Effect of Population Levels of Soybean on Physiological Growth Parameters of Sorghum CO 24 in Sole and Intercropped Stand

A field experiment was conducted during kharif, 1985 and summer, 1986 in sandy clay loam soil under irrigated condition at Tamil Nadu Agricultural University, Coimbature, with a view (i) to assess the suitable method of planting of sorghum CO 24 when intercropped with soybean, (ii) to evaluate the suitable planting ratio of sorghum - soybean intercropping system, (iii) to find out the compatible population level of soybean when intercropped with sorghum CO 24.
Direct sown sorghum at 4: 2 and 2: 2 recorded grater leaf area (LA) compared to transplanted sorghum in both kharif and summer. Sorghum transplanted with 14 days old seedlings recorded higher Crop Growth Rate (CGR) compared to 21 days old seedlings. Increased Net Assimilation Rate (NAR) were recorded in sorghum transplanted with 14 days old seedlings as compared to direct sown and 21 days old transplanted crop. Transplanted sorghum recorded higher Relative Growth Rate (RGR) as compared to direct sown sorghum. Summer sorghum recorded higher Relative Growth Rate (RGR) as compared to kharif season.     

Growth Analysis of Onion (Allium cepa L.) in Relation to Irrigation and Nitrogen Fertilization

Studies were carried out at the Indian Institute of Horticultural Research, Bangalore during winter seasons of 1982—83 and 1983—84 to analyse the growth rhythm of onion in relation to irrigation and N fertilization. It was observed that irrigation at 0.45 to 0.65 bar soil water potential recorded higher dry matter accumulation and distribution, leaf area index (LAI), leaf area duration (LAD), leaf area ratio (LAR) and crop growth rate (CGR) during most of the stages, while net assimilation rate (NAR) and relative growth rate (RGR) were not markedly affected. Highest harvest index was noticed with irrigation at 0.65 bar.
Nitrogen fertilization significantly increased dry matter accumulation and distribution into different parts, LAI, LAD, LAR, CGR and harvest index. Although NAR and RGR showed an increasing trend with N fertilization, the effect was not significant during most of the stages. There was no significant interaction between soil water potential and N fertilization on any of the growth parameters.     

Analysis of Growth and Productivity of Indian Mustard (Brassica juncea) in Relation to FYM, Nitrogen and Source of Fertilizer

A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha⁻¹ significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha⁻¹), N (75 kg ha⁻¹) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages.     

新疆北疆不同积温条件下棉花生育进程及生长解析

以新疆北疆玛河流域棉田为例,通过分期播种的方式调控积温,分析了不同积温下棉花的生育进程,并利用植物生长解析法研究了棉花干物质积累与分配、叶面积指数、净同化率、相对生长率以及群体生长率的动态变化规律,研究了不同积温水平下棉花群体生长率与叶面积指数的关系。研究结果表明：棉花完成各生育阶段所需的有效积温是一定的,而活动积温具有一定的波动性,但是较生育期天数而言波动性小;不同积温水平下的棉花结铃盛期至吐絮期的干物质积累量差异最为明显;群体生长率（CGR）和叶面积指数（LAI）之间具有一元二次函数的关系,由此可以确定棉花的最适宜叶面积指数。     

Growth and Drymatter Partitioning of Sorghum under Moisture Stress Condition

Field studies were carried out at Tamil Nadu Agricultural University, during summer 1988 to find out the effect of moisture stress of growth indices and dry matter accumulation of sorghum (cv. CO 26 ) at three phenophases. Crop under adequate moisture supply, throughout, exhibited greater crop growth rate (CGR) and relative growth rate (RGR) compared to the crop under moisture stress condition. Growth indices were at lesser rate when the crop experienced moisture stress during phenophase I, and subsequently picked up during phenophase II due to adequate moisture supply to the crop. This reflects the ability of sorghum crop to recover from the effects of early moisture stress at later stages. The dry-matter accumulation in the stem was favoured by adequate moisture while in the leaves it was favoured by moisture stress.     

Light Interception, Leaf Area Index and Dry Matter Yield in Fodder Sorghum at Different Plant Populations

Fodder sorghum (M. P. Chari) was grown at varying populations to examine its influence on light interception, leaf area index and biomass production. DMY, CGR and IPAR depending on LAI reached maximum at LAI 5 of 150 000 plants ha⁻¹ stand and thus yielded higher biomass. Therefore, physiological potential of fodder sorghum crop was found to be maximum at a population density of 150 000 plants ha⁻¹. Further increases in population developed mutual shading and adversely affected the crop growth rate and dry matter accumulation. Significant linear relationships of dry matter yield with IPAR, plant population densities, LAI and CGR clearly indicate the interdependence of these characters.     

