EFFECT OF NEEM KERNEL (Azadirachta indica A Juss) POWDER ON THE GROWTH AND DRY MATTER YIELD OF MAIZE (Zea mays L.) IN SAVANNAH ECOLOGICAL ZONE OF NIGERIA

A Greenhouse experiment was conducted to evaluate the effect of powdered neem (Azadirachta indica A Juss) kernel on the growth and dry matter yield of maize (Zea mays L.). Three soil textural classes, namely: loamy sand (LS), sandy clay loam (SCL) and clay (C) soils in Bauchi State, a savannah ecological zone of Nigeria were used for the study. For each soil, 18 samples of 4 kg each contained in 5 litre plastic pots were used. Maize (Zea mays L) variety TZ-DMR was the test crop and all except absolute control pots received 100kgN, 50 kg P2Os and 50 kg K20 per hectare along with the Neem kernel powder treatment corresponding to 0, 2.5, 5.0, 7.5 and 10.0 % of the applied urea. Plant heights were measured at intervals of four days starting from 13th to 45th days after sowing (DAS). Dry shoot and root weights of the plants and their respective N contents were determined at the end of the experiment (45 DAS). Results of the study have shown that between 17 and 41 DAS, Neem kernel powder treatments did not significantly affect plant height in all the soils. At 45 DAS, however, Neem treatment significantly (p<0.05) affected plant height in all the soils, plant shoot weight in SCL and C soils but not in LS. Dry root weight was significantly affected (p<0.01 in SCL and p≤0.05 in LS & C) by the Neem treatment in all the soils. Pots that received 5, 7.5 and 2.5% levels of Neem kernel powder recorded the highest shoot weight in LS, SCL and C soils respectively, while absolute control pots recorded the highest root weight in all the soils. Treatment had no significant effect on N content in shoots from LS and SCL soils but significantly (p≤0.01) affected the roots N content in all the soils. When the data for the three soils were pooled and analysed, treatment was found to have significantly (p<0.01) affected the N content and dry matter yields of both shoot and roots, signifying the effect of the treatment on N uptake by the plant and its positive effect on its growth.