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Linkage of loci controlling nodulation and testa variegation was examined for cultivated peanut. The main objective of this study was to determine whether the gene controlling testa variegation was linked to a gene or genes controlling nodulation.

Maize ( Zea mays L.) is a valuable commodity throughout the world, but corn rootworms (Chrysomelidae: Diabrotica spp.) often cause economic damage and increase production costs. Current rootworm management strategies have limitations, and in order to create viable management alternatives, researchers have been developing novel maize lines using Eastern gamagrass ( Tripsacum dactyloides L.) germplasm, a wild relative of maize that is resistant to rootworms. Ten maize Tripsacum-introgressed inbred lines derived from recurrent selection of crosses with gamagrass and teosinte ( Zea diploperennis Iltis) recombinants and two public inbred lines were assessed for susceptibility to western corn rootworm ( Diabrotica virgifera virgifera LeConte) and yield in a two-year field study. Two experimental maize inbred lines, SDG11 and SDG20, had mean root damage ratings that were significantly lower than the susceptible public line B73. Two other experimental maize inbred lines, SDG12 and SDG6, appeared tolerant to rootworm damage because they exhibited yield increases after rootworm infestation in both years. In the majority of cases, mean yield per plant of experimental maize lines used in yield analyses was equal to or exceeded that of the public inbred lines B73 and W64A. Our study indicates that there is potential to use Tripsacum-introgressed maize germplasm in breeding programs to enhance plant resistance and/or tolerance to corn rootworms, although further research on insect resistance and agronomic potential of this germplasm needs to be conducted in F1 hybrids. [ABSTRACT FROM AUTHOR]

Examines the inheritance of nonnodulation in peanut using the nonnodulating peanut line, M4-2, selected from the original nonnodulating germplasm described by D. W. Gorbet and J. C. Burton in 1979. Details on nonnodulation mutants derived either spontaneously or through mutagenesis; Comparison of foliage color with nodule characteristics; Description of three nodule characteristics observed.

With limited access to P fertilizers, soybean (Glycine max (L.) Merr.) varieties cultivated in the moist savanna zone of West Africa should use P as efficiently as possible. Field trials were conducted on the effect of P application on grain yield per unit P accumulated (physiological efficiency or PPE), amount of P accumulated in plant biomass per unit P applied in fertilizer (recovery efficiency or PRE), and the amount of grain produced per unit of applied P (yield efficiency or PYE) in soybean. There was greater proportional root proliferation at lower P rates, and at sites where soil test P was low. Physiological efficiency was higher under these conditions. Although a greater proportion of total dry weight was accumulated in the roots of the early and medium (27-28%) compared with the late varieties (22-23%), root dry weight and PPE in the latter were higher. At maturity, PPE was significantly reduced from 245 kg kg-1 with no P applied to an average of 173 kg-1 (or by about 29%) with P application. Phosphorus yield efficiency was higher at sites (Kasuwan Magani and Gidan Waya) and in the late varieties where response to P was highest. PYE with 60 kg ha-1 P applied rate was almost half the value observed with 30 kg P ha-1. [ABSTRACT FROM AUTHOR]