The Pattern of Dry‐Matter Distribution during Development in Onion

Potassium requirements for growth—dry matter (DM) and leaf area (LA) and related processes — relative leaf growth rate (RLGR), relative growth rate (RGR), net assimilation rate (NAR) and crop growth rate (CGR) were determined by plant analysis during the entogeny of wheat. Wheat (Triticum aestivum cv. HD 2329) plants were supplied with different amounts of K from deficient to adequate through nutrient solution. Samples were taken at specific stages for K determinations. The DM and LA were recorded at 45d, 75d and 105d. The growth related processes RGR, NAR and CGR were estimated between 30–45d, 45–75d and 75–105d. In case of RLGR the observations were carried out between 15–30d, 30–45d and 45–75d. These physiological processes and grain yield were correlated with K concentration in whole plant at 30 and 45d and top two leaves at 75 and 105d.

Net assimilation rate (NAR), relative growth rate (RGR) and relative leaf growth rate (RLGR) of soybeans [Glycine max (L.) Merrill] declined throughout the season; much of this decline and most effects of plant population on growth could be attributed to a rise in leaf area index (LAI). Increase in LAI from 0.3 to 1.0 was associated with a marked decrease in NAR. Crop growth rate (CGR) increased for the first 50 to 60 days, falling sharply thereafter. There was no optimum value of LAI.Fertilizer increased final plant weight mainly by delaying the fall in NAR and CGR. LAI was increased slightly by fertilizer application, presumably because of a higher RLGR between 50 and 70 days.The classical and regression techniques of growth analysis gave similar results, but the lower standard errors obtained with the latter revealed additional treatment effects. In some circumstances, smoothed curves used to describe growth might conceal growth fluctuations due to environmental stress.

Spaced plants of soybean (Glycine max (L.) Merrill) cultivars were subjected to classical growth analysis. Varietal differences in mean net assimilation rate (NAR), relative growth rate (RGR), relative leaf growth rate (RLGR), leaf area ratio (LAR), specific leaf weight (SLW), and shoot/root ratio (S/R) were detected within a group of 21 cultivars grown in three tests over 3 years. Only LAR and SLW differed within another group of 23 cultivars grown in 2 years. Comparisons of cultivars with their parents showed that selection for yield had resulted in increased NAR and SLW, and in decreased LAR, S/R, plant weight, and leaf area. Many of the cultivars were transgressive segregants for higher NAR and SLW and for lower LAR. Phenotypic correlations showed that NAR was highly correlated with SLW and inversely correlated with LAR. SLW might be a useful character for indirect selection of soybean yield.

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh to investigate the effect of age of tiller seedlings, number of tiller seedlings hill-1 and application of urea super granules (USG) on some physiological attributes of transplant Aman rice cv. BRRI dhan52. The experiment consisted of two ages of tiller seedlings viz. 25- and 35-day old, three levels of tiller seedlings hill-1 viz.1, 3 and 5 seedlings hill-1 and three USG levels viz. 0, 1.8g and 2.7g USG per four hills in every alternate row. The experiment was laid out in a randomized complete block design with three replications. The effect of age of tiller seedlings, number of tiller seedlings hill-1 and USG application were significant on crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR) and leaf area index (LAI). The highest CGR and RGR were found by transplanting 35-day old tiller seedlings during the period at 15-30 and 60-75 DAT when 5 tiller seedlings hill-1 were transplanted. The highest NAR was observed at 60-75 DAT with transplanting 5 tiller seedlings hill-1 and the lowest one was recorded at 30-45 DAT. The highest LAI was found at 35-day old tiller seedlings during the period at 60 and 75 DAT when 5 tiller seedlings hill-1 were transplanted. CGR and RGR were found highest by applying 1.8 g USG at 45-60 and 60-75 DAT while NAR was the highest with application of 2.7g USG at 60-75 DAT and lowest one was found in control (0 g USG) at 45-60 and 60-75 DAT. The highest LAI was found by applying 1.8g USG at 15, 30, 45 and 60 DAT and the lowest one was found at 60 DAT in control and at 15, 30 and 45 DAT when 2.7g USG was applied. The highest LAI and CGR were found in older tiller seedlings (35- day old) by transplanting five tiller seedlings hill-1 fertilized with 1.8g USG whereas the highest RGR and NAR were obtained in younger tiller seedlings (25-day old) by transplanting single tiller seedling hill-1 fertilized with 1.8g USG per four hills of every alternate row.DOI: http://dx.doi.org/10.3329/pa.v24i1-2.19094 Progress. Agric. 24(1&2): 17 - 27, 2013

