CULTURAL MANAGEMENT OF RUSSIAN WHEAT APHID INFESTATION OF BREAD WHEAT VARIETIES IN KENYA

Abstract

Wheat ( Triticum aestivum L.) is ecologically suited to East African countries and is the second important cereal after maize in Kenya. It is an important source of food, livestock feeds and income. However, its production (442,000 MT) does not meet annual domestic demand (1,750,000 MT), due to cereal aphids infestation. The most serious cereal aphid in Kenya is the Russian wheat aphid (RWA) ( Diuraphis noxia Kurdjumov), causing yield losses of >90% when not controlled. The objective of this study was to develop low cost cultural, sustainable and environmentally safe practices for the management of the RWA in East Africa. Treatments included nine varieties, three seeding rates and three rates of nitrogen application. Nine commercial wheat varieties, K. Tai, K. Kingbird, K Wren, K. Korongo, K. Hawk, K. Sunbird, Robin, K. Eagle, and NBWII were sown. Main plots were assigned to wheat varieties, sown at three seeding rates 75, 100 and 125 kg ha-1. Sub-plots were assigned to three rates of nitrogen, 75, 100 and 130 kg N ha-1, applied at tillering stage (GS 22). Variety K. Korongo supported the lowest aphid count of 3.6 per 5 plants; followed by K. Hawk (3.8) and Robin (2.9 aphids). Robin gave the highest grain yield (2.9 t ha-1), followed by K. Korongo (2.7 t ha-1) and K. Hawk (2.5 t ha-1). Application of 100 kg N ha-1 and seeding at 100 kg ha-1 were the best rates.Le bl\ue9 ( Triticum aestivum L.) convient \ue9cologiquement aux pays de l\u2019Afrique de l\u2019est et est la deuxi\ue8me c\ue9r\ue9ale importante apr\ue8s le ma\uefs au Kenya. C\u2019est une source importante de nourriture, nourritures de b\ue9tail et revenu. Pourtant, sa production (442,000 MT) ne satisfait pas de demande domestique annuelle (1,750,000 MT), en raison de l\u2019infestation de pucerons de c\ue9r\ue9ale. Le puceron de c\ue9r\ue9ale le plus s\ue9rieux au Kenya est le puceron de bl\ue9 russe (RWA) ( Diuraphis noxia Kurdjumov), en provoquant des pertes de production de> 90 % sinon contr\uf4l\ue9s. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9velopper bas le prix les pratiques culturelles, durables et environnementalement s\ufbres pour l\u2019administration du RWA \ue0 Afrique de l\u2019est. Les traitements ont inclus neuf vari\ue9t\ue9s, trois taux seeding et trois taux d\u2019application d\u2019azote. Neuf vari\ue9t\ue9s de bl\ue9 commerciales, K. Tai, K. Kingbird, K le Troglodyte, K. Korongo, K. Faucon, K. Sunbird, Robin, K. L\u2019aigle et NBWII ont \ue9t\ue9 sem\ue9s. Les complots principaux ont \ue9t\ue9 allou\ue9s aux vari\ue9t\ue9s de bl\ue9, sem\ue9es \ue0 trois taux seeding 75, 100 et \ue0 125 kg ha 1. Les sous-complots ont \ue9t\ue9 allou\ue9s \ue0 trois taux d\u2019azote, 75, 100 et de 130 kg N ha-1, appliqu\ue9 au stade tillering (GS 22). Vari\ue9t\ue9 K. Korongo a soutenu le compte de puceron le plus bas de 3.6 par 5 usines; suivi par K. Le faucon (3.8) et Robin (2.9 pucerons). Robin a donn\ue9 la plus haute production de grain (2.9 t ha-1), suivi par K. Korongo (2.7 t ha-1) et K. Le faucon (2.5 t ha-1). L\u2019application de 100 kg N ha-1 et de seeding \ue0 100 kg ha-1 \ue9tait les meilleurs taux