Abstract

Seed Priming to Enhance Drought Tolerance of Pigeon Pea (Cajaunus cajan L.) under Dryland Conditions of Kenya

Author(s): Chris Gikonyo Kahungu, Maurice E Oyoo*, Paul K Kimurto

Drought is a major abiotic stress that affects plant growth and productivity. Poor seed emergence due to water stress is a key impediment to obtaining high pigeon pea yield. Seed priming has been used to accelerate synchronized seed germination, improve seedling establishment, stimulate vegetative growth and crop yield in many plants. Field experiments were conducted to determine the effect of different seed priming methods on yield and yield parameters of pigeon peas under drought conditions. The seeds of three pigeon pea genotypes, EUMDP 3, Egerton Mbaazi M1 and Kat 60/8 were primed with distilled water, 30% Polyethene Glycol (PEG), 1% Potassium Nitrate (KNO3) and Gibberellic acid (GA3) at 300 ppm. Unprimedseeds as the control was also incorporated. The trials were planted in Kerio Valley (37.7235°E, 2.2172°S) and agricultural training centre, Koibatek (10 35’S, 36°66’E) in a Randomized Complete Block Design (RCBD) splitplot arrangement, with three replicates for two seasons. Seed emergence, seedling growth, days to 50% flowering, number of branches, days to harvesting and grain yields were recorded. Data was subjected to analysis of variance at p ≤ 0.05 level of significance using General Linear Model (GLM) procedure of Statistical Analysis System (SAS) and means separated by Tukeys’ honestly significant difference test at 5%. Results showed that seeds treated with KNO3 had higher significantly (P ≤ 0.05) different effects on 50% germination, days to harvesting, seed yield, days to 50% flowering and plant height that any other seed priming agents. Distilled water and PEG showed less effect on yield and yield parameters compared to KNO3 and GA3. Seed priming treatment could serve to increase seed germination, early seedling establishment and yield of pigeon pea under drought stress conditions and 1% KNO3 as a priming agent should be recommended for farmers in arid and semi-arid areas to ensure maximum productivity of pigeon peas.