Growth Analysis Using Classical and Functional Techniques in Relation to Soil Moisture in Mustard

A Reid experiment was conducted to study the effect of soil moisture on growth of two mustard cultivars using classical and functional techniques of growth analysis. Two soil moisture levels were irrigated at 10-day intervals and a rainfed control was included. Total dry matter (TDM), leaf area index (LAI) and leaf area duration (LAD) were significantly increased by irrigation at most of stages of growth. Starting from a lower value, LAI and LAD reached a peak and then gradually declined. Among the growth attributes, crop growth rate (CGR), leaf area ratio (LAR) and leaf weight ratio (LWR) increased significantly under irrigation. Net assimilation rate (NAR) decreased more in the irrigated plants than the rainfed plants at the later stages of growth. LAR and LWR declined throughout with increasing time and plant weight. Seed yield of the irrigated plants was positively correlated with the pre-flowering LAI and the post-flowering CGR and NAR. In the rainfed plants, seed yield was positively correlated with LAI and CGR at the post-flowering stage and negatively with the post-flowering NAR and pre-flowering LAR.     

两个超级杂交水稻品种物质生产的特性

定量分析超级杂交水稻若干群体指标的动态特征,以期为其高产栽培提供依据。于2011年和2012年在大田条件下,以超级杂交水稻准两优527、Q优6号和对照品种II优838为试材,通过连续测定干物质和叶面积,建立了水稻群体干物质和相对叶面积指数动态模型,进而以群体干物质和相对叶面积指数模型为基础,分析了超级杂交水稻作物生长率、相对生长率、光合势、净同化率、叶面积比率动态变化特征。结果表明,超级杂交水稻快增期的干物质积累量及其占总生物量的比例均高于对照。作物生长率(CGR)随移栽后时间呈先升高后下降的单峰曲线变化,其快增期的CGR较大。与对照相比,超级杂交水稻相对生长率(RGR)表现出上升快、峰值大、下降快的特点。准两优527在移栽后23 d至成熟期高于对照,Q优6号的RGR在移栽后43 d以前低于对照,移栽后43 d至113 d高于对照,两者在移栽后113 d至成熟期的RGR相差不大。不同水稻净同化率(NAR)随移栽后时间呈先上升后下降的单峰曲线变化,最大NAR出现在移栽后43~53 d。总光合势与快增期光合势及与快增期绿叶面积持续时间均呈极显著正相关。2个超级杂交水稻叶面积比率(LAR)在移栽后23 d至43 d迅速下降,移栽后43 d至73 d缓慢下降,移栽后73 d至成熟期快速下降,其快增期的LAR较大。     

Canopy Development and Light Absorption of Grain Legume Species in a Short Season Mediterranean-type Environment

Leaf area index (LAI), fractional canopy light interception (F) and plant mortality at maturity, were determined for nine short-duration pigeonpea ( Cajanus cajan [L.] Millsp.) genotypes in response to drought during the late-vegetative and flowering (stress 1), the flowering and early podfill (stress 2), or podfill (stress 3) stages. LAI and F were reduced, but plant mortality did not increase under drought. Stress 2 reduced LAI to the greatest extent, consistent with the effects on seed yield. At the end of stress 1, seed yield was closely related to LAI for the different genotypes in stressed but not in unstressed (control) plots. Reductions in LAI due to reproductive growth were as great or greater than those due to water stress. Indeterminate genotypes had smaller but more leaves per plant compared to the determinate genotypes. The importance of these differences to drought resistance was not apparent. Production of leaves with decreasing specific leaf area throughout plant growth may be advantageous, especially when drought is likely to occur during reproductive growth. Values of F during and following water stress gave an indication of genotypic drought resistance, with the most drought-sensitive genotype showing the largest reduction in F under water stress and the slowest rate of recovery following rewatering. For short-duration pigeonpea, where plant mortality is not a factor under water stress, the maintenance of both LAI and F appears to indicate genotypic drought resistance.     

Physiological Analysis of Growth and Yield of Watermelon (Citrullus ianatus Thunb Musf) in Relation to Irrigation and Nitrogen Fertilization

Analysis of growth and yield of watermelon in relation to irrigation and N fertilization carried out at the Indian Institute of Horticultural Research, Bangalore, during 1983–84 and 1984–85 indicated that frequent irrigations when the soil matric potential at 15 cm depth reached -25 kPa resulted in maximum dry matter accumulation and distribution, leaf area index (LAI), leaf area duration (LAD), net assimilation rate (NAR) and crop growth rate (CGR) leading to higher fruit yield as compared to irrigations at -50 and -75 kPa. Imposing a stress of -75 kPa either during pre-flowering or flowering or fruit development phase adversely affected various growth parameters resulting in reduced yield as compared to that irrigated uniformly at -25 kPa. Increasing levels of N fertilization increased the dry matter accumulation and distribution through higher LAI, LAD and CGR and contributed larger proportion of the dry matter to fruits resulting in higher fruit yield.     

