Stem Growth Rate Research Articles

Growth pattern in tropical mangrove trees of Bunaken National Park, North Sulawesi, Indonesia

Abstract. Djamaluddin R. 2019. Growth pattern in tropical mangrove trees of Bunaken National Park, North Sulawesi, Indonesia. Biodiversitas 20: 1713-1720. Seasonal diameter growth patterns in mangrove are often related to rainfall, temperature and moisture regime. At any localities, specific environmental factors may influence growth rate of individual trees. I asked whether stem growth of tropical mangrove in BNP is constant over a year, and whether stem growth rates are different by sites, species, and trees of the same species. Dendrometer bands were installed on trees from twelve different sites in BNP to measure stem growth rates. Measurements were made at two months intervals from July 1999 to June 2001 and March 2014 to December 2016. Growth rates measured in trees at the twelve sites varied significantly from 0.83 ± 0.27 to 1.71 ± 0.31 mm month-1. Growth rates were higher on Sonneratia alba (1.65 ± 0.69 mm month-1), low on Rhizophora stylosa, Xylocarpus moluccensis, Avicennia marina, Ceriops tagal (0.82 ± 0.16, 0.82 ± 0.18, 0.85 ± 0.18, 0.88 ± 0.28 mm month-1, respectively), and medium on Rhizophora apiculata, Bruguiera parviflora, Bruguiera gymnorrhiza, Rhizophora mucronata (1.19 ± 0.16, 1.22 ± 0.69, 1.25 ± 0.49, 1.31 ± 0.22 mm month-1, respectively). Statistically, growth rates were higher in trees with initial girths more than 50 cm compared to trees with initial girth less than 50 cm on B. gymnorrhiza, C. tagal, and R. mucronata, but these were slower for R. apiculata and S. alba. Between individual trees in six species tested, the differences in diameter growth rate were statistically significant. Growth rates varied among different site conditions, and the effect of soil water salinity on these was significant at higher intertidal sites. Growth rates exhibited seasonal patterns, and these were correlated positively with rainfall and negatively with temperature. The effect of the 2015-2016 El Nino was significant on reduced growth rates.

Photosynthesis, respiration, and growth patterns of Rhizophora stylosa seedlings in relation to growth temperature

Rhizophora stylosa Griff. exhibits thermal acclimatization of leaf respiration, but does not maintain high photosynthetic performance under new growth temperatures. Mangrove plants are distributed across the majority of the world’s tropical and subtropical coastlines. How they respond to new growth temperatures is poorly understood. To obtain this information, we collected Rhizophora stylosa Griff. diaspores from a subtropical region with average daily mean and maximum temperatures of 24.0 and 26.7 °C. After 1-year-old seedlings had been grown in four glasshouse chambers at an air temperature of 15, 20, 25, or 30 °C for about 50 days, we evaluated photosynthesis, respiration, and growth. Seedlings grown at 15 and 20 °C showed PSII photoinhibition, especially in newly emerged leaves. The assimilation rate was greatest at 25 °C. Thermal acclimatization of respiration was observed at 20–30 °C in both newly emerged and pre-existing leaves, was unclear in stems, and was absent in roots. Stem growth rate was greatest at 25 °C, but seedlings grown at 30 °C produced the largest number of new leaves and marginally decreased biomass allocation to roots, which lacked thermal acclimatization capacity. These results indicate that R. stylosa growing in subtropical regions adapts its photosynthesis to the average daily mean or maximum temperatures, and minimizes carbon loss due to warm temperatures by use of the thermal acclimatization capacity of leaf respiration and plasticity of biomass allocation, which contribute to optimizing growth performance.

