Browsing by Author "Mwatawala, M.W."

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Deriving appropriate pest management technologies for smallholder tomato (Solanum lycopersicum Mill.) growers: A case study of Morogoro, Tanzania
(Journal of Animal & Plant Sciences, 2010) Maerere, A.P.; Sibuga, K.P.; Bulali, J.E.M.; Mwatawala, M.W.; Kovach, J.; Kyamanywa, S.; Mtui, H.D.; Erbaugh, M
The current standard farmer practice for insect pests and disease control in tomatoes is routine weekly pesticide sprays which are not always required. Field experiments were conducted at Morogoro, Tanzania to evaluate the effect of seven management practices (sub plots) on pest incidence and yields during May-September 2007 (normal production season) and October 2007 - February 2008 (off-season) using two determinate varieties CALJ and Tanya (main plots) in a RCBD with five replications. Practices involving intercropping with Vigna unguiculata or Cleome gynandra, application of fertilizer or mulch were severely infested by insects particularly thrips (Frankinlla occidentalis) which averaged 30 insects/plant at 64 days after transplanting. The standard and integrated pest management (IPM) practices led to similar low levels of insect pest and disease control though in the IPM only 3 pesticide sprays were applied compared to 10 for the standard practice. In the normal season, disease incidences of early blight (Phytophthrora infestans), late blight (Altenaria solani), leaf spot (Septoria lycopersici) and leaf curl were low (<10%) except for fertilizer and mulch treatment where incidences were close to 50%. The greatest fruit damage (>50%) was ascribed to Helicoverpa armigera. Purple nutsedge (Cyperus rotundus), the most dominant weed, was initially controlled by pre-transplanting application of Round-up® and mulch suppressed the growth of the dominant broadleaf weeds Digera muricata (false amaranth); Amaranthus spp (pigweeds) and Commelina benghalensis (wondering jew). In the normal season, tomato yields with current farmer practice were highest averaging 18.5 t/ha which was not significantly different (P=0.05) from mulch application (14 t/ha) followed by IPM (12.1 t/ha). Similarly, in the off-season crop, yields were highest and similar for mulch and standard practice (4.8 t/ha) followed by IPM (3.4 t/ha). Farmers selected mulch application and IPM for on-farm demonstration to verify production costs and benefits.
Effects of biopesticides on developmental biology of fall armyworm (spodoptera frugiperda (jesmith) (lepidoptera:noctuidae) in maize crops in Morogoro, Tanzania
(Tanzania Journal of Agricultural Sciences, 2024) Simon, E; Kudra,A.B; Mwatawala, M.W.
The Fall armyworm (Spodoptera frugiperda (J.E. Smith), is a highly mobile and polyphagous herbivore threatening crop production and the livelihoods of millions of smallholder farmers in the newly invaded areas in Africa, including Tanzania. 353 host plant species, principally Poaceae (maize, sorghum, rice, wheat, sugarcane, millet), Asteraceae (sunflower), Malvaceae (cotton), Fabaceae (soybean), families, groundnuts, potatoes, several fruit trees, ornamental plants, weed species, and vegetable crops are also hosts to FAW. This study aims to determine the effect of biopesticides on the developmental biology of FAW. A completely randomized design (CRD) was used to establish an experiment involving biopesticides; Bacillus thuringiensis Bt, Metarhizium anisopliae and Azadirachta indica seed extract each applied at a lower dose of 2 millimeters, 2 millimeters and 30gram per liter of water respectively, and tested against FAW in the laboratory. Each treatment was replicated four times. Results showed the developmental duration of FAW stages differed significantly between treatments. The time for each growth stage; egg incubation, larval, pupation and the total developmental were significantly longer (p < 0.001) in the biopesticides- treated colony compared to the untreated ones. The shortest developmental duration of FAW stages was observed on control colonies at 2.1 ± 0.18, 14.88 ± 0.18, and 27.7 ± 0.34 days for egg, larva and pupa stages respectively. The longest developmental duration of 3.5 ± 0.37, 22.03 ± 0.59, 12.68 ± 0.23 and 37.7± 0.54 days for egg, larva and pupa stages respectively was observed in colonies under B. thuringiensis treatment. These results confirmed that biopesticides can work effectively to keep FAW levels under control. Therefore, these are promising biocontrol alternatives to be included in the integrated pest management scheme.
Host range and distribution of fruit-infesting pestiferous fruit flies (Diptera, Tephritidae) in selected areas of Central Tanzania
(Cambridge University Pres, 2009) Mwatawala, M.W.; Meyer, M. De; Makundi, Rhodes H.; Maerere, A.P.
