EFFECTS OF MULCHING MATERIALS ON SOIL PROPERTIES, WEEDS AND PINEAPPLE GROWTH AND DEVELOPMENT IN AKURE, NIGERIA

Abstract

A field experiment was conducted to investigate the effectiveness of mulching materials for weed control, enhancement of soil conditions and pineapple performance. The study was carried out at the Teaching and Research Farm of the Federal University of Technology, Akure during the early season of 2014 and late season of 2015. The mulching materials were Wood shavings, Oil palm bunch refuse, Cassava peel, Leuceana leaves, Gliricidia leaves, Polythene sheets (black). Weed control was effected using diuron and manual method. Plot size was 2 x 2 m, pineapple suckers were planted at 30 x 30 cm spacing, while 60 cm spacing was allowed between plots and between blocks. Pineapple growth parameters of leaf length, breadth and number of leaves were collected at 2, 4 and 6 months after planting. Soil moisture content and temperature were determined at 2 weeks interval. Other growth parameters of pineapple collected were weed count, weed fresh weight and dry weight (g), fruit weight, length and girth. Soil core samples were collected at the end of the experiment (12 months) to determine the soil bulk density and chemical properties of pH, organic matter, N, P, K, Ca and Mg. The mulched soil significantly improved in organic matter, available N, available P, and K contents of the soil. Significant decrease was observed in the bulk density of the mulched soil. Cassava peel mulching decreased bulk density in all layers and cassava peel mulching significantly increased soil water. Trends of soil moisture contents were not significantly different among mulching materials except for manual weed treatment and polythene sheet treatment. All mulch materials evaluated significantly (p>0.05) conserve soil water. Polythene sheets, diuron and manual weeding treatment were not significantly different (p<0.05) for soil moisture. The mulch treatments had significant reduced soil temperatures. Soil temperatures were highest (30.8 0C) for wood shaving treatment and for Gliricidia leaf mulch while the overall lowest temperature was observed for poly sheet mulch (32.3 0C). Significant differences among the mulching materials and weed control methods were obtained for weed density and biomass. Plots mulched with polythene sheets mulch and manual weeding had significantly lowest weed count compared with other mulching materials. Among the treatments, there were significant differences in pineapple growth components of height, leaf length and breadth, number of leaves. Biomass development and accumulation of pineapple showed that fresh leaf weight of pineapple from oil palm bunch waste mulch was highest (6788.7 g), followed by diuron (5577.6 g). Leaf biomass for manual weeding, polythene sheets and wood shavings treatments were not significantly different. Total weight of root and stem is significantly higher for oil palm bunch mulch (8961 g) and diuron treatment (8308.3 g). Diuron treatment with oil palm much treatment is significantly higher for pineapple total stem weight. The number of fruit, fruit length, and fruit weight and fruit girth were significantly different among mulch materials and herbicide or manual based weed control. Wood shavings produced highest number of fruits (2.56) and fruit weight (741.75 g). Polythene sheet mulch produced significantly higher fruit yield (843.4 g) and fruits average length (11.56 cm) compare with other treatments. Manual weeding plots had shortened duration of fruit harvest compared to mulched plants. Mulching plots promoted fruit setting; total fruits harvested from mulched pineapple were close to double values obtained for the manual weeding pineapple plants. Therefore, for efficient weed control, good vigour, growth, development and enhanced yield of pineapple, it is recommended that plastic mulch be used by farmers