scholarly journals CRITICAL VARIABLES OF MORPHO-PHYSIOLOGICAL RICE PLANT UNDER STAGNANT FLOODING CONDITIONS

2021 ◽  
Vol 22 (1) ◽  
pp. 1
Author(s):  
Nurwulan Agustiani ◽  
Sujinah Sujinah ◽  
Indrastuti Apri Rumanti

<p class="abstrakinggris"><span lang="EN-US">Stagnant flooding (SF) stress has contributed decreasing rice production in Indonesia. The study aimed to explore critical variables of rice growth that contribute to the decreasing grain yield under SF conditions and a common irrigation system (control). The experiment was arranged in a complete randomized block design with four replications to test 10 rice genotypes (Inpari 30 Ciherang Sub-1, Inpara 3, Inpara 4, Inpara 8, IRRI119, IRRI154, IR42, IR14D121, IR14D157, and Tapus). The water depth was managed according to the farmer’s practices for control, while for SF plots the standing water depth was gradually increased from 35 days after transplanting and was maintained at 50 cm until harvest. Results showed that plant height, tillering ability, leaf greenness, panicle number per hill and grain filling percentage were critical growth variables that affect grain yield at optimal conditions. The yield of the 10 genotypes decreased by 25–50% under SF conditions. Inpara 3 had the stable yield in those two watering conditions. Therefore, it could be used as a check variety for SF condition. Inpara 9 and IRRI119 experienced decreased yield of more than 50% under SF conditions. The key factors determining the decreased yield were tillering ability and green leaf level. Optimization of the two variables at SF conditions will largely determine rice yield associated with panicle number per hill and grain number per panicle. Results of the study are useful as preliminary recommendations for designing new variety and cultivation techniques to reduce the impact of SF stress on rice yield.</span></p>

1970 ◽  
Vol 11 ◽  
pp. 31-36
Author(s):  
NK Dangal ◽  
D Sharma-Poudyal ◽  
SM Shrestha ◽  
C Adhikari

A pot experiment was conducted during July-November 2006 in a glass house at the Institute of Agriculture and Animal Science, Rampur, Chitwan to find out the impact of soil infestation of rice root-knot nematode (Meloidogyne graminicola Golden and Birchfield) and flooding on its development and rice yield. The experiment was conducted in a 4 factorial randomized complete block design with 5 replications. Rice cv. 'Sabitri' was sown in M. graminicola infested soil and infestation free (healthy) soil. Both beds were further divided to give wet bed (flooded) and dry bed condition. Twenty-one days old seedlings from each seedbed were transplanted into plastic pots containing 5 kg of M. graminicola infested and healthy soil each treated with lowland (continuously flooded) and upland condition. Simulated field conditions were created throughout the experiment period. Results revealed that rootknot index (RKI) and population of second stage juveniles of M. graminicola (J2) in soil and roots were significantly lower and grain yield was higher in pots containing seedlings transplanted from wet seedbed than dry bed. Lower RKI, root lesion index (RLI) and J2 population in soil and roots and higher grain yield were observed in pots containing seedlings transplanted from healthy seedbed than the nematode infested seedbed. Similarly, RKI, RLI and J2 population in soil and roots were significantly lower in simulated lowland as compared to upland condition. Transplanting on healthy soil also resulted in lower RKI, RLI and J2 population in soil and roots and higher grain yield than in the nematode infested soil. Interactions revealed that highest grain yield was obtained from seedlings grown under healthy seedbed transplanted in healthy soil under simulated lowland condition. Thus, M. graminicola infestation may be minimized by growing seedlings in healthy and wet seedbed. Seedling transplanting into M. graminicola free soil and lowland condition may be another important control measure for it. Key words: dry bed; lowland; upland; wet bed; rice root-knot nematode; Meloidogyne graminicola DOI: 10.3126/njst.v11i0.4086Nepal Journal of Science and Technology 11 (2010) 31-36


2020 ◽  
Vol 12 (4) ◽  
pp. 128
Author(s):  
Wellington Junior Candido da Silva ◽  
Flávio Carlos Dalchiavon

