Nitrogen and weed management in transplanted tomato in the Nigerian forest-savanna transition zone

Weed infestation and inherent low soil fertility are among primary reasons for low yields of tomato in Nigeria. Field trials were carried out during the wet season of 2015 and 2016 to evaluate yield response of tomato to nitrogen (N) application and weed control methods in the forest-savanna transition zone of Abeokuta, Nigeria. Positive relationship exists between growth of weed species and increase in N application. Across the years of study, increase in N up to 90 kg/ha increased weed density by 11–25%, however, the increased N gave the transplanted tomato competitive advantage and thus enhanced weed smothering. Pre-transplant application of butachlor (50% w/v) or probaben® (metolachlor 20% w/v+prometryn 20% w/v) each at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 weeks after transplanting (WAT) significantly reduced weed density by at least 15% and increased fruit yield of tomato by at least 32%, compared to use of the pre-transplant herbicides alone, across both years of study. The greatest tomato fruit yield of 12.2 t/ha was obtained with pre-transplant application of butachlor at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 WAT, averaged for both years. In general, this study suggests that increased application of N up to 90 kg/ha, and complementary weed control by pre-transplant herbicide and hoe weeding at 6 WAT would improve yield of tomato in the forestsavanna transition zone of Nigeria

THE PERIODICITY OF BUILDING HONEY COMBS BY HONEY BEES AND PEST INFESTATION IN TWO APIARIES IN OGUN STATE, SOUTH WESTERN NIGERIA

The study examined the periodicity of comb building by Honey bee, Apis mellifera in some hivesin Ogun State and pest of the honey bee in hives for twenty weeks. Four Kenya top bars hives wereeach placed in two apiaries located in University of Agriculture, Abeokuta (UNAAB), Ogun State, Nigeriaand Olupakun village in Abeokuta North Local Government Area, Ogun State, Nigeria. Each of the22 top bars and the flight entrances were smeared with honey as bait to attract bees to the hive. Datawere collected weekly from two colonized hives in each apiary on: number of honey combs built, sizeof newly built honey combs along and across the bars and pest infestation. The results indicated thatthe bees initiated comb building as early as first week after colonization. In the first week, two combsbuilt in hives at UNAAB had mean size of 8.61cm2 and one and half combs built in hives at Olupakunmeasured 1.65 cm2. As at the 20th week, seven and half combs measuring 662.71 cm2 and eightcombs measuring 352.28cm2 were built at UNAAB and Olupakun respectively. Although, higher numbersof combs were built at Olupakun; they were of relatively smaller sizes than combs built in hives atUNAAB. The pests encountered in the hives were greater wax moth (Galleria mellonella), grass hopper(Zonocerus variegatus), termites (Macrotermites nigeriense), Cockroach (Periplanata americana),snakes, Lizard (Agama agama) and Praying mantis (Stanomantis spp.

EVALUATION OF INFESTATION AND DAMAGE BY THE LARGER GRAIN BORER (PROSTEPHANUS TRUNCATUS) (HORN) (COLEOPTERA: BOSTRICHIDAE) ON SELECTED FOOD GRAIN CROPS

