A study was conducted during the early planting season of 2011 at Asaba, Delta State, Nigeria to evaluate eight varieties of cowpea (IT80D-699, IT82 (e-18), Ife Brown, IT870-9411 and TVX3236, IT90K-277-2, IT870-9411 and IT828-146) for adaptation in the altisol of Asaba agro ecological zone with a view to recommending the suitable varieties to farmers in the area for planting. The results showed that significant differences (P<0.05) existed among the varieties tested in all the growth characters measured. Ife Brown, IT8482246-4 and TVX3236 varieties performed significantly better both in the growth and yield as well as yield related parameters when compared to IT800D-699, IT82(e-18), IT870-9411 and IT828-146 varieties. This study hereby recommends Ife Brown, IT848-2246-4 and TVX3236 varieties which performed appreciably better to farmers in Asaba agro ecological zone for planting.

The management of major field insect pests of cowpea under calendar and monitored sprays of cypermethrin was studied. The major insect pests studied were the cowpea aphid, Aphis craccivora Koch, legume bud thrips Megalurothrips sjostedti Tryb, legume pod borer, Maruca vitrata Fab. and pod sucking bugs. Influence of insect pest management on yield was also determined. The calendar sprays consisted of 7 days' spray intervals carried out 5 times and 10 days' spray intervals, carried out 4 times. Monitored spray was carried out only when insect pest infestation/damage reached or exceeded the action threshold. The experiments were conducted in the Teaching and Research Farms of the Agronomy department, Asaba Campus, Delta State University, Nigeria. Comparison of insect pests and grain yield from the calendar and monitored spray treatments was made if differences existed among them. Results indicated that all the cypermethrin treatments effectively controlled M. sjostedti, M. vitrata, flower bud thrip population and pod sucking bugs when compared to control in the early season. There was however, no significant difference (P>0.05) in calendar and monitored sprays. Similar observation was made for grain yield. In the late season, all treatments significantly (P<0.05) controlled pest population/damage on cowpea. Grain yield increase was similarly recorded but no differences among the treatments. Cowpea growers sometimes apply insecticides as many as 8 to 10 times to control insect pests during the growing season; the study here provides evidence (1) that 10 days' interval spray and monitored spray can be as profitable as 7 days' interval spray in cowpea production and (2) this could reduce the number of chemical application, save cost as well as environmental pollution and hazards to consumers.

The study took place during the early planting season of 2005, in Asaba and Abraka, both in Delta State, Southern Nigeria. Asaba occupies the drier northern part of the state while Abraka, in the south, experiences a more humid weather. Insect species that decimate cowpea (Vigna unguiculata (L.) Walp in both locations, about 135 kilometres apart were identified and compared. The results showed that the occurrence and distribution of insect species followed different trends. Asaba recorded 10 insect orders, 34 families and 50 species, compared to Abraka with 8 orders, 25 families and 37 species in the same season. The dominant species in both locations were coleoptera. Asaba recorded slightly more coleoptera, heteroptera, diptera, hymenoptera and lepidoptera than Abraka. Conversely, there were slightly more orthoptera than Asaba. Ootheca mutabilis Sahl, Aphis craccivora Koch, Megalurothrips sjostedti Tryb, Maruca vitrata Fab, and coreid bugs such as Cravigralla tomentosicollis Stal, Anoplocnemis curvipes Fab, C. shadabi Doll, Aspavia armigara Fab, Nezara virudula L, Mirperus jaculus Thnb were the commonest major insect pests on cowpea at Asaba and Abraka. More insect species occurred at Asaba than Abraka in the early season.

Many commercial cowpea farmers control insect pests on cowpea with synthetic chemicals and may sometimes spray their farms during the growing season as many as 8 to 10 times. This leads to health hazards and environmental pollution. The present study was conducted to reduce the number of times, cypermethrin (conventional chemical) is applied before harvest and still, produce the expected cowpea grains. The experiments were carried out in two agro-ecological zones - Asaba and Abraka of Delta State during the late cropping season. The experiments consisted of 4 treatments - cowpea plots sprayed 4 times (at 7 days’ intervals), cowpea plots sprayed 5 times (at 10 days’ intervals), cowpea plots whose insect infestation were monitored before chemical application and control plots (without chemical treatment). Each treatment was replicated 3 times. The experiments were organised into a randomised complete block design (RCBD). The results indicated that cypermethrin controlled the major insect pests of cowpea.  Second, grain yield was high at both locations; significant differences did not exist (P>0.05) in insect number and grain yield among the treatments. The study provides the evidence that (i) high cowpea grain yield is obtained at reduced number of chemical application of 4 or 5 times during the growing season (ii) Grain yield was significantly (P<0.05) higher at Abraka with1400.60kg ha^-1 than Asaba (714.40kg ha^-1) during the late cropping season

Yam as an important staple food and major source of energy in the diet of most people in the tropics, belongs to the genius and family Diocoreaceae. It is a monocot crop. Important species mostly grown and cultivated in Nigeria are:(white guinea yam), (water yam or winged yam) and (yellow yam). Species with less economic importance but are cultivated in Nigeria include:(bitter or trifoliate yam), (Chinese yam) and (aerial yam). Global yam output was estimated at 32.9 million metric tones in which Nigeria alone produces 23.9 million metric tones equivalent to 71% of the total world production. (FAOSTAT 1997; FAO, 1998; IITA, 1995). Yam is reputed for the high prices it commands as a result of its socio-cultural values (Chukwu and Chukwu, 2002; Agbaje ; 2002).Many factors limit yam production in Nigeria which include high labour demand for most cultural operations; high cost of labour and other inputs such as planting materials; declining soil fertility, pests and diseases (Onwueme, 1978). Yams are attacked by several insects both in the field and during storage. Foliar insect pests are less serious compared to tuber pests. The yam leaf beetles (Dalm) and (Fab.) both occur together in yam farm but has been reported to be the dominant species in Nigeria (Onwueme, 1978). Mealybug species known to attack yam include , Ezat McConnel (Akinlosotu, 1984). Other insects that attack yam include yam cricket with species such as , , all belong to (Orthoptera:Gryllidae). Other minor field insect pests of yam include leaf miner spp (Cecidomiidae) which induces galls on yam leaves while termite (Isoptera) with species like , and are widely distributed in West Africa.