Due to the change in the environment, diseases and insects can reduce the leaf area of agricultural crops. The objective of this study was to determine the impact of induced defoliation on the vegetative and reproductive phases of corn on its agronomic characteristics. The experiment was carried out in the experimental area of the Mato Grosso Federal Institute of Education, Science and Technology, Campo Novo do Parecis campus, in a second crop system in the 2017/2018 agricultural year, with sowing in March. This study used a randomized complete block design, consisting of 24 treatments and three replications, comprising eight phenological stages. The treatments were performed from the fourth leaf stage (V4) to physiological maturation (R5), with defoliation in the lower, middle and upper thirds of the plant. The characteristics evaluated were: plant height, stem diameter, ears insertion height, ears length, ears diameter, ears weight, number of rows per ears, number of grains per row, weight of grain per ears, prolificity; harvest index, weight of one thousand grains and grain yield. Defoliation between the fourth (V4) and twelfth leaves (V12) does not interfere in the evaluated characteristics. Grain and ear weight are interfered when defoliation occurs in the middle and upper third of plants in V12. Defoliation between flowering (R1) and beginning of grain filling (R2) negatively affects the weight of one thousand grains, grain and ear weight, and may reduce grain yield by up to 30%. Defoliation in the upper third of the plant significantly reduces the diameter and length of ears, grain and corn ear of the corn crop.


2020 ◽  
Author(s):  
Bishnu Kandel

Abstract Objectives A field experiment was conducted to evaluate ten hybrid maize for photosynthetic traits. Ten hybrid were replicate thricely under Randomized Complete Block Design (RCBD) during winter season of 2018. SPAD 502 Plus meter was used for SPAD value measurement. Vegetative stage all photosynthetic measurement taken from T1 (top most leaf) and T3 (2nd leaf from top leaf) leaves of 5 plants of one plot during 30 days interval. For reproductive phase data taken from Eo/ eo (Leaf attach to cob/ear), E2 or e2 (2nd leaf from Eo /eo leaf) leaves during entire period of grain filling at 10 days intervals. Same leaves were used for overall data collection.Results Result showed that significantly different SPAD value were observed for different age and leaves of maize during pre and post anthesis. SPAD value increase with increase in age and decrease at the time of maturity. During vegetative and juvenile phase T3 leaf has more SPAD value than T1. During reproductive stage eo leaves had more SPAD than e2 leaves, so center leaf of maize contributes more to grain yield. Correlation studies showed that there is strong positive correlation between different stage of SPAD with grain yield.


2020 ◽  
Vol 1 (1) ◽  
pp. p47
Author(s):  
Nyasha Sakadzo ◽  
Gift Bvekwa ◽  
Kasirayi Makaza

Finger millet is a climate compliant crop; its production remains low due to poor establishment methods. A field experiment was conducted during the rainy season of 2018/19 at Dorcas Charare plot in ward 24, Zaka district to investigate the effects of establishment methods on yield and yield parameters of finger millet (Eleusine coracana L. Gaertn). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three treatments namely broadcasting, hand drilling and transplanting replicated three times. Results on grain yield showed that transplanting method had the highest yield of 0.51t/ha whilst drilling and broadcasting scored 0.40t/ha and 0.35t/ha respectively. Transplanting method significantly (p<0.05) influenced higher number of tillers (7.13) per hill followed by drilling (2.40) and lastly broadcasting (2.13). Significant differences (p<0.05) were noted on panicle number with transplanting scoring the highest (8.13) and broadcasting the lowest (3.13). It can be concluded from the study that transplanting method realized a higher panicle number, tiller number and grain yield. Farmers must adopt transplanting as an establishment method in finger millet production.