O objetivo deste trabalho foi analisar o crescimento de três cultivares de Panicum maximum: Mombaça, Tanzânia e Vencedor cultivados em vasos, sob cobertura de lona plástica transparente. Os vasos foram cheios com 6 dm³ de latossolo vermelho-amarelo, textura argilosa, contendo alto teor de matéria orgânica. O solo, após ser peneirado, recebeu calagem e enriquecimento com N e P, 150 mg/dm³ de cada elemento. As sementes foram plantadas em vasos, num total de 54. Após desbaste, cinco plantas foram deixadas por vaso. Diariamente os vasos foram molhados e quinzenalmente fertilizados, cada um, com 50 mg/dm³ de N e K, em solução aquosa. Cada cultivar foi colhido às idades de 17, 24, 31, 38, 45 e 52 dias após emergência da semente. Houve três repetições para cada cultivar e idade. Em cada colheita, as plantas foram cortadas próximo à superfície do solo e separadas em folhas, colmo, raízes e material morto. A área das lâminas foliares foi medida em integrador de área foliar. Lâminas foliares, colmo e sistema radicular foram pesados após secagem a 60ºC por 72 horas. Valores instantâneos foram estimados para os índices de crescimento: área foliar específica (AFE), razão de peso foliar (RPF), razão de área foliar (RAF), taxa assimilatória líquida (TAL) e taxa de crescimento relativo (TCR), de todos três cultivares. Houve diferenças entre os cultivares quanto aos valores instantâneos de RAF e TCR à idade de 17 dias. As variações de AFE foram as principais causas das mudanças em RAF. Nenhuma diferença foi observada entre os cultivares quanto à TAL.

A field experiment was conducted during khariff 1984 in sandy clay loam soil under irrigated condition at the Tamil Nadu Agricultural University, Coimbatore, with a view (i) to find out the possibility of introducing short duration dwarf variety of sorghum CO 22 as an intercrop with pigeonpea genotypes, (ii) to study the effect of different plant population levels and intercropping of sorghum CO 22 on pigeonpea genotypes, and (iii) to find out compatible pigeonpea genotypes and plant population level for pigeonpea based intercropping system with sorghum CO 22.It was observed that increased plant density significantly increased the dry matter production, leaf area index (LAI) and crop growth rate (CGR) during early stages and reduced the net assimilation rate (NAR), relative growth rate (RGR) and CCR during later part of the growth. Intercropping of sorghum CO 22 significantly reduced the dry matter production LAI, CGR, NAR and RGR. Plants in the intercropped stands recorded higher CGR, NAR and RGR during later part of the growth. Among pigeonpea genotypes CO 5 was much affected due to intercropping with sorghum CO 22.

The effect of rice bran on dry matter production of different rice cultivars, namely the Chinese panicle weight types and Japanese panicle number types, was evaluated in field conditions, with growth, canopy production structure and the root system determined over a period of 60 days. The treatments consisted of rice cultivars with 1000 kg ha1 rice bran without agrochemicals (RB), cultivars with chemical fertilizer and cultivars with herbicide, with the latter serving as a control. The crop growth rate (CGR) and mean leaf area index (mLAI) in RB treatment were lower than that of the control; however, the net assimilation rate (NAR) was higher for all growth stages in this treatment. It was noted that CGR in RB and the control treatment depended greatly on mLAI during the early and middle growth stages, whereas CGR was more dependent on NAR in the late growth stage. Correlation between CGR in middle stage and the extinction coefficient of the canopy (k) at heading was apparent (p < 0.05). NAR in middle stage was positively correlated with mean leaf color and specific leaf weight (SLW). The correlations between NAR in the late stage and bleeding rate per number of primary roots, and per leaf area at maturity was apparent (p < 0.01). Root vitality and NAR were higher in RB treatment. The photosynthesis-related traits after heading in RB treatment were better than the control. Reduction of ∆W in RB treatment as well as the spikelets number (SN) was unapparent. The panicle number type cultivars did not inhibit growth during the early and middle growth stages with the presence of rice bran. The difference between growth, panicle number and weight cultivars was insignificant in the late stage. Discipline: Crop production Additional key words: bleeding rate, growth analysis, light extinction coefficient, the panicle number type cultivars, root system. This research was supported in part by Tianjin natural science fund for Scientific Research (No.11JCYBJC27100) from the Tianjin Municipal Science and Technology Commission, China. The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (No.46). This research was supported in part by the ScienceT accepted 2 March 2015 Introduction The use of nitrogen in paddy cultivation in China is three times higher than in Japan. In this context, excess application of chemical fertilizer in paddy cultivation pollutes the environment and has adverse effects on both aquatic and terrestrial organisms. The use of chemical fertilizers increases operation costs, resulting in higher rice and rice product prices. It is, therefore, important to find new alternatives as substitutes for chemical fertilizer in paddy farming to alleviate environmental issues arising from their use. Rice bran is often used in the organic paddy farming in Japan because of its efficacy as a fertilizer and herbicide. This cultivation technique fulfills the growing demand for agriculture products with fewer or no agrochemicals to

