proportions. Moreover, explanations based on fire disregard that in addition to fire protection, bark carries out several other crucial functions for plants including translocation of photosynthates; storage of starch, soluble sugars, water, and other compounds; protection from herbivores, pathogens, and high temperatures; wound closure, as well as mechanical support, photosynthesis, and likely being involved in xylem embolism repair. All these functions are crucial for plant performance and are involved in synergistic (e.g., storage of water and insulation) and trade-off relationships (e.g., protection from fire vs photosynthetic activity). Focusing on only one of these functions, protection from fire has provided an incomplete picture of the selective forces shaping bark diversity and has severely hindered our incipient understanding of the functional ecology of this crucial region of woody stems. Applying a multifunctional perspective to the study of bark will allow us to address why we observe such high intracommunity variation in bark traits, why some bark trait combinations are ontogenetically impossible or penalized by selection, how bark is coordinated functionally with other plant parts, and as a result, to understand how bark contributes to the vast diversity of plant ecological strategies across the globe.

RcPAL, a key gene in lignin biosynthesis in Ricinus communis L.

BackgroundCastor (Ricinus communis L.) is an important seed oil crop. Castor oil is a highly demanded oil for several industrial uses. Current castor bean varieties suffer from low productivity and high risk of insect pests and diseases. High productive and pest/disease resistance varieties are needed. Lignin has been associated to the resistance for pest, disease and lodging. Lignin is produced from several metabolites of the phenylpropanoid pathway. PAL is the key enzyme of the phenylpropanoid pathway. The gene PAL may assist in the improvement of resistance of castor bean.ResultsThe RcPAL CDs was amplified and its function was examined by transgenic overexpression and antisense expression, lignin histochemical staining, real-time PCR, lignin content measurement and morphological investigation. Its full length was 2145 bp, encoding 714 amino acids. The overexpression of RcPAL (7.2 times) increased significantly the PAL activity, dyeing depth of xylem cells and lignin content (14.44%), resulting in a significantly lower plant height, deeper and thicker blade, more green leaves, shorter internode, thicker stem diameter, and opposite in antisense expression plants (lignin content lowered by 27.1%), demonstrated that the gene RcPAL was a key gene in castor lignin biosynthesis.ConclusionsThe gene RcPAL is a key gene in castor lignin biosynthesis and can be induced to express under mechanical damage stress. When up-regulated, it increased the lignin content significantly and dwarfed the plant height, and opposite when down-regulated. The gene RcPAL may assist in the improvement of resistance and plant type of castor bean.

Plant growth, yield and bioactive compounds of two culinary herbs as affected by substrate type

This study reports on the influence of growing substrates on plant yield, quality, and valuable bioactive compounds of two aromatic leafy vegetables; dill and parsley, grown in net house. The treatments comprised seven substrates; basis substrate (Stender, Germany soil); peat moss; sandy soil; Germany soil + peat moss (1:1 v/v); Germany soil + sandy soil (1:1 v/v); peat moss + sandy soil (1:1 v/v) and Germany soil + peat mass + sandy soil (1:1:1 v/v). Yield traits (stem length and diameter, number of leaves and leaf area), quality (shoot and root fresh and dry weights), as well as spectrophotometric analysis of bioactive components, including chlorophyll content, phenolics and flavonoids, and antioxidant activity based on radical scavenging activity assays DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [(2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)], and ferric reducing antioxidant power (FRAP) were measured. The higher yield and quality were observed in dill and parsley grown in Germany soil, followed by that grown in Germany soil + peat, which showed better performance such as greater plant height, number of leaves and leaf areas, thicker stem diameter, and higher shoot and root fresh and dry weights when compared with other substrates. The highest content of chlorophyll, phenolics, flavonoids, DPPH and ABTS radical scavenging activity, and FRAP was found in dill and parsley plants grown in Germany soil. Dill showed higher antioxidant capacity than parsley owing to the lower content of phenolics and flavonoids compounds in parsley.

Exploring the bark thickness-stem diameter relationship: clues from lianas, successive cambia, monocots and gymnosperms.

Bark thickness is ecologically crucial, affecting functions from fire protection to photosynthesis. Bark thickness scales predictably with stem diameter, but there is little consensus on whether this scaling is a passive consequence of growth or an important adaptive phenomenon requiring explanation. With a comparative study across 913 species, we test the expectation that, if bark thickness-stem diameter scaling is adaptive, it should be possible to find ecological situations in which scaling is predictably altered, in this case between species with different types and deployments of phloem. 'Dicots' with successive cambia and monocots, which have phloem-free bark, had predictably thinner inner (mostly living) bark than plants with single cambia. Lianas, which supply large leaf areas with limited stem area, had much thicker inner bark than self-supporting plants. Gymnosperms had thicker outer bark than angiosperms. Inner bark probably scales with plant metabolic demands, for example with leaf area. Outer bark scales with stem diameter less predictably, probably reflecting diverse adaptive factors; for example, it tends to be thicker in fire-prone species and very thin when bark photosynthesis is favored. Predictable bark thickness-stem diameter scaling across plants with different photosynthate translocation demands and modes strongly supports the idea that this relationship is functionally important and adaptively significant.