Growth Analysis in Relation to Pigeonpea Improvement

An attempt was made to assess possible constraints to higher production, with respect to partitioning of total dry matter to reproductive sinks in early pigeonpea. Growth, dry matter accumulation and yield components were determined in four diverse genotypes under four dates of sowing and different plant densities. Data on growth characteristics, dry matter accumulation (vegetative and reproductive) were obtained for three sowings, while the data on yield components were obtained for two dates of sowing. Growth analysis showed that the total dry matter was low upto 30 days after sowing and increased linearly upto 120 days. Coversely, LAD was high for the first 30 days and reduced at later stages of growth. The mean LAI of genotypes did not very much at initial stage of growth. However, it has given interesting picture during 70 to 90 days of growth. The higher biological yield and seed yield were attributable to high LAI and LAD coupled with thick stem, more effective branches, more pods per plant and larger raceme length. Harvest index was the maximum with increased plant populations in all sowings. Indeterminate varieties under high plant density and narrow row spacing (50 cm) developed a large leaf area and were presumably able to make better use of light. Growth and branching of individual plants were reduced at the higher plant population, but on per unit basis more dry matter was produced. It is suggested that breeding should be concentrated to improve an inability to accumulate adequate vegetative dry matter for the maintenance and filling of pods, may force the plant to continue vegetative production into the reproductive dry matter to support production of ultimate seed yield.     

Primary Growth Parameters of Three Alfalfa Cultivars Adapted to Highland Climatic Conditions

An irrigated field study was conducted to determine the relative importance and inter‐relationships of growth parameters of three dormant alfalfa (Medicago sativa L.) cultivars grown in the highlands of Eastern Anatolia, Turkey, in 2000–2003. The fast‐growing cultivar Savas had the greatest dry matter (DM) yield at the final sampling date with the greatest mean crop growth rate. In addition to a greater relative growth rate (RGR), this cultivar had more stem branching and greater leaf area in the canopy, which resulted in greater leaf area index (LAI) and greater leaf area duration. Despite the considerable increase in leaf area ratio (LAR: leaf area per unit shoot DM), the reduction in RGR of all cultivars over time was the result of a large decline in net assimilation rate (NAR) due to increasing specific leaf area (SLA). Intracultivar variation in the RGR of alfalfa is mainly determined by NAR and SLA, and both were significantly higher for Savas than the other two cultivars. The relative importance of NAR and SLA to RGR changed due to increasing self‐shading as the LAI of the canopy increased, creating a trade‐off between NAR and SLA.     

干旱区滴灌模式和种植密度对棉花生长和产量性能的影响

以高产棉花品种新陆早45为材料,自初花至吐絮设置常规滴灌(I500)和有限滴灌(I425) 2种处理,每种滴灌模式下设低(D12)、中(D24)和高(D36)3个种植密度,分析棉花不同生育时期叶面积指数(LAI)、群体生长率(CGR)、棉铃生长率(BGR)、净同化率(NAR)以及产量、灌溉水分利用效率(IWUE)等变化。结果表明,与I500相比,I425将LAI到达顶峰的时间推迟至盛铃期并延缓了盛铃期以后的叶片衰老,显著提高了盛花期至吐絮期NAR,在不显著降低籽棉产量的前提下,提高了IWUE。在I500条件下,LAI、CGR、BGR、NAR、总生物量(TDW)、铃生物量(BDW)、总铃数(BN)、生殖器官与营养器官质量的比例(RVR)均以D24较高,D12最低;I425条件下,上述参数均以D36最高。籽棉产量以I500D24、I425D36较高,IWUE则以I425D36较高。相关分析表明,籽棉产量和IWUE与BN、RVR呈显著正相关,IWUE与NAR呈显著正相关。表明盛花期至盛铃期较快的群体生长速率、较强的物质生产能力以及较多的干物质持续向棉铃的供应,是I425D36提高产量的重要原因。     

Estimation of Nitrogen Fixation by the Natural 15N-abundance Technique and Nitrogen Uptake by Pigeonpea Genotypes of Different Maturity Groups grown in an Inceptisol1