This study was conducted to clarify the dry matter production of grain sorghum and growing behavior with relation to planting rate and amount of fertilizer in order to obtain high grain yield. The hybrid variety, GS76Y was seeded on May 24 in 1972. The dry weight of each organ of plant was measured at intervals about 2 weeks apart ranging from the early stages of growth to ripening time. Irrigation was applied at half bloom stage. The results obtained were as follows; 1. The maximum rate of dry matter production was 42 g per m2 of field per day with the high planting density and heavy manuring plot during 14 days near heading date. In this period, mean daily solar radiation was 502 cal per cm2 of field and mean daily temparature was 28.4°C. 2. The mean maximum value of net assimilation rate in heavy manuring plots and in light manuring plots were 17.7 and 14.2 g per m2 of leaf area per day, respectively. The value of net assimilation rate was high at the early stages of plant growth and decreased with grow. 3. Grain yield was significantly varied with the planting density. The highest grain yield per are was 82 kg on the basis of dry matter. lt was obtained at planting densities of 25 and 40 plants per m2 of field on heavy manuring plots. 4. Total dry matter produced in ripening period ranged from 62 to 81 kg per are and was equivalent to above 90 percent of grain yield. 5. Dry matter production was depended largely upon leaf area before heading, and net assimilation rate after heading. The value of net assimilation rate during the ripening period decreased with higher leaf area index. However, in case 4 and beyond that of leaf area index, net assimilation rate was increased as the percent of nitrogen content of leaf blade, namely, there was positive correlation between net assimilation rate and percent of nitrogen content of leaf blade in the ripening period. 6. It was recognized that the number of grains per unit field was closely related to the amount of nitrogen absorption of top at heading date. The amount of nitrogen, phosphorus, and potassium absorption at ripening time were in the range of 17.8 to 25.1, 3 to 4 and 26 to 34 kg per 10 are, respectively.

به منظور بررسى اثر تنش کم‏آبى بر عملکرد و شاخص های رشد سیب‏زمینى رقم آئولا از روش آبیارى بارانى با حجم های مختلف آب در مرکز تحقیقات کشاورزى و منابع طبیعی خراسان رضوی (مشهد) استفاده شد. در فواصل 75/0، 75/3، 75/6، 75/9 و 75/12 متر از خط لوله آبیارى میزان آب دریافتى اندازه‏گیرى شد و به ترتیب تحت عنوان تیمار بدون تنش، تنش بسیار ملایم، تنش ملایم، تنش شدید و تنش بسیار شدید بررسى شدند. در این تحقیق، عملکرد در شاهد 47/26، تنش بسیار ملایم 3/22، در تنش ملایم 31/17، در تنش شدید 88/9 و در تنش بسیار شدید 04/2 تن در هکتار به دست آمد. اثرات تنش کم آبی بر روى تغییرات ماده خشک اندام هاى گیاهى، کل ماده خشک گیاه (TDM)، سرعت رشد نسبى (RGR)، سرعت رشد محصول (CGR)، شاخص سطح برگ (LAI)، دوام سطح برگ (LAD) و سرعت جذب خالص (NAR) بسیار زیاد بود. حداکثر سرعت رشد نسبى در سطوح تنش کم‏آبى بین 004/0 تا 005/0 گرم بر گرم در GDD محاسبه شد. در تنش‏هاى شدید و بسیار شدید حداکثر سرعت رشد محصول زودتر انجام شد (به ترتیب در 1300 و 1200 درجه روز رشد) و سایر تیمارها دیرتر (در 1600 درجه روز رشد) به حداکثر سرعت رشد محصول رسیدند. بیشترین مقدار LAD در تیمار بدون تنش به میزان 478 شاخص سطح برگ روز و در GDD1600 به دست آمد.

