scholarly journals Effects of carbonaceous nanomaterials on soil-grown soybeans under combined heat and insect stresses

2019 ◽  
Vol 16 (6) ◽  
pp. 482 ◽  
Author(s):  
Ying Wang ◽  
Zoe S. Welch ◽  
Aaron R. Ramirez ◽  
Dermont C. Bouchard ◽  
Joshua P. Schimel ◽  
...  

Environmental contextEngineered nanomaterials have the potential to accumulate in agricultural soils where they may influence crop plants. There is, however, little information about how adverse environmental conditions may interact with nanomaterial effects on plants and plant-microbe interactions. We report the comparative effects of three carbonaceous nanomaterials on the growth, nodulation and foliar health of a globally important legume crop, soybean, under the combined stresses of high temperature and insect pests. AbstractBecause carbonaceous nanomaterials (CNMs) are expected to enter soils, the exposure implications to crop plants and plant–microbe interactions should be understood. Most investigations have been under ideal growth conditions, yet crops commonly experience abiotic and biotic stresses. Little is known how co-exposure to these environmental stresses and CNMs would cause combined effects on plants. We investigated the effects of 1000mgkg−1 multiwalled carbon nanotubes (CNTs), graphene nanoplatelets (GNPs) and industrial carbon black (CB) on soybeans grown to the bean production stage in soil. Following seed sowing, plants became stressed by heat and infested with an insect (thrips). Consequently, all plants had similarly stunted growth, leaf damage, reduced final biomasses and fewer root nodules compared with healthy control soybeans previously grown without heat and thrips stresses. Thus, CNMs did not significantly influence the growth and yield of stressed soybeans, and the previously reported nodulation inhibition by CNMs was not specifically observed here. However, CNMs did significantly alter two leaf health indicators: the leaf chlorophyll a/b ratio, which was higher in the GNP treatment than in either the control (by 15%) or CB treatment (by 14%), and leaf lipid peroxidation, which was elevated in the CNT treatment compared with either the control (by 47%) or GNP treatment (by 66%). Overall, these results show that, while severe environmental stresses may impair plant production, CNMs (including CNTs and GNPs) in soil could additionally affect foliar health of an agriculturally important legume.

2021 ◽  
pp. 60-66
Author(s):  
Mohammad Hussain Faiq ◽  
Mohammad Safar Noori

Stress is an external factor that exerts a detrimental effect on overall growth of a plant. Environmental stress is a serious threat for sustainable crop production, and a main cause for food insecurity. Agricultural crops are exposed to a variety of environmental stresses including extreme temperatures and unfavorable chemical and physical soil conditions. Drought stress adversely affects some physiological and biochemical processes in plants, including transpiration, translocation of assimilates and nutrient metabolism. Salinity stress is responsible for loss of turgor, reduction in growth, wilting, leaf abscission, reduction in photosynthesis and respiration, loss of cellular integrity, tissue necrosis and finally death of the plant. Drought and salinity stress negatively affects the growth and yield of crop plants more than all the other stresses combined. Cold stress affects cellular components and metabolism, and temperature extremes impose stresses of variable severity that depend on the intensity and duration of the stress. Many approaches are being used to alleviate the deleterious effects of environmental stresses on successful agricultural crops production in recent years.  Application of phytohormones (Abscisic acid, Indole-3-Aacetic Acid, Jasmonic acid and salicylic acid) is one of the curative measures to mitigate the environmental stresses in agricultural crops. Phytohormones play a significant role in enhancing stress tolerance and therefore, reduce the yield loss in crop plants. In this paper, the impacts of environmental stresses on productivity and physiological activities of crop plants, and the effective role of some phytohormones in alleviation of environmental stresses have been reviewed.


Akta Agrosia ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 7-12
Author(s):  
Roy S.O. Sumbayak ◽  
Merakati Handajaningsih ◽  
Hartal Hartal ◽  
Marwanto Marwanto

Compost has been commonly used as the primary organic matter in organic plant production, especially in vegetable production.  Different sources of compost materials give different medium structures and chemical characteristics. The objectives of this research were: 1) to evaluate the response of growth and yield of chili pepper to a rate of compost and source of animal waste which were used as compost; 2) to determine the optimum rate of fertilizer for the highest growth and yield of chili pepper. The research was carried out from November 2015 until March 2016. Compost material treatments consisted of cow dung, empty palm oil bunches, and mixed of vegetable residue and weeds. The compost rate treatments consisted of 0 ton ha-1, 10 ton ha-1, 20 ton ha-1, and 30 ton ha-1. No interaction between the two treatments was found to influence plant growth and yield variables.   The type of compost materials affected plant height of 5, 6, and7 weeks after transplanting.  Cow dung as a source of compost showed the best effect in increasing chili plant height.  Plant height, the number of plant dichotomous, and plant canopy responded linearly  to the increase of the compost rate. The usage of compost at 20 ton ha-1 and 30 ha-1 resulted in higher fruit length, the number of fruit, and fruit weight per plant.   Keywords: chili pepper, compost, organic, growth, yield 