Cassava Growth Analysis of Production during the Off‐Season of Paddy Rice

Cassava (Manihot esculenta Crantz) grown in upper paddy fields after rice (Oryza sativa L.) could increase cassava yield and improve land use efficiency. The objective of this study was to evaluate growth, yield, and starch content of four cassava genotypes grown after the harvest of rice in upper paddy fields in Thailand. Four cassava genotypes—cultivars Kasetsart 50, Rayong 9, and Rayong 11—and line CMR38‐125‐77 were evaluated during the 2015–2016 and 2016–2017 growing seasons for five environments. Each experiment had a randomized complete block design with four replications. Soil characteristics were assessed prior to planting, and crop growth and development and local weather conditions were recorded during the experiments. Environment affected all traits, but genotype and genotype × environment effects were nonsignificant for starch content at 180 d after planting (DAP) and for leaf growth rate (LGR) at 120 to 180 DAP. Average storage root dry weights across five environments were 4301, 3933, 3128, and 5824 kg ha−1 for Kasetsart 50, Rayong 9, Rayong 11, and CMR38‐125‐77, respectively. CMR38‐125‐77 was the most stable genotype for storage root fresh and dry weights, and total dry weight. Physiological determinants of both storage root yield and total biomass of cassava were crop growth rate (CGR) and net assimilation rate (NAR) for 30 to 90 DAP and LGR, stem growth rate (SGR), CGR, and NAR for 120 to 180 DAP, as well as storage root growth rate (SRGR) for 90 to 180 DAP. Leaf growth rate during 120 to 180 DAP is likely to be a new criterion for supporting cassava varietal selection. This investigation showed the feasibility of growing cassava between paddy rice seasons.

Corrigendum: Carbon limitation, stem growth rate and the biomechanical cause of Corner's rules.

Corrigendum: Carbon limitation, stem growth rate and the biomechanical cause of Corner's rules.

Field evidences for the positive effects of aerosols on tree growth.

Theoretical and eddy covariance studies demonstrate that aerosol-loading stimulates canopy photosynthesis, but field evidence for the aerosol effect on tree growth is limited. Here, we measured in situ daily stem growth rates of aspen trees under a wide range of aerosol-loading in China. The results showed that daily stem growth rates were positively correlated with aerosol-loading, even at exceptionally high aerosol levels. Using structural equation modeling analysis, we showed that variations in stem growth rates can be largely attributed to two environmental variables covarying with aerosol loading: diffuse fraction of radiation and vapor pressure deficit (VPD). Furthermore, we found that these two factors influence stem growth by influencing photosynthesis from different parts of canopy. Using field observations and a mechanistic photosynthesis model, we demonstrate that photosynthetic rates of both sun and shade leaves increased under high aerosol-loading conditions but for different reasons. For sun leaves, the photosynthetic increase was primarily attributed to the concurrent lower VPD; for shade leaves, the positive aerosol effect was tightly connected with increased diffuse light. Overall, our study provides the first field evidence of increased tree growth under high aerosol loading. We highlight the importance of understanding biophysical mechanisms of aerosol-meteorology interactions, and incorporating the different pathways of aerosol effects into earth system models to improve the prediction of large-scale aerosol impacts, and the associated vegetation-mediated climate feedbacks.

Sand mulching and its relationship with soil temperature and light environment in the cultivation of Lilium longiflorum cut flower

Abstract Lilium longiflorum is one of the most important cut flowers both in the world and in Argentina. To plan a commercial crop, it is necessary to understand tools that relate environmental variables to crop growth and development. One of these tools is leaf expansion, which can be determined from the evolution of the leaf area index (LAI). The technique known as sand mulching substantially modifies the soil temperature but can also alter other environmental variables such as light quality. The objective of this work was to determine whether the application of sand mulching affects the growth rate and leaf expansion of a lilium cut flower crop. The experiment was carried out in a greenhouse at the Faculty of Agronomy, University of Buenos Aires, Argentina, where a lilium crop was planted in the soil, adding a 5-cm layer of fine sand over the entire soil surface to reduce soil temperature. Plant height and number of leaves were measured twice a week and the LAI was estimated by spectral reflectance once a week. The cycle length was also recorded, and the accumulation of dry matter was measured at the end of the experiment. The soil temperature was lower in the first month of cultivation, and there were differences in the light environment and in the water status of the crop. Although there were no significant differences in the cycle length or leaf appearance, sand mulching led to differences in the stem growth rate, LAI and final plant height, resulting in a better quality of the product.

Carbon limitation, stem growth rate and the biomechanical cause of Corner's rules.

