EFFECTS OF PLANT MULCH, N.P.K FERTILIZER AND STAKING ON SOIL PR0PERTIES, GROWTH AND YIELD OF CUCUMBER (Cucumis sativus L.)

Abstract

Cucumber yield in Nigeria is limited by low soil fertility and vine training that affects fruit’s shape and quality with consequent implication on consumer preference. Three field experiments separated in time and space were conducted in Abeokuta, southwestern Nigeria in year 2015 and 2016 cropping seasons; they examined the effect of selected treatments on soil fertility, cucumber growth and yield parameters and fruit physical qualities. The three experiments were laid out in 4 x 3, 3 x 3 and 3 x 4 factorial schemes arranged in Randomized Complete Block Design (RCBD) with three replicates. Experiment one had four levels of NPK (400 kgha-1) nutrient formulations (control, NPK15-15-15, NPK 20-10-10, NPK-Mg 12-12-17-2) and three vine cares (un-staked, staked, trellised). Experiment two had three types of plant mulch (control, 10 t ha-1 Tithonia diversifolia, 10 t ha-1 Chromolaena odorata) and three vine cares (un-staked, staked, trellised) while experiment three had three levels of NPK-Mg 12-12-17-2 fertilizer (0 % , single dose of 400 kgha-1, split application at 50 % at planting + 50 % at 4 WAP) and four times of T. diversifolia mulch application (zero mulch, 10 t ha-1 at planting, 10 t ha-1 at 2 WAP, 10 t ha-1 at 4 WAP). Soil samples were collected before and after the experiment for physical and chemical analysis, leaf nutrient contents of cucumber were also determined. Plant growth and yield data were measured. The results revealed that Tithonia and Chromolaena mulches (Exp. 2) significantly (p ≤ 0.05) reduced soil bulk density and temperature as well as increased soil moisture content and total porosity. NPK fertilizers, plant mulch and combinations of NPK-Mg fertilizer and Tithonia mulch significantly (p ≤ 0.05) increased soil pH (except Experiment 1) O C, N, P, K, Mg, Ca, (except P, K and Mg Experiment 3), leaf P, K, Ca and Mg concentrations, growth and yield of cucumber compared with the control. Vine training further enhanced performance of cucumber. Staked and trellised cucumber performed better than the un-staked in most growth and yield parameters. In the first experiment, the interactive effect of NPK-Mg 12-12-17-2 + trellised vine care gave the highest average and significant (p ≤ 0.05) fruit yield (32.53 t ha-1) compared with others and was recommended for cucumber production. In the second experiment the interactive effect of Tithonia divesifolia + trellised gave the highest average and significant (p ≤ 0.05) fruit yield ( 37.94 t ha-1 ) compared with others and was recommended for cucumber production while in the third experiment, the average combined effect of split NPK-Mg 12-12-17-2 and application of Tithonia divesifolia mulch at two weeks after planting gave the highest average fruit yield (79.82 t ha-1 ) compared with others and was therefore recommended for cucumber production.