2019 ◽  
Vol 20 (20) ◽  
pp. 5241 ◽  
Author(s):  
Kiyoon Kang ◽  
Yejin Shim ◽  
Eunji Gi ◽  
Gynheung An ◽  
Nam-Chon Paek

Exploring genetic methods to improve yield in grain crops such as rice (Oryza sativa) is essential to help meet the needs of the increasing population. Here, we report that rice ONAC096 affects grain yield by regulating leaf senescence and panicle number. ONAC096 expression increased rapidly in rice leaves upon the initiation of aging- and dark-induced senescence. Two independent T-DNA insertion mutants (onac096-1 and onac096-2) with downregulated ONAC096 expression retained their green leaf color during natural senescence in the field, thus extending their photosynthetic capacity. Reverse-transcription quantitative PCR analysis showed that ONAC096 upregulated genes controlling chlorophyll degradation and leaf senescence. Repressed OsCKX2 (encoding cytokinin oxidase/dehydrogenase) expression in the onac096 mutants led to a 15% increase in panicle number without affecting grain weight or fertility. ONAC096 mediates abscisic acid (ABA)-induced leaf senescence by upregulating the ABA signaling genes ABA INSENSITIVE5 and ENHANCED EM LEVEL. The onac096 mutants showed a 16% increase in grain yield, highlighting the potential for using this gene to increase grain production.


2017 ◽  
Vol 68 (11) ◽  
pp. 985 ◽  
Author(s):  
Muhammad Farooq ◽  
Faisal Nadeem ◽  
Nirmali Gogoi ◽  
Aman Ullah ◽  
Salem S. Alghamdi ◽  
...  

Thermal stress during reproductive development and grain-filling phases is a serious threat to the quality and productivity of grain legumes. The optimum temperature range for grain legume crops is 10−36°C, above which severe losses in grain yield can occur. Various climatic models have simulated that the temperature near the earth’s surface will increase (by up to 4°C) by the end of this century, which will intensify the chances of heat stress in crop plants. The magnitude of damage or injury posed by a high-temperature stress mainly depends on the defence response of the crop and the specific growth stage of the crop at the time of exposure to the high temperature. Heat stress affects grain development in grain legumes because it disintegrates the tapetum layer, which reduces nutrient supply to microspores leading to premature anther dehiscence; hampers the synthesis and distribution of carbohydrates to grain, curtailing the grain-filling duration leading to low grain weight; induces poor pod development and fractured embryos; all of which ultimately reduce grain yield. The most prominent effects of heat stress include a substantial reduction in net photosynthetic rate, disintegration of photosynthetic apparatus and increased leaf senescence. To curb the catastrophic effect of heat stress, it is important to improve heat tolerance in grain legumes through improved breeding and genetic engineering tools and crop management strategies. In this review, we discuss the impact of heat stress on leaf senescence, photosynthetic machinery, assimilate translocation, water relations, grain quality and development processes. Furthermore, innovative breeding, genetic, molecular and management strategies are discussed to improve the tolerance against heat stress in grain legumes.


2014 ◽  
Vol 47 (1) ◽  
pp. 107-114
Author(s):  
Z. Fooladivanda ◽  
M. Hassanzadehdelouei ◽  
N. Zarifinia

ABSTRACT Water stress is known as the major threat to reduced growth and yield of plants in arid and semi-arid regions. Potassium is one of the indicators of plant responses to water stress. To evaluate the impact of water stress and levels of potassium on yield and yield components of two varieties of mung bean (Vigna radiata) (promising lines VC6172 and Indian), an experiment in the form of split factorial, based on randomized complete block design with three replicates was conducted in 2011, at the research farm of Safi-Abad Dezfool, Iran (latitude 32°16’ N, longitude 48°26’ E and altitude 82.9 m above sea level) .Water stress in three levels: irrigation at 120 (no stress), 180 (moderate stress) and 240 (severe stress) mm evaporation from pan, were allocated to the main plots and potassium fertilizer at three levels (0, 90, 180 kg /ha) and two varieties of mung bean (promising line VC6172 and Indian) were allotted to the sub-plots. Results showed that water stress and potassium fertilizer significantly affect all traits. The highest grain yield (2093 kg /ha) was obtained from no stress treatment in the case of 180 kg /ha potassium. Total dry matter, number of pods and grain yield, were significantly different between the two varieties. The interaction between fertilizer and variety, on dry matter and grain yield and the interaction between irrigation and variety, on dry matter were significant. We conclude that use of potassium fertilizer can reduce the adverse effects of water stress.