The modulation, nitrogen fixation and nitrogen uptake of four pigeonpea genotypes belonging to extra short duration, short duration and long duration maturity groups grown on an Inceptisol were studied to examine why, despite the poor nodulation of pigeonpea in this soil, it still produces greater yields, than in Alfisols and Vertisols. The percentage nitrogen derived from the atmosphere (%Ndfa) was estimated by ¹⁵N natural abundance and N-difference methods using a long duration sorghum as the non-fixing reference crop. In general, nodulation of pigeonpea in the Inceptisol was much lower than that reported in Alfisols and Vertisols. The above-ground dry matter ringed from 3.1 to 17.1 t ha^?1 while the N uptake ranged from 62.3 to 215 kg ha^?1 The fallen plant parrs of pigeonpea genotypes ranged from 1.4 to 4.9 t ha^?1 and their N contents ranged from 25 to 84 kg ha^?1. The estimates of percentage Ndfa obtained by the two methods were different. Those obtained by the ¹⁵N natural abundance appeared more appropriate as the δ¹⁵N of sorghum harvested along with short duration pigeonpea and later when it was mature did not change significantly. The extra short duration pigeonpea genotype ICPL 84023 contained very little N from atmospheric N₂, while the short duration pigeonpea cv. ICPL 151 had 17% Ndfa and the long duration genotypes. ICPL 366 and T7 had up to 36 % Ndfa. It can be concluded that one of the causes of high yields of pigeonpea on Inceptisols compared to Alfisols and Vertisols despite poor nodulation could be the high N supplying capacity of these Inceptisols. Strategies have been suggested as to how pigeonpea genotypes grown in Inceptisols could improve their nodulation and nitrogen fixation and thus better contribute to a sustainable agriculture.     

不同水稻氮利用效率基因型的物质生产与积累特性

选用氮素利用高效型和低效型具有代表性的12个粳稻品种，研究225 kg hm^-2施氮条件下各基因型水稻物质生产与积累特性及其与氮利用效率的相互关系。结果表明，不同氮效率类型水稻群体茎蘖数没有鲜明的特征差异，但氮高效类型水稻的茎蘖成穗率极显著高于氮低效类型。氮高效类型水稻物质生产与积累具有“前稳、中小、后高”的特性，即在有效分蘖临界叶龄期前具有适宜的叶面积、光合势和群体生长速率，物质积累具一定优势，但其占全生育期总积累量的比例较少；有效分蘖临界叶龄至拔节阶段，无效分蘖发生少，叶面积指数、光合势、群体生长速率低，物质积累也不具优势；拔节以后，具有良好的群体质量，叶面积增长较快，群体光合势和生长速率加大，物质积累优势较为明显。不同氮效率类型水稻物质生产与积累的特性不仅可以解释水稻氮素利用的品种间差异，同时也为生产上提高水稻氮利用效率提供了可行的调控途径。     

新疆石河子棉区高密条件下冠层结构和光分布特征

对新疆石河子5个棉花主栽品种全生育期的干物质积累、生长参数、产量和盛铃期的冠层结构、光渗透能力和光分布等进行了测量分析。结果表明,作物生长速率、铃生长率以及子棉产量等均与总受光量呈正相关关系,净同化率则与单位叶面积受光量呈正相关关系,说明受光量是决定干物质生产和产量的重要因素;单位叶面积受光量即光的渗透能力与单位土地面积总受光量呈正相关关系、而与LAI呈负相关关系,说明冠层结构也是影响冠层受光量的主要因素;总受光量与LAI呈显著的正相关关系,说明LAI最大值并未达到最适宜水平。新疆地区棉花高产棉田的主要特征可以总结为叶数少、叶片大、冠层结构为椭圆形。由于叶面积指数尚未达到最适宜水平,增加种植密度可能是提高产量的一个途径。     