Comparing bark thickness: testing methods with bark–stem data from two South African fire‐prone biomes

AbstractAimsBark thickness–stem diameter relationships are non‐linear above a stem diameter threshold in many woody species, which makes relative bark thickness measures dependent on the range of stem diameters that are sampled. This influences the appropriateness of different methods for comparing fire responses of woody plants across studies. Here we develop a framework for bark thickness comparisons by evaluating relative bark thickness estimates and bark thickness predictions obtained from linear and curved models fitted to raw and log‐transformed bark–stem data. We use this framework to contrast bark thickness among fynbos and savanna plant functional groups.LocationFynbos (17 species) and savanna (21 species) systems in South Africa.MethodsThe linear subset of bark–stem data was identified using a three‐step procedure. Linear regressions (with and without an intercept) and curved models (allometric and modified exponential models) were fitted to the linear subset and complete raw bark–stem data set, respectively. In addition, linear regression models were fitted to the log‐transformed complete bark–stem data set. Regression slopes and bark thickness predictions obtained from these different approaches were compared, to determine which method provides the most robust metric for comparing bark thickness. Bark thickness was compared among fynbos resprouter guilds and acacias from low‐ and high‐fire savannas.ResultsThe slope of the regression model fitted to the linear subset of raw bark–stem data provides a reliable metric for general comparisons of relative bark thickness. Bark thickness predictions from the curved and log models were comparable at 20‐cm stem diameter, but the log model underestimated bark thickness at 5 cm for certain species. Relative bark thickness was significantly higher in: (1) fynbos fire resisters and epicormic resprouters than in non‐resprouters; and (2) acacias from high‐ vs low‐fire savannas.ConclusionsThe slope of the regression model fitted to the linear subset of raw bark–stem data is a useful metric for bark thickness comparisons across studies, and compares favourably with bark thickness predictions derived from models fitted to the complete bark–stem data set. Fynbos and savanna trends support the proposition that relative bark thickness reflects differences in woody plant responses to fire and indicate the modal fire regime of ecosystems.

Microclimate Modification Using Eco-friendly Nets for High-quality Tomato Transplant Production by Small-scale Farmers in East Africa

Unfavorable environmental conditions, pests, and viral diseases are among the major factors that contribute to poor growth and quality of tomato (Solanum lycopersicum) seedlings in tropical areas. Improving crop microclimate and excluding insects that transmit viruses may improve transplant quality and yield in production fields. This study was carried out in two seasons at the Horticulture Research and Teaching Field of Egerton University in Njoro, Kenya, to investigate the effects of agricultural nets herein called eco-friendly nets (EFNs) on germination and performance of tomato seedlings. Tomato seeds were either raised in the open or under a permanent fine mesh net (0.4-mm pore diameter). Eco-friendly net covers modified the microclimate resulting in significantly higher day temperatures and relative humidity, compared with the open treatment. Nets increased temperature and relative humidity by 14.8% and 10.4%, respectively. Starting seeds under a net advanced seedling emergence by 2 days and resulted in higher emergence percentage, thicker stem diameter, more leaves, and faster growth leading to early maturity of seedlings and readiness for transplanting. Netting improved root development by increasing root quantity and length. Stomatal conductance (gS) and estimates of chlorophyll content were higher in seedlings under net covering compared with those in the noncovered control treatment. Insect pests and diseases were also reduced under net covering. The use of the net in the production of tomato transplants presented a 36.5% reduction in the cost of seeds, through improved emergence and reduced pest damage. All other factors held constant, healthy and quality transplants obtained under a net covering also translate into better field performance; hence, increasing economic returns for commercial transplants growers, as well as for tomato farmers. Results of this study suggest that EFNs can be customized not only for their effective improvement on growth and quality of tomato transplants but also for their pest and disease management in the nursery alone or as a component of integrated pest and disease management.