The host range of major fruit fly pests in Central Tanzania was evaluated from October 2004 to October 2006. Samples of 48 potential hosts were collected and incubated for fruit fly emergence. Bactrocera invadens was the dominant species in incidence expressed as the ratio of infested to total number samples collected, as well as infestation rate, expressed as number of flies emerging per unit weight. Eight new host fruits are reported. Infestation by native pests, such as Ceratitis capitata and C. cosyra, was minor compared to B. invadens. Ceratitis rosa was the dominant species in temperate fruits, and Cucurbitaceae were mainly infested by Bactrocera cucurbitae, a specialized cucurbit feeder. Among commercial fruits, high infestation incidences were observed in mango and guava, but they decreased throughout the fruiting season. Low infestation rates were observed in all Citrus species and in avocado, indicating these fruits as poor hosts for the studied fruit fly pests in this region. Widespread availability and abundance of fruit species studied here ensures year-round breeding of B. invadens. Seasonal infestation dif- fers, with mango being the most important host in October to January, while guava being important from February to August. Tropical almond showed very high incidence and infestation rate for B. invadens and might act as an important reservoir host, bridging the fruiting seasons of mango and guava. Soursop acts as an important host for C. cosyra after the mango season. Ceratitis capitata is a pest of minor importance of the commercial fruits studied in this region
An overview of bactrocera (Diptera: Tephritidae) invasions and their speculated dominancy over native fruit fly species in Tanzania
(Journal of Entomology, 2009) Mwatawala, M.W.; Makundi, Rhodes H.; De Meyer, M.; Maerere, A. P.
The dominancy of introduced Bactrocera species (Diptera: Tephritidae) over the native fruit fly species was assessed based on data collected from a trapping and sampling program in Morogoro, Tanzania, from 2004 to 2006. Two invasions by Bactrocera species namely the invasive fruit fly Bactrocera invadens Drew, Tsuruta and White and the Solanum fruit fly Bactrocera latifrons (Hendel) have been recorded in 2003 and 2006, respectively. These add to an earlier introduced melon fly Bactrocera cucurbitae (Coquillett). Points and exact times of entry of these species are still unknown. Dominance of Bactrocera species over the native Ceratitis species has been speculated from other parts of the world. Results of this study also suggest the dominancy of Bactrocera species over native Ceratitis species in Tanzania. B. cucurbitae seems to dominate the other cucurbit infesters in terms of abundance and infestation rate. Similarly, B. invadens seems to dominate the native Ceratitis species in orchard fruits in terms of abundance, host range and infestation rate. B. latifrons, whose distribution in the country is still unclear, seems to be the dominant species in its main hosts from family Solananaceae. The outcome of the competition resulting from these introductions is speculated upon. Presence of these pests calls for strong surveillance systems and quarantine regulations to protect the infant fruit industry of Tanzania.
An overview of bactrocera (Diptera: Tephritidae) invasions and their speculated dominancy over native fruit fly species in Tanzania
(Journal of Entomology, 2009) Mwatawala, M.W.; De Meyer, M.; Makundi, Rhodes H.; Maerere, A. P.
The dominancy of introduced Bactrocera species (Diptera: Tephritidae) over the native fruit fly species was assessed based on data collected from a trapping and sampling program in Morogoro, Tanzania, from 2004 to 2006. Two invasions by Bactrocera species namely the invasive fruit fly Bactrocera invadens Drew, Tsuruta and White and the Solanum fruit fly Bactrocera latifrons (Hendel) have been recorded in 2003 and 2006, respectively. These add to an earlier introduced melon fly Bactrocera cucurbitae (Coquillett). Points and exact times of entry of these species are still unknown. Dominance of Bactrocera species over the native Ceratitis species has been speculated from other parts of the world. Results of this study also suggest the dominancy of Bactrocera species over native Ceratitis species in Tanzania. B. cucurbitae seems to dominate the other cucurbit infesters in terms of abundance and infestation rate. Similarly, B. invadens seems to dominate the native Ceratitis species in orchard fruits in terms of abundance, host range and infestation rate. B. latifrons, whose distribution in the country is still unclear, seems to be the dominant species in its main hosts from family Solananaceae. The outcome of the competition resulting from these introductions is speculated upon. Presence of these pests calls for strong surveillance systems and quarantine regulations to protect the infant fruit industry of Tanzania.
Seasonality and host utilization of the invasive fruit fly, Bactrocera invadens (Dipt., Tephritidae) in central Tanzania
(Blackwell Verlag, Berlin, 2006) Mwatawala, M.W.; De Meyer, M; Makundi, Rhodes H.; Maerere, Apia W.
The temporal occurrence of the invasive and economically important pest fruit fly, Bactrocera invadens was studied in three agro-ecological areas of Morogoro Region, central Tanzania, during 2004–2005. Weekly and monthly trappings were carried out with methyl eugenol, protein bait and synthetic food attractant. Bactrocera invadens was permanently present at low and mid-altitudes (380–520 m a.s.l.) with peak periods coinciding with the fruiting season of mango (Mangifera indica) and guava (Psidium guajava). At high altitude (1650 m a.s.l.) its incidence was only temporal and apparently the result of dispersal from lower altitudes after the mango fruiting season. Rearing results showed mango, loquat (Eriobotrya japonica), guava and grapefruit (Citrus · paradisi) to be the favoured commercial host fruits. Other Citrus species, cucurbits, papaya (Carica papaya) and avocado (Persea americana) were less favoured.