Plant Damage and Yield Response to the Russian Wheat Aphid (Homoptera: Aphididae) on Susceptible and Resistant Winter Wheats in Colorado

Population increase of the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), and its effect on early plant growth and damage were studied under laboratory conditions on two winter wheat genotypes, susceptible ‘Stephens’ and resistant 10085-5. Three early plant growth stages (one-, two-, and three-leaf stage), and three insect densities (0, 5 and 20 aphids per plant) were compared. Insect counts, plant damage assessments, plant height, leaf number and dry weight measurements were made. Diuraphis noxia population increase was greater on ‘Stephens’ than on 10085-5, but this was highly influenced by plant growth stage at time of infestation and initial aphid density. Host quality of ‘Stephens’ decreased rapidly when plants were infested at the 1 -left stage, especially with the high initial density (20 aphids), resulting in low aphid population increase. For all plant developmental stages and genotypes, D. noxia per capita population increase was lower at initial densities of 20 compared to 5 aphids per plant, probably due to a density-dependent reduction in reproductive rate associated with a reduction in host-plant quality and/or crowding. Diuraphis noxia significantly affected plant growth, but the magnitude of the effect was influenced by genotype. In general, susceptible ‘Stephens’ had significantly more damage and a greater reduction in growth than resistant 10085-5.

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Occurrence of, and yield response to, Russian wheat aphid, Diuraphis noxia (Hemiptera: Aphididae) in irrigated wheat in Ethiopia

International Journal of Tropical Insect Science ◽

10.1017/s1742758414000587 ◽

2015 ◽

Vol 35 (01) ◽

pp. 3-10 ◽

Cited By ~ 1

Author(s):

Tebkew Damte

Keyword(s):

Russian Wheat Aphid ◽

Diuraphis Noxia ◽

Yield Response ◽

Irrigated Wheat

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Developing crop production functions of wheat using experimentally determined yield response factors

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v32i2.300 ◽

2007 ◽

Vol 32 (2) ◽

Author(s):

M.S. Islam ◽

M.A Hossain ◽

M. Abdullah ◽

ME Hossain

Keyword(s):

Crop Production ◽

Production Functions ◽

Yield Response ◽

Response Factors

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Responses of soybean genotypes to intercropping with maize in the Southern Guinea Savanna, Nigeria

Acta Agronomica Hungarica ◽

10.1556/aagr.52.2004.2.6 ◽

2004 ◽

Vol 52 (2) ◽

pp. 157-163

Author(s):

C. U. Egbo ◽

M. A. Adagba ◽

D. K. Adedzwa

Keyword(s):

Seed Yield ◽

Block Design ◽

Field Trials ◽

Yield Response ◽

Ecological Zone ◽

Land Equivalent Ratio ◽

Guinea Savanna ◽

Days To Maturity ◽

Soybean Genotypes ◽

Location Interaction

Field trials were conducted in the wet seasons of 1997 and 1998 at Makurdi, Otukpo and Yandev in the Southern Guinea Savanna ecological zone of Nigeria to study the responses of ten soybean genotypes to intercropping. The experiment was laid out in a randomised complete block design. The genotypes TGX 1807-19F, NCRI-Soy2, Cameroon Late and TGX 1485-1D had the highest grain yield. All the Land Equivalent Ratio (LER) values were higher than unity, indicating that there is great advantage in intercropping maize with soybean. The yield of soybean was positively correlated with the days to 50% flowering, days to maturity, plant height, pods/plant and leaf area, indicating that an improvement in any of these traits will be reflected in an increase in seed yield. There was a significant genotype × yield × location interaction for all traits. This suggests that none of these factors acted independently. Similarly, the genotype × location interaction was more important than the genotype × year interaction for seed yield, indicating that the yield response of the ten soybean genotypes varied across locations rather than across years. Therefore, using more testing sites for evaluation may be more important than the number of years.

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