Author(s):  
Juan Francisco Aguirre-Medina ◽  
Juan Francisco Aguirre- Cadena ◽  
Jorge Cadena-Iñiguez ◽  
María de Lourdes Arevalo-Galarza ◽  
Raymundo Rosas-Quijano ◽  
...  

The impact of Rhizophagus intraradices (RI) interaction with phosphorus fertilization on the yield of Phaseolus vulgaris L. var. Negro Tacaná, and the N and P content in plant tissue and grain were determined. The experiment consisted of six treatments:1) Control, 2) RI, 3) 40 kg.ha-1 of P2O5, 4) RI + 40 kg.ha-1 of P2O5, 5) RI + 26 kg.ha-1 of P2O5, and 6) RI + 13 kg.ha-1 of P2O5, using a randomized block design with four replicates. Results probed that inoculation of plants with RI promoted a better health, growth and grain yield. In particular, grain yield inoculated with RI presented similar values as obtained with inorganic fertilization of 40 kg.ha-1 of P2O5, indicating that inorganic fertilization can be fully substituted by RI. The use of this technology provides an efficient use of soil nutrients, which is translated into a lower investment for producers.


2013 ◽  
Vol 46 (3) ◽  
pp. 29-38
Author(s):  
S.H. Mosavifeyzabadi ◽  
F. Vazin ◽  
M. Hassanzadehdelouei

Abstract In hot and arid regions, drought stress is considered as one of the main reasons for yield reduction. To study the effect of drought stress, nitrogen and zinc spray on the yield and yield components of corn, an experiment was carried out during the crop seasons of 2010 and 2011 on Emam Khomeyni research Farm in Mahvellat as a split factorial within randomized complete block design with three replicates. The main plots with irrigation factor and three levels were considered: full irrigation, stopping irrigation at anthesis step and stopping irrigation at the seed filling stage. Subplots were considered with and without nitrogen and zinc spray. The drought stress reduced the grain yield in anthesis stage more than other stages. Drought stress effects significantly on stem and ear diameter, ear length, chlorophyll value, leaf area index, leaf relative water content, stem, ear and leaves dry weight, number grain in ear and row, number row in ear, unfilled seed percentage and thousand grains weight. Nitrogen increased the seed yield and yield component except thousand grains weight and the number of row in ear. Using Zn, as compared with control treatment, causes the increase of grain yield, thousand grains weight and number grain in ear 16.5, 9 and 5.5%, respectively. The results obtained from the present research showed that anthesis stage was most sensitive stage to drought stress. Also nitrogen and Zn could somewhat reduce the impact drought stress on corn.


Author(s):  
C. P. McCabe ◽  
J. I. Burke

Abstract Factorial experiments were carried out on spring- and winter-sown oat crops in Ireland in 2016–2019 to identify plant responses in yield formation and grain filling procedures. Two cultivars (Husky and Keely), three seed rates (250, 350 and 450 seeds/m2), six applied nitrogen (N) rates (40, 70, 100, 130, 160 and 190 kg N/ha) with a plant growth regulator (PGR) were examined in spring and winter sowings, using the same cultivars at five rates of applied N (80, 110, 140, 170 and 200 kg N/ha). The applied N rate and seed rate significantly (P < 0.05) modified the yield components determining grains/m2 in spring- and winter-sown crops with increases in panicle number of key importance. Increases were also observed in the proportion of primary grain by weight (0.9–1.6%) and number (0.7–1.4%) ratios in spring-sown crops in response to applied N rate, with winter-sown crops exhibiting a more consistent pattern of grain fill. Seed rate and PGR application had minor effects on yield components and panicle conformation. Grain fill procedures played an important role in the maximization of grain yield under seasonal conditions. Significant positive correlations were observed between the number of aborted grain sites and yield under drought conditions (0.22), with negative associations observed in near-optimal conditions (−0.22 to −0.41). Agronomic effects on grain site abortion were minimal in comparison with seasonal effects. In seasons characterized by cool, consistent conditions, grain yield was maximized by the utilization of all available grain sites. Where assimilate shortages were encountered during grain fill the abortion of grains sites was positively associated with grain yield.


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