Author(s):  
T. C. Hsiao ◽  
E. Fereres ◽  
E. Acevedo ◽  
D. W. Henderson

Author(s):  
Meenakumari Muthuramalingam ◽  
Yong-Fang Li ◽  
Ramamurthy Mahalingam

2005 ◽  
Vol 85 (1) ◽  
pp. 15-21 ◽  
Author(s):  
D. D. Douds Jr. ◽  
G. Nagahashi ◽  
P. E. Pfeffer ◽  
W. M. Kayser ◽  
C. Reider

Arbuscular mycorrhizal (AM) fungi colonize the roots of the majority of crop plants, forming a symbiosis that potentially enhances nutrient uptake, pest resistance, water relations, and soil aggregation. Inoculation with effective isolates of AM fungi is one way of ensuring the potential benefits of the symbiosis for plant production. Although inocula are available commercially, on-farm production of AM fungus inoculum would save farmers the associated processing and shipping costs. In addition, farmers could produce locally adapted isolates and generate a taxonomically diverse inoculum. On-farm inoculum production methods entail increasing inoculated isolates or indigenous AM fungi in fumigated or unfumigated field soil, respectively, or transplanting pre-colonized host plants into compost-based substrates. Subsequent delivery of the inoculum with seed to the planting hole in the field presents technological barriers that make these methods more viable in labor-intensive small farms. However, a readily available method for utilization of these inocula is mixing them into potting media for growth of vegetable seedlings for transplant to the field. Direct application of these inocula to the field and transplant of seedlings precolonized by these inocula have resulted in enhanced crop growth and yield. Key words: AM fungi, sustainable agriculture, biofertilizer


2010 ◽  
Vol 37 (1) ◽  
pp. 74 ◽  
Author(s):  
Michael Frei ◽  
Yunxia Wang ◽  
Abdelbagi M. Ismail ◽  
Matthias Wissuwa

Zinc deficiency reduces rice growth and yield, and this is, in part, due to leaf damage caused by reactive oxygen species (ROS). The aim of this study was to identify biochemical mechanisms conferring tolerance to Zn deficiency-induced oxidative stress. A field experiment and three nutrient solution experiments were conducted with the intolerant genotype IR74 and recombinant inbred lines (RILs) derived from a cross between IR74 and the tolerant landrace Jalmagna. After 2 weeks of growth in low Zn soil, stress symptoms developed in leaves of IR74, but not in the tolerant RIL46. Activity of antioxidant enzymes showed clear treatment effects, but did not explain tolerance of RIL46. On the contrary, the intolerant IR74 showed higher activities of superoxide dismutase (SOD), guaiacol peroxidase (POX), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) under Zn deficiency. This contrasted with a constitutively higher level of total and reduced ascorbic acid (AsA) in RIL46. Three further nutrient solution experiments focussed on enzymes and reducing substrates of the ascorbate–glutathione cycle. The first experiment included the highly sensitive RIL76 in addition to the genotypes used in the field trial, to test whether the patterns of antioxidant response observed in the field were specific to the genotypes used. This genotype had similarly low AsA level as IR74, but did not respond to Zn deficiency with an increase in enzyme activity, leading to even more pronounced leaf symptoms. In a second experiment, co-segregation of AsA concentration and Zn deficiency tolerance was confirmed in five genotypes from the IR74/Jalmagna quantitative trait loci (QTL) mapping population. A third experiment was conducted to determine whether the observed patterns of antioxidant response were specific to Zn deficiency or would also apply to oxidative stress caused by iron deficiency. Although high AsA level apparently conferred tolerance under both types of stress, the enzymatic response to iron deficiency differed from that to Zn deficiency. In particular, APX activity showed a decrease instead of an increase under low iron stress. In conclusion, we suggest that a high AsA level is a promising target for developing rice genotypes with tolerance to oxidative stress.


2014 ◽  
Vol 14 ◽  
pp. 51-58
Author(s):  
M.M. Degri ◽  
I.B. Richard

Field experiments were conducted at faculty of Agriculture teaching and research farm, university of Maiduguri in 2010 and 2011 rainy seasons. The aim was to investigate the impact of intercropping sorghum with okra on the incidence of flea beetle of okra (Podagrica spp) in the semi-Arid zone of Nigeria. The results showed that sole crop okra suffered flea beetle attack which affected its growth, fruit formation, fruit weights and fruit yield. Intercropping okra with sorghum significantly reduced the flea beetle populations, leaf damage caused by Podagrica spp (Coleoptera: Chrysomelidae). While increasing number of leaves for photosynthetic activities, plant height, fruit formation, fresh fruit weight and total fruit yield. The study concluded that okra intercropping at 1:1, 1:2 and 2:2 are the most efficient and productive intercrop systems in flea beetle management. Okra intercropping with cereal sorghum was found to be good for sustainable agriculture and organic farming in Nigeria due to its numerous advantages, particularly with respect to insect pests’ control.


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