Smooth bromegrass (Bromus inermis Leyss.) seedlings grown in four environments were used to study effects of temperature and irradiance on seedling growth. Differences between environments, between stages of growth, and their interaction were significant for tiller number, leaf number, leaf area, specific leaf weight, shoot‐to‐root ratio, dry weight of leaf, shoot and root, and seedling dry weight. Both main effects and their interaction were highly significant for relative growth rate (RGR) and leaf area ratio (LAR), while for net assimilation rate (NAR) differences between environments were non‐significant. Seedlings grown in high light and high temperature environments produced higher dry matter than those grown in low light or low temperature. The effect of irradiance was greater than that of temperature for most characters studied. Both RGR and NAR declined gradually with advancing plant age in all environments; LAR declined only in high light environments. Simple correlation coefficients revealed that increasing RGR and LAR could be accompanied by increasing tiller number, leaf number, leaf area, seedling dry weight and shoot‐to‐root ratio. Highly significant correlations were obtained between RGR and LAR (0.69 to 0.93 at 0.001 level), whereas there was no correlation between RGR and NAR. It is apparent that variation among environments in dry matter production of bromegrass seedlings was attributed to differences in LAR rather than NAR. Specific leaf weight was negatively correlated with RGR at the 0.001 level (−0.90) and LAR (−0.97), but positively correlated with NAR at the 0.05 level (0.47).

Pot experiment was conducted at the Department of Agronomy Crop Pavilion of the University of Ilorin, Ilorinto assess the effects of water stress at different growth stages on the physiological parameters of soybean genotypes. Six soybean genotypes (TGX 536-02D, TGX 1830-2DE, TGX 1019-2EN, TGX 1740-2F, TGX 1485-1D and TGX 1817-12E) were subjected to water stress at three growth stages (vegetative, flowering and post-flowering stages) with a well-watered control. The experiment was designed as a factorial trial and laid out in split- plot arrangements. Morphological growth characters such as number of leaves, leaf area, branching and dry matter production were measured during growth which were used to determine physiological growth indices.Results show that crop growth rate (CGR), relative leaf growth rate (RLGR), net assimilation rate (NAR) and leaf area ratio measured at vegetative growth were significantly reduced by water stress occurring at the vegetative stage.Amongst the investigated genotypes TGX 536-02D was the most tolerant while 1485-1D was the least tolerant genotypes.

The study aimed to determine the response of growth and yield of kailan on the interaction effect of a dolomite lime with bokashi of cow manure and its single factor effect. The experiment was conducted in Completely Randomized Design (CRD) with two factors in three replications. The first factor was dolomite lime which consists of 2 t ha-1 (k1), 5 t ha-1 (k2), 10 t ha-1 (k3) and 15 t ha-1 (k4), while the second factor was bokashi of cow manure consisting of 0 t ha-1 (b0), 10 t ha-1 (b1), 15 t ha-1 (b2), and 20 t ha-1 (b3). By observing growth components consisting of relatif growth rate (RGR), crop growth rate (CGR), net assimilation rate (NAR), shoot/root ratio (S/R), and crop yield. As well as the components of soil nutrient content of N, P, K, C-organic content, pH and cation exchange capacity (CEC). The results showed that the application of dolomite lime at a dose of 15 t ha-1 with bokashi fertilizer at a dose of 20 t ha-1 give the highest value of crop growth rate (CGR), net assimilation rate (NAR), shoot/root ratio (S/R), C-organic content, phosphorus (P), and Potassium in peat soil. The application of bokashi fertilizer at a dose of 15 t ha-1 was not different with 20 t ha-1 in terms of relatif growth rate (RGR), crop yield and cation exchange capacity (CEC), and respectively higher than the dose of 10 t ha-1 and without bokashi fertilizer. The application of dolomite lime at a dose of 10 t ha-1 was not different with 15 t ha-1 on the relative growth rate (RGR), and pH of peat soil, and each dose was higher than the doses of 5 t ha-1 and 2 t ha-1 . In terms of nitrogen (N) content, the application of dolomite lime at a dose of 5 t ha-1 was not different with the dose of 10 t ha-1 , and 15 t ha-1 , the N content was higher than the dose of 2 t ha-1 . The increase in the dose of dolomite lime at 20 t ha-1 of bokashi fertilizer showed a positive linier correlation, except for the Potassium which showed a quadratic correlation. The increase dose of dolomite lime in the bokashi fertilizer, the plant growth rate (PAR), net assimilation rate (NAR), shoot/root ratio (S/R), C-organic content, and phosphorus (P) would increase as well. Each single factor of the dose of dolomite lime and bokashi fertilizer showed a positive linier relationship to the relatif growth rate (RGR), crop yield, N-total, pH, and cation exchange capacity (CEC) of peat soil, except for N-total and pH in bokashi fertilizer.

