EVALUATION OF INSECTICIDES AND Jatropha curcas EFFICACY AGAINST MAIZE STEM BORER ( Busseola fusca ) ON MAIZE ( Zea mays L . ) IN BATI WORED A , NORTH EASTERN ETHIOPIA

Abstract

Maize is extremely important crops grown in Ethiopia for human consumption . Of the various insect pests attacking the crops in Ethiopia, lepidopteran stem borers are by far the most injurious. Yield losses due to stem borers are variable but ranges from 10% in les s infestation area to complete crop failure under outbreak conditions. A study was conducted to evaluating insecticides and J atropha curc as against maize stem bor er during 2017 cropping season. The experiment was laid out in randomized complete block design (RCBD) with three replications The early maturing maize variety ‘melkassa 6Q’ adapted top to the area was used in this trial. The treatments included water extracts of seed powder of Jatropha , oil extracts of seed powder of Jatropha (Jatropha curca s Lam.) , Lambda cyhalothrin ( Karate 5% EC), Endosulfan 35% EC, Endosulfan 5% dust , Malathion 50% EC , Carbaryl 85% WP, Diazinon 60% EC, and untreated check.. All The insecticide s and J atropha curc as treatments resulted in control of stem borers as compared to the untreated check. The best control was obtained when maize was treated with Karate 5% EC at 30 and 45 days after em ergence (DAE) of maize seedling . At 45 and 60 DAE of maize seedlings the number of eggs, larvae percentage , leaf feeding injury and dead heart were low in Karate 5% EC treated plots than other t rea ted plot in both locations . Similarly, significantly low percentage damag e cob (1.696 and 2.78 ) , tunnel length (31.33 and 28.33 ) , stalk holes ( 3.33 and 5.0 ) and infested internodes ( 21.89 and 21.29) were recorded in Karate 5% EC applied plots as compared to untreated check in both locations. Significant variations among the maximum yield for Karate at Salmane (52.33 q/ha ) and at Birra ( 51.2 q/ha ) and the minimum yield of the untreated one at Salmane ( 40.27 q/ha) and at Birra ( 37.6 q/ ha) were observed. In all treatments, 19.9 - 26.56 % at S almane and 14.63 - 23.04 % at B irra grain yield losses were recorded due to stem borer damage . Partial economic benefit analysis showed that protection of maize by these treatments resulted in positive return, although the amount varied from 4737 - 10340 Birr/ha at Salmane and 3810 - 8956 Birr/ha at B irra. It was concluded that all tested insecticides provided effective control of B. fusca , under field conditions and have positive effect on maize yield than untreated control. However, insecticides were most effective than J atropha curc as regarding least maize stem borer infestation and high yield. Moreover, lambda cyhalothrin ( karate) 5% EC at 30 and 45 days after seedling emergence had a significant role in managing stem borers and increasing yield while minimizing cost of chemical in each for. Key words: Busseola fusca , Jatropha curcas I nsecticides , Maize, Maize stem borer 1 INTRODUCTION Maize ( Zea mays L . ) is one of the world’s three most important cereal crops proceeded only by wheat and rice. Maize originated in America prior to 5000 B.C. Several thousand years of selection by indigenous growers has resulted in a number of different races in many different geographical areas. These races along with undomesticated relati ves constitute a very diverse genetic base (White, 1999). It is grown from below sea level to elevations exceeding 3000 meters above sea level and at latitudes ranging from 60 0 North to about 40 0 South (Singh, 1987). It can also grow in arid regions with 2 50 mm of annual rainfall and in highly humid areas with a precipitation of 5000 mm (Dowswell et al ., 1996). Maize is the most important cereal crop in sub - Saharan Africa. It is a staple food for an estimated 50% of the population (IITA, 2009). It is an im portant source of carbohydrate, protein, iron, vitamin B and minerals. Africans consume maize in many forms (e.g. for porridges, pastes and beer). Green maize fresh on the cob is eaten baked, roasted or boiled. Every part of the maize plant has economic va lue: the grain, leaves, stalk, tassel, and cob can all be used to produce a large variety of food and non - food products (IITA, 2009). Maize is widely produced in all parts of Ethiopia. An area of 2.1 million hectares of land is covered with maize and the a nnual mai ze production is not less than 7.8 million tons (CSA, 2017). Maize productivity (3.6 tons ha - 1) is leading all c ereals in the country (CSA, 2017 ) but compared to the world’s average production (3.7 tons ha - 1) and to that of developing countries (3 .6 tons ha - 1) is still low. Several factors are responsible for this, among them insect pests are very important. Stem borer damage to maize posses a significant constraint on national maize production by damaging the vascular tissue of the plant and prov iding a portal of entry for stalk and ear rots. Stem borer is of high economic significance to maize as it attacks all parts of maize except roots, producing dead hearts at seedlings stage and causing higher yield losses . Yield losses due to stem borers ar e variable but ranges