Report 51. Cowpea variety trials in northwest Haiti

Abstract

This report summarizes cowpea variety trials conducted in Northwest Haiti between 1993 and 1995 by the Productive Land Use Systems Project. The results of these trials indicate that farmers can substantially increase cowpea yields and substantially increase shelf life without use of insecticide by adopting high-yielding varieties with resistance to seed storage pests. Adoption of these varieties can contribute to increased farmer income and increased sustainability of the food production system. Varieties with host plant resistance to storage weevils offer a low-cost, safe solution to Haitian farmers who cannot afford the cost of pesticides. The USAID/Haiti mission and other donors can make a significant contribution to sustainable agriculture in cowpea-growing areas of Haiti by supporting the multiplication and distribution of seed of selected cowpea varieties, and by supporting cowpea variety testing and studies to address insect pest problems. Cowpea (Vigna unguiculata), known locally as pois inconnu, is an incomplete crop in drier areas of Haiti, with greater tolerance to drought and low soil fertility than crops such as common bean. One of the major problems with cowpea is its susceptability to insect pests, among them, weevils that destroy the seed during storage. With local Haitian varieties, significant loss of feed grain and seed occur in storage due to damage by weevils. The International Institute of Tropical Agriculture (IITA) has a program to breed cowpea for resistance to weevils, as well as to other insect pests and diseases. Cowpea varieties obtained from the International Institute of Tropical Agriculture were divided into two groups of extra early maturity varieties and one group of early maturity varieties and tested in field trials in Northwest Haiti, together with one or two local cowpea varieties. The crops were grown without input of fertilizer or insecticide. Yields were generally low, due to drought, as well as other problems. Out of 10 trials in which statistically significant differences were recorded, IITA varieties gave yields superior to those of the local varieties in five trials. In one trial, IT87D-885 yielded 900 kg/ha, nearly 600 kg more than the local variety. In several more trials, higher yields were recorded for introduced varieties than for the local variety, but differences did not test significant. In no case did the local variety yield significantly higher than all introduced varieties. Grain from two of the trials were stored in paper bags on shelves in Barbe Pagnole to test their resistance to storage pests. In each, the local variety had the greatest seed damage (100% of seeds damaged) and greatest loss of seed weight after 6 1/2 months storage. Among extra early maturity varieties, IT89D-374-57 suffered the least damage, and seed weight loss was reduced to half that of the local variety. Among early maturity varieties, IT89D-792 had the least weight loss and IT87D-670-2 had the least percentage seed damage. Damage to the local variety was 15 fold and 20 fold higher, respectively, than these two varieties. At Bombardopolis, several farmers were asked to assess the performance of the varieties tested. Four varieties were selected as superior, based on yield, early maturity and large seed size: IT87D-879-1, IT87D-885, CNCX252-IE, and IT86D-444. Not all varieties were available to the farmers for assessment. Information on the best performing varieties are summarized in the document. These include varieties that yielded more than the local variety in the extreme environmental conditions of Northwest Haiti, varieties least damaged by weevils and varieties preferred by Haitian farmers, because of grain quality and agronomic performance. Although our information is incomplete, we can identify varieties that appear promising based upon the criteria reported here. Four varieties in each maturity class were outstanding in at least two of the three varieties. Recommendations: - The most promising cowpea varieties should be multiplied and distributed to farmers in the Northwest, and to the Ministry of Agriculture and non-governmental organizations (NGOs) for on-farm testing in other parts of Haiti. - Storage tests should be conducted with those varieties whose resistance to storage weevils has not yet been reported, in order to complete gaps in our information on these varieties. - Additional yield trials should be conducted, especially where poor growing conditions did not allow very conclusive assessments. Trials should also be conducted to compare the best varieties from all three groups, regardless of maturity class, as well as promising varieties from other sources. - Information should be gathered on Haitian consumer preferences for cowpea and on consumer and farmer assessment of the most promising varieties in order to better target recommendations to client farmers and consumers.

