Evaluation of Eucalyptus tereticornis, Tagetes minuta and Carica papaya as stored maize grain protectants against Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae)

https://www.researchgate.net/publication/266910539,Sitophilus zeamais (Motsch.) is an important storage pest of maize grain in several parts of Africa including Zimbabwe. Although synthetic pesticides are effective at controlling the pest, environmental and health hazards of these chemicals are of increasing concern. The study assessed efficacy of botanical leaf powders of Eucalyptus tereticornis, Tagetes minuta and Carica papaya in controlling S. zeamais using rates of 5 g, 10 g and 20 g per 200 g of open pollinated maize grain (variety ZM421). The trial was laid in a completely randomised design (CRD), with 12 treatments replicated three times. The grain was put in a freezer at -4oC for a fortnight, before the botanicals were added, to kill any prior sources of weevil inoculum and eggs which might be already pre-existing in the grain. 200 g maize grain was infested with 200 three week old unsexed pure culture weevils in 750 ml jars. After 14, 28, 42, 56 and 70 days, weevils were sieved and their mortality determined. Percentage grain weight loss was assessed after 35 days post pests introduction. There were significant differences (p<0.05) in number of weevil mortality and grain weight loss among treatments and their application rates. The findings showed that conventional chemical control was most effective than all botanicals used. E. tereticornis was the most effective of all the botanical pesticides at an application rate of 20 g as evidenced by high weevil mortality and less grain weight loss. It was concluded that botanicals have storage pesticidal properties to suppress S. zeamais in maize grain and could be used as an alternative control option to synthetic pesticides

Screening of Stored Maize (Zea mays L.) Varieties grain for tolerance against maize eeevil, Sitophilus zeamais (Motsch.)

Insect pests cause major damage to stored maize grain thereby reducing its weight, quality and germination vigour. Five open pollinated maize varieties (ZM401, ZM309, ZM521, ZM421 and Hickory King) and one hybrid maize variety (SC709) were evaluated for tolerance and their effects on progeny development against the maize weevil, Sitophilus zeamais (Motsch.). The experiment was laid in a randomised complete block design, with 6 treatments replicated 5 times. 100g maize grain was infested with 100 three week old unsexed pure culture adult weevils in 750 ml jars. After 14 days oviposition period, adult weevils were sieved out and parent weevil mortality determined. After a further 45 days, number of weevils emerged, percentage grain weight loss and number of damaged kernels were determined. Percentage kernel germination was determined through a germination test after 45 days of weevil attack. There were significant differences (p<0.05) in number of parent weevil mortality, number of weevils emerged, grain weight loss, kernel damaged and germination percentage among varieties. ZM421 and ZM521 varieties showed potential to S. zeamais progeny suppression and tolerance as evidenced by high parent weevil mortality, low weevil emergence, less grain weight loss, low grain damage and high germination percentage

Evaluation of Eucalyptus tereticornis, Tagetes minuta and Carica papaya as stored maize grain protectants against Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae)

https://www.researchgate.net/publication/266910539,Sitophilus zeamais (Motsch.) is an important storage pest of maize grain in several parts of Africa including Zimbabwe. Although synthetic pesticides are effective at controlling the pest, environmental and health hazards of these chemicals are of increasing concern. The study assessed efficacy of botanical leaf powders of Eucalyptus tereticornis, Tagetes minuta and Carica papaya in controlling S. zeamais using rates of 5 g, 10 g and 20 g per 200 g of open pollinated maize grain (variety ZM421). The trial was laid in a completely randomised design (CRD), with 12 treatments replicated three times. The grain was put in a freezer at -4oC for a fortnight, before the botanicals were added, to kill any prior sources of weevil inoculum and eggs which might be already pre-existing in the grain. 200 g maize grain was infested with 200 three week old unsexed pure culture weevils in 750 ml jars. After 14, 28, 42, 56 and 70 days, weevils were sieved and their mortality determined. Percentage grain weight loss was assessed after 35 days post pests introduction. There were significant differences (p<0.05) in number of weevil mortality and grain weight loss among treatments and their application rates. The findings showed that conventional chemical control was most effective than all botanicals used. E. tereticornis was the most effective of all the botanical pesticides at an application rate of 20 g as evidenced by high weevil mortality and less grain weight loss. It was concluded that botanicals have storage pesticidal properties to suppress S. zeamais in maize grain and could be used as an alternative control option to synthetic pesticides

Screening of Stored Maize (Zea mays L.) Varieties grain for tolerance against maize eeevil, Sitophilus zeamais (Motsch.)