Corner's rules describe a global spectrum from large-leaved plants with thick, sparingly branched twigs with low-density stem tissues and thick piths to plants with thin, highly branched stems with high-density stem tissues and thin piths. The hypothesis was tested that, if similar crown areas fix similar amounts of carbon regardless of leaf size, then large-leaved species, with their distantly spaced leaves, require higher stem growth rates, lower stem tissue densities and stiffnesses, and therefore thicker twigs. Structural equation models were used to test the compatibility of this hypothesis with a dataset on leaf size, shoot tip spacing, stem growth rate and dimensions, and tissue density and mechanics, sampling 55 species drawn from across the angiosperm phylogeny from a morphologically diverse dry tropical community. Very good fit of structural equation models showed that the causal model is highly congruent with the data. Given similar amounts of carbon to allocate to stem growth, larger-leaved species require greater leaf spacing and therefore greater stem extension rates and longer stems, in turn requiring lower-density, more flexible, stem tissues than small-leaved species. A given stem can have high resistance to bending because it is thick (has high second moment of area I) or because its tissues are stiff (high Young's modulus E), the so-called E-I trade-off. Because of the E-I trade-off, large-leaved species have fast stem growth rates, low stem tissue density and tissue stiffness, and thick twigs with wide piths and thick bark. The agreement between hypothesis and data in structural equation analyses strongly suggests that Corner's rules emerge as the result of selection favouring the avoidance of self-shading in the context of broadly similar rates of carbon fixation per unit crown area across species.

Contribution of basal and aerial tillers to sward growth in intermittently stocked elephant grass

AbstractElephant grass (Pennisetum purpureum Schumach. cv. Napier) is characterized by high dry matter production and a high contribution of aerial tillers to the tiller population. However, grazing management strategies that favor an increase in aerial tillers, such as long regrowth periods, particularly when associated with severe grazing, can result in a decrease in sward growth, as they are subject to a high level of intraclonal competition. We evaluated the contribution of basal and aerial tillers to sward growth in Napier elephant grass to comprehend how strategies of intermittent stocking management interfere with the relative contribution of each tiller class. Treatments corresponded to combinations of two post‐grazing heights (35 and 45 cm) and two pre‐grazing conditions (95% and maximum canopy light interception during regrowth—LI95% and LIMax, respectively) and were allocated to experimental units (850 m2 paddocks) according to a 2 × 2 factorial arrangement in a randomized complete block design with four replicates from January 2011 to April 2012. Basal tillers were the main contributors to sward growth in elephant grass. In this way, although the production of aerial tillers is an important adaptive response of this forage grass species, grazing management strategies that maximize aerial tillering do not result in greater leaf growth or minimize stem growth rates. The frequency of defoliation was the main modulator of plant responses related to light competition, and the higher leaf growth associated with lower stem growth rates were obtained with the LI95% pre‐grazing target. Severe grazing (35 cm) associated with LI95% is the grazing management strategy recommended to maximize leaf and sward growth rates in Napier elephant grass subjected to rotational stocking.

Insights into intraspecific wood density variation and its relationship to growth, height and elevation in a treeline species.

The wood economics spectrum provides a general framework for interspecific trait-trait coordination across wide environmental gradients. Whether global patterns are mirrored within species constitutes a poorly explored subject. In this study, I first determined whether wood density co-varies together with elevation, tree growth and height at the within-species level. Second, I determined the variation of wood density in different stem parts (trunk, branch and twigs). In situ trunk sapwood, trunk heartwood, branch and twig densities, in addition to stem growth rates and tree height were determined in adult trees of Nothofagus pumilio at four elevations in five locations spanning 18° of latitude. Mixed effects models were fitted to test relationships among variables. The variation in wood density reported in this study was narrow (ca. 0.4-0.6gcm-3 ) relative to global density variation (ca. 0.3-1.0gcm-3 ). There was no significant relationship between stem growth rates and wood density. Furthermore, the elevation gradient did not alter the wood density of any stem part. Trunk sapwood density was negatively related to tree height. Twig density was higher than branch and trunk densities. Trunk heartwood density was always significantly higher than sapwood density. Negative across-species trends found in the growth-wood density relationship may not emerge as the aggregate of parallel intraspecific patterns. Actually, trees with contrasting growth rates show similar wood density values. Tree height, which is tightly related to elevation, showed a negative relationship with sapwood density.

