Diurnal and Developmental Changes in Canopy Gas Exchange in Relation to Growth in Transplanted and Direct-Seeded Flooded Rice

1990 ◽  
Vol 17 (2) ◽  
pp. 119 ◽  
Author(s):  
M Dingkuhn ◽  
HF Schnier ◽  
SKD Datta ◽  
E Wijangco ◽  
K Dorffling

Transplanted and direct-seeded flooded rice were compared in a field experiment using identical planting density and geometry. Leaf area index (LAI), plant dry weight, and tiller number were determined at 7-14 d intervals from seeding to maturity. Canopy CO2 and H2O exchange were measured using a mobile depletion-chamber system which requires 1-1.5 minutes per measurement. The canopy CO2 assimilation rates confirmed the plant dry matter accumulation observed. Diurnal measurements of net CO2 assimilation and night respiration indicated a mild midday/afternoon depression that depended on the atmospheric vapour pressure deficit (VPD). Light response of canopy CO2 assimilation exhibited light saturation at full daylight when LAI was lower than 1. No light saturation was observed at higher LAI. Transplanting shock in transplanted rice reduced net assimilation rates and delayed foliage expansion and tillering by 15 days. Crop development was retarded by 7 days. Uninhibited growth of direct-seeded rice during the vegetative stage led to superior biological yield and tiller number at maturity while grain yield was equal to that of transplanted rice. Potential yield increase in direct-seeded flooded rice is discussed on the basis of growth kinetics and assimilate source/sink relationships.

1999 ◽  
Vol 133 (3) ◽  
pp. 321-324 ◽  
Author(s):  
S. KOWSURAT ◽  
P. SRINIVES ◽  
P. KASEMSAP ◽  
S. LAMSEEJAN

Near-isogenic lines of mungbean (Vigna radiata) were produced from backcrossing two Thai recommended cultivars, KPS 1 and CN 36, with the multiple leaflet line, V 5926, until BC9. The isogenic lines were evaluated against the two recipients at Kasetsart University, Thailand, in the rainy season of 1996 and the dry season of 1997. The effect of the gene controlling the multiple leaflet on physiological and agronomical characters was investigated. Seed yield, plant height, and number of pods per plant were greater in the trifoliate leaflet cultivars than in the multiple leaflet near-isogenic lines, whereas the numbers of seeds per pod and 1000-seed weights were not significantly different. Light saturation and photosynthetic rate did not differ, while light interception and dry matter accumulation were greater in the trifoliate leaflet cultivars than in the multifoliate lines. The leaf area index (LAI) of the trifoliate parents was greater at the vegetative stage but lower at the flowering and young pod stages, due to the greater number of leaflets per plant of the multifoliate lines. After the beginning of the podding stage, the LAI of the multifoliate lines was less than that of the parents, as the number of leaflets per plant of these lines hardly changed while that of the trifoliate parents increased.


Weed Science ◽  
1976 ◽  
Vol 24 (1) ◽  
pp. 63-67 ◽  
Author(s):  
D. Nangju ◽  
D. L. Plucknett ◽  
S. R. Obien

Several methods were used to overcome herbicide phytotoxicity to upland rice (Oryza sativaL., ‘IR8′). Seed pelleting with activated carbon and band application of activated carbon slurry over the rice seed were ineffective in reducing the toxicity of chloramben (3-amino-2,5-dichlorobenzoic acid) and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] to upland rice. In contrast, a 2.5-cm layer of activated carbon and vermiculite mixture (1:1) placed over the rice seed was effective in overcoming the toxicity of these herbicides. Deep sowing (3.0 to 4.5 cm) of rice seed was adequate in protecting upland rice from herbicides which are toxic to direct seeded, flooded rice but are not toxic to transplanted rice. The degree of protection from deep sowing, however, was determined by site of uptake, herbicide adsorption by soil, leaching, and inherent toxicity of the herbicides to rice seedlings.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 488
Author(s):  
Zhi Dou ◽  
Yangyang Li ◽  
Halun Guo ◽  
Linrong Chen ◽  
Junliang Jiang ◽  
...  