충남지역 논 재배에 적합한 사일리지용 옥수수 품종 선발

본 시험은 중부지방에 배수가 불량한 논에 벼 대체 여름 사료작물인 옥수수를 파종하여 논 재배에서 적응성 및 생산성이 우수한 품종을 선발하여 양질의 조사료를 생산할 목적으로 충남 서천농가의 배수가 불량한 논에서 수행하였다. 국내육성 4품종과 도입품종 14품종 등 18품종을 시험한 결과 생육 특성면에서는 P32T83이 경직경이 15.1 mm로 굵고 착수고가 57 cm로 낮으며, 당도가 <TEX>$12B^{\circ}$</TEX>로 높고 생초수량이 ha당 55,220 kg, 건물수량이 19,680 kg, TDN 수량이 13,280 kg으로 가장 높게 나타났으며, ADF 및 NDF 함량이 낮고, 건물소화율도 81.9%로 가장 높게 나타나 사료가치도 우수하였다. 다음으로 NC7117이 경직경이 15.5 cm로 굵고 생초수량이 ha 당 50,890 kg, 건물수량이 19,110 kg, TDN 수량이 12,160 kg으로 양호한 특성을 가진 것으로 보여 밭작물 옥수수와 같은 수준의 수량 및 품질을 낼 수 있을 것으로 보인다. 이와 같은 특성을 가진 사일리지용 옥수수 품종을 논에 재배하면 밭 재배에서와 같은 수준의 수량을 얻을 수 있을 것으로 보인다. This experiment was carried out to know adaptability, forage production and quality of corn hybrid for silage at paddy field at Chungnam region. Among agronomic characteristics, 'P32T83' hybrid was somewhat strong for waterlogging and good stay green, and low ear height as 57 cm and thicker stem diameter as 15.1 mm, and higher sugar content as 12 (Bo, %). The fresh and dry matter yield of 'P32T83' hybrid were the highest 55,220 kg/ha and 19,680 kg/ha, respectively. 'NC7117' hybrid was thicker as 15.5 cm and somewhat strong for waterlogging. The fresh and dry matter yield of 'NC7117' were 50,890 kg/ha and 19,110 kg/ha, respectively. The 'P32T83' hybrid was high as 81.9% in vitro dry matter digestibility (IVDMD). The result of this study indicated that 'P32T83' and 'NC7117' hybrid could be recommended as having good characters according to production, waterlogging tolerance, stay green, sugar content, and stem diameter at paddy field in Chungnam region.

EFFECT OF POLYETHYLENE GLYCOL (PEG) AND PLANTING METHODS ON SWEET CORN PRODUCTIVITYEFFECT OF POLYETHYLENE GLYCOL (PEG) AND PLANTING METHODS ON SWEET CORN PRODUCTIVITY

This study was conducted in loamy soil at Qaha Experimental Station, Horticulture Research Institute, ARC, Kalubia governorate, during 2002/2003 and 2003/2004 seasons to study the effect of PEG and planting methods on sweet corn productivity. The obtained results indicated that GSS 9377 F1 hybrid plants produced vigorous growth and higher early and total yield than those of Endeavor F1 hybrid. Direct seeding in the open field or under tunnels increased plant height, stem diameter, number of leaves/plant, plant fresh weight, unhusked ear weight, husked ear weight and total yield compared to transplanting methods. Transplanting produced the higher early yield ei-ther with open field or under tunnels. Primed seeds of sweet corn F1 hybrids (GSS 9377 and Endeavor) in PEG 6000 dalton for 6 hours at the concentration of 400 g/L produced taller plants with thicker stem diameter, higher number of leaves/plant and greater fresh weight, higher un-husked and husked ear weight, ear length, higher TSS as well as early and total yield compared to check untreated seeds

Residual Effects of Composted and Fresh Solid Swine (Sus scrofa L.) Manure on Soybean [Glycine max (L.) Merr.] Growth and Yield

Applying livestock manure to soil can enhance soil fertility and crop growth; however, little information is available on the residual effects of manure on crop growth. The objective of this study was to investigate the residual effect of fresh or composted hoop house swine manure on the growth and yield of soybean [Glycine max (L.) Merr.]. During 2000 and 2001 near Boone, IA, research plots received applications of composted or fresh solid swine manure from hoop structures or one of four levels of urea (0, 60, 120, and 180 kg N ha−1) before planting maize (Zea mays L.). During the growing season following maize harvest, we evaluated the responses of soybean to the eight treatments applied the previous year. During both years, soybean plants from manure‐amended plots were significantly taller and had a thicker stem diameter than plants from the other plots. The manure‐treated plots produced 39% greater soybean leaf area than the control in 2001 and 11% greater leaf area than the urea‐amended plots in 2002. There was a 21 to 34% greater K concentration in soybean plants grown in the manure‐amended sites than in the other plots. Soybean grain yield was 0.2 to 0.5 Mg ha−1 greater in the manure‐treated plots than the control or urea‐fertilized plots. Responses to manure were unaffected by the time of application (fall or spring) or the form of manure (composted or fresh). We have shown that fresh and composted swine manure application before growing maize resulted in detectable, positive residual effects on soybean growth and yield.