The study evaluated the ability of the larger grain borer (LGB), Prostephanus truncatus (Horn) to infest and damage two varieties of sorghum (Sorghum bicolour), Sesame (Sesamum indicum) Cowpea (Vigna unguiculata) and maize (Zea mays). 100 g each of the grain products were infested with 5 pairs (5 males and 5 females) of 1-10 day old LGB for 90 days. At 90 days post-infestation of the crops, the insects and grain dust generated by the feeding activities of the insects were sieved out of the grains; the grains were separated into damaged and undamaged and data were taken on number of adult P. truncatus, number of larvae and pupae, number of larvae and pupae, number of adult mortality, weight of dust (g), weight of damaged grains (g), weight of undamaged grains (g) and final weight of grains (g). The results showed that all the 5 pairs of adult LGB introduced into the cowpea and sesame varieties died. Likewise, neither larvae nor pupae were found in the two grain products. The highest mean number of larvae and pupae (18.5) was recorded in the Suwan-1 maize variety, and it was significantly (P < 0.05) higher than the mean number found in the other grain products studied. The mean number of larvae (7.25) in Solo maize variety was significantly (P < 0.05) higher than the mean larvae number of 4.25 and 2.50 in Eyinfun and Ex- Minna sorghum varieties respectively.  Significantly (P < 0.05) higher percentage grain damage (49.76) and percentage weight loss (12.89) were recorded in the Solo maize variety compared to percentage grain damage and percentage weight loss in other grain products. Likewise, the grain damage (23.06 %) and weight loss (8.04 %) in the Ex-Minna sorghum variety were significantly  < 0.05) higher than percentage grain damage and percentage weight loss obtained in other grain products except Solo maize. A significantly (P < 0.05) lower grain damage (1.35 %) and grain weight loss (1.43 %) were obtained in the NICRIBEN and E8 sesame varieties respectively. The result of this study indicates the ability of LGB to bore and damage sorghum, maize, sesame and cowpea; with breeding restricted only to maize and sorghum. There were varietal differences in response of the grain products to LGB infestation and damage. Considering the importance of sorghum, maize, sesame and cowpea as a cheap source of carbohydrate and protein; concerted effort should be geared at controlling infestation of the grain products by LGB

From ‘Vagabonds’ to Ethnobotanical Relevance: Weeds of the Campus Sites of Olabisi Onabanjo University, Ago-Iwoye, Nigeria

A survey of the weed flora of the campus sites of the Olabisi Onabanjo University was undertaken. Several visits were made to the disturbed and undisturbed vegetation of the sites for collection of weeds after which the weeds were prepared in accordance with conventional herbarium practice. A total of seventy-three (73) weed species belonging to twenty-seven (27) families were identified and found to be present within the area of study. The family Poaceae seems to have the highest number of weed species (twelve) available within the area followed by Asteraceae with ten (10) species. Amaranthaceae, Cyperaceae and Euphorbiaceae are also in abundance. These weeds have been discovered to be useful, against the mindset of the uninformed that they are useless or ‘vagabond’ plants. Medicinal uses as well as percentage occurrence of each family are presented. From this study it is obvious that the University sites are not only rich in plant biodiversity but that the plants are also very rich in socio-economic values. It is therefore advisable that these plants should be protected from going into extinction so that all would not be lost due to developmental activities

Effect of cropping system and age of plant at harvest on tuber rot and performance of elite cassava varieties in derived savannah

Devastated tuber rot disease among farmers prompted the evaluation of the elite improved varieties in the intercrop and the practice of delaying harvesting when there is glut in the market necessitated this study. Trial was carried out at the Federal University of Agriculture, Abeokuta between 2011 and 2014 to evaluate yield performance of 21 elite cassava varieties planted as sole crop verse intercropped and harvested at different age. The 2 x 21 x 3 factorial experiment was laid out in randomized complete block design and replicated three times. The tuber yield obtained from sole plot in 2011/2012 cropping season was significantly higher than intercrop whereas those of 2012/2014 cropping season were similar. Land Equivalent Ratio was above one in both cropping seasons indicating that the performance of the improved varieties in intercrop was efficient. The pooled mean tuber yield showed that TMS 30572, 92/0326, 95/0211, 01/1371, 00/0338, 01/0046, 00/0098, 01/1097, 01/0085, 98/0581 and 98/510 were among the top eight varieties. Harvesting could be delayed up to 15 months after planting to reduce tuber rot

To what extent arbuscular mycorrhiza can protect chicory (Cichorium intybus L.) against drought stress