Rice–crayfish continuous production system offers high economic and ecology benefits, which developed rapidly in China. To investigate the effects of different mechanical transplanting methods and planting densities on rice yield and quality, Nanjing 2728 was used to determine rice growth performance under mechanically transplanted carpet seedling (MTCS) with equal row spacing (30 cm) at five spacings and mechanically transplanted pot seedling (MTPS) with wide and narrow rows (23 + 33 cm) at five spacings. The results showed that MTPS presented significantly higher rice yields than MTCS as more spikelets per panicle. Rice yields of both mechanical transplanting methods first increased and then reduced with decreasing planting density, and its highest value was obtained at 77.9 × 104 seedlings ha−1. Compared with MTCS at the same stage, rice tiller dynamics of MTPS first increased and then decreased. Additionally, its dry matter accumulation per stem at jointing, heading, and maturity stages, leaf area index, photosynthetic potential, crop growth rate, and net assimilation rate were all significantly higher relative to MTCS. For each mechanical transplanting method, dry matter accumulation per panicle, leaf area index, photosynthetic potential, crop growth rate, and net assimilation rate from the sowing to jointing stages declined with decreasing planting density, while dry matter accumulation per stem and net assimilation rate from the heading to maturity stages increased. Compared with MTCS, MTPS significantly improved rice milling and appearance quality, decreasing density was also beneficial to rice milling and appearance quality, while grain content of amylose and protein were not sensitive to both transplanting method and planting density. Consequently, MTPS with 13.8 cm plant spacing is a suitable mechanical transplanting method for Nanjing 2728 to obtain better yield and quality under rice–crayfish continuous production system.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2479
Author(s):  
Wenxuan Mai ◽  
Buhailiqem Abliz ◽  
Xiangrong Xue

With increasing water shortages and labor costs, rice planting is gradually undergoing a transformation from traditional transplanting to direct seeding. However, the yield of direct-seeded rice is unstable and the reasons for this instability are disputed. Therefore, we established a field experiment conducted over 3 years to investigate the reasons for the difference in rice yield under different planting methods. The planting methods compared were transplanting (TR), broadcast sowing (BS), and sowing in line (SL). The yield of rice under TR was higher (10,390 kg ha−1) than that of BS (7790.7 kg ha−1) and SL (9105.2 kg ha−1). Given that the harvest index showed little variation among the three planting methods, the yield differences reflected that shoot dry matter production under TR was higher. Two reasons for the latter observation are suggested: (1) the planting density under TR was lower than that under BS and SL, thus competition for nutrient resources would have been reduced; (2) the growth period of TR was longer. The higher shoot dry matter accumulation under TR contributed to enhanced panicle number per m2 and number of spikelets per panicle than under BS. A significant correlation between number of spikelets per panicle and yield was observed. Although yield was highest under TR, the costs under TR were the highest among the three planting methods. In contrast, the benefit-to-cost ratio under SL was higher than that of TR and BS. The higher yield under TR reflected the production of larger spikelets per panicle than those produced under direct-seeding methods. However, the benefits of SL are conducive to enhanced profitability of rice production.


1978 ◽  
Vol 91 (2) ◽  
pp. 265-278 ◽  
Author(s):  
O. P. Ifenkwe ◽  
E. J. Allen

SUMMARYData are reported from three experiments from 1972 to 1974 in which the effects of two row widths (66 and 132 cm) and five planting densities on the growth of two maincrop potato varieties (Désirée and Maris Piper) were studied. The results were consistent over the 3 years and showed that the effects of widening the row width were to reduce the number of axillary branches and their leaves per plant, in Maris Piper L (leaf area index), and early in the season in both varieties dry weights of leaf, stem and underground parts per plant. Row width had no effect on tuber dry weight for most of the season but at the end of sampling, tuber dry weights were greater from 132cm than from 66 cm rows. Increasing planting density reduced number of axillary branches and their leaves per plant, dry weight of leaf, stem, underground parts and tubers per plant, but increased stem length and tuber dry weight per unit area.Leaf growth of all treatments was rapid during May and high planting densities reached an Lof 3 before the end of this month. L was increased by increased planting density throughout growth, but the lower densities were able to maintain an L of 2–3 formuch of the season. The rapid early increase in L was not associated with any prematuredecline and high rates of tuber dry-matter accumulation were achieved and maintained throughout the season. It is suggested that as the pattern of leaf growth in this environment is coincident with changing light receipts, the environment is almost ideal for the growth of maincrop potatoes.