Insect pests cause major damage to stored maize grain thereby reducing its weight, quality and germination vigour. Five open pollinated maize varieties (ZM401, ZM309, ZM521, ZM421 and Hickory King) and one hybrid maize variety (SC709) were evaluated for tolerance and their effects on progeny development against the maize weevil, Sitophilus zeamais (Motsch.). The experiment was laid in a randomised complete block design, with 6 treatments replicated 5 times. 100g maize grain was infested with 100 three week old unsexed pure culture adult weevils in 750 ml jars. After 14 days oviposition period, adult weevils were sieved out and parent weevil mortality determined. After a further 45 days, number of weevils emerged, percentage grain weight loss and number of damaged kernels were determined. Percentage kernel germination was determined through a germination test after 45 days of weevil attack. There were significant differences (p<0.05) in number of parent weevil mortality, number of weevils emerged, grain weight loss, kernel damaged and germination percentage among varieties. ZM421 and ZM521 varieties showed potential to S. zeamais progeny suppression and tolerance as evidenced by high parent weevil mortality, low weevil emergence, less grain weight loss, low grain damage and high germination percentage

Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium sativum L. and Solanum incanum L. in controlling aphids (Brevicoryne brassicae L.) in rape (Brassica napus L.)n controlling aphids (Brevicoryne brassicae L.) in rape (Brassica napus L.)

Cabbage aphid (Brevicoryne brassicae L.) is one of the most problematic pests in smallholder vegetable production, causing significant yield losses in heavy infestations. Current control strategy focuses on use of synthetic pesticides that consequently lead to decimation of natural enemies, development of insect resistance and resurgence and upset biodiversity. Botanical pesticides have been used widely in smallholder farmers but not much documented literature exists on efficacy of these products. A field trial was done to assess the efficacy of crude aqueous extracts of Tephrosia vogelii, Allium sativum and Solanum incanum in controlling Brevicoryne brassicae in Brassica napus production. The trial was laid in a randomized complete block design (RCBD) with five treatments replicated four times. The five treatments used in the experiment were T. vogelii, A. sativum, S. incanum, dimethoate and control. Wingless adult female aphids were inoculated three weeks after transplanting of seedlings. Spraying and data collection were done weekly for four weeks. Data was collected on aphid nymph and adult counts on the third leaf from the aerial plant part of randomly selected plants from each treatment for 24 hours after the application of treatments and total plant fresh weight per each treatment. There were significant differences (p<0.05) in the efficacy of botanicals and synthetics in controlling aphids, with dimethoate being the most effective followed by T. vogelii, A. sativum, S. incanum and lastly the control. The treatments applied had a significant effect (p<0.05) on the yield of rape. It was concluded that T. vogelii, S. incanum and A. sativum aqueous crude extracts have some pesticidal effects on aphid in rape production

Screening of Stored Maize (Zea mays L.) Varieties grain for tolerance against maize eeevil, Sitophilus zeamais (Motsch.)

Insect pests cause major damage to stored maize grain thereby reducing its weight, quality and germination vigour. Five open pollinated maize varieties (ZM401, ZM309, ZM521, ZM421 and Hickory King) and one hybrid maize variety (SC709) were evaluated for tolerance and their effects on progeny development against the maize weevil, Sitophilus zeamais (Motsch.). The experiment was laid in a randomised complete block design, with 6 treatments replicated 5 times. 100g maize grain was infested with 100 three week old unsexed pure culture adult weevils in 750 ml jars. After 14 days oviposition period, adult weevils were sieved out and parent weevil mortality determined. After a further 45 days, number of weevils emerged, percentage grain weight loss and number of damaged kernels were determined. Percentage kernel germination was determined through a germination test after 45 days of weevil attack. There were significant differences (p<0.05) in number of parent weevil mortality, number of weevils emerged, grain weight loss, kernel damaged and germination percentage among varieties. ZM421 and ZM521 varieties showed potential to S. zeamais progeny suppression and tolerance as evidenced by high parent weevil mortality, low weevil emergence, less grain weight loss, low grain damage and high germination percentage

Effects of different pulse solutions on vase life and quality of roses (Rosa hybrid L.)