Variability in temperature dependence of stem CO2 efflux from Norway spruce trees.

This study presents results from continuous measurements of stem CO2 efflux carried out for seven experimental seasons (from May to October) in a young Norway spruce forest. The objectives of the study were to determine variability in the response of stem CO2 efflux to stem temperature over the season and to observe differences in the calculated relationship between stem temperature and CO2 efflux based on full growing season data or on data divided into periods according to stem growth rate. Temperature sensitivity of stem CO2 efflux (Q10) calculated for the established periods ranged between 1.61 and 3.46 and varied over the season, with the lowest values occurring in July and August. Q10 calculated using data from the full growing seasons ranged between 2.30 and 2.94 and was often significantly higher than Q10 calculated for the individual periods. Temperature-normalized stem CO2 efflux (R10) determined using Q10 from growing season data was overestimated when the temperature was below 10 °C and underestimated when the temperature was above 10 °C, compared with R10 calculated using Q10 established for the individual periods. The differences in daily mean R10 calculated by these two approaches ranged between -0.9 and 0.2 μmol CO2 m-2 s-1. The results of this study confirm that long periods for determining the temperature dependence of stem CO2 efflux encompass different statuses of the wood (especially in relation to stem growth). This may cause bias in models using this relationship for estimating stem CO2 efflux as a function of temperature.

Detecting the fingerprint of drought across Europe\u2019s forests: do carbon isotope ratios and stem growth rates tell similar stories?

BackgroundUnderstanding how trees respond to drought is critical to forecasting both short and long-term impacts of climate change on forests. The isotopic ratio of 13C to 12C stored in wood – referred to as δ13C – is widely used as an indicator of plant water status. Yet whether changes in δ13C linked to drought are also associated with declines in annual carbon assimilation and allocation to stem growth remains unclear.MethodsHere we used tree ring data from over 3000 trees – representing 26 populations of 16 common European tree species sampled at six locations that span more than 20° in latitude – to test whether drought induces coordinated changes in carbon isotope ratios and stem basal area increments (BAI).ResultsWe found that δ13C is a reliable indicator of drought across a wide range of species and environmental conditions. All but one of the populations sampled in this study showed a statistically significant increase in δ13C under drought conditions. However, when considering the effects of these same drought events on BAI, we found no evidence to suggest that increases in δ13C were coupled with significant declines in stem growth. While BAI was 11.9% lower on average in drought years, this decline in BAI was not significant when analysed across species. In fact, only seven of the 26 populations we sampled exhibited significant declines in BAI under drought conditions – four of these from a single study site in the Carpathian Mountains of Romania.ConclusionsWhile δ13C responded strongly and consistently to drought across a diverse group of tree species and environmental conditions, we found that most tree species were able to sustain growth even under conditions of low soil water availability. Consequently, while δ13C provides a powerful indicator of past drought occurrence, by themselves carbon isotope ratios tell us little about how carbon sequestration and allocation to wood are affected by conditions of low water availability across Europe’s forests.

Summer solstice marks a seasonal shift in temperature sensitivity of stem growth and nitrogen-use efficiency in cold-limited forests