Water deficiency is one of the most significant limiting factors resulting in severe crop yield reduction. This study hypothesizes that the inoculation of arbuscular mycorrhiza (AM) minimize the detrimental effects of drought in chicory (Cichorium intybus L.). The objective was to evaluate how AM inoculation affects agro-biochemical traits of chicory under different irrigation rates. Field experiments were conducted in 2017 and 2018 in north of Iran and designed as a factorial combination of three irrigation rates [40, 65 and 90 % of maximum allowable depletion of available soil water (IR1, IR2 and IR3, respectively)], two AM inoculations [inoculated and not inoculated (AM+ and AM−, respectively)] and two chicory ecotypes [Sefid Isfahan and Siyah Shiraz (E1 and E2, respectively)]. Crop growth, pigments and minerals content, carbon exchange rate, transpiration rate and stomatal conductance were evaluated. The data showed that the mycorrhizal colonization increased chicory growth performance by 12.4 %, 16.1 % and 21.0 %, under I1, I2, and I3 water regime, respectively. The mineral content and photosynthesis parameters decreased as irrigation water decreased, irrespective of whether plants were inoculated or not. Similarly, AM+ plants had higher inulin percentage and the mean inulin degree of polymerisation than AM− plant under all of irrigation levels. Furthermore, inoculated chicory plants under drought stress showed an enhanced activity of the antioxidant system, such as superoxide dismutase, peroxidase, ascorbic acid and glutathione, while the accumulation of hydrogen peroxide and the oxidative damage were reduced. The two ecotypes tended to respond similarly to irrigation and AM treatments for all growth and quality parameters measured in the experiment, even if ecotype Siyah Shiraz performed better than ecotype Sefid Isfahan. The improved plant performance and inulin content in the inoculated plants demonstrate that AM has the potential to minimize the detrimental effects of drought stress on chicory under semi-arid conditions

CO2 flux and C balance due to the replacement of bare soil with agro-ecological service crops in Mediterranean environment

Intensive agriculture practices often results in decomposition of organic matter, thus causing soil CO2 emissions. Agro-ecological service crop could be profitably cultivated to improve soil characteristics and reduce CO2 emissions under Mediterranean environment. Two-year field trials were conducted in central Italy. The treatments were three agro-ecological service crops (hairy vetch, oat, and oilseed rape) and a no-service cover. Plant development, soil characteristics, and CO2 emissions were measured. Oat and oilseed rape showed a rapid growth, while hairy vetch started to grow rapidly only after the cold period. Soil CO2 emissions trend was similar among the agro-ecological service crops and tended to decrease during the cold period, then gradually increased until April when warm temperatures were observed. The high soil CO2 emissions and respiration index observed in hairy vetch probably stimulated mineral nutrients, especially nitrogen, to become more available in the soil compared to oat and oilseed rape throughout the decomposition of soil organic matter. These results confirmed that the cultivation of agro-ecological service crops, especially hairy vetch, could represent a suitable strategy for enhancing carbon sequestration and lead to a mitigation of CO2 emissions during the fallow period and could thus contribute to the climate change mitigation

Nitrogen and weed management in transplanted tomato in the Nigerian forest-savanna transition zone

Weed infestation and inherent low soil fertility are among primary reasons for low yields of tomato in Nigeria. Field trials were carried out during the wet season of 2015 and 2016 to evaluate yield response of tomato to nitrogen (N) application and weed control methods in the forest-savanna transition zone of Abeokuta, Nigeria. Positive relationship exists between growth of weed species and increase in N application. Across the years of study, increase in N up to 90 kg/ha increased weed density by 11–25%, however, the increased N gave the transplanted tomato competitive advantage and thus enhanced weed smothering. Pre-transplant application of butachlor (50% w/v) or probaben® (metolachlor 20% w/v+prometryn 20% w/v) each at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 weeks after transplanting (WAT) significantly reduced weed density by at least 15% and increased fruit yield of tomato by at least 32%, compared to use of the pre-transplant herbicides alone, across both years of study. The greatest tomato fruit yield of 12.2 t/ha was obtained with pre-transplant application of butachlor at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 WAT, averaged for both years. In general, this study suggests that increased application of N up to 90 kg/ha, and complementary weed control by pre-transplant herbicide and hoe weeding at 6 WAT would improve yield of tomato in the forestsavanna transition zone of Nigeria