The influence of green kyllinga and white kyllinga on common bermudagrass growth was compared by planting one to three green or white kyllinga rhizomes with two bermudagrass stolons. White kyllinga reduced bermudagrass shoot fresh weight to 56% of the control, but green kyllinga did not reduce bermudagrass shoot fresh weight significantly. Increased planting densities of both kyllinga species linearly increased kyllinga shoot fresh weight and decreased bermudagrass shoot fresh weight similarly. White kyllinga produced more leaf fresh weight, leaf area, and roots and rhizomes than green kyllinga, which produced more shoots and inflorescences.

Field studies were conducted in 1996 and 1997 to determine the response of Cyperus rotundus and Cyperus esculentus, Kyllinga brevifolia, and Kyllinga gracillima to mowing regimens common to recreational turfgrass. Treatments were selected to simulate Cynodon dactylon golf course management and included mowing at 1.3 and 3.8 cm with mowing frequencies of three times per week and once a week, respectively. A nonmowed check was included for comparison. Reductions in C. rotundus shoot number were observed beginning 6 wk after initial treatment (WAIT) in 1996 and 9 WAIT in 1997 for the 1.3-cm mowing regime. The 3.8-cm mowing regime did not reduce C. rotundus shoot number until the final evaluation of each year. Reductions in C. rotundus rhizome length, tuber number, and tuber size were observed for both mowing regimes in both years. Cyperus esculentus shoot number was reduced by the 1.3-cm treatment at each evaluation date in 1996 and 1997. Cyperus esculentus shoot number reductions in the 3.8-cm regime were first observed 4 and 6 WAIT in the 2 yr and continued until termination. The 1.3-cm regime reduced C. esculentus spread beginning 6 WAIT in 1996 and 3 WAIT in 1997. Cyperus esculentus spread was also reduced by the 3.8-cm treatment, but reduction began at later evaluations (8 and 9 WAIT). Tuber production by C. esculentus was completely inhibited by the two mowing regimes in both years. The only treatment effect observed in K. brevifolia and K. gracillima in 1996 was a reduction in internode length of K. gracillima by the 1.3-cm mowing regime. In 1997, the 1.3-cm regime reduced K. brevifolia shoot number at 15 and 18 WAIT and plant spread beginning 6 WAIT and continuing until termination. The 3.8-cm treatment did not affect K. brevifolia shoot number and reductions in spread were only observed at the final evaluation. Kyllinga gracillima shoot number and plant spread were reduced by the 1.3-cm mowing regime at each 1997 evaluation. Reductions in K. gracillima shoot number occurred at the final evaluation, and reductions in spread began 12 WAIT when subjected to the 3.8-cm treatment. Both mowing regimes reduced K. brevifolia and K. gracillima internode length. Kyllinga brevifolia total rhizome length and total node number were reduced by the 1.3-cm regime only. Kyllinga gracillima rhizome length, internode length, and node number were reduced by both regimes in 1997.

Surveys were completed in Eritrea, Ethiopia, Kenya, Madagascar, Mozambique, Tanzania, Uganda and Zanzibar to assess the lepidopteran stem borer species diversity on wild host plants. A total of 24,674 larvae belonging to 135 species were collected from 75 species of wild host plants belonging to the Poaceae, Cyperaceae and Typhaceae. Amongst them were 44 noctuid species belonging to at least nine genera, 33 crambids, 15 pyralids, 16 Pyraloidea species not yet identified, 25 tortricids and three cossids. The noctuid larvae represented 73.6% of the total number of larvae collected, with 66.3, 3.5 and 3.8% found on Poaceae, Cyperaceae and Typhaceae, respectively. The Crambidae, Pyralidae, Tortricidae and Cossidae represented 19.8, 1.9, 2.5 and 0.1% of the total larvae collected, respectively, with 90.4% of the Crambidae and Pyralidae collected from Poaceae, and 99.7% of the Tortricidae collected from Cyperaceae. The lepidopteran stem borer species diversity in the wild host plants was far more diverse than previously reported.

Using examples from surveys to collect natural enemies of the indigenous African sugarcane borer Eldana saccharina Walker throughout Africa, insight is given into what factors should be investigated should biological control of other indigenous African stemborers be considered. Indigenous host plant range, parts of indigenous and crop hosts attacked, types of natural enemies found in these different niches and natural enemy attack strategies are all important factors to consider when planning redistribution of indigenous natural enemies from one part of Africa to another. This knowledge is important when choosing the correct natural enemy for mass rearing and release into the affected crop, and can be used to manage the crop habitat, using the indigenous tritrophic systems identified, to increase crop diversity and thus effectiveness of indigenous natural enemies.

Previous work in the Colorado alpine ecosystem has shown that amino acids are a potentially important N source for the sedge, Kobresia myosuroides. This plant is the only known sedge to harbour associations with ectomycorrhizal fungi. The aim of the present work was to test the hypothesis that these ectomycorrhizas transfer N from amino acids in the soil solution to the host plant, and thereby have an important role in the N nutrition of this species. We used a two-chamber system (rhizoboxes) in which K. myosuroides plants were separated from a soil chamber by nylon mesh that allowed fungal hyphae, but not plant roots, to cross it. Injections of [15N, 2-13C]glycine were made into the soil chamber. The hyphal crossings on half of the rhizoboxes were regularly disrupted to control for leakage of label across the barrier. Plants in the intact rhizoboxes showed significantly higher 15N enrichment than those in controls, and mycorrhizal root tips were significantly more enriched than bulk roots. The mycorrhizas transferred an average of 1.3% of the added 15N label to plants, a figure comparable to those obtained in previous studies in which plant roots were directly exposed to label. We conclude that fungal associations have an important role in the N nutrition of K. myosuroides by transferring N from amino acids to their hosts.

Bulbostylis somaliensis Lye (Cyperaceae) is described from Somalia. It is closely related to B. hispidula (Vahl) R. Haines, but differs in its smaller achenes as well as in the shape and surface structure of the achenes. The major diagnostic characters are the non-triangular achene and the outermost cells to the pericarp, which have several papillae in each cell. Three subspecies are distinguished, viz. subsp. somaliensis, subsp. confusa Lye and subsp. microcarpa (Chiov.) Lye.