Differences in growth and yield responses to Aphis gossypii Glover between different okra varieties

Abstract

The reactions of five commercial varieties of okra, <i>Abelmoschus esculentus</i>, to <i>A. gossypii</i> were evaluated under semiarid field conditions. Each experimental plant of varieties Clemson spineless, Clemson spineless 80, Lee, Perkins dwarf, and Local was infested 60 days after emergence by three late-nymphal instars of the aphid. The results showed that aphid populations increased constantly on the varieties, except for days 42 and 49 after infestation, attaining a peak at about the end of the growing season. Differences in aphid densities were recorded between varieties. The aphids were most numerous on var. Local, while lowest in number on var. Lee. Infestation by aphids on okra varieties reduced yield by 57% on var. Perkins dwarf, 56% on var. Lee, 24% on var. Clemson spineless, 21% on var. Clemson spineless 80, and 5% on var. Local. Reduction in the number of pods produced per plant followed the same pattern as observed for total yield. Aphids had not altered significantly the vegetative plant growth at day 37 following infestation. At day 66, a substantial decrease in shoot fresh and dry weights and also leaf area was evident on var. Perkins dwarf while on var. Clemson spineless only the leaf area was significantly reduced. Moreover, aphid-free controls varied widely in their growth and productivity at the end of growing season. Varieties Clemson spineless and Clemson spineless 80 produced the highest total yield and pod numbers, var. Local the lowest. The varieties Perkins dwarf and Clemson spineless produced significantly higher shoot fresh and dry weight, as well as leaf area, than vars. Lee and Local.

Ant attendance of the cotton aphid is beneficial for okra plants: deciphering multitrophic interactions

“…Okra ( Abelmoschus esculentus Moench) is an economically important vegetable crop grown worldwide and is widely consumed in West Africa. In Cameroon, the cotton aphid ( Aphis gossypii Glover) is one of the dominant pests of okra (Leite et al ., ; Shannag et al ., ) and has evolved resistance to pesticides, particularly on cotton plant (Brévault et al ., ). An annual survey conducted by the International Institute of Tropical Agriculture (IITA) in Cameroon (2011) found that okra farmers grow many different okra varieties, various ant species attend aphids on okra, and ants of genus Pheidole were the dominant ant species found attending aphids on okra plants in 75% of the surveyed okra farms (IITA annual survey report, 2011).…”

Chili pepper genotypes assay approach for resistance to Aphis gossypii (Hemiptera: Aphididae)

“…Cotton aphids (CA) were reported to reduce chili pepper production up to 65% if not controlled chemically (Fereres et al, 1996). In addition, CA as also reported to serve as vectors for 50 types of viruses in the Solanaceae family (Shannag et al, 2007;da-Costa et al, 2011). Farmers have intensively used pesticides to control these pests.…”

Influence of Okra (Abelmoschus spp.) Accessions on Colonization by Aphis gossypii (Hemiptera: Aphididae) and Their Effects on Aphid Biological Parameters

“…Heavily infested okra plants show distorted and stunted leaves and also reduced fruit set (Wanja et al 2001). Yield losses can be up to 57% (Shannag et al 2007) when aphid infestation is higher (> 1,000 aphids per plant) (Mohamed-Ahmed 2000; Nderitu et al 2008) or 100% (Doumbia & Seif 2008) if the attack is at the seedling stage. The severity of aphid infestation has led to widespread use of chemical pesticides for control.…”