Rapò sa a se yon rezime kèk esèy ki te fè sou plizyè varyete pwa enkoni. Esèy yo te fèt nan Nòdwès peyi d Ayiti ant 1993 ak 1995 pa Pwojè PLUS la. Rezilta esèy sa yo montre ke plantè yo kapab ogmante rannman pwa enkoni anpil, e an menm tan ogmante tou kapasite konsèvasyon l. E yo ka fè sa, san yo pa sèvi ak pestisid, si yo chwazi yon varyete ki donnen byen epi ki gen rezistans a pès nou jwenn nan estokaj. Adopsyon varyete sa yo ka kontribye a yon ogmantasyon revni plantè yo epi yon amelyorasyon dirabilite sistèm pwodiksyon an. Varyete ki reziste a pès ensèk brich nan estokaj la ofri yon solisyon bon mache e san risk pou sante plantè ayisyen ki pa ka peye pou pestisid. USAID/Ayiti ak lòt bayè de fon yo ka fè yon kontribisyon enpòtan pou agrikilti dirab nan zòn ki pwodwi pwa enkoni an Ayiti, si bayè de fon yo apiye efò pou miltipliye ak distribye semans varyete pwa enkoni seleksyone, epi si yo apiye lòt esèy sou varyete pwa enkoni ak etid ki gen pou bi rezolisyon pwoblèm pès ensèk yo. Pwa enkoni (Vigni unguiculata) se yon danre enpòtan pou zòn ki sèk yo an Ayiti, paske li ka tolere sechrès ak feblès sòl pi byen pase anpil lòt kalite pwa. Youn nan pi gwo pwoblèm ki genyen nan pwa enkoni, se jan l siseptib a pès ensèk, tankou brich ("bruche" an franse; yon egzanp se Callosbruchus maculatus) ki konn fin manje li nan estokaj. Ak varyete lokal ayisyen, brich se lakòz yon gwo pèt nan pwa enkoni ki estoke, ni pou manje ni pou semans. Estiti Entènasyonal pou Agrikilti Twopikal (IITA) gen yon pwogram pou kwaze pwa enkoni pou bay li rezistans a brich ak lòt pès ensèk ak maladi. Nou te jwenn kèk varyete pwa enkoni nan IITA, epi nou te klase yo an gwoup: de gwoup varyete ki donnen bonnè anpil, ak yon gwoup varyete ki donnen bonnè. Nou te teste tout varyete sa yo nan esèy sou teren nan Nòdwès Ayiti, ansanm ak youn ou de varyete lokal. Tout varyete te kiltive san aplikasyon ni angre ni ensektisid. An jeneral, pwa enkoni yo pa t donnen byen, akòz sechrès ak lòt pwoblèm. Nan 10 esèy ki te demontre yon diferans estatistik enpòtan, varyete IITA te donnen pi byen pase varyete lokal yo nan senk esèy. Nan youn esèy IT87D-885 te donnen 900 kg/ha, preske 600 kg plis pase varyete lokal la. Nan kèk lòt esèy, varyete entwodwi yo te donnen pi byen pase varyete lokal la, men pa t gen yon diferans estatistik enpòtan. Pa t gen yon ka kote varyete lokal la te donnen pi byen pase tout varyete entwodwi yo yon fason estatistikman enpòtan. Semans pwa ki te keyi nan de esèy te estoke nan sache papye sou yon etajè a Bab Panyòl pou teste rezistans yo a pès nou jwenn nan estokaj. Nan chak esèy, varyete lokal la te soufri pi plis donmaj (100% grenn yo te donmaje) ak pi plis pèt nan pwa grenn yo apre 6 mwa edmi estokaj. Nan varyete ki donnen bonnè anpil yo, IT89D-374-57 te soufri mwens donmaj, epi pèt nan pwa grenn li yo te redwi a mwatye pèt varyete lokal la. Nan varyete ki donnen bonnè, IT89D-792 te soufri mwens pèt nan pwa grenn yo epi IT87D-670-2 te gen pi piti pousantaj grenn donmaje. Donmaj varyete lokal la te 15 fwa ak 20 fwa plis pase de varyete sa yo. Nan Bonbadopolis, nou te mande kèk plantè evalye pèfòmans varyete nou te teste yo. Yo te chwazi kat varyete ki siperyè, sou kritè rannman, tan pou varyete a donnen, ak gwosè grenn yo: IT87D-879-1, IT87D-885, CNCX252-IE ak IT86D-444. Plantè yo pa t gen tout varyete yo a dispozisyon yo pou evalyasyon. Tab anba a bay enfòmasyon sou varyete ki te demontre pi bon pèfòmans. Varyete sa yo se sa yo ki te donnen pi byen pase varyete lokal la nan kondisyon anviwònman difisil ki genyen nan Nòdwès, sa ki te soufri mwens donmaj brich, ak sa ke plantè aysisyen yo te prefere akòz kalite grenn yo ak pèfòmans agrikòl. Malgre enfòmasyon nou an pa konplèt, nou kapab identifye kèk varyete ki genlè ap bon dapre kritè nou te bay isit yo. Kat varyete nan chak gwoup rekòt te eksepsyonnèl nan omwen de sou twa kritè yo. Rekòmandasyon: - Nou ta dwè miltipliye varyete pwa enkoni ki pi bon, epi distribye yo bay plantè nan Nòdwès, ansanm ak Ministè Agrikilti ak òganizasyon non-gouvènmantal (ONG) yo pou yo ka teste yo nan jaden nan lòt rejyon peyi d Ayiti. - Nou ta dwè fè esèy estokaj sou varyete ki patko teste pou rezistans a brich nan estokaj, pou nou ka konplete enfòmasyon nou sou varyete sa yo. - Nou ta dwè fè lòt esèy sou rannman, an patikilye kote movèz kondisyon kiltivasyon pa t pèmèt nou fè bon jan evalyasyon. Nou ta dwè fè esèy tou pou konpare varyete ki te pi bon nan touletwa gwoup yo, ansanm ak lòt varyete ki soti nan lòt kote ki kapab bon. - Nou ta dwè ranmase enfòmasyon sou preferans konsomatè ayisyen pwa enkoni, epi sou evalyasyon konsomatè ak plantè sou varyete ki pi bon yo, pou nou ka pi byen fè rekòmandasyon pou plantè kliyan ak konsomatè. - Yon moun ki fòme nan entomoloji (etid ti bèt) ta dwè etidye pwoblèm pès ensèk ki gen yon enpak sou rannman pwa enkoni an Ayiti, pou idantifye ki pès ki pi enpòtan, ki nivo enfestasyon ak donmaj, epi nan ki faz yo atake pwa enkoni. Lè kiltivasyon pwa enkoni ogmante, pès ensèk nan jaden ap vin pi gwo obstak a amelyorasyon rannman. Nou ta dwè devlope yon estrateji pou rezoud pwoblèm sa yo, yon estrateji ki baze sou konnesans ki kalite ensèk ki fè pi plis donmaj epi nan ki faz yo atake pwa enkoni yo.