PRODUCTIVITY OF COMPONENT CROPS IN CUCUMBER (Cucumis sativa L.) / MAIZE (Zea mays L.) INTERCROP AS INFLUENCED BY NITROGEN RATE AND MAIZE DENSITY IN A DERIVED SAVANNA AGROECOLOGY

Abstract

ABSTRACT Cucumber/maize intercropping demonstrates potential for increased productivity; however, a notable knowledge gap exists concerning the optimal nitrogen rate and maize density required to maximize yields. Field trials were established in 2021 and 2022 late season to investigate the productivity of cucumber/maize intercrop as influenced by varying maize density and nitrogen rate at the Teaching and Research Farms, Federal University of Agriculture, Abeokuta, Ogun State (Latitude 7° 20' N, 3° 23' E, Longitude 3° 23' E, altitude 76 m above sea level). The trial was laid out in a Randomized Complete Block Design in a split-plot arrangement with three replicates. Treatments consisted of Maize density (MD): MD1-53,333 plants/ha, MD2- 35,555 plants/haand MD3-26,666 plants/ha each with cucumber density of 53,333 plants/ha staked in a single alternate row arrangement as the main-plot treatment and nitrogen rates (0, 60, 90, and 120 kg N/ha) on the sub-plots with blanket application each of 30 kg P2O5/ha and K2O/ha. Data were collected on maize plant height, stem girth, number of leaves, leaf area at 4, 8, and 12 WAP; cob length, cob girth, number of grain/cobs, number of grains/rows, 100 grain weight and grain yield at harvest. Cucumber number of leaves/plant, leaf area (cm2), main vine length (cm), total fruit weight (t ha-1), fruit length (cm) and fruit girth (cm) were determined as was done for maize. Land equivalent ratio (LER), area time equivalent ratio (ATER), actual yield loss (AYL) and aggressivity (A) were determined. In 2021, at 8 and 12 WAP, the biggest maize stem girth was recorded with application of fertilizer at 120 kg N/ha while in 2022, treatment with MD1 produced (p<0.05) bigger maize stem girth (13 cm) in contrast to MD2 and MD3. In 2021, treatments with MD1 had the highest (p<0.05) leaf area (2044 cm2) in contrast to MD2 and MD3 while in 2022, treatments in MD3 produced (p<0.05) the highest leaf area (1969 cm2). In 2021, grain yield of maize was highest (p<0.05) in MD1 (9.84 t ha-1), maize density had no significant effect on total fruit yield of cucumber (6.07 – 6.57 t ha-1 and 6.44 – 6.08 t ha-1) in both years. Application of 120 kg N/ha was significant for most maize growth and yield parameters except number of rows cob-1 in both years, treatment with MD1 and application of 120 kg N/ha resulted in longer vine length (40 cm - 170 cm), number of leaves/plant (7-22/plant) and leaf area (107 cm2 - 220 cm2) of cucumber. Maize plants in MD1 in both years produced (p<0.05) highest number of leaves/plant (8 and 14/plant). Interaction of maize density (MD1)) by 120 kg N/ha on actual yield loss which gave significant positive value (0.23) and LER of 2.2 is a yield advantage in the intercrop. Therefore, using MD1 and 120 kg N/ha was optimal for cucumber/maize mixture in this study.