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Andres A. Estrada-Luna, Fred T. Davies Jr., and Jonathan N. Egilla

Micropropagated chile ancho pepper (Capsicum annuum L. cv. San Luis) plants were transferred to ex vitro conditions to study plantlet performance and selected physiological changes that occur during acclimatization and post-acclimatization. The physiology of the plantlets was characterized by measuring leaf gas exchange and water status. Plant growth was determined by assessing plant height, leaf number, total leaf area, relative growth rate (RGR), and leaf, root, and stem dry mass. Measurements were taken at 0, 1, 2, 3, 6, 12, and 24 days after transplanting. After initial transplanting ex vitro to liner pots with soilless media, plantlet wilting was observed that correlated with reduced leaf relative water content (RWC). Water stress was partially alleviated by a reduction in stomatal conductance (gs), confirming that the in vitro formed stomata were functional and able to regulate transpiration (E) to minimize desiccation losses. Because of this stomatal control, plantlets had minimal transplant shock, recovered, and survived. Prior to transplanting, micropropagated plantlets showed heterotrophic/mixotrophic characteristics as indicated by low photosynthesis [(A) 4.74 μmol·m2·s-1]. During acclimatization, RWC, gs, E, and A were significantly lower 2 days after transplanting. However, within 6 days after transplanting, plantlets recovered and became autotrophic, attaining high A (16.3 μmol·m-2·s-1), gs, and E. The stabilization and improvement of plantlet water status and gas exchange during acclimatization and post-acclimatization closely correlated with dramatic increases in plantlet growth.

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Paul W. Bosland

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Paul W. Bosland, Jaime Iglesias, and Max M. Gonzalez

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J.A. Thies, J.D. Mueller, and R.L. Fery

A 3-year field study was conducted at Blackville, S.C., to evaluate the potential of using resistant pepper (Capsicum annuum L.) cultivars as a rotation crop for managing the southern root-knot nematode [Meloidogyne incognita (Kofoid and White) Chitwood]. The experiment was a split-plot with main plots arranged in a randomized complete-block design. In 1993, the entire experimental site was infested with M. incognita by inoculating a planting of susceptible PA-136 cayenne pepper with eggs of M. incognita race 3. In 1994, the main plots were planted to either highly resistant `Carolina Cayenne' or its susceptible sibling line PA-136. In 1995, `Carolina Cayenne' and the susceptible bell cultivars California Wonder and Keystone Resistant Giant were grown as subplots in each of the original main plots. `Carolina Cayenne' plants were unaffected by the previous crop. Previous cropping history, however, had a significant impact on the performance of the bell cultivars; the mean galling response was less (P < 0.01) and the yield was 2.8 times greater (P < 0.01) in the main plots previously cropped with `Carolina Cayenne' than in those previously cropped with PA-136. These results suggest that resistant pepper cultivars have considerable merit as a rotation crop for managing M. incognita infestations in soils used for growing high-value vegetables.

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E. Zamora, P.W. Bosland, and S. Thomas

The resistance of `Carolina Cayenne' (Capsicum annuum L.) to root-knot nematode Meloidogyne incognita (Kofoid & White) Chitwood races 1, 2, 3, and 4 was measured. Egg counts from roots were used to determine the plant's resistance to M. incognita. Few eggs were observed on `Carolina Cayenne' roots, whereas all races of M. incognita produced numerous eggs on the susceptible `NuMex R Naky' roots. The results indicated `Carolina Cayenne' is a source of resistance to all known races of M. incognita.

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Paul W. Bosland, Yayeh Zewdie, and Stephen H. Thomas

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Paul W. Bosland and Eric J. Votava

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Eric J. Votava and Paul W. Bosland