2016 ◽  
Vol 8 (4) ◽  
pp. 1855-1860
Author(s):  
R. B. Negalur ◽  
A. S. Halepyati ◽  
B. G. Masthanaredy

Field experiment on effect of land preparation methods and planting geometry on growth and yield of machine transplanted rice (Oryza sativa L.) was conducted at Agricultural Research Station, Gangavathi, University of Agricultural Sciences, Raichur, Karnataka during kharif, 2012 and 2013 in clay soil under irrigated condition.Pooled mean indicated that, among the different land preparation methods and planting geometry puddling with rotovator fb levelling with spike tooth harrow and planting geometry of 30 x 21 cm recorded significantly higher growth parameters viz., Leaf area index ( 2.87 and 1.56, respectively) , dry matter accumulation in leaves (13.44 and 14.43 g plant-1, respectively), dry matter accumulation in stem (26.25 and 29.31 g plant-1 , respectively), dry matter accumulation in panicles ( 37.21 and 41.38 g plant-1 , respectively), total dry matter accumulation in plant (73.82 and 85.12 g plant-1, respectively), thousand grain weight (18.17 and 18.71,g respectively), grain yield (4906 and 5192 kg ha-1 , respectively), straw yield (6247 and 6508 kg ha-1, respectively), gross returns (Rs. 87,733 and 92779 ha-1, respectively), net returns (Rs. 46329 and 50007 ha-1) and benefit cost ratio (2.14 and 2.20 ). Puddling with rotovator fb levelling with spike tooth harrow and 30 x 21 cm spacing were found better for transplanting of rice by self propelled mechanical transplanter. Land preparation would be helpful as one of the important pre requirement in machine transplanting of rice, which in turn will decide the time (time required for settling of soil particle) and type of machine to be used for transplanting of rice.


2019 ◽  
Vol 2 (2) ◽  
pp. 357-369
Author(s):  
Nguyen Thi Loan ◽  
Nguyen Ngoc Hung

To study the effects of organic fertilizer and HB101 organic plant vitalizer on the growth and yield components of the BH9 rice variety, a field experiment with 4 x 3 factorial design was conducted at Hong Thai commune, Kien Xuong district, Thai Binh province in 2017 summer season using a randomized complete block design with 3 replications. Organic fertilizer derived from chicken manure and peat was applied at 3 levels (0 ton ha-1, 4 tons ha-1, and 6 tons ha-1) while the HB101 plant vitalizer was sprayed in 4 levels (0%, 0.015%, 0.025%, and 0.035%; the amount of water to dilute HB101 was 1000 litre ha-1). The application of the organic fertilizer alone and the combination of organic fertilizer and HB101 positively increased the total tiller number, effective tiller number, leaf area index (LAI), SPAD value, dry matter accumulation, yield components, and grain yield of rice. There were also differences in the SPAD values (at flowering stage), dry matter weight (at active tillering stage), and 1000 grain weight under the influence of the HB101 solution. The combination of 6 tons ha-1 organic fertilizer and  HB101 significantly increased the grain yield as compared to the other treatments, and the highest grain yield (3.03 tons ha-1) was obtained when  organic fertilizer (6 tons ha-1) was applied in combination with HB101 plant vitalizer (0.025%).


2021 ◽  
Vol 30 (1) ◽  
pp. eSC01
Author(s):  
Paulo Cañete-Salinas ◽  
Francisco Zamudio ◽  
Marco Yañez ◽  
Héctor Valdés-Gómez ◽  
Cristian Espinosa ◽  
...  

Aim of study: The productivity of poplar plantations in Mediterranean climates might be reduced due to lower precipitations in a climate change scenario. Therefore, understanding the water consumption in these plantations is essential for their management. The objective of this study was to estimate water consumption and preliminary crop coefficients (kc) of two universally used poplar clones (Populus x Canadensis ‘I-214’ and ‘I-488’).Area of study: Central Chile (36º 05 'LS; 72º 47' LW; 470 m.a.s.l.).Materials and methods: Commercial stands of poplar clones established in 2009 and 2010 at low density (6×6 m) were used to experiment during the 2016-2017 growing season. In each of them, water balance was measuring, by determining evaporation using micro lysimeters and transpiration using the sap flow. Additionally, the water status and the leaf area index (LAI) were measured to understand the behaviour of both clones.Main results: Although the water supplied to both clones was the same, the transpiration (T) was higher for ‘I-488’ than ‘I-214’, at those moments in which the evapotranspiration (ETr) and the vapour pressure deficit (VPD) was higher. On the other hand, differences were observed in plant water status, ‘I-488’ had more negative xilematic water potential (Ψx) compared to ‘I-214’. In turn, I-214 proved to have a higher Leaf Area Index (LAI) than I-488 and grew more during the season, refuting its greater efficiency.Research highlights: These results allow characterizing the water behaviour of both clones in Mediterranean climate condition, but it is necessary to extend the study to more seasons and different age ranges.Keywords: Crop coefficient; water consumption; water balance; poplar.