In boreal forests and alpine treelines, it is debatable how the temperature sensitivity of tree-ring growth should vary with changes in climate over time and the extent to which seasonal stem increments are controlled by leaf physiology. We aim to test the hypothesis that, in cold-limited forests, maximizing stem growth rate around summer solstice is closely related to foliage turnover, which generally results in high sensitivity of stem growth and less sensitivity of nitrogen-use efficiency (NUE) to early-season temperatures. Our analysis was based on repeat-census observations of stem radial increment (2008–2013; made with dendrometers) and monthly litterfall (2007–2015) as well as the measurements of tree-ring width series (1960–2015; made with tree-ring cores) in two Tibetan treeline forests. NUE was estimated as the inverse of leaf-litter nitrogen concentration. We further examined a global dataset of tree-ring chronologies (1931–1990) from 139 sites across temperate and boreal coniferous forests in the northern high-latitude region. Weekly stem increments across species and years synchronously peaked around summer solstice, with more than half of annual increment produced in the first 28–35days of the growing season when air and soil temperatures were still low. Monthly stem increments were positively related to previous-month litterfall, and higher litterfall generally resulted in higher NUE. NUE was insensitive or less sensitive to soil temperature in the early growing season. Among years, pre-peak increments were positively correlated with pre-solstice temperatures while post-peak increments varied little. The annual increment was dominated by and coherent with the pre-peak increment and well correlated with the ring-width measurements of monitored trees during 2008–2013. Variations in tree-ring width chronologies from the two Tibetan treelines and the global 139 forest sites mainly reflected the change of early summer temperatures. The findings suggest a day-length control on the linkage between seasonal stem growth and nitrogen cycling in a cold-limited forest ecosystem, and provide the basic for predicting responses of tree-ring growth and NUE to climatic warming.

Xylem Anatomical Trait Variability Provides Insight on the Climate-Growth Relationship of Betula nana in Western Greenland

ABSTRACTClimate change has been reported to affect shrub growth positively at several sites at high northern latitudes, including several arctic environments. The observed growth rates are, however, not uniform in space and time, and the mechanistic drivers of these patterns remain poorly understood. Here we investigated spatio-temporal interactions between climatic conditions, xylem anatomical traits, and annual growth of 21 Betula nana L. individuals from western Greenland for the period 2001–2011. Structural equation modeling showed that summer precipitation and winter temperature are affecting annual growth positively. Furthermore, vessel lumen area and vessel grouping, which are related to water conductivity and hydraulic connectivity of the xylem, respectively, positively influenced annual growth. To optimize growth B. nana was thus able to adjust its water transporting system. Annual variation in vessel lumen area seemed to be driven mostly by spring and summer temperatures, whereas annual variation in vessel grouping was driven by winter temperature. Linear models did not reveal a pattern in the spatial variation of xylem anatomical traits across the sampled climatic gradient. However, growth was positively correlated with local variation in insolation. Our results suggest that B. nana can adjust its hydraulic capacity to annual fluctuations in climatic conditions in order to optimize its total radial stem growth rate.

Stem growth and phenology of three subtropical mangrove tree species

The present study aimed to investigate the relationships among stem circumference growth, phenology and abiotic variables, of three mangrove tree species of southern Brazil. Species circumference growth, measured using dendrometer bands, and phenological events were followed for 12 months. Data were correlated with day length, temperature and precipitation using a model based on the method of least squares, taking into account temporal autocorrelation of the data. During the study period, temperature influenced the fruiting of Avicennia schaueriana Stapf and Leechm. ex Moldenke, while it was strongly related to the production of leaves and flowering in Laguncularia racemosa (L.) Gaertn and Rhizophora mangle L., respectively. Monthly precipitation was related to the flowering of only R. mangle. No abiotic variable (day length, temperature and rainfall) was correlated with stem growth for the L. racemosa and R. mangle during the period. However, the highest rate of increase in stem circumference for all three species occurred during the period of highest temperature and rainfall. Our results demonstrate that the reproductive phenophases are more intense in wetter and hotter conditions. Combined with endogenous factors, these abiotic variables influence vegetative and reproductive phenophases and stem circumference growth. Stem growth rates were different for each studied species, but they all exhibited high peaks of stem growth concomitant with periods of higher temperature and precipitation. Phenological events, and how they correlate with the analysed abiotic variables, differed among the three species and stem growth showed a direct relationship with phenophases during the study period only for A. schaueriana.