Roses from different continents travel long distances to reach the international flower market in Holland and result in them reaching the market while they have aged thus reducing vase life and quality which are vital for consumer satisfaction. An experiment was carried out to assess the effects of five different pulse solutions (distilled water, aluminium sulphate + HTH + V90, aluminium sulphate + pentakill + V90, 3% sucrose solution + aluminium sulphate + V90, and water acidified with citric acid to a hydrogen potential of 4.2) on preserving the vase life of three rose (Rosa hybrid L.) varieties (Amore, Escimo and Calibra). The experiment was arranged as a 3×5 factorial treatment structure laid out in a completely randomised design (CRD). There was an interaction (p<0.001) between the three rose varieties and the five different pulse solutions. Escimo and Amore recorded the highest vase life days in solution containing 3 % sucrose averaging 19 and 18 days respectively. Calibra recorded the least vase life (17 days) in water acidified with citric acid to a hydrogen potential of 4.2. It was concluded that pulsing solutions prolong vase life of roses

Effects of soil type and manure level on the establishment and growth of moringa oleifera

Moringa oleifera is considered one of the most useful trees being promoted across the world for its nutritional value. However, the production requirements of this crop are seldom known. The study was conducted to investigate the effects of soil type and cattle manure on initial establishment and growth of M. oleifera. Greenhouse experiments were conducted at Africa University, Zimbabwe in a 4×4 factorial treatment structure laid in a randomized complete block design replicated 3 times. Sandy, sandy loam, clay loam and clay soils were used while cattle manure was applied to all the soils at levels of 0, 10, 20 and 40% on mass to mass basis. Results showed that, plant height, number of branches, basal stem diameter, root, shoot and total dry biomass significantly increased (p<0.05) with an increase in the amount of cattle manure applied. An increase of 173% in M. oleifera height was recorded where 40% manure was applied. Clay loam soils significantly increased (p<0.05) M. oleifera growth rate. The study showed that application of cattle manure in acidic granitic sandy soils enhances the production of M. oleifera. A combination of clay loam and 40% manure was concluded as the best for M. oleifera establishment and growth

Screening indigenous nematicidal plants in Zimbabwe against Meloidogyne javanica: paper presented at a conference held on the 14th-16th July 2015, Elephant Hills Resort, Victoria Fallls, Zimbabwe

Theme: 1st International Research Conference On Driving Socio-Economic Development Through Value Addition And Sustainable Use Of ResourcesPlant parasitic nematodes are one of the major economically important pests of Solanaceous plants in many regions of the world including Zimbabwe, with Meloidogyne javanica, (rootknot nematode) being considered the most destructive. Recent prohibition of main soil chemical fumigants for the control of Meloidogyne javanica has prompted for the search of other alternatives to manage root knot nematodes in the horticultural industry. The present research explored plants with nematicidal properties against root knot nematode, M. javanica. Depending on plant medicinal value, leaves or bark or roots of 19 indigenous medicinal plants were screened invivo on highly susceptible tomato variety (Red khaki). Ten plant extracts caused more than 50% gall reduction during screening under acetone extraction method. Application of botanicals was found to significantly (p≤ 0.05) reduce the formation of root galls on tomato plants. It was concluded from this study that plant extracts are potential botanical nematicides as they have ability to suppress the attack of tomato plants by phyto- nematodes and they can be used as a safe and resourceful control strategy, which can complement other control tools

The effect water hyacinth (Eichhornia crassipes, L) compost application on heavy metal concentration and agronomic performance of cabbage

Water hyacinth compost prepared from polluted water bodies that receive municipal waste water has a potential to improve soil fertility and crop yields. However there is a potential health risk of heavy metal toxicity if the compost is used in vegetable production. A field study was conducted at Masvingo Polytechnical College in central Zimbabwe to assess the effect of different application rates of water hyacinth compost on the yield of cabbage and the associated heavy metal accumulation. The research was set up in a randomized complete block design with four treatments replicated three times. The treatments comprised of four levels of decomposed water hyacinth compost applied per planting station at an application rate of 0 t ha-1, 37.0 t ha-1, 55.6 t ha-1 and 74.1t ha-1. Variables days-to-maturity, yield and concentration of heavy metals (Pb, Ni, Cu and Zn) in the edible portion of cabbage were measured. Results showed that an increase in water hyacinth compost application rate significantly increases the number of days to maturity by 14%, 18% and 18% for application rates of 37, 55.6 and 74.1tha- 1respectively. The days to maturity differ significantly between the control and application rates e”55.6 tha-1 but there is no significant difference between application rate of 55.6tha-1 and 74.1tha-1. A positive and significant (p<0.05) yield response to increased water hyacinth compost rate was recorded. Water hyacinth compost application rates of 37, 55.6 and 74.1 t ha-1 recorded yield increases of 13%, 45% and 63% in comparison to the control. Significant differences (p<0.05) in the concentration of Pb in edible portions of the cabbage crop amended with different rates of water hyacinth were recorded. Basing on WHO (2003), permissible levels, Cu, Ni, and Zn concentration in cabbages were within the safe limits for human consumption but Pb concentration in cabbages exceeded the permissible levels indicating a threat on human health. Water hyacinth compost has a high potential as a fertility amendment however at higher application rates there tends to be accumulation of some heavy metals beyond the permissible levels for human consumption