籼、粳超级稻光合物质生产与转运特征的差异研究

为阐明籼、粳超级稻干物质积累及光合生产特征的差异,以江苏地区大面积推广种植的5个超级杂交籼稻组合和5个常规粳型超级稻品种为试验材料,对稻麦两熟制条件下籼、粳超级稻干物质积累、分配、运转及叶面积、光合势、群体生长率、净同化率、秧苗素质、叶型等方面进行了系统的比较研究。结果表明,粳稻生育前期(移栽至拔节期)干物质积累量、光合势、群体生长率、净同化率及上三叶叶长、叶基角、叶开角、披垂度和叶面积衰减率、收获指数均小于籼稻,而生育中后期(拔节至成熟期)干物质积累量、光合势、群体生长率、净同化率及有效叶面积率、高效叶面积率、粒叶比(颖花/叶、实粒/叶、粒重/叶)、最大叶面积指数、总充实量、实收产量、生物产量、茎鞘最大输出量和表观输出量及比率均大于籼稻,差异显著或极显著。虽然粳稻主要生育期单茎干物重均不及籼稻,但群体数量优势保证粳稻具有较高的群体干物质积累量和叶面积,且随着生长发育的持续,群体光合物质生产优势不断加大,群体干物质积累量于抽穗后25 d前后超过籼稻。粳稻灌浆后期(乳熟至成熟期)仍保持强劲生长优势,而灌浆初期(抽穗至乳熟期)茎鞘贮存物质合理输出,有效保障了高效光合层的安全支撑及高积累产量库的流畅充实。高生物学产量的稳定形成和叶面积“稳升缓降”态势以及拔节至成熟期较强的高效光合物质生产,是粳稻光合系统高效持续产出、灌浆充实多及高产形成的重要特征和原因。     

Growth analyses of tomato genotypes grown under low night temperatures and low light intensity

Summary In three experiments the growth of 16 genotypes of tomato was examined. The plants were raised in growth rooms at a day temperature of 19°C and night temperatures of 14, 10 or 6°C respectively under a light intensity of 24 Wm^-2 visible radiation and a daylength of 8 hours. The results were analysed by a multivariate analysis of variance.Relative growth rate (RGR), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) decreased with time. The change in net assimilation rate (NAR) was small. The decrease in RGR was mainly due to the decrease in LAR.RGR, LAR and SLA were lower and LWR slightly higher at lower night temperatures. NAR was hardly affected. The lower RGR at lower night temperatures was mainly due to a lower SLA.Significant differences between genotypes were found in total dry weight, NAR, LAR, SLA and LWR, but hardly in RGR. Significant genotype × temperature interactions occurred.LAR and SLA were positively, NAR and LAR, and NAR and SLA negatively correlated.     

Planting density and sowing proportions of maize–soybean intercrops affected competitive interactions and water-use efficiencies on the Loess Plateau,China

In field trials on the Loess Plateau, China, in 2012–13, maize (Zea mays L.) and soybean (Glycine max L.) were sole cropped and intercropped at three densities and with three sowing proportions. Maize was generally more growth efficient for biomass accumulation than soybean during the entire growth interval, as assessed using the relative efficiency index (REI_c). However, most of sowing proportion at each density displayed a trend of decreased growth with development. Throughout the growth period, the dry matter production and leaf area index (LAI) of maize increased as the plant density increased irrespective of whether it was grown as a sole crop or as an intercrop. However, the effect of increasing cropping density was less obvious for soybean. The LAI values of the sole crop treatment for both maize and soybean were greater than that of the intercropping system, indicating that the presence of maize and soybean together suppressed the respective growth of the two crops. At the final harvest, land equivalent ratios (LER) of 0.84–1.35 indicated resource complementarity in most of the studied intercrops. Complementarity was directly affected by changes in plant densities; the greatest LER were observed in 2 rows maize and 2 rows soybean intercrops at low density. The water equivalent ratio (WER), which characterized the efficiency of water resource use in intercropping, ranged from 0.84 to 1.68, indicating variability in the effect of intercropping on water-use efficiency (WUE).     

Ontogenic Changes in Growth and Assimilate Distribution as Influenced by N Supply in Rapeseed-mustard

Brassica juncea , cv. Pusa Bold, and Brassica campestris , cv. Pusa Kalyani, were raised under field conditions with varying levels of N fertilization, i.e. 0, 40, 80 and 120 kg N ha⁻¹. Changes in dry matter accumulation in various plant parts as influenced by N supply were measured throughout the crop ontogeny. N supply up to 120 kg had an increasing effect on the growth of leaves, stem and pods during the entire period till maturity. Analysis on the assimilate distribution pattern revealed that 84–87% of the total was accumulated during the post-flowering phase. Dry matter partitioning profile during the ontogeny indicated that about 72–83 % of the total DM was accumulated in the leaves, while 17–28 % in the stem, in the preflowering phase. This trend was found nearly opposite during the postflowering phase. At maturity, however, stem and pods accounted for nearly equal amounts of dry matter accumulation. Among the genotypes, Pusa Bold recorded significantly higher DM accumulation and seed yield over Pusa Kalyani which, on the other hand, exhibited a better assimilate-partioning ability than the former. Nitrogen levels had a favourable effect on LAI, LAD and CGR in both genotypes. Highly significant correlations were obtained between seed yield vs. LAI, LAD and CGR. N fertilization up to 120 kg ha⁻¹ was found beneficial in enhancing growth and yield of rapeseed-mustard.