Progression and stability analysis of rain forest tree growth under environmental stochasticity

AbstractChanges in relative stem growth rate (rgr) across periods of multi‐censused plot data in tropical forest allow response indices (RIs) to be related to environmental (climatic) variation over time. Among small trees (12.5 to <50 cm girth at breast height [gbh]) in two permanent 4‐ha plots at Danum, Sabah, Borneo (lowland dipterocarp formation), growth responses were followed before, during, and after a major ENSO drying event in 1998 (censuses of 1986, 1996, 1999, 2001, and 2007 in subplots). Overall, RI was negative in the interval with the drought, increased or reflected overcompensation in rgr immediately afterwards, and then settled back to pre‐event levels. However, among the various tree species, responses and trajectories were very different: Some species showed positive or negative trends, while others showed stabilizing ones, and several had stable and unstable oscillations. Response index was graphed for pairs of periods in two ways: “consecutive” and “constitutive,” allowing, respectively, progression (fundamental, implicit and explicit) and stability (fundamental, intended, and extended) to be examined. Strongest RIs were found among the understory species. Variation in RI was, nevertheless, very high between individuals within species and masked most average species' differences. Environmental stochasticity appears to lead to strong mixing effects of species composition over time, not necessarily randomly, but in a highly complicated manner depending on tree size, topographic location, neighborhood, and over–understory status, which would compound demographic stochasticity in recruitment to the small‐tree class. Fluctuating responses cascade over one another in a highly unpredictable manner. These pluralistic responses may form the basis to a new understanding of tree population dynamics within the forest ecosystem, and to an improved theory about the maintenance of high species richness. Plasticity in allocation of resources to roots vs. shoots under water limitation offers a feasible hypothesis for high individual variation in growth. Instead of tropical rain forests being viewed as “complex,” an empirically more sound way is to regard them as being highly “complicated” within a mechanistic and functional approach. Multi‐species tree population dynamics are accordingly highly unpredictable and quasi‐indeterminate.

Responses of sapwood ray parenchyma and non‐structural carbohydrates of Pinus sylvestris to drought and long‐term irrigation

Summary Non‐structural carbohydrates (NSC) play a crucial role in tree resistance and resilience to drought. Stem sapwood parenchyma is among the largest storage tissue for NSC in mature trees. However, there is a limited mechanistic understanding of how NSC reserves, stem parenchyma abundance and growth rates are interrelated, and how they respond to changing water availability. We quantified NSC, ray parenchyma abundance and ring width along four successive 5‐year radial sapwood segments of the stem of 40 mature Pinus sylvestris trees from a 10‐year irrigation experiment conducted at a xeric site in Switzerland. Percentage of ray volume (PERPAR) varied from 3·75 to 8·94% among trees, but showed low intra‐individual variability. PERPAR responded positively to irrigation with a lag of several years, but was unrelated to %NSC. %NSC was lower in wider rings. However, wider rings still contained a larger NSC pool that was positively related to next year's ring growth. Our results suggest that stem ray parenchyma does not limit NSC storage capacity, but responds to long‐term environmental drivers with years of delay. The observed carbon allocation patterns indicate a prioritization of storage over growth independent of growth conditions, likely as a mechanism to ensure long‐term survival. Furthermore, NSC pool size proved to be a determinant for the inter‐annual autocorrelation in tree‐ring growth. Our study highlights the importance of long‐term multi‐parameter studies to better understand tree responses to environmental variability at different time‐scales. A lay summary is available for this article.

Changes in biomass allocation buffer low CO2 effects on tree growth during the last glaciation

Isotopic measurements on junipers growing in southern California during the last glacial, when the ambient atmospheric [CO2] (ca) was ~180 ppm, show the leaf-internal [CO2] (ci) was approaching the modern CO2 compensation point for C3 plants. Despite this, stem growth rates were similar to today. Using a coupled light-use efficiency and tree growth model, we show that it is possible to maintain a stable ci/ca ratio because both vapour pressure deficit and temperature were decreased under glacial conditions at La Brea, and these have compensating effects on the ci/ca ratio. Reduced photorespiration at lower temperatures would partly mitigate the effect of low ci on gross primary production, but maintenance of present-day radial growth also requires a ~27% reduction in the ratio of fine root mass to leaf area. Such a shift was possible due to reduced drought stress under glacial conditions at La Brea. The necessity for changes in allocation in response to changes in [CO2] is consistent with increased below-ground allocation, and the apparent homoeostasis of radial growth, as ca increases today.

