PRESENTER: JOYCE KAMENE KIMEU AD/NO. A138/19361/2011 DIPLOMA IN CROP PROTECTION SUPERVISOR: DR. E.S. ARIGA EFFECT OF BEAN PLANTING ARRANGEMENT ON WEED POPULATION AND YIELDS IN MAIZE / BEAN INTER – CROPPING.

INTRODUCTION/BACKGR OUND Maize – most important and popular cereal in the world.

PRODUCTION developing countries – Half sub sahara – 50%

Uses Human - staple food Livestock – Industry – raw materials

Intercropping with legumes Challenges: weeds – A major constraint to production Contact– Hand weeding, Herbicides & intercropping

Materials and methods: Site – Field station at Kabete Campus Size – 08 Plot 2m x 2m In 3 repricates Time – july 2012 – Maize spacing 75x25cm Beans 45x20 Intercrop-single row 37.5cm Double row 17.5 x 40cm x 15 Maize variety H520 Beans GLP2

TreatmentAmaranthius SPPBlack JackGallant soldierKikuyu GrassOxalis Beans pure stand1.7 b 6.2 ab 17.5 b 10.7 a 32.5 b double row3.8 a 6.0 ab 33.8 a 9.3 a 65.8 a Maize pure stand2.8 ab 2.7 b 26.7 ab 16.5 a 18.8 c single row3.2 a a 18.8 a 67.5 a Lsd Cv % Table 1: Weed count Means followed by the same letter (s) along the column are not significant.

TreatmentCob length un-weeded double row4.8 b un-weeded single rows4.9 b un-weeded pure stand maize5.1 ab weeded double row5.7 a weeded pure stand maize5.7 a weeded single row5.5 a Lsd0.9 cv %13.7 Table 2: Height of Maize Means followed by the same letter (s) along the column are not significantly different.

TreatmentCob length un-weeded single row15.1 ab un-weeded double rows13.6 ab un-weeded pure stand maize11.0 b weeded double row16.1 a weeded pure stand maize13.3 b weeded single row16.4 a Lsd3.9 cv %18.5 Table 3: Cob length Means followed by the same letter (s) along the column are not significantly different.

TreatmentWeight (grams) un-weeded double row99.4ab un-weeded single row106.0ab Un-weeded Pure stand maize87.1ab un-weeded pure stand beans21.1bc weeded double row148.3a weeded pure stand beans57.8b Weeded Pure stand maize96.5a weeded single row149.9a Lsd77.7 cv%59.5 Table 4: Weight (grams ) Means followed by same letter (s) along the column are not significantly different.

RESULTS AND DISCUSSIONS Weed count The most common weeds identified in all the treatments were fine (Table 1). The most significant weed in three of the treatment was Black jack except in the single row. In the maize pure stand, Oxalis was also significant while in single row Amaranthus Spp was significant. Therefore weed control is necessary within the first 4 weeks after planting. Height of maize There were no significant differences in all the weeded treatments (Table 2). It shows that intercropping and weed control can reduce the effect of plant height and contribute to higher yields. Among the un-weeded treatments, pure stand maize significantly differed with other treatments.

Cob length There were no significant differences in both the single and double row weeded treatments. Weeded and un-weeded pure stand maize showed no significant difference. For un-weeded single and double, there was an effect to the length of the cobs. Uncontrolled weeds can therefore affect both the plant in the field as well as the produce. Maize yield There was no significant difference in un-weeded double row, single row and pure stand. Weeds affected all the treatments. For the weeded single, double and pure stand, no significant differences were shown. Un-weeded pure stand beans were most affected for there was significant difference. Weeds affect yields in any crop arrangement. The significant difference within the weeded and un-weeded is evident.

CONCLUSION AND RECOMMENDATION The analysis done within the above different parameters showed that weed affects crops in all stages of growth. In the intercrops, suppression of weeds was evident. I therefore encourage farmers to intercrop maize with beans or other leguminous crops as a way of managing weeds since it is cheap, requires low technical knowhow, is environmentally friendly and has no chance of weed resistance build up.

REFERENCES 1.Bremer, 2008; Plessis, 2003: Ntage at el, Bryan, E. Rigler, C. Okoba, B. Koo, J. Heraw M. and Silrestri. s {2011} 3.Ita B. Nyaga, Michieke w. Ratemo, Ariga E. Safari, Muiru w. Maina 4.Jaetzold and Schmidt 5.Joel. K. Ransom 6.Khaliq, T,T. michieke, w. Ratemo; Ariga, E. safari mbivo w. maina. 7.Lavabre, E.M {1991}Lavabre, E.M {1991} 8.Leaky, {1970} 9.Ofori, E. and Kyei, B.N {2004’’a} 10.Stinter and Weiss {1986} STIGTER C.J and WEISSA {1986} 11.Stork et al, {1991}