Author
Robinson, Arin | |
Cook, Charles | |
Percival Jr, Albert | |
Bridges, Alan |
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only Publication Acceptance Date: 1/16/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Four growth chamber experiments were conducted to compare reproduction by Meloidogyne incognita race 3 (root-knot nematode) and Rotylenchulus reniformis (reniform nematode) on 59 cotton varieties. The major cottons in each of the major production regions in each decade from 1950-1995 were represented. Population increases by the two nematode species were directly compared on each variety in each experiment. Auburn 623 was included as a resistant control for M. incognita; Deltapine 16 was included as a susceptible control for both nematodes. Overall, it was found that all varieties supported high levels of reproduction by R. reniformis; also, R. reniformis delayed fruiting by most varieties in all decades. Moderate levels of resistance to M. incognita was measured in several earlier varieties, including Coker 100, Coker 100W, Acala SJ-1, Tamcot SP-21, Stoneville 825. The Pima (G. barbadense) cottons S-5, S-6, and S-7 (planted 1970-1996) supported exceptionally high levels of reproduction by M. incognita, with population multiplication factors above 200; Pima S-2, however, which was planted in the early 1960's, was as resistant as most resistant varieties of G. hirsutum. The highest and most consistent levels of resistance to M. incognita were measured in relatively new varieties including CPCSD, Nem-X, Stoneville LA887, Hartz 1560, Paymaster HS-26, Suregrow 501, and Deltapine 5415. Results indicate that increased levels of resistance to M. incognita but not R. reniformis in recently released cultivars may favor population buildup by the latter in regions where they both occur. |