2005 ◽  
Vol 53 (4) ◽  
pp. 405-415 ◽  
Author(s):  
P. Janaki ◽  
T. M. Thiyagarajan

Field experiments were conducted during 1998 and 1999 in June-September with rice variety ASD18 at the wetland farm, Tamil Nadu Agricultural University, Coimbatore, India to find out theeffect of N management approaches and planting densities on N accumulation by transplanted rice in a split plot design.The main plot consisted of three plant populations (33, 66 and 100 hills m-2) and the sub-plot treatments of five N management approaches. The results revealed thatthe average N uptake in roots and aboveground biomass progressively increased with growth stages. The mean root and aboveground biomass Nuptake were 26.1 to 130.6 and 6.4 to 17.8 kg ha-1, respectively. The N uptake of grain and straw was higher in theSesbania rostratagreen manuring + 150 kg N treatment, but it was not effective in increasing the grain yield. The mean total N uptake was found to be significantly lower at 33 hills m-2(76.9 kg ha-1) and increased with an increase in planting density (100.9 and 117.2 kg ha-1at 66 and 100 hills m-2density). N application had a significant influence on N uptake and the time course of N uptake in all the SPAD-guided N approaches. A significant regression coefficient was observed between the crop N uptake and grain yield. The relationship between cumulative N uptake at the flowering stage and the grain yield was quadratic at all three densities. The N uptake rate (µN) was maximum during the active tillering to panicle initiation period and declined sharply after that. In general, µNincreased with an increase in planting density and the increase was significant up to the panicle initiation to flowering period.thereafter, the N uptake rate was similar at densities of 66 and 100 hills m-2.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaodan Wang ◽  
Yaliang Wang ◽  
Yuping Zhang ◽  
Jing Xiang ◽  
Yikai Zhang ◽  
...  

AbstractDetermination of the optimal fertilization method is crucial to maximize nitrogen use efficiency and yield of different rice cultivars. Side-deep fertilization with controlled-release nitrogen, in conjunction with machine transplanting and subsequent topdressing, was applied to Indica–japonica hybrid rice ‘Yongyou1540’ (YY1540) and indica hybrid rice ‘Tianyouhuazhan’ (TYHZ). Four nitrogen treatments were applied in 2018 and 2019: traditional nitrogen application with quick-release nitrogen (T1), single-dose deep fertilization at transplanting with 100% controlled-release nitrogen (T2), and deep fertilization of 70% controlled-release nitrogen and topdressing of 30% quick nitrogen at tillering (T3), or at panicle initiation (T4). Side-deep fertilization reduced the fertilizer application frequency without causing yield loss, T4 enhanced the yield of YY1540 by increasing the number of productive tillers and number of spikelets per panicle compared with T1, T2 and T3. The yield of TYHZ showed no significant difference among treatments. The T4 treatment decreased the number of tillers at the tilling peak stage and increased the percentage productive tillers and number of differentiated spikelets. Compared with the other treatments, T4 increased dry matter accumulation and leaf area index during panicle initiation and grain ripening, and contributed to enhanced nitrogen uptake and nitrogen utilization in YY1540. On average, nitrogen uptake and utilization in YY1540 were highest in T4, but no significant differences among treatments were observed in TYHZ. Dry matter accumulation and nitrogen uptake from panicle initiation to heading of YY1540 were correlated with number of spikelets per panicle, but no significant correlations were observed for TYHZ. Supplementary topdressing with quick-release nitrogen at the panicle initiation stage was required to increase yield of indica–japonica hybrid rice, whereas single-dose deep fertilization with controlled-release nitrogen is satisfactory for the indica hybrid cultivar.


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