Physiological determinants of storage root yield in three cassava genotypes under different nitrogen supply

SUMMARYPhysiological traits can be used to improve the efficiency of selecting suitable genotypes to grow under nitrogen (N) limitation. The objective of the current study was to investigate the relationship between physiological characteristics and storage root yield of three cassava genotypes under three rates of N fertilizer. The experiments were conducted from 2014 to 2016 at farm fields in Thailand. A split-plot randomized complete block design with four replications was used. Three different rates of N fertilizer, i.e., 46·9, 90·0 and 133·2 kg N/ha and three cassava genotypes, Rayong 9, Rayong 11 and Kasetsart 50, were used. Kasetsart 50 had the highest mean performance for most crop traits. Growth rate of stem (SGR), storage root (SRGR) and crop (CGR) during 180–210 days after planting (DAP) and leaf area index (LAI) at 120 DAP were related to storage root dry weight for all three rates of N fertilizer. Storage root growth during 90–120 DAP, CGR during 180–210 DAP and specific leaf area (SLA) at 210 DAP contributed most to storage root dry weight of the three genotypes grown at 46·9 kg N/ha, while the combination of SRGR during 90–120 DAP, SRGR during 180–210 DAP, LAI at 210 DAP and SLA at 210 DAP was best for N fertilizer at 90·0 kg N/ha and the combination of leaf growth rate (LGR) during 180–210 DAP and LAI at 210 DAP was best for N fertilizer at 133·2 kg N/ha.

EFFECT OF MINERALS ON SOME BIOMETRICAL PARAMETERS OF GREEN HOUSE TOMATO

In the present study, the length of growth and developmental stages and some biometrical parameters of tomato grown in winter greenhouse were investigated in relation to mineral fertilizer doses and combinations. Results of the study demonstrated that flowering synchrony of both the variants P150K150N150 and P150K150N350, basic norms of nitrogen in which increased by 100 to 200 kg and the variants N250P250K250, basic norms of triangular mineral fertilizer in which, increased by 100 kg was later by 5 to 10 days than the variants, which have no fertilizers and other combined doses. It also revealed growth of vegetative organs of the plant is stimulated, whereas the growth of reproductive organs inhibited. Investigation of growth rates of main stem of the tomato plant for each variants shows height of main stem is 368 cm for no fertilizer variant, 381 cm for N150P150, and 387 cm for N150P150K250 variant, which is the tallest among other variants. It is taller by 19 cm than control.

Rice panicle plasticity in Near Isogenic Lines carrying a QTL for larger panicle is genotype and environment dependent.

BackgroundPanicle architectural traits in rice (branching, rachis length, spikelet number) are established between panicle initiation and heading stages. They vary among genotypes and are prone to Genotype x Environment interactions. Together with panicle number, panicle architecture determines sink-based yield potential. Numerous studies analyzed genetic and environmental variation of plant morphology, but the plasticity of panicle structure is less well understood. This study addressed the response of rice panicle size and structure to limited light availability at plant level for near-isogenic lines (NILs) with IR64 or IRRI146 backgrounds, carrying the QTL qTSN4 (syn. SPIKE) for large panicles. Full light and shading in the greenhouse and two population densities in the field were implemented. The image analysis tool P-TRAP was used to analyze the architecture of detached panicles.ResultsThe qTSN4 increased total branch length, branching frequency and spikelet number per panicle in IRRI146 background in the field and greenhouse, and in IR64 background in the greenhouse, but not for IR64 in the field. In the field, however, qTSN4 reduced panicle number, neutralizing any potential yield gains from panicle size. Shading during panicle development reduced spikelet and branch number but qTSN4 mitigated partly this effect. Spikelet number over total branch length (spikelet density) was a stable allometry across genotypes and treatments with variation in spikelet number mainly due to the frequency of secondary branches. Spikelet number on the main tiller was correlated with stem growth rate during panicle development, indicating that effects on panicle size seemed related to resources available per tiller.ConclusionsThe qTSN4 effects on panicle spikelet number appear as indirect and induced by upstream effects on pre-floral assimilate resources at tiller level, as they were (1) prone to G x E interactions, (2) non-specific with respect to panicle architectural traits, and (3) associated with pre-floral stem growth rate.Electronic supplementary materialThe online version of this article (doi:10.1186/s12284-016-0101-x) contains supplementary material, which is available to authorized users.