Silver maple (Acersaccharinum L.) and eastern cottonwood (Populusdeltoides Bartr.) seedlings were treated with either 0.0, 0.1, 0.2, or 0.3 ppm ozone for 12 h/day for up to 60 consecutive days. Six seedlings were harvested from each treatment at 10-day intervals to construct growth curves for leaf area, leaf weight, and stem plus leaf weight. Relative growth parameters were calculated from these curves. Relative growth rate, relative leaf-area growth rate, and relative leaf-weight growth rate declined with an increase in time and ozone concentration. Net assimilation rate declined with time in both species. Specific leaf area and leaf-area ratio had no consistent trends.

A field experiment was conducted at the Agronomy Farm, S.K.N. College of Agriculture, Jobner, Rajasthan, during the Kharif 2022 to assess the impact of different levels of potassium and stress-mitigating chemicals on mungbean [Vigna radiata (L.) Wilczek]. The experiment was laid out in a factorial randomized block design with three replications. Treatments comprised of potassium doses of 20, 30 and 40 kg K2O/ha with a control and stressmitigating chemicals [KNO3 @ 100 ppm, thioglycolic acid @ 100 ppm and kinetin @ 50 ppm and control]. Data showed that application of 40 kg K2O/ha significantly increased plant height, dry matter accumulation and plant growth indices, viz. crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR) and leaf area index (LAI) over control and 20 kg K2O/ha. However, it was at par to 30 kg K2O/ha in terms of RGR and NAR. Further, foliar sprays of TGA @ 100 ppm at 30 and 45 days after sowing significantly improved plant height and dry matter accumulation at 50 DAS and maturity, CGR, RGR and NAR at 25–50 DAS and LAI at 50 DAS over control and KNO3 @ 100 ppm while it remained on par with kinetin @ 50 ppm. The highest net returns (`61,554 and 62,543) and B:C ratio (3.16 and 3.40) were also recorded by application of 40 kg K2O/ha and foliar spray of TGA @ 100 ppm, respectively. Hence, application of 40 kg K2O/ha and two foliar sprays of TGA @ 100 ppm at 30 and 45 days after sowing may be recommended to achieve higher growth and profitability of mungbean.

High temperatures, whether of shoot or root, are reported to affect shoot and root growth of various plant species. The scanty information available on the differential response of wheat genotypes to high shoot and root‐zone temperatures triggered this investigation to study the response and adaptation of shoot and root growth of three wheat genotypes to high shoot and root‐zone temperatures during early growth stages. Three wheat genotypes; Fang (heat tolerant), Siete Cerros (heat sensitive) and Imam (recent cultivar adapted to a hot irrigated environment) were grown in soil and hydroponically. Three shoot/root‐zone temperatures (23/23, 23/35 and 35/35 °C for the soil experiment and 22/22, 22/38 and 38/38 °C for the hydroponic experiment) were applied at three‐leaf growth stage. High root‐zone temperature alone or combined with high shoot temperature reduced xylem sap flow rate, root dry weight, root length and root/shoot ratio. Unexpectedly, shoot fresh and dry weights and relative growth rate (RGR) were not significantly affected by the high root‐zone temperature except for the susceptible genotype, Siete Cerros, after prolonged exposure in the hydroponic experiment. In contrast, high shoot/root‐zone temperature significantly reduced shoot fresh and dry weights from as early as the first week of the hydroponic experiment. The 38/38 °C treatment also caused significant reduction in RGR and net assimilation rate during the first 2 weeks, but no significant differences were found during the last 2 weeks compared with 22/22 °C. Interesting responses were observed among genotypes in terms of shoot and root dry weights and root/shoot ratio at 38/38 °C treatment. The heat‐sensitive Siete Cerros showed the least reduction in these traits during the first 2 weeks while the heat‐tolerant Fang and Imam responded by greatly reducing their shoot and root weights. The situation was almost reversed with the duration of treatments such that Siete Cerros became the most affected genotype while Fang and Imam were better adapted to high shoot/root‐zone temperature. Specific root weight was the exceptional trait that increased under high temperature treatments. Results indicate that despite the reduction in root length and weight observed under high root‐zone temperature, shoot growth was not much affected suggesting that the use of suitable cultivar coupled with proper management could alleviate most of high root‐zone temperature effects during early growth stages.